HNNS Important Questions I Flashcards
[PP]
A junior doctor was asked to collect a sample of cerebrospinal fluid from a 30-year-old patient for analysis. Where should he insert the spinal needle?
A. Epidural space at L3/L4 interspinous level
B. Intervertebral foramen between L3 and L4
C. Subarachnoid space at L3/L4 interspinous level
D. Suburban space at L3/L4 interspinous level
C
or L4/L5
[PP]
The middle cerebral artery (MCA) is a major source of blood supply to the brain. Which of the following would MOST LIKELY occur following an acute MCA occlusion?
A. Cortical blindness
B. Double vision
C. Speech disorder
D. Unsteady gait
C
[PP]
A 45-year-old male came to the clinic due to oculomotor nerve palsy. After examination, the clinician concluded that his symptoms were caused by compression. The aneurysm of which artery MOST LIKELY compressed the root of the oculomotor nerve?
A. Anterior inferior cerebellar artery
B. Basilar artery
C. Posterior inferior cerebellar artery
D. Superior cerebellar artery
D
Superior cerebellar artery arises near the end of the basilar artery, passing laterally around the brainstem
Its course is immediately inferior to the oculomotor nerve
[PP]
Occlusion of the internal carotid artery will diminish blood supply to the brain regions supplied by it. Which of the following structures is MOST LIKELY to be affected?
A. Calcarine gyrus
B. Cerebellar hemisphere
C. Inferior frontal gyrus
D. Pons
C
[Old PP]
Which of the following cranial nerves does not have nucleus in brainstem?
A. Abducent nerve
B. Optic nerve
C. Trochlear nerve
D. Vagus nerve
E. Vestibulocochlear nerve
B
Optic nerve nucleus: in retinal ganglion cells
11244
Telencephalon: CN I
Diencephalon (thalamus): CN II
Mesencephalon (midbrain): CN III, IV
Metencephalon (pons): CN V, VI, VII, VIII
Myelencephalon (medulla): CN IX, X, XI, XII
[Old PP]
Which cranial nerve is not part of PNS?
A. Ophthalmic nerve
B. Optic nerve
C. Trochlear nerve
D. Abducent nerve
E. Oculomotor nerve
B
Optic nerve is an outgrowing of diencephalon
[Old PP]
Following cranial nerves branch from pons except:
A. Trochlear nerve
B. Abducent nerve
C. Facial nerve
D. Vagus nerve
E. Hypoglossal nerve
A, D, E
A: midbrain
D, E: medulla oblongata
[Old PP]
Which cranial nerves does is responsible for gustatory sensation of anterior two third of tongue?
Facial nerve (VII)
[Old PP]
Which cranial nerve is responsible for motor function of masticatory muscles?
Trigeminal nerve (V)
[Old PP]
Which cranial nerve is responsible for up rolling of eyeball (i.e. contraction of superior rectus muscle)?
Oculomotor nerve (III)
[Old PP]
Which cranial nerve is responsible for autonomic supply to major salivary gland?
Glossopharyngeal nerve (IX)
[Old PP]
Which cranial nerve is responsible for supply to cardiac plexus?
Vagus nerve (X)
[Old PP]
Which cranial nerve is responsible for motor function of muscles of tongue?
Hypoglossal nerve (XII)
[Old PP]
Which of the following cranial nerves is purely sensory?
A. Olfactory nerve
B. Abducens nerve
C. Glossopharyngeal nerve
D. Hypoglossal nerve
E. Trigeminal nerve
A
B, D: purely motor
C, E: mixed
[Old PP]
Nuclei of cranial nerves mostly lie in brainstem. Which of the following nerves have its nucleus lying in midbrain?
A. Hypoglossal nerve
B. Oculomotor nerve
C. Optic nerve
D. Trigeminal nerve
E. Vagus nerve
B
A, E: medulla oblongata
C: diencephalon (thalamus)
D: pons
[Old PP]
Infarction to medial part of pontomedullary junction and patient presented with diplopia. Which nerve is most likely affected?
Abducens nerve (VI)
[Old PP]
A guy is severely injured in a car accident. X-ray shows that condyle of mandible of right side is broken. Surgery on TMJ but later found with abnormal facial expression on right side, suspected damaged right side facial nerve during operation. Which is/are functional component(s) of facial nerve?
Brachial motor, visceral motor, special sensory, general sensory
[Old PP]
Which of the following about ANS is incorrect?
A. Parasympathetic innervations arise from cervical and sacral nerve roots
B. Sympathetic trunk extends from C1 to T12
C. Vagus nerve branches out from brainstem and supplies many thoracic and abdominal organs
D. Parasympathetic ganglions are closer to target organs than sympathetic ganglions
E. Acetylcholine is the primary neurotransmitter at parasympathetic ganglion
A, B
Parasympathetic innervations: from brainstem & S2-S4
Sympathetic trunk: C1-S3
[Old PP]
Pain is detected by nociceptors. Which of the following is a cutaneous nociceptor?
A. Free nerve endings
B. Meissner corpuscle
C. Merkelâs disc
D. Pacinian corpuscle
E. Ruffini corpuscle
A
Free nerve ending: touch, injurious forces
Meissner corpuscle: dynamic deformation (e.g. skin motion, slippery objects)
Merkelâs disc: indentation depth (pressure receptor) e.g. texture
Pacinian corpuscle: vibration
Ruffini endings: stretch receptor
[Old PP]
Which of the following is receptor for noxious stimuli?
A. Free nerve ending
B. Meissnerâs corpuscle
C. Merkelâs disc
D. Pacinian corpuscle
E. Ruffini endings
A
[Old PP]
Skin has specific structures for sensation of touch, pain and temperature. In which of the following layers are Meissnerâs corpuscles located?
A. Epidermal-dermal junction
B. Epidermis
C. Hypodermic
D. Papillary layer of dermis
E. Reticular layer of dermis
D
[Old PP]
Which has the best 2-point discrimination?
A. Back of neck
B. Palm
C. Forehead
D. Sole
E. Finger tip
E
Tip of tongue > tip of index finger > lips > side of tongue > palm of hand > forehead > back of hand > dorsum of foot > neck > back
[Old PP]
Which of the following lowers threshold for two-point discrimination?
A. Lateral inhibition from afferent fibres
B. Higher convergence to xxx from afferent fibres
C. Local anaesthetic
D. Larger receptive field
E. Low innervation density
A
[Old PP]
Which type of receptors has fastest rate of adaptation?
A. Merkelâs disc
B. Meissner corpuscle
C. Nociceptor
D. Pacinian corpuscle
E. Ruffini corpuscle
D
[Old PP]
Panician corpuscle and Ruffini corpuscle detect different stimuli. Skin receptor for vibration, stretch respectively. How do they differentiate from each other? What is the mechanism behind that allows them to detect different stimuli?
A. Rate of adaptation
B. Velocity in action potential conduction
C. Size of receptive field
D. Type of receptor
E. Localisation in skin
A
B: determined by nerve fibre
C: affect resolution of spatial discrimination
D: both are mechanoreceptor
E: Pacinian = more superficial, but no effect
[Old PP]
A 2-month-old baby boy is presented with high fever and hyperirritability. Meningitis is suspected. What is most likely causative pathogen?
A. Streptococcus agalactiae
B. Haemophilus influenzae
C. Streptococcus pneumoniae
D. Staphylococcus aureus
E. Neisseria meningitidis
A
0-8 weeks:
- E. coli (K1) / other Enterobacteriaceae (Citrobacter, Salmonella)
- S. agalactiae (GBS)
- Listeria monocytogens
3 months - 18 years:
- With vaccination: H. influenzae serotype b, S. pneumoniae
- Without vaccination: N. meningitidis
Head trauma / neurosurgery:
- S. aureus / epidermidis, aerobic GNB
[Old PP]
From CSF result below, what is the most likely diagnosis?
Appearance: slightly turbid
Glucose: lowered
Protein: elevated
Cells: Mononuclear cells predominant
A. Bacterial meningitis
B. Viral meningitis
C. Viral encephalitis
D. Tuberculous meningitis
E. Thberculous encephalitis
D
TB meningitis;
Low glucose, high protein, lymphocytic pleocytosis: predominantly lymphocytes / mononuclear cells predominant A
[Old PP]
Meningitis in immunocompromised patients is mostly caused by
A. Naegleria fowleri
B. Angiostrongylus cantonensis
C. Cryptococcus neoformans
D. Herpes simplex virus I
E. Pneumocystis carinii
C
Cryptococcal meningitis:
- underlying immunodeficiency esp. HIV
Naegleria fowleri: contaminated fresh water / swimming pool
Angiostrongylus cantonensis: raw mollusks (eosinophilia)
[Old PP]
A 56-year-old male with meningitis caused by Cryptococcus neoformans. What is the MOST LIKELY underlying disease of patient?
A. Head injury with fracture of skull
B. Infection with human immunodeficiency virus
C. Presence of ventriculoperitoneal shunt
D. Prolonged neutropenia as a result of cancer chemotherapy
E. Uncontrolled diabetes mellitus
B
[Old PP]
What cerebrospinal fluid (CSF) finding is UNLIKELY to be seen in a patient with tuberculous meningitis?
A. Acid-fast bacilli on Ziehl-Neelsen staining
B. High protein
C. Low sugar
D. Lymphocytic pleocytosis
E. Mollaret cell
E
ZN smear: 15%
LJ culture: <50%
CSF for TB PCR: similar to culture
Sputum LJ culture: <40%
CXR: TB foci <30%
S/S & CSF findings fluctuate from day to day
Mollaretâs meningitis (recurrent benign lymphocytic meningitis): HSV-2
[Old PP]
Bacterial meningitis. What is NOT seen?
A. Increased white cell count
B. Increased CSF glucose
C. Increased CSF opening pressure
D. Increased CSF protein
E. Increased neutrophil
B
CSF: increased protein, reduced glucose (<50% of blood), increased WBC, neutrophil (>80%)
[Old PP]
A 7-year-old boy presents with fever, neck stiffness and headache. Lumbar puncture is done and it is neutrophil dominant. Which of the following organisms is MOST LIKELY to have caused the disease?
A. GBS
B. Meningococcus
C. Cryptococcus
D. Mycobacterium tuberculosis
E. Virus
B
[PP]
Which brain area is regulated by the neurotransmitter serotonin?
A. Hypoglossal nucleus
B. Locus coeruleus
C. Raphe nucleus
D. Substantia nigra
E. Vestibular nucleus
C
[PP]
Which nucleus of the brain is mediated by the neurotransmitter serotonin?
A. Basal nucleus of Meynert
B. Locus coerulus
C. Raphe nucleus
D. Vestibular nucleus
C
A: Acetylcholine
B. Norepinephrine
[PP]
A 50-year-old man is diagnosed with Parkinson disease. The patient has undergone positron emission tomography scan examination for dopaminergic neurons. Which brain region shows loss of dopaminergic neurons?
A. Medial longitudinal fasciculus
B. Periaqueductal gray
C. Substantia nigra
D. Superior colliculus
C
Most populated region with dopaminergic neurons
= substantia nigra
[PP]
The cerebral peduncle is a region of the midbrain. Which of the following structures passes through the cerebral peduncle?
A. Corticospinal tract
B. Medial lemniscus
C. Medial longitudinal fasciculus
D. Spinothalamic tract
A
[Old PP]
Where is vomiting centre located in central nervous system?
A. Cerebral cortex
B. Cerebellum
C. Medulla
D. Brainstem
E. Midbrain
C
[Old PP]
Where is vestibular nucleus located?
A. Basal ganglia
B. Medulla oblongata
C. Midbrain
D. Pons
E. Spinal cord
D
[Old PP]
Brainstem contains many important nuclei and fibre tracts. Which structure in the following mediated pain signal of toothache?
A. Caudate nucleus
B. Corticospinal tract
C. Nucleus gracilis
D. Rubrospinal tract
E. Trigeminal nucleus
E
[Old PP]
Where is red nucleus located?
A. Pons
B. Basal ganglia
C. Midbrain
D. Medulla
E. Pyramid
C
[Old PP]
Superior colliculus is responsible for visual reflex. It is located in which brain region?
A. Basal ganglia
B. Medulla oblongata
C. Midbrain
D. Pons
E. Thalamus
C
[Old PP]
Reticular formation location?
A. Caudate nucleus
B. Cerebellum
C. Cerebral cortex
D. Hypothalamus
E. Pons
E
ARAS -> thalamus, hypothalamus, cortex
DRAS -> cerebellum, sensory nerves
[Old PP]
Neural tissue is formed from
A. Endoderm
B. Mesoderm
C. Ectoderm
D. Neuroderm
E. Germ layer
C
Both epidermis & neural tissue from ectoderm
[Old PP]
Which of the following is not a brainstem function?
A. Maintain posture
B. Maintain consciousness
C. Plan and execute precise movement
D. Synapse upper neuron to lower neuron
E. None of the above
C
Mainly by primary motor cortex
[Old PP]
Which of the following is correct regarding micurition?
A. Contain voluntary and involuntary components
B. Micurition centre is in brainstem
C. There is urge in micurition when over 400mL urine in bladder
D. Parasympathetic signal travels from pudendal nerve
B
Pontine micturition centre
[PP]
After tonsillectomy, a boy experienced absence of tactile and taste sensation in the posterior 1/3 of the tongue. Which nerve was inadvertently severed during tonsillectomy?
Glossopharyngeal nerve
CN IX:
Inferior (petrosal) ganglion (special sensory)
-> solitary nucleus (rostral part)
-> taste buds in posterior 1/3 of tongue
-> taste
Damage
=> (Ipsilateral) loss of taste in posterior 1/3 of tongue
[PP]
The pterygopalatine ganglion plays a major function in the nasal cavity and surrounding regions. What is the MOST COMMON sign manifested if maxillary tumours spread to the medial wall and invade this ganglion?
A. Double vision
B. Dryness of the nasal walls
C. Excessive secretion of tears
D. Hyposecretion of tears
C
Pterygopalatine ganglion: predominantly parasympathetic
Invasion => parasympathetic > sympathetic response (vasodilation & increased glandular secretions)
Excessive tear secretion through greater petrosal nerve (CN VII)
X A: extraocular muscles are supplied by CNIII, IV, VI
[PP]
A 30-year-old female was diagnosed with skull base meningioma compressing at CNVI. Which muscle movement does the patient have difficulties with on the right side?
A. Directing the pupil laterally
B. Elevating the upper eyelid
C. Forcibly closing the eyelids
D. Pupillary constriction
A
[PP]
Which pair of muscles are primarily involved in whistling?
- Orbicularis oris
- Buccinator
[PP]
Name a cutaneous nerve which innervates the vertex of the cranium.
Supraorbital nerve of CN V (CN V1 occipital)
CN V:
- sensory supply to face & anterior half of scalp
Anterior & posterior rami of spinal nerves (C2-C3):
- posterior half of scalp & neck
[PP]
Name a cutaneous nerve which innervates the tragus of the ear.
Auriculotemporal nerve of CN V (V3 mandibular)
X greater articular nerve (C2-C3, from cervical plexus): angle of mandible
[PP]
A 30-year-old male sustained a left eye trauma during a football game. He was found to have orbital left floor fracture on imaging. Clinically; he had left hypoesthenia around his left upper cheek. Which of the following nerves is MOST LIKELY involved as a result of his injury?
A. Facial nerve
B. Infraorbital nerve
C. Lacrimal nerve
D. Trochlear nerve
E. Zygomatic nerve
B
[PP]
The infraorbital nerve can be damaged during an orbital blow-out fracture. Which of the following nerves gives rise to the infraorbital nerve?
A. Facial nerve
B. Maxillary nerve
C. Nasociliary nerve
D. Ophthalmic nerve
B
Ophthalmic nerve (CN V1):
-> Supraorbital
-> Supratrochlear
-> Infratrochlear
-> External nasal
-> Lacrimal
Maxillary nerve (CN V2):
-> Zygomaticotemporal
-> Zygomaticofacial
-> Infraorbital
Mandibular nerve (CN V3):
-> Auriculotemporal
-> Buccal
-> Mental
[PP]
Which muscle primarily contracts during smiling?
A. Levator anguii oris
B. Orbicularis oris
C. Zygomaticus major
D. Zygomaticus minor
C
Open, bright smile: zygomaticus major, risorius
Fake smile: levator anguii oris (less powerful)
[Old PP]
A patient with lateral scalp injured with profuse bleeding & a gaping wound. Which of the following concerning scalp is INCORRECT?
A. Frontal bellies of occipitofrontalis can corrugate skin
B. Infection of scalp wound can spread to superior sagittal sinus
C. Its blood vessels run in loose subaponeurotic layer
D. Skin, superficial fascia & aponeurosis move as one layer
E. Occipitalis is innervated by facial nerve
C
Occipitofrontalis:
- raise the eyebrows
- wrinkle (corrugate) the forehead
Dense subcutaneous connective tissue (2nd layer of scalp):
- site of blood vessels
Loose areolar tissue (4th layer of scalp):
- allow spread of infections to intracranial sinuses through emissary veins within
Skin, superficial fascia (dense subcutaneous connective tissue), aponeurosis:
- tightly bound & move as one unit
[Old PP]
Which facial muscle helps keep pizza between teeth during chewing?
Buccinator
[Old PP]
Which facial muscle keeps food inside mouth?
Orbicularis oris
[Old PP]
Pressing upon examination of ulcerated area causes patient to frown. Which facial muscle is involved?
Corrugator supercilli
[Old PP]
Motorcyclist hit his head, scalp laceration, diagnosed as meningitis and superior sagittal sinus thrombosis, suspected that it is an infection from scalp to sinus. Which layer of scalp most likely facilitated this spread?
A. Areolar tissue
B. Dense connective tissue
C. Skin
D. Epicranial aponeurosis
E. Periosteum
A
Through emissary veins within
[Old PP]
A middle-aged man was hit over his head with a bottle. Haematoma developed. Which layer of scalp is involved?
A. Aponeurotic layer
B. Loose connective tissue
C. Periosteum
D. Subcutaneous tissue
E. Skin
B
[Old PP]
A patient had Bellâs palsy. Doctor asked him to close his eye forcefully, puff his cheeks out and reveal his teeth as physical examination. Which cranial nerve was being tested?
CN VII (facial nerve)
[PP]
List two muscles innervated by facial nerve (CN VII). (2 marks)
- Any muscles of facial expression
- Stapedius muscle
- Digastric muscle (posterior belly)
- Stylohyoid muscle
[PP]
What is the name of the condition that causes temporary dysfunction of facial nerve?
Bellâs palsy
[PP]
A 24-year-old woman is brought to the Accident and Emergency Department after a motor vehicle collision. Radiological studies show a frontal bone fracture. Physical examination reveals a lack of sensation over the forehead. Which nerve is MOST LIKELY injured in this patient?
A. Anterior ethmoidal
B. Oculomotor
C. Supraorbital
D. Zygomatic
C
[PP]
The patient has not undergone any dental work or has a history of dental caries but describes pain across left upper jaw as sharp, lancinating (âshootingâ), and that the pain is aggravated by chewing, brushing teeth, and talking. Which nerve carries nociceptive signals?
A. Buccal branch of facial nerve
B. Great auricular
C. Maxillary
D. Supratrochlear
C
Neuropathic pain
Maxillary nerve (CN V2)
- sensory impulses from hard palate
[PP]
A 24-year-old woman is brought to the Accident and Emergency Department after a motor vehicle collision. Radiological studies show a frontal bone fracture. Physical examination reveals a a lack of sensation from the lateral aspect of the forehead. Which nerve is MOST LIKELY injured in this patient?
A. Anterior ethmoidal
B. Oculomotor
C. Supraorbital
D. Zygomatic
D
[PP]
A patient was diagnosed with a left-sided facial paresis and was asked to perform a teeth showing smile. The patient could not move the left lower lip while the movements of the left upper lip and other facial muscles were intact. Which branch of the left facial nerve is injured?
A. Buccal branch
B. Marginal mandibular branch
C. Temporal branch
D. Zygomatic nerve
B
[Old PP]
Hyperacusis (complained of excessive acuteness of hearing) is due to
A. Ossification of ossicles
B. Ossicles (stapes of malleus) have too much vibration
C. Immobility of ossicles
D. Hyperstimulation of tensor tympani
E. Paralysis of stapedius
E
[Old PP]
40/M unilateral facial nerve palsy affecting lower face but upper face normal. Other cranial nerves normal. No limb weakness. Whatâs the most likely site of disease?
A. Frontal lobe
B. Parietal lobe
C. Parotid gland
D. Medulla oblongata
E. Caudate nucleus
A
[Old PP]
Which cranial nerve or branch is most likely involved in the following situation?
A woman has abscess in her left submandibular gland. She has incision and drainage of gland done. After surgery, she complained of weakness in moving lower part of her left face.
Mandibular branch of facial nerve (CN VII)
[Old PP]
A guy is severely injured in a car accident. X ray shows that condyle of mandible of right side is broken. Surgery on TMJ but later found with abnormal facial expression on right side, suspected damaged right side facial nerve during operation. What is/are functional component(s) of facial nerve?
Branchial motor, visceral motor, general sensory, special sensory
A fracture in superior orbital fissure is likely to damage which nerve?
A. Nasociliary nerve
B. Nasopalatine nerve
C. Zygomaticofacial nerve
D. Zygomaticotemporal nerve
A
Nasociliary nerve (from CN V1 ophthalmic nerve)
- gives rise to infratrochlear, external nasal nerves, etc.
Nasopalatine nerve (from CN VII maxillary nerve)
[PP]
Explain why a tumour located in the parotid gland can produce unilateral facial paralysis. (2 marks)
- Facial nerve traverses the parotid gland from deep to superficial, dividing into its branches.
- Tumour => compression of facial nerve => unilateral facial paralysis (ipsilateral)
[Old PP]
A 10-year-old boy has a brain tumour at midline of cerebellum. Pathology shows small cells with darkly stained nucleus. What is the diagnosis?
A. Medulloblastoma
B. Schwannoma
C. Meningioma
D. Metastatic carcinoma
A
[Old PP]
Patient (3X, F) presented with progressive hearing loss and headache. CT shows tumour at cerebellopontine angle. Which of the following is the most likely histological type of tumour?
A. Medulloblastoma
B. Meningioma
C. Metastatic carcinoma
D. Schwannoma
E. Malignant carcinoma
D
Acoustic Schwannoma
- Infratentorial
- Cerebellopontine angle
- Adults
[Old PP]
A 45-year-old female with a 9-month history of nausea and vomiting present to you with left hemiplegia. CT scan revealed a large mass attached to right side of falx cerebri. Surgical biopsy showed psammoma bodies and cellular whorls. What is the pathological diagnosis of this mass?
Meningioma (of arachnoid cells)
- Infratentorial, adults
- Parasagittal, falx cerebri, base of brain
- Gross: well-circumscribed, lobulated
- Histology: cellular whorls with psammoma bodies (calcified) at the centre
[Old PP]
A 10-year-old boy, two-month history of headache, with recent deterioration of consciousness. After CT scan, a tumour is found on midline of cerebellum. Physical examination found no abnormalities in any other parts of the body. CSF pathological examination shows presence of small cells with darkly stained nuclei and little cytoplasm. What is the MOST COMMON tumour he is having?
Medulloblastoma
- Small cells with darkly stained nuclei and little cytoplasm
- Horner Wright rosettes with central fibrils
[Old PP]
Which of the following tumours is histologically most malignant?
A. Meningioma
B. Glioblastoma multiforme
C. Medulloblastoma
D. Ependymoma
E. They are equally malignant histologically
B
[Old PP]
Which of the following is most likely found in a 2-year-old toddler?
A. Lymphoma of brain
B. Glioblastoma multiforme
C. Meningioma
D. Medulloblastoma
E. Astrocytoma
D
[Old PP]
3-year-old female develops poor limb coordination and unsteady gait. CT reveals mass in posterior cranial fossa.
A. Cerebral cortex
B. Cerebellum
C. Midbrain
D. Medulla
E. Thalamus
B
Medulloblastoma
- vermis in midline of cerebellum in posterior fossa
[Self-assessment]
Predict the consequence of injury at the site of origin of facial nerve branches near the right parotid gland.
A. Peripheral injury of lower motor neurons in the right side followed by complete paralysis on the contralateral side.
B. Paralysis of the contralateral muscles of facial expression in the lower half of the face
C. Increased lacrimation and salivation or loss of taste sensation in the posterior two-thirds of the tongue
D. The patient cannot wrinkle the forehead, the corner of the mouth sags, articulation is impaired, and the eyelid cannot be fully closed
D
Bellâs palsy
A: paralysis of âipsilateralâ side
B:
UMN lesion
=> ipsilateral: upper half of face paralysed
=> contralateral: lower half of face paralysed
C: loss of taste sensation in âanteriorâ two-thirds of tongue
[Self-assessment]
Which of the following is the most likely tumour type for a 54-year-old lady who presented with progressive onset of motor dysfunction on the right side of her body for 6 months, with CT scan showing a 4cm tumour at the superficial part of the left cerebral hemisphere, which appears to be attached to the dura.
A. Schwannoma
B. Meningioma
C. Neuroepithelial tumour such as glioma
B
Meningioma:
- from arachnoid cells
Schwannoma:
- cranial nerve roots at brainstem
- most common: acoustic nerve (CN VIII)
Neuroepithelial tumour such as glioma:
- brain substance
[PP]
Depth perception is the visual ability to perceive the distance of an object. Both monocular cues and binocular cues can provide depth information to our nervous system. Apart from binocular parallax (~disparity), which depth cue can only be detected using both eyes?
A. Interposition
B. Linear perspective
C. Ocular convergence
D. Relative size
E. Texture gradient
C
[PP]
Visual features are extracted and interpreted at specific parts of the brain. Where is spatial and form recognition being perceived along the visual pathway?
A. Higher visual cortex
B. Lateral geniculate nucleus
C. Optic radiation
D. Parietal lobe
A
D: should be âtemporalâ lobe
[Self-assessment]
Which feature in the visual cortex helps to perceive depth and distance between objects?
A. Ocular dominance column
B. Ventral temporal pathway
C. Orientation column
A
B, C: form recognition
[Old PP]
Lesions in visual pathway can lead to visual field defect. A lesion in which of the following structures will lead to inferior quadrantanopia?
A. Occipital area
B. Parietal area
C. Prefrontal area
D. Primary motor area
E. Temporal area
B
Contralateral inferior quadrantanopia:
- damaged superior optic radiation (parietal pathway)
Contralateral superior quadrantanopia;
- damaged inferior optic radiation (temporal pathway)
[Old PP]
Which clinical finding is most likely in a patient who suffered a left occipital lobe injury?
A. A loss of right visual field
B. A loss of left visual field
C. A bitemporal field deficit
D. An enlarged blind spot
E. A bilateral scotoma
A
Occipital lobe damage:
Contralateral homonymous hemianopia with macular sparing
Optic chiasm damage (e.g. pituitary tumour)
Bitemporal hemianopia
Enlarged blind spot:
e.g. Papilledema
[Old PP]
Tumour growth compressing left visual cortex below calcarine fissure, how will patientâs vision be affected?
A. Left upper and lower quadrant
B. Left upper quadrant
C. Left lower quadrant
D. Right upper quadrant
E. Right lower quadrant
D
Damage to inferior optic radiation (temporal pathway, axons project to lingual gyrus inferior to calcarine fissure)
=> contralateral homonymous superior quadrantanopia
Damage to superior optic radiation (parietal pathway, axons project to cuneus gyrus superior to calcarine fissure)
=> contralateral homonymous inferior quadrantanopia
[Old PP]
What mediated pupillary light reflex?
A. Oculomotor nucleus
B. Superior colliculus
C. Contraction of iris sphincter
D. Contraction of ciliary muscle
E. Frontal eye field
C
A: should be âaccessory oculomotor / Edinger-Westphalâ nucleus
[Old PP]
What will be the response in right eye if there is lesion in left optic nerve?
A. Both direct and consensual responses are intact
B. Both direct and consensual responses are lost
C. Pupillary dilation in response to stimuli
D. Intact direct response and impaired consensual response
E. Intact consensual response but direct response is lost
A
[Old PP]
Pupillary light reflex is an important test for brainstem function. Which of the following is involved in controlling intensity of light reaching retina?
A. Pupillary constriction by innervation from neurons at superior cervical ganglion
B. Pupillary constriction by contraction of ciliary muscle
C. Pupillary constriction by contraction of iris sphincter muscle
D. Pupillary dilation by neurons in ciliary ganglion
E. Pupillary dilation by parasympathetic innervation mediated by oculomotor nucleus
C
A: dilation
B: ciliary muscle is for accommodation
D: constriction
E: constriction, EW nucleus
[Old PP]
Which cranial nerve is the efferent limb of pupillary light reflex?
CN III
[Old PP]
Clinical examination of pupillary light reflex is a useful diagnostic tool for testing integrity of reflex pathway and sensorimotor function of eye. Which of the following is manifested in left eye of a patient with a lesion in right oculomotor nerve?
A. Both direct and consensual responses are intact
B. Both direct and consensual responses are lost
C. Pupillary dilation in response to stimulus
D. Direct response is intact but consensual response is lost
E. Direct response is lost but consensual response is intact
D
[Old PP]
Pupillary reflex is an important test for brainstem function. Which of the following is involved in controlling intensity of light reaching the retina?
A. Pupillary constriction is caused by sympathetic system
B. Pupillary constriction is caused by fibres originating from inferior cervical ganglion
C. Pupillary constriction is caused by contraction of iris sphincter muscle
D. Pupillary dilation is caused by neurons in ciliary ganglion
E. Pupillary dilation is caused by fibres originating from accessory oculomotor nucleus
C
[PP]
Eye movements are controlled by muscles innervated by the cranial nerves: What clinical observation is a characteristic of a lesion of cranial nerve III?
A. Deviation of eye laterally and downwards
B. Deviation of eye laterally and upwards
C. Deviation of eye medially and downwards
D. Deviation of eye medially and upwards
A
[PP]
Eye movements are controlled by muscles innervated by the cranial nerves. What clinical observation is characterised by a lesion of cranial nerve IV?
A. Deviation of eye medially and downwards
B. Deviation of eye medially and upwards
C. Deviation of eye outwards and downwards
D. Deviation of eye outwards and upwards
D
[PP]
Pupillary light reflex regulates the intensity of light that reaches the retina. Pupillary response is controlled by which of the following?
A. Pupil constriction is due to activation of neurons in the interstitial nucleus of Cajal
B. Pupil constriction is due to relaxation of sphincter muscle
C. Pupil dilation is regulated by neurons in the Edinger-Westphal nucleus
D. Pupil dilation is regulated by sympathetic nerve fibres
D
[PP]
The amount of light reaching the retina is regulated by the pupillary light reflex. Which process mediates the pupillary response?
A. Activation of neurons in the oculomotor nucleus
B. Activation of neurons in the superior colliculus
C. Contraction of the ciliary muscle
D. Contraction of the iris sphincter muscle
E. Descending activity of the frontal eye field
D
[Self-assessment]
Which of the following extraocular muscles can intort the eye?
A. Inferior oblique
B. Superior oblique
C. Lateral rectus
B
SO: intorsion + depression
IO: extorsion + elevation
LR: abduction
[Self-assessment]
Which of the following is false?
A. Lesion in the medial longitudinal fasciculus (MLF) may result in internuclear ophthalmoplegia (INO)
B. Paramedian pontine reticular formation (PPRF) controls contralateral horizontal gaze
C. CN III palsy may result in ptosis and pupil dilatation
B
PPRF: ipsilateral horizontal gaze
Frontal eye fields: contralateral horizontal gaze
[Old PP]
Receptive field of a sensory neuron is defined as region where adequate stimulus triggers firing of neuron. What is unique feature of receptive field among simple cells in striate cortex?
A. Concentric circles with antagonistic surround
B. High sensitivity to edge of shadows on patch of retina
C. Parallel on-off zones with convergent inputs from superior colliculus
D. Parallel on-off zones with receptive field aligned along one axis, and is orientation specific
E. Reception of convergent input, receptive field along multiple axes, input from thalamic nuclei
D
Rectangular RF, circles in a line with lateral inhibition instead of concentric circles
[Old PP]
Which of the following represents receptive field of simple cells in primary visual cortex?
A. On-off centres with antagonistic arrangement
B. Convergence of LGB cells aligned with multiple axes
C. Convergence of LGB cells aligned on a linear axis
C
LGB cells are on-off centres with antagonistic arrangement (concentric-surround RF)
Simple cells: orientation-specific neurons with rectangular RF, on-centre or off-centre region flanked by antagonistic surround, elongated along a linear axis
[Old PP]
Which one is true?
A. Cataract surgery cannot fix astigmatism
B. Cataract surgery does not need injection of anaesthesia
C. Cataract surgery requires suture for water tightness
D. Lens extraction and implantation for intraocular lens cannot treat myopia and hypermetropia
E. Cornea is over 2mm thick in centre for strength
C
E:
thickness at centre: ~0.5-0.6mm
thickness at periphery: ~0.6-0.8mm
diameter: ~11.5mm
[Old PP]
Which of the following is true?
A. Cataract patients may complain of worse vision in bright light
B. High intraocular pressure is the only cause of glaucoma
C. Non-proliferative diabetic retinopathy should be treated by panretinal laser photocoagulation
D. On examination, an eye with cataract may have increased red reflex
E. Open angle glaucoma is more common than angle closure glaucoma in Chinese
A
A:
cataract near back of lens (posterior subcapsular cataract), visual acuity worse when pupil constricts
VS
cataract at centre (inside) of lens (nuclear cataract), distant vision worsens
B:
glaucoma; damaged optic nerve, can have other causes
C:
laser photocoagulation: seal BV, destroy abnormal BV, seal retinal tears, destroy abnormal tissue at back of eye
for diseases with abnormal retinal BV growth (neovascularisation)
e.g. proliferative diabetic retinopathy or retinal vein occlusion
D: diminished red reflex
E: angle closure glaucoma is more common
[Old PP]
A gardener presented in eye department with complaints with right decreased vision and red eye. On examination he had redness more marked on right nasal side with a fibrovascular growth extending 3mm onto cornea from lesion at same site which was operated one year earlier. How will you manage this recurrent lesion preferably?
A. Observation along till it reaches visual
B. Excision of conjunctiva
C. Topical steroids for resolution of lesion
D. Surgical excision with mitomycin application
E. Penetrating keratoplasty
D
Pterygium:
- raised, wedge-shaped growth of conjunctiva
- most common among those living in tropical climates or spend a lot of time under sun
A: recurrent pterygium is usually aggressive, can involve deeper tissues of cornea
C: can only suppress inflammation
D: anti-mitotic agent is treatment of choice in recurrent pterygium
E: lamellar keratoplasty may be required if involving deeper cornea
[Old PP]
Which of the following statements is correct?
A. Cataract is only present in old patients
B. Direct ophthalmoscope is an important tool for examination of anterior part of eye
C. Retinal detachment is not associated with myopia
D. Glaucoma is always presented with red eye
E. Distant visual problem is only form of refractive error
B
[Old PP]
Which cranial nerve carries afferent component of VOR?
CN VIII
[Old PP]
Conjugate eye movement means motor control of eyes, which involves voluntary bilateral fixation of eyes to a fixed object. Which of the following is involved in conjugate eye movement?
A. Paralateral medullary reticular formation
B. Paralateral pontine reticular formation
C. Paramedian medullary reticular formation
D. Paramedian pontine reticular formation
E: Paramedian vestibular formation
D
[Old PP]
About saccades system,
A. Can be modified by visual feedback
B. Depth perception
C. Saccades are triggered by voice commands
D. Saccades are guided by temporal cortex
E. Triggered by vergence system
A
Saccades can be voluntary
[Old PP]
Gaze shifting can be achieved by smooth pursuit system. Which of the following is true?
A. Hold images of visual world steady on retina
B. Activated by movement of entire visual world
C. No time for visual feedback to modify course of saccade
D. Assures foveal fixation
E. Evoked in response to verbal commands
D
A:
- optokinetic system: gaze stabilisation driven by retina slip => keep image steady on retina
B: optokinetic system
C:
- smooth pursuit is slow and quasi-voluntary, require visual feedback to calculate speed of object movement and avoid unnecessary movement
E:
- smooth pursuit (tracking moving objects) is triggered by moving stimuli
[Old PP]
Which of the following is a characteristic of smooth pursuit system?
A. Allows foveal fixation
B. Does not allow time for visual feedback
A
[Old PP]
Saccadic generator (system):
A. Triggered by movement of whole visual field
B. Triggered by movement of head
C. Connected to flocculus nucleus
D. Burst output for moving eyes to new object
D
Saccade:
- Rapid, ballistic, conjugate eye movement
- Modified by visual feedback
- Burst of signals initiate
Flocculus nucleus (cerebellum):
- vestibulo-ocular reflex for gaze stabilisation brought about by ocular movement opposite to head movement
[Old PP]
Smooth pursuit system
A. Assures foveal fixation
B. Does not allow time for visual feedback
C. Holds images of visual world steady on retina
D. Is evoked in response to verbal commands
E. Is linked to gaze stabilisation
A
E: should be gaze-shifting
Gaze stabilisation:
- vestibulo-ocular reflex
- optokinetic system
- vertical gaze maintenance: interstitial nucleus of Cajal (INC)
- horizontal gaze maintenance: nucleus prepositus hypoglossi (nPH)
- cerebellum
[PP]
A low level or a deficit in the function of neurotransmitters is suggested to be the cause of depression. What is the mode of action of noradrenaline (NA) reuptake inhibitor on treating depression?
A. It blocks the alpha-2 adrenoceptor on the presynaptic cell to prevent the reuptake of NA
B. It blocks the NA receptor on the postsynaptic cell to prevent the reuptake of NA
C. It blocks the NA reuptake transporter on the presynaptic cell to reduce the reuptake of NA
D. It inhibits the NA reuptake transporter on the postsynaptic cell to prevent the negative feedback loop and increase the release of NA
C
[PP]
Monoamine hypothesis suggests that depression is caused by low levels of a deficit in function of neurotransmitters. What is the mode of action of alpha-2 adrenoceptor antagonist (NASA) in treating depression?
A. It induces the synthesis of the neurotransmitter
B. It prevents the binding of the neurotransmitter to their autoreceptors on presynapse
C. It prevents the degradation of the neurotransmitter
D. It prevents the reuptake of neurotransmitters by the transporters on the post-synapse
B
[PP]
Depression is caused by low levels or a deficit in function of neurotransmitters. Which of the following is the hypothesis for the pathogenesis of depression?
A. Dopamine hypothesis
B. Melatonin hypothesis
C. Monoamine hypothesis
D. Tricyclic hypothesis
C
[PP]
What is the mechanism of action of selective serotonin reuptake inhibitors as antidepressants in the treatment of depression?
A. It enhances the release of serotonin at the postsynaptic cell
B. It enhances the release of serotonin at the presynaptic cell
C. It limits the reabsorption of serotonin into the postsynaptic cell
D. It limits the reabsorption of serotonin into the presynaptic cell
D
[Self-assessment]
The evaluation and diagnosis of patients with psychiatric illnesses on the categories of depression is based on the which manual / handbook?
Diagnostic and Statistical Manual of Mental Disorders
[Self-assessment]
Which of the following is the hypothesis for the pathogenesis of depression?
A. Lithium hypothesis
B. Serotonin hypothesis
C. Neurotrophic hypothesis
D. Dopamine hypothesis
E. Tricyclic hypothesis
C
Impaired growth of neurons
[Self-assessment]
What is the mode of action of serotonin selective reuptake inhibitors in treating depression?
A. It blocks the reuptake transporters on the presynapse to prevent the reuptake of the neurotransmitters
B. It promotes the binding of serotonin to the reuptake transporters on the presynapse
C. It blocks the autoreceptors on the presynapse to prevent reuptake of the neurotransmitters
D. It increases the synthesis of the neurotransmitters
E. It prevents the degradation of the three neurotransmitters that regulate mood
A
[Self-assessment]
What is the mode of action of tricyclic antidepressant?
A. It increases the synthesis of dopamine, serotonin and noradrenaline
B. It only blocks the reuptake of noradrenaline
C. It blocks the reuptake of dopamine, serotonin and noradrenaline
D. It only blocks the reuptake of dopamine
E. It only blocks the reuptake of serotonin
C
[PP]
What is the mode of action of alpha-2 adrenoceptor antagonist?
A. It reduces the binding affinity of noradrenaline to its specific receptor on the post-synapse
B. It blocks the reuptake of noradrenaline
C. It blocks the reuptake of dopamine
D. It increases the synthesis of noradrenaline
E: It blocks the reuptake of serotonin
D
Blocks alpha-2 adrenoceptor on pre-synapse
=> inhibit negative feedback loop
=> increase synthesis and release of noradrenaline
[Self-assessment]
In addition to medications, name two other therapies that can provide for depressive patients.
- Cognitive-behavioural therapy
- Interpersonal therapy
[PP]
What is expected at the lumbar puncture and examination of the cerebrospinal fluid in a patient with tuberculosis or cryptococcal meningitis?
A. A high opening pressure
B. A high percentage of neutrophils
C. A low concentration of proteins
D. A normal concentration of glucose
A
[PP]
Intorsion is an internal rotation of the eyeball. What are the muscles involved in this action?
A. Inferior rectus muscle and inferior oblique
B. Medial rectus muscle and inferior rectus muscle
C. Medial rectus muscle and superior rectus muscle
D. Superior rectus muscle and superior oblique muscle
D
[PP]
A 55-year-old man had a trouble reading newspaper. The visual field examination showed a right homonymous inferior quadratic hemianopia / quadrantanopia. Lesion at which location would MOST LIKELY correlate with his visual problem?
A. Left Meyerâs loop
B. Left superior bank of primary visual cortex
C. Right lateral geniculate nucleus
D. Right parietal optic radiation
B
[PP]
Fungi can cause infection of the central nervous system. However, most fungal infections are opportunistic, affecting patients with underlying impaired cellular immunity. Which of the following fungi is MOST LIKELY to cause fungal meningitis in an otherwise healthy individual?
A. Aspergillus
B. Candida
C. Cryptococcus
D. Mucormycosis
C
[PP]
A woman has recently become depressed. Which of the following is the MOST LIKELY trigger?
A. A forthcoming stressful event
B. A lack of external stimulation
C. Disturbance of normal routine
D. The loss of a significant resource
D
Depression: actual or anticipated loss of rewards or capacity to obtain rewards (e.g. resources)
Lack of stimulation -> boredom
Stressful event / disturbance -> more likely anxiety
[PP]
The skin of the forehead, the upper eyelid, the conjunctiva, and the sides and tip of the nose is innervated by 5 major branches of one nerve. What is this nerve?
A. Auriculotemporal
B. Ophthalmic
C. Zygomaticofacial
D. Zygomaticotemporal
B
[PP]
A 63-year-old male fell down a flight of stairs and was admitted to the Accident and Emergency Department. Examination revealed impaired pupillary constriction. Radiological imaging revealed a fracture of the superior orbital fissure. Which nerve was MOST LIKELY injured?
A. Abducens
B. Oculomotor
C. Ophthalmic
D. Optic
B
[PP]
Extorsion is an external rotation of the eyeball. What are the muscles involved in this action?
A. Inferior rectus and inferior oblique
B. Medial rectus and inferior rectus
C. Medial rectus and superior rectus
D. Superior rectus and superior oblique
A
[PP]
A 65-year-old woman with a history of poorly controlled diabetes attended the Accident and Emergency Department complaining of double vision. On examination, her best corrected visual acuities in both eyes were 6/6, on extraocular movement testing, the ocular motility of her right eye was normal, but she was noted to have limited abduction of her left eye, which was unable to cross midline. Which of the following is a likely cause of her symptoms?
A. Left IV nerve palsy
B. Left VI nerve palsy
C. Refractive error
D. Right IV nerve palsy
B
[PP]
Monoamine hypothesis suggested that depression is caused by low levels or a deficit in function of neurotransmitters. What is the mechanism of action of monoamine oxidase inhibitor in treating depression?
A. It inhibits the monoamine oxidase from activating the neurotransmitter reuptake inhibitor
B. It inhibits the monoamine oxidase from degrading the neurotransmitters
C. It inhibits the monoamine oxidase from degrading the tyramine
D. It inhibits the monoamine oxidase from producing noradrenaline
B
[PP]
A 55-year-old man had a brain tumour located in the Meyerâs loop (temporal optic radiation) in the left hemisphere and he had partial vision loss. What kind of visual field defect did he suffer from?
A. Left lower quadrant homonymous hemianopia
B. Left upper quadrant homonymous hemianopia
C. Right lower quadrant homonymous hemianopia
D. Right upper quadrant homonymous hemianopia
D
[PP]
Which muscle depresses the eye from a starting adducted position?
Superior oblique
Obliques: abduction
VS
Rectus: adduction (except lateral rectus)
[PP]
Name a muscle of the eye which is adjacent to the frontal nerve (branch of CN V1).
Levator palpebrae superioris
Frontal nerve (CN V1)
- Enters the orbit through superior orbital fissure (extraconal / extracorpuscular)
- Superior to LPS (further superior to SR)
[PP]
A 3-day-old neonate presented with temperature instability, respiratory distress, lethargy, irritability, and vomiting. Cerebrospinal fluid and blood culture yielded beta-haemolytic gram-positive cocci in chains. What is the most likely causative organism?
Streptococcus agalactiae
[PP]
A 33-year-old woman with cochlear implant presented with 3 days of fever, headache, and neck stiffness. Cerebrospinal fluid and blood culture yielded gram-positive cocci in chains. What is the MOST LIKELY causative organism?
Streptococcus pneumoniae
[PP]
A 5-year-old child developed high fever, neck rigidity and decrease in consciousness. The cerebrospinal fluid showed a high white cell count with predominantly polymorphs. Name the most likely disease and a possible causative organism.
Meningitis
Meningococcal / H. influenzae / Pneumococcal
[PP]
A 15-year-old child had history of low grade fever and night sweating for the recent one month. He developed progressive headache, vomiting, decreased consciousness and died. Postmortem examination showed thickening of the meninges with multiple tiny white nodules around 1mm in diameter each in the subarachnoid space. Histological examination revealed aggregates of epithelioid cells and Langhanâs giant cells surrounded by lymphocytes. What is the most likely disease?
Tuberculous meningitis
[PP]
If corticospinal tract is damaged in brain trauma, name one of the functional deficits.
Spastic paralysis / Hyper-reflexia / Babinski sign / Loss of upper motor control
[PP]
What is the efferent projection of medial lemniscus?
Thalamus (ventral posterior lateral / medial nucleus)
[PP]
Which neurotransmitter binds to the ectodomain of the post-synaptic N-methyl-D-aspartic acid receptor (NMDAR) and causes the opening of a transmembrane channel that allows the flow of Na+ and Ca2+ into the post-synapse, thereby facilitating excitatory transmission across the synapse?
A. Acetylcholine (ACh)
B. gamma-aminobutyric acid (GABA)
C. Glutamate (Glu)
D. Glycine (Gly)
C
[PP]
Which nucleus of the brain is mediated by neurotransmitter serotonin?
A. Basal nucleus of Meynert
B. Locus coeruleus
C. Raphe nucleus
D. Vestibular nucleus
C
-> Sites of production of NT
Serotonin
- Raphe nucleus (@reticular formation)
Norepinephrine
- Locus coeruleus (@rostral pons)
Dopamine
- Substantia nigra pars compacta (SNc)
- Ventral tegmental area (VTA)
Acetylcholine
- Pons (pontomesencephalotegmental complex)
- Basal nucleus
- Medial septal nuclei
[PP]
Visual features are extracted and interpreted at specific parts of the brain. Where is spatial and form recognition being perceived along the visual pathway?
A. Cuneus gyrus
B. Lateral geniculate nucleus
C. Optic radiation
D. Superior temporal gyrus
A
Ventral (temporal) pathway:
V1 -> V2 -> V4 (form recognition, spatial task)
Dorsal (parietal) pathway:
V1 -> V2 -> MT / middle temporal visual area / V5 (motion perception)
[PP]
A 54-year-old alcoholic man with HIV infection was admitted with a history of fever and headache for the last 6 weeks. Physical examination revealed neck stiffness, Ziehl-Neelsen-stained smear of the cerebrospinal fluid showed acid-fast bacilli.
What is the MOST LIKELY clinical diagnosis and causative organism?
Chronic meningitis caused by Mycobacterium tuberculosis
[PP]
What are the expected findings in the cerebrospinal fluid of a patient with chronic TB meningitis?
(i) predominant type of leukocyte
(ii) protein level
(i) Lymphocyte
(ii) Increased
[PP]
Name two first-line antimicrobial drugs for treating chronic TB meningitis.
Isoniazid
Rifampicin
Ethambutol
Pyrazinamide
[PP]
What is the MOST IMPORTANT specimen to obtain to diagnose central nervous system infection?
Cerebrospinal fluid
[PP]
Name one bacterial pathogen that can cause chronic meningitis.
Mycobacterium tuberculosis
Borrelia burgdorferi (Lyme disease)
Treponema pallidum (syphilis)
Brucella spp.
Nocardia spp. (immunosuppressed)
Listeria monocytogenes
[PP]
Name one fungal pathogen that can cause chronic meningitis.
Cryptococcus species (e.g. Cryptococcus neoformans)
Histoplasma capsulatum
Coccidioides species
Sporothrix species
X Candida / Aspergillus
[PP]
A 36-year-old man presented to the Emergency Department with low-grade fever, headache, and blurring of vision for 4 weeks. He had unprotected sex with several male partners. The blood test showed lymphopenia. HIV serology was reactive. Computed tomography scan of the brain did not reveal any space-occupying lesion. Name one serological test that can help diagnose the fungal pathogen that can cause chronic meningitis in this setting.
Cryptococcal antigen test
[PP]
Name one antifungal medication that is active against Cryptococcus species.
Fluconazole (or other triazoles)
Amphotericin B
Flucytosine
[PP]
A 44-year-old man fell down eight concrete steps and later admitted to the Accident and Emergency Department. On initial head and neck physical examination, the patient displayed left periorbital edema and ecchymosis, left lid ptosis, loss of sensation of the forehead, and full restriction of motion of the left globe in all fields of gaze.
Name one subdivision of ophthalmic division of trigeminal nerve that is affected in this patient.
Supraorbital / Supratrochlear
[PP]
A 44-year-old man fell down eight concrete steps and later admitted to the Accident and Emergency Department. On initial head and neck physical examination, the patient displayed left periorbital edema and ecchymosis, left lid ptosis, loss of sensation of the forehead, and full restriction of motion of the left globe in all fields of gaze.
Which cranial nerve(s) is/are affected leading to full restriction of motion of eyeball? (3 marks)
Oculomotor nerve (CN III)
Trochlear nerve (CN IV)
Abducens nerve (CN VI)
[PP]
A 44-year-old man fell down eight concrete steps and later admitted to the Accident and Emergency Department. On initial head and neck physical examination, the patient displayed left periorbital edema and ecchymosis, left lid ptosis, loss of sensation of the forehead, and full restriction of motion of the left globe in all fields of gaze.
What is the response of the right pupil if you shine light to the left eye? (1 mark)
Normal pupil constriction of the right pupil
[PP]
The upper lip, the lateral surfaces of the nose, the lower eyelid and conjunctiva, the skin of the cheek and the side of the head behind the eye are supplied by branches of one nerve. What is this nerve?
A. Buccal
B. Facial
C. Great auricular
D. Maxillary
D
Maxillary n. (CN V2 division of trigeminal nerve)
[PP]
Congenital myasthenic syndromes (CMS) are autosomal recessive disorders that affect quantal acetylcholine release into the neuromuscular junction (NMJ). What is a viable means to maintain acetylcholine level in the NMJ for neurotransmission in patients with CMS?
A. Increase choline uptake at the NMJ
B. Increase dietary intake of choline
C. Inhibit acetylcholinesterase activity in the NMJ
D. Stimulate choline acetyltransferase activity at the nerve terminal
C
Treatment for CMS:
- AChE inhibitor (prophylactic pyridostigmine)
[PP]
Calcium-triggered neurotransmitter release requires specific docking of synaptic vesicles to target membrane proteins at the presynaptic terminal. Which presynaptic protein is a proteolytic target of botulinum toxins?
A. Ca2+/calmodulin dependent protein kinase
B. Clathrin
C. Synaptotagmin
D. Syntaxin
E. Voltage-gated Ca2+ channel protein
D
BoTX B, D, F, G: synaptobrevin (V-SNARE / VAMP)
BoTX C: syntaxin (T-SNARE)
BoTX A, E: SNAP-25 (T-SNARE)
[Old PP]
Botox (botulinum toxin) is used to inhibit release of neurotransmitters from presynaptic nerves. What does it target?
A. Clathrin
B. Synaptobrevin
C. Synaptophysin
D. Synaptotagmin
E. Voltage-gated Ca2+ channel protein
B
Synaptobrevin (V-SNARE / VAMP): BoTX B, D, F, G
VGCC:
- targeted by IgG (auto-antibodies) in Lambert-Eaton Myasthenic Syndromes (LEMS)
[Old PP]
Botox toxin acts on which presynaptic membrane component?
A. Ca/Calmodulin dependent protein kinase
B. Clathrin
C. SNARE protein
D. Synaptotagmin
E. Voltage-gated Ca2+ channel
C
[Old PP]
Related to a chemical channel being activated causing neurotransmitter to be released. Which channel opened at presynaptic neurons to allow neurotransmitter exocytosis?
A. Na+ channel
B. Ca2+ channel
C. K+ channel
D. Cl- channel
B
[Old PP]
Related to clostridium toxin,
A. Inhibits recycling of acetylcholine
B. Cleaves SNARE proteins
C. Inhibits binding of Ca2+ to synaptotagmin
B
[Old PP]
Synapse is important for neurotransmitter between excitable cells. Which of the following blocks the release of neurotransmitters in chemical synapse?
A. Absence of extracellular calcium
B. Inactivation of ligand-gated channel
C. Inactivation of gap junction
D. Spatial summation of inhibitory postsynaptic potential
E. Temporal summation of excitatory postsynaptic potential
A
Ca2+ influx
=> fusion of synaptic vesicles with pre-synaptic membrane
[Old PP]
Localised injection of Botox (purified botulinum toxin) has been exploited to relax overactive muscle that causes frown lines and wrinkles. How does the toxin act to limit neurotransmitter release at motor nerve endings?
A. Cleave clathrin involved in endocytic budding of pre-synaptic vesicles
B. Cleave SNARE proteins involved in vesicle apposition at the presynaptic membrane
C. Cleave synapsin involved in cross-linking vesicles to pre-synaptic cytoskeleton
D. Cleave synaptotagmin involved in Ca2+ mediated vesicle fusion with presynaptic membrane
E. Cleave voltage-gated Ca2+ channels at pre-synaptic terminal
B
[Old PP]
Which of the following is NOT a known mechanism for termination of neurotransmitter action at synaptic cleft?
A. Degradation of neurotransmitter
B. Oxidation of neurotransmitter
C. Receptor mediated endocytosis of neurotransmitter
D. Reuptake by glial cells
E. Reuptake into presynaptic terminals
B
E.g. ACh
Degraded by acetylcholinesterase (AChE)
Reuptake
Diffusion away (spillover) from synaptic cleft -> peri-synaptic astrocytes
[Old PP]
Which of the following neurotoxins could alter exocytosis of neurotransmitter?
A. alpha-bungarotoxin
B. omega-conotoxin
C. Botulinum toxin
D. Cobra toxin
E. Saxitoxin
C
Cleaves SNARE proteins
=> prevent synaptic vesicles from docking / priming / fusion with presynaptic membrane
[Old PP]
Which of the following statements concerning neurotransmission is TRUE?
A. Excitatory postsynaptic potentials (EPSPs) can be recorded at axons of nerve cells
B. EPSPs cause hyperpolarisation of cell membrane
C. Inhibitory postsynaptic potentials (IPSPs) are caused by increase of membrane permeability to Na+ ions
D. Neurotransmission contributes to integrative properties of neurones
E. There is a time delay of about 1 sec in normal synapse
D
EPSPs: at dendrites / cell body, cause depolarisation
IPSPs: Cl- / K+
Time delay at chemical synapse: ~0.5ms
[PP]
A 5-year-old with myasthenic symptoms and episodic apnoea since birth indicated no decrement at baseline response on 2-Hz repeated stimulation of motor nerves (RNS). 10-Hz RNS for 5 minutes however triggered (i) decremental response on 2-Hz RNS, (ii) drop in compound muscle action potential (CMAP) amplitude, and (iii) subsequent post tetanus recovery of CMAP amplitude for up to 30 minutes. What synaptic protein is MOST LIKELY the causative molecular defect in this patient?
A. Acetylcholine receptor (AChR)
B. Choline acetyltransferase (ChAT)
C. High-affinity presynaptic choline transporter (ChT)
D. Synaptosomal-associated protein, 25 kDa (SNAP25)
B
AChR defect (postsynaptic):
- MG (autoimmune, adult onset)
- Electro-diagnostic testing; decremental response to 2Hz RNS and increased jitter/blocking upon single fibre electromyography
ChAT (presynaptic)
- catalyse synthesis of ACh from choline & acetyl-CoA
- recessive mutations => CMS(-EA)
- decline in vesicular stores upon 10-Hz stimuli
- subsequent slow recovery of CMAP amplitude suggests defect in ACh resynthesis
ChT:
- cleavage of ACh by AChE in synaptic cleft => re-uptake of choline via ChT for resynthesis of ACh
- recessive mutations also cause CMS-EA
- BUT decremental response even to low frequency RNS or after few seconds of conditioning with high frequency RNS
SNAP25
- deficiency => X vesicle priming and fast Ca2+ -triggered vesicular release of neurotransmitter
- symptoms even in utero
- decremental response even to low frequency RNS
[Self-assessment]
Acute epiglottitis is most commonly caused by:
Haemophilus influenzae serotype b
H. influenzae:
Gram -ve coccobacilli
Growth requirements: X (hemin) & V (NAD) factors
6 types (a - f) / non-typeable
Produce beta-lactamases
[Self-assessment]
Mediastinitis is a known complication of:
A. Submandibular and sublingual space infections
B. Croup
C. Acute epiglottitis
D. Retropharyngeal space infections
E. Mucositis
D
Spread of infection along the space to mediastinum as they are anatomically connected
Retropharyngeal space
1. -> Mediastinum
2. -> Carotid sheath -> Cranium / Mediastinum
3. -> Lateral pharyngeal space -> Submandibular / Sublingual spaces
[PP]
A 15-year-old boy complained of fever and progressive sore throat for two days. He also experienced pain and difficulty in swallowing. Physical examination showed inspiratory stridor and bilateral inflamed tonsils with medial displacement. The patient recovered after emergency surgical drainage and antibiotic treatment.
What is the (i) MOST LIKELY diagnosis and (ii) causative agent?
(i) Peritonsillar abscess / quinsy
(ii) Group A Streptococcus / Streptococcus pyogenes
Infection in oropharynx: peritonsillar abdcess (quinsy)
- Mostly adolescents & young adults
Clinical features
- severe sore throat
- low grade fever
- dysphagia
- inflammation of peritonsillar area with medial displacement of tonsils
-> bilateral airway obstruction => stridor
Causative agents:
- GAS
- Mixed (oropharyngeal organisms: Viridans Streptococci, anaerobes e.g. Fusobacterium, Bacteroides)
Management
- Airway protection
- Antibiotics
- Surgical drainage of abscess
[PP]
Describe the gram stain appearance of S. pyogenes.
Gram-positive cocci in chains
[PP]
Name the cardiovascular disease complication that may occur after repeated infections caused by S. pyogenes.
Chronic rheumatic heart disease
[PP]
Name one serious skin and soft tissue infection with high mortality caused by S. pyogenes.
Necrotising fasciitis
[Old PP]
A 60-year-old woman with fever, sore throat and hard swelling of submandibular space. Pus culture recovered Gram-positive cocci in chains which is alpha-haemolytic, bile-insoluble and resistant optochin.
What is the most likely causative pathogen?
Viridans Streptococci
Differentiation between alpha-hemolytic streptococci
S. pneumoniae: optochin-sensitive, bile-soluble
VS
Viridans streptococci: optochin-resistant, bile-insoluble
[Old PP]
A 2-year-old boy with fever, severe sore throat and drooling of saliva. Blood culture recovered Gram-negative coccobacilli which grows on chocolate agar but not blood agar. What is the most likely causative agent?
Haemophilus influenzae serotype b
Acute epiglottitis (oropharynx):
2-4 y/o
Fever (6-12 h)
Severe sore throat
Dysphonia, drooling oral secretions, stridor
[Old PP]
A 15-year-old girl with fever, sore throat, cervical lymphadenopathy and difficulty in breathing; examination showed bilateral enlarged tonsils with exudates; monospot test was positive.
Epstein-Barr virus
Oropharynx:
- EBV mononucleosis (anginose form)
[Old PP]
A 60-year-old intravenous drug user with fever, sore throat and neck stiffness. Computed tomography of cervical spine showed vertebral osteomyelitis and retropharyngeal abscess. Blood culture recovered Gram-positive cocci in clusters which is positive for coagulase. What is the most likely causative pathogen?
Staphylococcus aureus
Retropharyngeal space infections
- fever, sore throat, dysphagia, neck stiffness
- causes: odonitis, peritonsillar abscess, cervical vertebral osteomyelitis, perforated pharynx
- mixed oral flora (from pharynx / dental source) OR S. aureus (from vertebral osteomyelitis)
[Old PP]
A 5-year-old boy from Bangladesh with fever, sore throat and stridor. Culture of pseudomembrane in throat recovered Gram-positive bacilli which is Elek test positive. What is the most likely causative pathogen?
Corynebacterium diphtheriae
(Gram +ve bacilli, aerobic, non-spore forming)
[Old PP]
A 15-year-old girl with sore throat and dysphagia, peritonsillar pus culture recovered a Gram-positive cocci in chains which is beta-haemolytic and sensitive to bacitracin. What is the most likely causative pathogen?
Streptococcus pyogenes (peritonsillar abscess / quinsy)
Beta-hemolytic:
- Bacitracin +ve: S. pyogenes (A)
- Bacitracin -ve: S. agalactiae (B), S. dysgalactiae (C)
[Old PP]
A 65-year-old woman with fever, dental caries and board-like swelling of floor of mouth, culture of debrided submandibular tissues recovered a Gram-positive cocci in chains which is alpha-haemolytic, bile insoluble and resistant to optochin. What is the most likely causative pathogen?
Viridans Streptococci
Submandibular & sublingual space infection (Ludwigâs angina)
- cause: mostly dental root abscess
Clinical features:
- Board-like swelling of bilateral submandibular & sublingual spaces
- High fever, systemic toxicity
- Mouth held open
- Dysphagia
[Old PP]
A 1-year-old girl with fever, running nose and stridor, nasopharyngeal aspirate was positive for a virus which possesses 8 RNA segments. What is the most likely causative pathogen?
Influenza virus
[PP]
The deep cervical fascia consists of three main layers. Which layer encloses the trapezius and sternocleidomastoid muscles?
Investing layer
Other two layers:
- Pretracheal
- Prevertebral
[PP]
Where do the three main layers of deep cervical fascia converge?
Carotid sheath
[PP]
List three main structures within carotid sheath.
Medial -> lateral:
1. Common carotid artery
2. Vagus nerve
3. Internal jugular vein
[PP]
List three structures passing through foramen ovale.
OVALE
Otic ganglion
*CN V3: mandibular nerve
* Accessory meningeal artery
* Lesser petrosal nerve
Emissary veins
[PP]
Name the cranial nerve that gives rise to the parasympathetic fibres passing through foramen ovale.
Glossopharyngeal nerve (CN IX)
Glossopharyngeal nerve
-> Tympanic plexus
-> Lesser petrosal nerve
-> Otic ganglion
-> Auriculotemporal nerve (V3)
-> Parotid gland
[PP]
If oculomotor nerve (CN III) is completely severed, what is the final position of the ipsilateral pupil?
Abducted and depressed
/ down and out
[PP]
List two motor functions of facial nerve.
- Muscles of facial expression
- Dampens loud sound in middle ear
[PP]
The infratemporal fossa is located between the skull base and the ramus of mandible. Through which opening in the skull base does the nerve which carries parasympathetic fibres to the parotid gland emerge?
A. Foramen ovale
B. Foramen spinosum
C. Petrotympanic fissure
D. Pterygomaxillary fissure
A
Otic ganglion (CN IX)
[PP]
A motorcyclist was sent to the Accident and Emergency Department after a traffic accident. He had sustained a traumatic injury on the left temporal region of the head. Epidural haematoma was suspected. Name the H-shaped bony landmark found at the temporal region of the skull that was MOST LIKELY fractured.
Pterion
[PP]
Which two bones form both the pterion and the roof of infratemporal fossa?
Temporal bone
Sphenoid bone
[PP]
A motorcyclist was sent to the Accident and Emergency Department after a traffic accident. He had sustained a traumatic injury on the left temporal region of the head. Epidural haematoma was suspected.
In which ganglion are the primary sensory neurons that detected the pain located in this case?
Trigeminal ganglion
[PP]
A motorcyclist was sent to the Accident and Emergency Department after a traffic accident. He had sustained a traumatic injury on the left temporal region of the head. Epidural haematoma was suspected.
Which artery was MOST LIKELY damaged, leading to the epidural haematoma?
Middle meningeal artery
Blow to lateral side of head
=> Fracture of pterion (overlie ant. branches of middle meningeal a.)
=> epidural haematoma
=> pressure on cerebral cortex
=> death in a few hours if untreated
[Self-assessment]
Middle meningeal artery (MMA) is one of the branches of maxillary artery. Skull fracture can severe this artery. What type of intracranial bleeding does this injury produce?
A. Subarachnoid haemorrhage
B. Epidural haemorrhage
C. Subdural haemorrhage
B
[Self-assessment]
What is the special feature in the 7 cervical vertebrae that is not seen in the thoracic and lumbar vertebrae?
A. Transverse foramina
B. Articular facets
C. Spinous process
A
Transmits vertebral artery (C6 -> C1)
[Self-assessment]
What is the nervous structure found within the carotid sheath?
A. Vagus nerve
B. Phrenic nerve
C. Sympathetic trunk
A
[Old PP]
Which skull foramen allows exit of olfactory nerve?
Perforations in cribriform plate
Cribriform plate
- Anterior cranial fossa
- Ethmoid bone
- Transmits CN1
[Old PP]
Which skull foramen allows exit of oculomotor nerve, trochlear nerve, branches of CN V1, abducens nerve and superior ophthalmic vein?
Superior orbital fissure
Between lesser and greater wings of sphenoid bone
- CN III, IV, V1, VI
- Superior ophthalmic vein
[Old PP]
Which skull foramen allows exit of middle meningeal artery?
Foramen spinosum
Greater wing of sphenoid bone
[Old PP]
Which skull foramen allows exit of chorda tympani?
Petrotympanic fissure
[Old PP]
Which skull foramen allows exit of cranial nerves IX, X, XI and sigmoid sinus?
Jugular foramen
Posterior cranial fossa
Between temporal and occipital bones
Transmits CN IX, X, XI and sigmoid sinus (becoming internal jugular vein)
[Old PP]
Which skull foramen allows exit of CN VII and VIII?
Internal acoustic meatus
Posterior cranial fossa
Temporal bone
[Old PP]
When Dr. Tony Wong was injured in motor vehicle accident, he sustained a deep gash in posterior triangle of neck. Vessel MOST LIKELY to be affected will be:
A. Common carotid artery
B. External carotid artery
C. External jugular vein
D. Internal carotid artery
E. Internal jugular vein
C
[Old PP]
Patients with cleft lip often require bone grafts when they are about 8-9 years old. Which bone is most commonly deficient in cleft lip patients?
A. Zygomatic arch
B. Alveolus
C. Palatine bones
D. Pterygoid plate
B
[Old PP]
Mrs Louisa Dimarzo is a 58-year-old woman who presents with tiredness and loss of appetite. Palpitation of neck reveals a slight diffuse enlargement of thyroid gland. Structures found in anterior triangle of neck include all of the following EXCEPT:
A. Submandibular lymph glands
B. Thyroglossal duct remnant
C. Supraclavicular lymph nodes
D. Parathyroid glands
E. Thyroid gland
C
[Old PP]
Which of the following statements is INCORRECT?
A. Posterior muscle of neck keeps head upright.
B. Scalene anterior muscle is behind roots of brachial plexus.
C. SCM covers part of cervical plexus
D. Sternohyoid lies over anterior part of trachea
E. Trapezius is innervated by spinal accessory nerve
B
Roots and trunks of brachial plexus enter posterior triangle of neck by passing between anterior and middle scalene muscles
[Old PP]
Through which opening does infratemporal fossa communicate with pterygopalatine fossa?
A. Foramen ovale
B. Foramen spinosum
C. Inferior orbital fissure
D. Pterygoid canal
E. Pterygomaxillary fissure
E
Pterygomaxillary fissure
-> pterygopalatine fossa
-> sphenopalatine foramen
[Old PP]
A 20-year-old girl has clear nasal discharge after sustaining a facial injury from a traffic accident. Which of the following bones is most likely fractured?
A. Ethmoid bone
B. Frontal bone
C. Maxillary bone
D. Nasal bone
E. Sphenoid bone
A
[PP]
Which nerve(s) crosses the same skull base opening as internal jugular vein?
A. Accessory nerve
B. Hypoglossal nerve
C. Phrenic nerve
D. Sympathetic nerves
A
Jugular foramen (between temporal & occipital bones)
- CN IX, X, XI
- Internal jugular vein
Hypoglossal foramen (occipital bone)
- CN XII
[PP]
The patientâs tongue deviated to the right when protruding. Which nerve was MOST LIKELY damaged?
A. Left CNIX
B. Left CNXII
C. Right CNIX
D. Right CNXII
D
[Old PP]
Maxillary sinus drains into âŚ
Hiatus semilunaris
-> Middle meatus
[Old PP]
Middle ethmoid sinus drains into âŚ
Ethmoidal bulla (on lateral wall of middle meatus)
[Old PP]
Sphenoid sinus drains into âŚ
Sphenoethmoidal recess
[Old PP]
Posterior ethmoid sinus drains into âŚ
Superior meatus
[Old PP]
Anterior ethmoid sinus drains into âŚ
Hiatus semilunaris
Anterior ethmoid sinus
-> Infundibulum
-> Hiatus semilunaris
-> Middle meatus
[Old PP]
Drainage sites of paranasal sinuses are located in âŚ
A. Bulla ethmoidalis of anterior ethmoid sinus
B. Inferior meatus of frontal sinus
C. Infundibulum of posterior ethmoid sinus
D. Sphenoethmoidal recess of sphenoid sinus
E. Superior meatus of maxillary sinus
D
Frontal sinus
-> Frontonasal duct
-> Infundibulum
-> Hiatus semilunaris
-> Middle meatus
[Old PP]
A 3-year-old came to your clinic presenting with fever. He has been having a sore throat for 2 days. On examination, boy was drooling and had stridor. What would your immediate action be?
A. Direct laryngoscopy
B. Nasopharyngeal aspirate for respiratory viruses
C. Throat swab for bacterial culture
D. CT head and neck
E. Urine culture for pneumococcus
A
Diagnosis:
- laryngoscopy: cherry-red epiglottis
Other investigations:
- XR neck: thumb sign
- Blood culture
Management:
- Airway protection
- Amoxicillin-clavulanate
- Rifampicin prophylaxis for unvaccinated household contacts <=4 y/o
[Old PP]
A 3-year-old boy is suffering from acute otitis media without other complications, which empirical treatment should be prescribed?
A. Oral amoxicillin-clavulanic acid
B. Clindamycin
C. IV vancomycin
D. IV ceftazidime
E. Oral penicillin V
A
[Old PP]
Which of the following pathogens has corresponding vaccine?
A. Pertussis
B. Parainfluenza
C. RSV
A
[Old PP]
10-year-old boy with stridor and barking cough. Which investigation is most appropriate?
A. Nasopharyngeal aspirate for virus detection
B. Throat swab for bacteria culture
C. Anti-streptolysin O
D. Urine streptococcal detection
E. Urine legionella detection
A
Croup (laryngotracheobronchitis)
- 3 months - 3 y/o (most common cause of stridor in children)
Clinical features
- URI symptoms (2-3 days)
- Barking cough, fever, hoarseness, stridor
- Parainfluenza virus, RSV, influenza virus, adenovirus, rhinovirus, Mycoplasma
Investigations:
- Neck XR: subglottic swelling, hourglass / steeple sign
- Nasopharyngeal aspirate
[Old PP]
A 60-year-old man with dental caries had fever, sore throat and neck pain for 1 week. Contrast CT scan shows left parapharyngeal abscess. What is a possible complication of this condition?
A. Jugular vein thrombophlebitis
B. Liver abscess
C. Meningitis
D. Myocarditis
E. Necrotising fasciitis
A
Lateral pharyngeal / parapharyngeal space infections
- Fever, sore throat, dysphasia, neck stiffness
Complications
- Jugular vein thrombophlebitis (Lemierre syndrome)
- Carotid artery erosion
[Old PP]
In which of the following is antibiotic therapy NOT indicated?
A. Acute epiglottitis
B. Quinsy
C. Croup
D. Parapharyngeal abscess
E. Retropharyngeal abscess
C
[Old PP]
Which of the following is prevented by universal vaccination?
A. Diphtheria
B. Mycoplasma pneumoniae
C. Respiratory syncytial virus
D. Parainfluenza virus
A
[Old PP]
Which of the following is a common causative agent of acute epiglottitis?
A. Gram-positive bacteria that is sensitive to bacitracin
B. Gram-negative coccobacilli that requires factor X and V
C. Gram-positive cocci that is coagulase positive
D. Gram-negative bacteria that is lactose fermenting
B
A: S. pyogenes
B: H. influenzae
C: S. aureus
D. E. coli, Klebsiella, Enterobacter, etc.
[Old PP]
Which nerve provides sensory supply to frontal sinus?
Ophthalmic nerve (CN V1)
Frontal, ethmoidal, sphenoid sinus: CN V1
Maxillary sinus: CN V2
[Old PP]
A 15-year-old male complained of frontal headache. This was accompanied by profuse clear nasal discharge. He was diagnosed with frontal sinusitis. What is the nerve supply and drainage of frontal sinuses?
A. Olfactory nerve and inferior meatus
B. Olfactory nerve and middle meatus
C. Trigeminal nerve and inferior meatus
D. Trigeminal nerve and middle meatus
E. Trigeminal nerve and superior meatus
D
CN V1
Frontonasal duct -> infundibulum -> hiatus semilunaris -> middle meatus
[Old PP]
A 10-year-old girl sustained facial injury in a vehicular accident. She had profuse nasal discharge of clear fluid and needs emergency treatment. Later, she also experienced transient loss of smell. What is the main pathology involved?
A. Fracture of ethmoid bone and involvement of cranial nerve I
B. Fracture of ethmoid bone and involvement of cranial nerve V
C. Fracture of frontal bone and involvement of cranial nerve I
D. Fracture of frontal bone and involvement of cranial nerve V
E. Fracture of maxillary bone and involvement of cranial nerve V
A
[Old PP]
A 18-year-old patient complained about pain in infraorbital region of face. This was accompanied with profuse clear nasal discharge. Diagnosis suggests that patient suffers from acute sinusitis. Which of the following are the nerve supply and drainage of maxillary sinuses?
A. Olfactory nerve and inferior meatus
B. Olfactory nerve and middle meatus
C. Trigeminal nerve and inferior meatus
D. Trigeminal nerve and middle meatus
E. Trigeminal nerve and superior meatus
D
[Old PP]
Which ganglion conveys pain sensation from anterior ethmoid sinus?
Trigeminal ganglion
Trigeminal ganglion
-> nasociliary nerve (V1)
-> anterior and posterior ethmoidal nerves
-> ethmoidal air cells
[PP]
A young man presents to the Accident and Emergency Department with epistaxis.
What is the most common site of epistaxis in young and normal adults?
Kiesselbach area (anterior 1/3 of nose)
[PP]
Name one bone and one cartilage of the nasal septum.
Bone:
1. Perpendicular plate of ethmoid bone
2. Vomer
Cartilage:
- Septal cartilage
[PP]
Name two arteries from the internal carotid artery that supply the most common site of epitaxis in young and normal adults.
- Anterior ethmoidal artery
- Posterior ethmoidal artery
Arise from ophthalmic artery (1st branch of ICA)
[PP]
Define borders and explain the clinical importance of the âdanger zone of the faceâ.
Borders:
- areas of face near the nose drained by facial veins
- corners of mouth to nose bridge
Clinical importance;
Infection of this zone may spread to cavernous sinus via facial vein, pterygoid plexus & ophthalmic veins
e.g. pterygoid plexus -> emissary veins -> cavernous sinus
Septicemia leads to meningitis / cavernous sinus thrombosis (neurological damage, life-threatening, may lead to stroke, meningitis or encephalitis) / brain abscess
- Pterygoid plexus is connected to facial vein via
1. inferior ophthalmic v.
2. deep facial v.
[Old PP]
Which nerve provides sympathetic innervation of nasal cavity?
Deep petrosal nerve
[Old PP]
Which nerve provides parasympathetic innervation of maxillary sinus?
Greater petrosal nerve
Postganglionic parasympathetic innervation:
- greater petrosal nerve (CN VII)
Sensory innervation:
- Superior alveolar (anterior, middle, posterior) nerves
- Branches of maxillary nerve (CN V)
[Old PP]
What is the sympathetic nerve supply of maxillary sinus?
Deep petrosal nerve
[Old PP]
Foramen rotundum leads into
A. Inferior orbital fissure
B. Orbit
C. Pterygoid canal
D. Pterygopalatine fossa
E. Sphenopalatine foramen
D
[PP]
A patient manifested nasal free flow of clear fluid after sustaining a severe head trauma. Which bone is fractured?
Ethmoid
Fracture of roof of nasal cavity including cribriform plate of ethmoid bone
=> tears meninges (e.g. dura)
=> CSF leaks
=> CSF rhinorrhea (discharge of clear fluid)
[Self-assessment]
What part of the nasal septum predominantly articulates with the maxillary bone?
A. Vomer
B. Septal cartilage
C. Perpendicular plate of ethmoid bone
A
Perpendicular plate of ethmoid:
- no articulation with maxilla
[Self-assessment]
What branch of the maxillary artery provides the major supply to the nasal cavity?
A. Inferior alveolar artery
B. Middle meningeal artery
C. Sphenopalatine artery
C
Inferior alveolar artery: lower teeth
Middle meningeal artery: meninges
ECA
-> Maxillary artery
-> 1. Sphenopalatine artery (traverse sphenopalatine foramen)
=> a. posterolateral nasal artery
=> b. posterior septal artery
-> 2. Greater palatine artery (traverse greater palatine foramen into hard palate)
[Self-assessment]
A surgeon needs to perform a sphenopalatine ganglionic block to relieve atypical facial pain. Where is the specific location of this ganglion?
A. Infraorbital fissure
B. Infratemporal fossa
C. Pterygopalatine fossa
C
[Old PP]
Depression is a mood disorder characterised by prolonged experience of sadness and loss of interest. In treatment of depression, main effect of fluoxetine is to block:
A. alpha-2 adrenoceptor
B. Dopamine D2 receptor
C. Monoamine oxidase
D. Noradrenaline reuptake transporter
E. Serotonin reuptake transporter
E
Fluoxetine: SSRI
[Old PP]
In which of the following patient groups do antidepressants such as fluoxetine increase risk of suicidal thinking and behaviour?
A. Asian
B. Children and young adults
C. Elderly patients (>65 years old)
D. Female
E. Male
B
[Old PP]
What is the major mechanism of serotonin selective reuptake inhibitor?
A. Agonist of serotonin 1C
B. Agonist of serotonin 2A
C. Blocker of serotonin 2C
D. Blocker of serotonin transporter in presynaptic terminal
E. Block some noradrenaline receptor
D
[PP]
The pterygopalatine ganglion has several branches which carry autonomic and sensory fibres to the nasal cavity. Which branch carries special visceral sensory fibres for taste to the roof of the oral cavity?
A. Lesser palatine nerve
B. Nasal branch
C. Nasopalatine nerve
D. Pharyngeal branch
A
Greater + lesser palatine nerves:
- SVS (taste)
- To palate, tonsils, nasal cavity
Nasal branch: nasal cavity (sensory)
Nasopalatine nerve:
- to incisive fossa
Pharyngeal branch (PNS + SNS + sensory);
- to roof of nasopharynx
[PP]
A 54-year-old woman complained of sharp, lancinating (âshootingâ) pain across her left lower jaw, and that the pain was aggravated by chewing, brushing her teeth, and talking. Which nerve is MOST LIKELY involved?
A. Facial
B. Lingual
C. Mandibular
D. Maxillary
C
[PP]
The pterygopalatine ganglion supplies autonomic, sensory and special visceral sensory fibres for taste to the nasal cavity and roof of the mouth. Which branch of this ganglion carries taste fibres to the roof of the oral cavity?
A. Deep petrosal nerve
B. Greater palatine nerve
C. Pharyngeal nerve
D. Posterior superior nasal nerve
B
[PP]
Which nerve carries parasympathetic secretory fibres to the nasal glands?
Greater petrosal nerve
[PP]
A 25-year-old man arrived at the hospital with a severe left periorbital haematoma. Computed tomography examination revealed a fracture of the inferior wall (floor) of the orbit and a related haemosinus (haemorrhage in a paranasal sinus). Two weeks after discharge, the patient could not yet gaze his eye laterally.
Which paranasal sinus was most likely to contain the haemorrhage?
Maxillary sinus
[PP]
Which paranasal sinus is medial to the orbit?
Ethmoidal cells
[PP]
A 25-year-old man arrived at the hospital with a severe left periorbital haematoma. Computed tomography examination revealed a fracture of the inferior wall (floor) of the orbit and a related haemosinus (haemorrhage in a paranasal sinus). Two weeks after discharge, the patient could not yet gaze his eye laterally.
Rupture of which artery resulted in the haemosinus?
Infraorbital artery
[PP]
Which dural venous sinus drains MOST of the blood from the orbits?
Cavernous sinus
[PP]
A 25-year-old man arrived at the hospital with a severe left periorbital haematoma. Computed tomography examination revealed a fracture of the inferior wall (floor) of the orbit and a related haemosinus (haemorrhage in a paranasal sinus). Two weeks after discharge, the patient could not yet gaze his eye laterally.
Which cranial nerve was compromised?
Abducens nerve / CNVI
[PP]
Extrinsic tongue muscles originate outside the tongue. Which extrinsic tongue muscle receives motor innervation that is different from that of all other extrinsic tongue muscles?
A. Genioglossus
B. Hyoglossus
C. Palatoglossus
D. Styloglossus
C
Palatoglossus: pharyngeal plexus (CN X)
Others: Hypoglossal nerve (CN XII)
Paris St. Germainâs Hour
[Old PP]
Injury during tonsillectomy and loss of sensation of the posterior 1/3 of tongue. Which nerve is damaged?
Glossopharyngeal nerve (CN IX)
[Old PP]
Which nerve provides sensory supply to skin over cheek?
Buccal nerve (CN V3)
[Old PP]
A construction worker fell and had floor of his jaw injured by penetration by a short metal pole that was perpendicular to ground. Despite extensive reconstruction, he still complained that his tongue deviates to left when he sticks his tongue out. Which nerve is injured?
A. Left anterior palatine nerve
B. Left hypoglossal nerve
C. Left lingual nerve
D. Right hypoglossal nerve
E. Right lingual nerve
B
LMN lesion:
- deviation of tongue to ipsilateral side
(only contralateral genioglossus can contract)
(? atrophy of tongue muscle => unbalanced action of left and right geniohyoid)
UMN lesion (e.g. stroke):
- deviation of tongue to contralateral side
[Old PP]
A woman has abscess in her left submandibular gland. She has incision and drainage of gland done. After surgery, she complained of weakness in moving lower part of her left face. Which cranial nerve / branch is involved?
Mandibular branch of facial nerve (CN VII)
[Old PP]
In a fight, a 30-year-old man suffers a penetrating injury to floor of his mouth. Despite extensive reconstruction surgery, he still complains of numbness in anterior 2/3 of his tongue. Which cranial nerve / branch is involved?
Lingual nerve (CN V3)
[Old PP]
Which nerve is involved in pain sensation of an enlarged tonsil?
Lesser palatine nerve (CN V2)
[Old PP]
A 7-year-old boy was treated for burn on roof of mouth from eating pizza. Intraoral examination shows enlarged bilateral tonsils near fauces and small area of superficial ulceration on anterior hard palate. Which nerve is involved in discomfort possibly felt by the patient due to thermal burn?
Nasopalatine nerve (CN V2)
Hard palate:
- nasopalatine nerve (cross nasal roof => descend on nasal septum => via incisive foramen => supply hard palate anterior to incisive fossa)
- greater / anterior palatine nerve (via greater palatine foramen => up to incisive foramen)
[Old PP]
A 23-year-old female had a dental procedure that required injection of local anaesthetic agent around left inferior alveolar nerve (inferior alveolar nerve block). After effects of local anaesthetic agent had worn off, patient complained of persistent numbness and pain on left side of anterior part of tongue. Which of the following structures (on left side) has probably been injured?
A. Buccal nerve
B. Glossopharyngeal nerve
C. Hypoglossal nerve
D. Lingual nerve
E. Submandibular duct
D
Lingual nerve (CN V3)
[Self-assessment]
Which muscle is different from the rest of muscles that move the soft palate, in terms of innervation?
A. Palatoglossus
B. Levator veli palatini
C. Tensor veli palatini
D. Palatopharyngeus
C
Tensor veli palatini: Mandibular nerve (CN V3, i.e. nerve to medial pterygoid)
Others (Levator veli palatini, palatopharyngeus, palatoglossus, musculus uvulae):
- Pharyngeal plexus (CN X)
[Self-assessment]
Which structure forms the floor of the oral cavity?
Mylohyoid muscle
Roof: hard palate (X soft palate which is part of pharynx)
Floor: mylohyoid
Lateral walls: Buccinator
[Self-assessment]
Which structure forms the posterior boundary of the oral cavity?
A. Palatine tonsil
B. Uvula
C. Palatopharyngeal arch
D. Palatoglossal arch
D
A: in fauces
B: in oropharynx
[Self-assessment]
Which nerve provides the main supply to the roof of the oral cavity?
A. CNV1
B. CNVII
C. CNV2
D. CNV3
C
CNV1 (ophthalmic nerve):
- roof of nasal cavity + orbit
CNV3 (mandibular nerve):
- floor of oral cavity + lower jaw
[Self-assessment]
Which structure is in the oral cavity?
A. Posterior 1/3 of the tongue
B. Fungiform papillae
C. Palatine tonsil
D. Soft palate
B
Fungiform papillae (anterior 2/3 of tongue)
- mushroom-shaped, red dots
- with taste buds
VS filiform (X taste buds) & foliate (taste buds + serous glands)
Soft palate: oropharynx
Palatine tonsil: fauces
[Self-assessment]
Which nerve provides the general sensory innervation to the anterior 2/3 of the tongue?
A. CNV1
B. CNVII
C. CNV2
D. CNV3
D
Via lingual nerve
CNV1: roof of nasal cavity + paranasal sinuses (frontal, ethmoidal, sphenoid) + orbit
CNV2: roof of oral cavity
CNVII (chorda tympani): taste (anterior 2/3) and sensorimotor (parasympathetic, whole tongue)
[Self-assessment]
Which structure passes medially to the hyoglossus muscle?
A. Lingual nerve
B. CNIX
C. CNXII
D. Submandibular duct
B
Medial:
- stylohyoid ligament
- glossopharyngeal nerve (CN IX)
- lingual artery
Lateral:
- lingual nerve (CN V3) suspending submandibular ganglion
- submandibular duct
- stylohyoid muscle
- hypoglossal nerve (CNXII)
[Self-assessment]
Which nerve provides the main supply to the lower teeth?
A. CNV2
B. CNVII
C. CNV1
D. CNV3
D
Via inferior alveolar nerve
CNV1: roof of nasal cavity + paranasal sinuses (frontal + ethmoid + sphenoid) + orbit
CNV2: upper teeth
[PP]
Clinically, hyoglossus can be used as a landmark for the major nerves and blood vessels in the floor of oral cavity.
List three nervous structures that travel lateral to the hyoglossus.
- Lingual nerve (CN V3)
- Submandibular ganglion
- Hypoglossal nerve (CN XII)
[PP]
Clinically, hyoglossus can be used as a landmark for the major nerves and blood vessels in the floor of oral cavity.
List one artery and one cranial nerve that travel on the medial surface of the hyoglossus.
Lingual artery (branch of external carotid artery)
Glossopharyngeal nerve (CN IX)
[PP]
Flavour arises from a mixture of sensory inputs composed of smell, taste, and the tactile sensation of food upon chewing. What is the structure involved in the detection of tactile sensation of food upon chewing?
A. Circumvallate papillae
B. Dermal papillae
C. Filiform papillae
D. Foliate papillae
E. Fungiform papillae
C
Filiform papillae:
- conical, furry appearance
- no taste buds
- tactile sensation
Foliate papillae:
- on posterolateral aspect
- taste buds + serous glands
Fungiform papillae:
- mushroom-shaped, red dots
- taste buds
No glands on dorsum
Vallate papillae:
- posterior 1/3, V-shaped alignment
- numerous taste buds
[Old PP]
Mr. Lee who is 50 years old undergoes a dental surgery and injured lingual nerve proximal to where it joins chorda tympani. Which of the following functional loss on ipsilateral tongue will be observed?
A. General sensation and taste of anterior 2/3 of tongue but not secretion of submandibular gland
B. General sensation but not taste of anterior 2/3 of tongue and secretion of submandibular gland
C. General sensation of anterior 2/3 of tongue and secretion of submandibular gland but not taste of anterior 2/3 of tongue
D. General sensation, taste of anterior 2/3 of tongue and secretion of submandibular gland
E. Taste of anterior 2/3 of tongue and secretion of submandibular gland but not general sensation of anterior 2/3 of tongue
B
[Old PP]
Which nerve provides motor supply to anterior belly of digastric?
Mylohyoid nerve
- branch of inferior alveolar nerve
- which branches from mandibular nerve (CN V3)
[Old PP]
20/M, with penetrating injury to left lower side of neck between sternocleidomastoid muscle and trapezius muscle. He later complains of numbness over left shoulder and weakness of left elbow flexion.
Which nerve or branch is involved?
C5 root of brachial plexus
[Old PP]
There is one mucosal fold anterior to and one posterior to palatine tonsil. What is muscle deep to mucosal fold?
A. Genioglossus and hyoglossus
B. Genioglossus and styloglossus
C. Hyoglossus and styloglossus
D. Palatoglossus and palatopharyngeus
E. Tensor veli palatini and levator veli palatini
D
Mucosal fold
- anterior to palatine tonsil: palatoglossal arch (anterior pillar of fauces)
- posterior to palatine tonsil: palatopharyngeal arch (posterior pillar of fauces)
Deep to palatoglossal arch
= palatoglossus
Deep to palatopharyngeal arch
= palatopharyngeus
[Old PP]
Branches of mandibular division of trigeminal nerve are commonly injured during oral surgery such as wisdom tooth extraction due to close proximity between tooth roots and nerves and blood vessels of mandible. Which of the following branch DOES NOT accompany artery that carries its name in most of their course?
A. Buccal nerve
B. Inferior alveolar nerve
C. Lingual nerve
D. Mental nerve
E. Mandibular nerve
C
Lingual artery: medial / deep to hyoglossus
Lingual nerve: lateral / superficial to hyoglossus
[Old PP]
Patient suffers from loss of taste and loss of sensation at his right half of tongue after having dental surgery to remove right lower wisdom tooth. Which nerve is damaged?
A. Glossopharyngeal nerve
B. Hypoglossal nerve
C. Inferior alveolar nerve
D. Lingual nerve
E. Mandibular nerve
D
[Old PP]
Which fissure / foramen allows exit of chorda tympani?
Petrotympanic fissure
[PP]
A patient came to the clinic complaining of slurred speech. Examination revealed the vagus nerve was damaged. Which muscle was impaired?
A. Genioglossus
B. Hyoglossus
C. Palatoglossus
D. Styloglossus
C
[PP]
Our body produces around 1.5 litres of saliva every day and it plays a vital role in lubricating food, digestion, and protecting the oral cavity. Which transporter is only involved in the formation of primary saliva?
A. Epithelial Na channels (ENaC)
B. Na-K-Cl cotransporter (NKCC)
C. Na/HCO3 cotransporter
D. Na/K-ATPase
B
[PP]
The salivary glands are exocrine glands that produce saliva through a system of ducts. Which of the following glands are related to the Wharton duct?
A. Infraorbital glands
B. Parotid glands
C. Sublingual glands
D. Submandibular glands
D
Parotid gland -> Stensen duct
Sublingual gland -> Rivinus duct
Submandibular gland -> Wharton duct
(Pass - So Rude Why)
[PP]
The salivary glands are controlled by the autonomic nervous system. Damage to which ganglia can disturb the saliva production from parotid glands?
A. Gasserian
B. Geniculate
C. Otic
D. Pterygopalatine
C
Pterygopalatine: lacrimal gland
[PP]
Human taste can be distilled down to the basic 5 taste qualities. Name one receptor for the taste of salt.
ENaC
[PP]
Human taste can be distilled down to the basic 5 taste qualities. Name one receptor for the taste of sour.
HCN / ASICs / PKD2L1
HCN: hyperpolarisation-activated cyclic-nucleotide-gated channels
ASICs: acid-sensing ion channels
PKD2L1: TRP ion channel family
[PP]
Human taste can be distilled down to the basic 5 taste qualities. Name one receptor for the taste of bitter.
T2Rs
[PP]
Human taste can be distilled down to the basic 5 taste qualities. Name one receptor for the taste of umami.
T1R1 / T1R3
[PP]
Human taste can be distilled down to the basic 5 taste qualities. Name one receptor for the taste of sweet.
T1R2 / T1R3
[PP]
List three cranial nerves that are involved in regulating salivary secretion.
Trigeminal nerve (CN V)
Olfactory nerve (CN I)
Facial nerve (CN VII)
Glossopharyngeal nerve (CN IX)
1579
[PP]
Name two outcomes in the salivary glands when they receive acetylcholine from the autonomic nerve terminal.
- Increase in intracellular calcium level => watery salivary secretion
- Contraction of myoepithelial cells => expulsion of saliva
[PP]
Name the structure within the olfactory bulb to which the axon of the olfactory receptor cell projects.
Glomerulus
[PP]
A 30-year-old man presents to the hospital with fever and shortness of breath. Chest X-ray shows light lower zone consolidation. Empirical antiviral for influenza virus is given. What is the MOST LIKELY antiviral given to this patient?
A. A neuraminidase inhibitor
B. A nucleoside analogue
C. A reverse transcriptase inhibitor
D. An inhibitor of DNA terminase complex
A
Nucleoside analogue: HBV
Reverse transcriptase inhibitor: HIV
Inhibitor of DNA terminase complex: CMV
Neuraminidase inhibitor:
- inhibit release of newly synthesised virions from cell surface (last step of viral life cycle)
- Oral oseltamivir (some resistant strains) / Inhaled zanamivir (bronchospasm)
[PP]
A 30-year-old man was brought to the hospital by his wife for acute confusion. Acute encephalitis was suspected, and the doctor prescribed intravenous acyclovir. What is the mechanism of action of acyclovir?
A. Inhibit attachment of the virus to cell surface receptor
B. Inhibit the release of the virus from cell surface
C. Inhibit viral genome replication
D. Inhibit viral protein synthesis
C
Acyclovir (DNA polymerase inhibitors, inhibit DNA synthesis)
- HSV, VZV
- Deoxyguanosine analogue
- Prodrug
=> converted to acyclovir monophosphate by viral thymidine kinase
=> further converted to acyclovir triphosphate (Active form) by cellular enzymes
- Neurotoxicity, renal dysfunction (crystalline nephropathy)
[PP]
Oral antivirals are now clinically approved for the treatment of COVID-19. What is the mechanism of action for molnupiravir?
A. Inhibit protease activity
B. Inhibit viral release
C. Lethal mutagenesis
D. Prevent endocytosis
C
Main protease inhibitor (SARS-CoV-2): Paxlovid (Nirmatrelvir + Ritonavir)
[PP]
A 33-year-old man presented to the hospital with confusion. MRI of the brain shows evidence of acute encephalitis. Lumbar puncture was performed. Herpes simplex virus was detected by PCR. What is the antiviral of choice?
Acyclovir
[PP]
Name two major side effects of acyclovir.
- Neurotoxicity
- Renal dysfunction (crystalline nephropathy)
[PP]
An 80-year-old man presented with shortness of breath. SARS-CoV-2 was detected in the nasopharyngeal swab. Which antiviral should be given to this patient?
A. Acyclovir
B. Foscarnet
C. Ganciclovir
D. Nirmatrelvir-ritonavir (Paxlovid)
D
Foscarnet: DNA polymerase inhibitor, CMV
Ganciclovir: DNA polymerase inhibitor, CMV
[PP]
A 36-year-old woman is admitted with fever, headache, confusion and abnormal behaviour for 5 days. Cerebrospinal fluid (CSF) examination showed elevated white cells (predominantly lymphocytes) with moderately elevated CSF protein and normal glucose levels. A diagnosis of herpes encephalitis is suspected.
What is the investigation of choice to confirm the aetiology?
PCR of CSF / skin and mucosal lesions
HSV: DNA virus
[PP]
A 36-year-old woman is admitted with fever, headache, confusion and abnormal behaviour for 5 days. Cerebrospinal fluid (CSF) examination showed elevated white cells (predominantly lymphocytes) with moderately elevated CSF protein and normal glucose levels. A diagnosis of herpes encephalitis is suspected.
What is the antiviral therapy of choice for this patient? For how long?
IV acyclovir for 14-21 days of treatment
[PP]
Name two routes by which the herpes simplex virus gets into the central nervous system to cause encephalitis.
- Spread along olfactory nerve to frontal lobe
- Reactivation from trigeminal ganglion which innervated pia mater => infection of brain
[PP]
A 75-year-old male developed increasing headache, fever and right-sided weakness after 3 weeks of left nasal purulent discharge. What is the LIKELY clinical diagnosis?
Intracranial / Intracerebral abscess
[PP]
Name two important radiological signs on contrast computed tomography (CT) scan.
- Central hypodense area
- Contrast enhancing rim
- Perilesional edema
- Midline shift
[PP]
A 75-year-old male developed increasing headache, fever and right-sided weakness after 3 weeks of left nasal purulent discharge.
Which type of bacterial flora from which anatomical site commonly causes this condition?
Aerobic and anaerobic oral flora
[PP]
A 75-year-old male developed increasing headache, fever and right-sided weakness after 3 weeks of left nasal purulent discharge. What is the clinical condition predisposing to his infection?
Sinusitis
[PP]
A 60-year-old man presented with low-grade fever, headache, and vomiting for 2 weeks. On admission, he had a body temperature of 37.9°C, BMI of 18.5 kg/m^2, and neck stiffness. He is a chronic smoker and construction site worker. What is the clinical diagnosis?
Subacute meningitis
[PP]
What precautionary investigation do you need to perform before obtaining CSF specimen for a patient with suspected meningitis?
CT scan to exclude space-occupying lesion
[PP]
Except HSV, name two other viruses that can cause encephalitis.
- Varicella-zoster virus (VZV)
- Enteroviruses e.g. EV71 (cause hand foot mouth disease)
- Arboviruses e.g. Japanese encephalitis virus (JEV), West Nile virus (WNV)
[PP]
A 4-year-old boy attending nursery school developed vesicular lesions on the fingers, feet and ulcers in the mouth of 2 days duration. He had a headache and fever. On examination he had neck stiffness and developed flaccid paralysis of his right arm. What is the MOST LIKELY diagnosis?
A. Chickenpox infection
B. Coxsackie A virus infection
C. Enterovirus 71 infection
D. Poliovirus infection
C
Hand, foot, mouth disease
[PP]
A 5-year-old boy developed acute fever, headache and neck stiffness. Analyses of the cerebrospinal fluid sample obtained before the use of antibiotics were as follows:
White cells count: 320/mm^3 (polymorph 10%, lymphocyte 90%)
Protein: 0.75 g/L (Normal: 0.15-0.45 g/L)
Glucose: 3.1 mmol/L (Normal: 2.8-3.9 mmol/L)
Serum glucose: 5.5 mmol/L
Gram-stained, Ziehl-Neelsen-stained, and Indian ink-stained smears: negative
Which of the following is the MOST LIKELY causative organism of his condition?
A. Echovirus
B. Neisseria meningitis
C. Rotavirus
D. Streptococcus suis
A
[PP]
A 7-year-old child developed a sudden onset of high fever and appeared drowsy when brought into the Accident and Emergency Department. The doctor found that the child showed neck rigidity. A lumbar puncture was performed and the cerebrospinal fluid showed a high white cell count with predominantly neutrophils. Which of the following is the MOST LIKELY diagnosis?
A. Cysticercosis
B. Group B streptococcal meningitis
C. Meningococcal meningitis
D. Tuberculous meningitis
E. Viral meningoencephalitis
C
[PP]
A 56-year-old butcher with good past health was admitted for fever, headache, neck stiffness, and hearing loss for 3 days. Gram-stained smear of his cerebrospinal fluid showed Gram-positive cocci in chains. What is the MOST LIKELY causative organism?
Streptococcus suis
S. suis: pigs, hearing loss -> deafness
[PP]
A 7-day-old baby girl, born at full term by normal vaginal delivery, was admitted with fever, convulsions, lethargy and bulging fontanelles. Gram-stained smear of her cerebrospinal fluid showed Gram-negative bacilli. What is the most likely causative organism?
Escherichia coli
[PP]
A 4-year-old girl developed fever and vesicular lesions over hands, feet and lips. Four days later, she developed myoclonic jerks, vomiting, and ataxia. Her skin lesions and faeces were positive for an RNA virus by reverse transcription-polymerase chain reaction. What is the most likely causative organism?
Enterovirus A71
[PP]
A 42-year-old man with HIV infection was admitted for fever, headache and neck stiffness for 6 weeks. Indian ink-stained smear of his cerebrospinal fluid showed yeast cells with surrounding halo. What is the most likely causative organism?
Cryptococcus neoformans
[PP]
A 7-year-old girl presented with an acute onset of fever, headache, and neck stiffness for 2 days. Cerebrospinal fluid (CSF) analysis revealed raised white cell count of 1300 cells/mm^3 with polymorph predominance, elevated protein level, and low CSF-to-serum glucose level. Gram-stained smear of the CSF showed Gram-negative diplococci. Which of the following is the MOST LIKELY organism causing her acute meningitis?
A. Corynebacterium diphtheriae
B. Escherichia coli
C. Klebsiella pneumoniae
D. Neisseria meningitidis
D
C. diphtheriae: Gram +ve bacilli
E. coli, Klebsiella: Gram -ve bacilli
[PP]
Cryptococcal meningitis is an important cause of chronic meningitis in patients with HIV and other immunosuppressed conditions. What is the MOST SENSITIVE way of making such a diagnosis?
A. Cryptococcal antigen test of CSF
B. Fungal culture of CSF
C. Indian ink examination of CSF
D. PCR test on CSF
A
Very abundant mucoid capsular material (glucuronoxylomannan) released into CSF even when no. of fungi is very low
[PP]
A patient develops severe headache after 1 month of foul left nasal discharge. Computed tomography scan showed a 4cm left frontal lobe hypodense lesion, perilesional oedema with midline shift. What is the MOST SUITABLE treatment regimen for this condition?
A. Drainage of brain abscess and paranasal sinusitis while giving intravenous antibiotics which cross blood-brain barrier and cover aerobes and anaerobes
B. Drainage of brain abscess and paranasal sinusitis while giving intravenous high dose antibiotics with anti-staphylococcal coverage
C. Intravenous anti-staphylococcal antibiotics for brain abscess and paranasal sinusitis
D. Intravenous high dose antibiotics with aerobic and anaerobic coverage for celebritis and paranasal sinusitis
A
[PP]
A 40-year-old man presented with headache and unsteadiness for 2 weeks. Cerebrospinal fluid (CSF) analysis showed lymphocytic pleocytosis, elevated protein, and low glucose. Indian ink smear on the CSF was positive. Which of the following is a useful antimicrobial to treat his condition?
A. Acyclovir
B. Amphotericin B
C. Isoniazid
D. Meropenem
B
[PP]
A 50-year-old man presented with low-grade fever, headache, decreased consciousness, and seizure. Which of the following is NOT a contraindication for immediate lumbar puncture?
A. Focal neurological deficit
B. Presence of fever
C. Presence of seizures
D. Severe thrombocytopenia
B
[PP]
A boy started to visibly contract muscles in the neck during an asthma exacerbation. Which of the following muscles is contracted during breathing in this boy?
A. Sternohyoid
B. Omohyoid
C. Sternothyroid
D. Anterior scalene muscle
D
[PP]
Which extraocular muscle lies lateral to the ciliary ganglion?
Lateral rectus
Ciliary ganglion (CN III)
- Parasympathetic
- Between optic nerve & LR
[PP]
The mandibular nerve carries both motor and sensory fibres and gives off all the branches in the infratemporal fossa. The branch from which nerve provides motor innervation to the mylohyoid muscle?
A. Auriculotemporal nerve
B. Buccal nerve
C. Inferior alveolar nerve
D. Lingual nerve
C
[PP]
Salivary stone can cause blockage of the salivary duct. Which muscle prevents the excretion of the stone from the parotid duct?
A. Buccinator
B. Masseter
C. Orbicularis oris
D. Zygomaticus major
A
[PP]
A 38-year-old woman shows up at the hospital with chronic jaw soreness and recurrent tension headaches. For weeks, the patient has been suffering from episodes of bruxism (teeth grinding). You intend to administer botulinum toxin injections in the noticeably hypertrophic muscles.
Name the precise location of the hypertrophic muscle covering the pterion.
Coronoid process of the mandible
[PP]
A 38-year-old woman shows up at the hospital with chronic jaw soreness and recurrent tension headaches. For weeks, the patient has been suffering from episodes of bruxism (teeth grinding). You intend to administer botulinum toxin injections in the noticeably hypertrophic muscles.
Which pharyngeal arch gives rise to these muscles?
First
Pharyngeal arches
1st: CN V2, V3
2nd (mesoderm): CN VII
3rd: CN IX
4th, 6th: CN X
[PP]
A 38-year-old woman shows up at the hospital with chronic jaw soreness and recurrent tension headaches. For weeks, the patient has been suffering from episodes of bruxism (teeth grinding). You intend to administer botulinum toxin injections in the noticeably hypertrophic muscles.
Which foramen in the skull transmits the nerve that supplies these muscles?
Foramen ovale
[PP]
A 38-year-old woman shows up at the hospital with chronic jaw soreness and recurrent tension headaches. For weeks, the patient has been suffering from episodes of bruxism (teeth grinding). You intend to administer botulinum toxin injections in the noticeably hypertrophic muscles.
Release of which neurotransmitter will be blocked with the injection?
Acetylcholine (ACh)
[PP]
A 38-year-old woman shows up at the hospital with chronic jaw soreness and recurrent tension headaches. For weeks, the patient has been suffering from episodes of bruxism (teeth grinding). You intend to administer botulinum toxin injections in the noticeably hypertrophic muscles.
What complication is expected if a salivary gland is injected instead?
Reduced salivation or dry mouth
[PP]
Meissner corpuscles and Merkel cells are mechanoreceptors on the skin that are important for detecting motion and texture of an object, respectively. Which property is MOST DIFFERENT between the two mechanoreceptors and BEST explains their functional specificity?
A. Conduction velocity of action potential
B. Localisation on the skin
C. Rate of adaptation
D. Size of receptive field
C
Meissner corpuscle (ss -> skin motion, slipping objects)
- dynamic deformation
Merkel cell
- indentation depth
- form & texture, fine tactile discrimination
Both in superficial skin (dermis)
[PP]
Loss of proprioception of the lower and upper body.
Select the most likely location of the causative lesion:
A. Caudate nucleus
B. Cuneate nucleus
C. Gracile nucleus
D. Lateral lemniscus
E. Medial lemniscus
F. Periaqueductal grey
G. Red nucleus
H. Spinothalamic tracts
I. Ventral posterolateral nucleus of thalamus
J. Ventral posteromedial nucleus of thalamus
E
[PP]
Loss of pain modulation.
Select the most likely location of the causative lesion:
A. Caudate nucleus
B. Cuneate nucleus
C. Gracile nucleus
D. Lateral lemniscus
E. Medial lemniscus
F. Periaqueductal grey
G. Red nucleus
H. Spinothalamic tracts
I. Ventral posterolateral nucleus of thalamus
J. Ventral posteromedial nucleus of thalamus
F
Spinomesencephalic tract
[PP]
Loss of upper body two-point discriminative touch sensation.
Select the most likely location of the causative lesion:
A. Caudate nucleus
B. Cuneate nucleus
C. Gracile nucleus
D. Lateral lemniscus
E. Medial lemniscus
F. Periaqueductal grey
G. Red nucleus
H. Spinothalamic tracts
I. Ventral posterolateral nucleus of thalamus
J. Ventral posteromedial nucleus of thalamus
B
Cuneate nucleus: Upper body (C1-T5)
Gracile nucleus: Lower body (T6 and below)
[PP]
Loss of facial sensation.
Select the most likely location of the causative lesion:
A. Caudate nucleus
B. Cuneate nucleus
C. Gracile nucleus
D. Lateral lemniscus
E. Medial lemniscus
F. Periaqueductal grey
G. Red nucleus
H. Spinothalamic tracts
I. Ventral posterolateral nucleus of thalamus
J. Ventral posteromedial nucleus of thalamus
J
Trigeminothalamic pathway
[PP]
Somatosensory evoked potentials are performed by applying electrical stimuli to the wrist while recording from the cortical region. Which neural structure represents the conduction time at P20?
A. Brachial plexus
B. Median nerve
C. Occipital lobe
D. Somatosensory cortex
D
Brachial plexus: P10
[PP]
Pain sensation can be modulated by different parts of the central nervous system. Which region of the brainstem integrates pain signals?
A. Periaqueductal gray
B. Pontine nucleus
C. Red nucleus
D. Substantia nigra
A
Spinomesencephalic tract
[PP]
Patients with myocardial infarction may manifest pain originating from the left arm. What feature of nociceptors in the arm and the heart can BEST explain the referred pain phenomenon by the patients?
A. They connect to the same second order neuron in spinal cord
B. They have different rates of action potential conduction
C. They have different sizes of receptive fields
D. They project to different areas of the brain
A
[PP]
A 78-year-old gentleman had a history of diabetes mellitus and hypertension. He developed a lacunar infarct involving the right basal ganglia region as a result of obstruction of the deep penetrating arteries by lipohyalinosis. Which of the following signs and symptoms is MOST LIKELY to be seen in this patient?
A. Sudden onset of fixed and dilated pupil on the right side
B. Sudden onset of headache and projectile vomiting
C. Sudden onset of left hemiplegia
D. Sudden onset of loss of consciousness
E. Sudden onset of right hemiplegia
C
[PP]
The cerebral arteries supply specific territories in the brain. An elderly man suddenly developed right lower limb weakness due to complete occlusion of one of the arteries. The right upper limb and left side of the body were not affected. Which of the following arteries is the MOST LIKELY culprit?
A. Left anterior cerebral artery
B. Left middle cerebral artery
C. Left posterior cerebral artery
D. Right posterior cerebral artery
E. Right vertebral artery
A
Right-sided weakness => left cerebrum affected
Go up the body -> more lateral side of brain
[PP]
A 4-year-old girl presented with right ear pain and fever for 2 days. She also suffers from nasal obstruction and thick nasal discharge. On examination, the tympanic membrane is very congested and bulging. Which of the following is the clinical diagnosis?
A. Acute otitis media
B. Chronic suppurative otitis media
C. Furunculosis
D. Otomycosis
A
Chronic suppurative otitis media
=> perforated tympanic membrane
Furunculosis
- localised external ear infection
=> obscure view of tympanic membrane
Otomycosis
- fungal
[PP]
A 50-year-old woman presents with episodic right otorrhoea for 1 year. Her hearing on the right side is also impaired. On examination, there is central perforation of the right tympanic membrane and congestion of the middle ear mucosa. Which of the following is the clinical diagnosis?
A. Cholesteatoma
B. Chronic suppurative otitis media
C. Labyrinthitis
D. Otomycosis
B
[Self-assessment]
Which of the following statements regarding dural fold is correct?
A. The tentorium cerebelli runs between the left and right cerebral hemispheres.
B. The tentorium cerebelli contains the straight sinus.
C. The brainstem traverses the tentorium hiatus.
C
Falx cerebri
- separate L & R cerebral hemispheres
- contains straight sinus which meets with midline of tentorium cerebelli
[Self-assessment]
Which of the following statements regarding arachnoid mater and subarachnoid space is correct?
A. The subarachnoid space extends below conus medullaris.
B. It forms the choroidal plexus.
C. It is deep to the pia mater.
A
Arachnoid
- superficial to pia mater
Pia mater
- forms choroid plexus
[Self-assessment]
Which of the following statements regarding the cerebrospinal fluid (CSF) system is correct?
A. CSF production is an entirely passive process
B. The two lateral ventricles are joined by the cerebral aqueduct
C. CSF is absorbed by arachnoid granulations
C
CSF production
- both active and passive processes
Lateral ventricles
- joined through interventricular foramen (of Monro) to third ventricle
[Self-assessment]
Which of the following statements regarding arterial blood supply to the brain is correct?
A. The internal capsule is supplied by branches of the middle cerebral artery
B. The posterior cerebral artery arises directly from the vertebral artery
C. The Circle of Willis forms a complete circle of anastomosis in over 90% of people
A
B: much lower than that
C: PCAs arise from basilar artery, which is formed by the two vertebral arteries
[Self-assessment]
Which of the following statements regarding the venous drainage system of the brain is correct?
A. The superior sagittal sinus drains into the sigmoid sinus through the transverse sinus
B. Superficial cerebral veins drain directly into the internal cerebral vein
C. The transverse sinus runs along the edge of the tentorium hiatus
A
Superficial cerebral veins drain into sagittarius sinuses
Transverse sinus runs along the posterior edge of the tentorium
[Old PP]
Which branch of internal carotid artery forms Circle of Willis?
A. Artery of pterygoid canal
B. Superior hypophyseal artery
C. Middle cerebral artery
D. Posterior communicating artery
E. Inferior hypophyseal artery
D
Posterior communicating artery connects to internal carotid artery prior to terminal bifurcation of ICA into anterior & middle cerebral arteries
Blood supply to brain
= ICA + post. cerebral a.
connected by post. communicating a.
[Old PP]
Which ion has lower concentration in CSF than in blood?
A. Cl
B. H
C. K
D. Mg
E. Na
C
Less K and Ca than plasma
More Na and Cl than plasma
Less glucose (~2/3 of plasma) and protein than plasma
No RBC
WBC <5/mm^3
[Old PP]
Where do arachnoid granulations go into?
A. Sigmoid sinus
B. Superior sagittal sinus
C. Straight sinus
B
[Old PP]
You are examining flow of blood in sinus of brain. Which of the sinuses below does great cerebral vein (of Galen) connect to?
A. Inferior sagittal sinus
B. Sigmoid sinus
C. Straight sinus
D. Superior sagittal sinus
E. Transverse sinus
C
[Old PP]
Posterior inferior cerebellar artery supplies lateral sides of medulla. Which cranial nerve will be affected in case of an obstruction?
A. Abducens nerve
B. Facial motor nerve
C. Oculomotor nerve
D. Trigeminal nerve
E. Trochlear nerve
D
[Old PP]
Many blood vessels supply basal side of brain to form Circle of Willis. An aneurysm is thinning of arterial wall that leads to dilation of artery that may compress on nearby structures. If clinical signs of an aneurysm manifest as compression of oculomotor nerve, on which of the arteries below is aneurysm likely located?
A. Anterior communicating artery
B. Basilar artery
C. Ophthalmic artery
D. Posterior cerebral artery
E. Posterior communicating artery
E
[Old PP]
At which level does subarachnoid space terminate inferiorly?
A. C7
B. T12
C. L2
D. L4
E. S2
E
[Old PP]
Which of the following is associated with formation of Circle of Willis?
A. Anterior and posterior cerebral arteries
B. Middle and posterior cerebral arteries
C. Anterior and middle cerebral arteries
A
[Old PP]
Which structure is responsible for draining cerebrospinal fluid from lateral ventricles to third ventricle?
A. Interventricular foramen
B. Lateral apertures
C. Central canal
D. Arachnoid granulations
E. Cerebral aqueduct
A
Choroid plexus (in lateral, third, fourth ventricles) -> lateral ventricles -> interventricular foramen (of Monro) -> third ventricle -> cerebral aqueduct (of Sylvius) -> fourth ventricle -> foramen of Magendie (median aperture * 1) / foramen of Luschka (lateral aperture * 2) -> subarachnoid space -> arachnoid granulations / villi of dural venous sinuses -> venous blood -> heart and lungs
[Old PP]
CSF is located between which of the following meningeal layers?
A. Dura and arachnoid mater
B. Arachnoid and pia mater
C. Pachymeninges and leptomeninges
D. Endosteal and meningeal layers
E. Arachnoid granulations
B
Subarachnoid space
[Old PP]
CSF is produced within ventricular system and circulated to subarachnoid space. Through which structure does the CSF flow from 3rd ventricle into 4th ventricle?
A. Aqueduct of Sylvius
B. Central canal of spinal cord
C. Arachnoid granulations
D. Interventricular foramen
E. Median and lateral apertures of 4th ventricle
A
[Old PP]
CSF is produced within ventricular system and circulated to subarachnoid space. Through which structure does CSF escape from ventricular system to subarachnoid space?
A. Arachnoid granulations
B. Central canal of spinal cord
C. Cerebral aqueduct
D. Interventricular foramen
E. Medial and lateral apertures of fourth ventricle
E
[Old PP]
A. Brachial artery
B. Oesophageal vein
C. Coronary artery
D. External carotid artery
E. Femoral artery
F. Hepatic portal vein
G. Internal carotid artery
H. Internal iliac artery
I. Left subclavian artery
J. Pulmonary artery
Select one vessel that contributes to formation of Circle of Willis.
G
[Old PP]
Which of the following arteries does NOT form part of Circle of Willis?
A. Anterior cerebral artery
B. Middle cerebral artery
C. Posterior cerebral artery
D. Anterior communicating artery
E. Posterior communicating artery
B
[Old PP]
A CT scan of an infant with an enlarged head shows dilatation of 3rd and lateral ventricles. Which site is most likely responsible for this patientâs hydrocephalus?
A. Foramen of Monro
B. Foramen of Magendie
C. Foramen of Luschka
D. Aqueduct of midbrain
E. Central canal of spinal cord
D
[PP]
Equalisation of pressure in the middle ear depends on the function of two essential muscles in the pharynx. What are these muscles?
A. Palatoglossus and salpingopharyngeus
B. Palatopharyngeus and salpinopharyngeus
C. Tensor veli palatini and levator veli palatini
D. Tensor veli palatini and palatoglossus
C
[PP]
Structures related to the middle ear
A. Chorda tympani
B. Fenestra cochlea
C. Greater petrosal nerve
D. Pharyngotympanic tube
E. Processus cochleariformis
F. Promontory
G. Pyramid
H. Tensor tympani
I. Tympanic canaliculus
J. Stapedius muscle
Select the MOST RELEVANT structure from the list of options above.
Carries parasympathetic secretory fibres to the nasal glands
C
Via pterygopalatine ganglion (PPG)
[PP]
Structures related to the middle ear
A. Chorda tympani
B. Fenestra cochlea
C. Greater petrosal nerve
D. Pharyngotympanic tube
E. Processus cochleariformis
F. Promontory
G. Pyramid
H. Tensor tympani
I. Tympanic canaliculus
J. Stapedius muscle
Select the MOST RELEVANT structure from the list of options above.
Is innervated by the mandibular nerve
H
Tensor tympani: CN V3
Stapedius: CN VII
Sensory supply of middle ear: tympanic plexus (CN IX)
[PP]
Structures related to the middle ear
A. Chorda tympani
B. Fenestra cochlea
C. Greater petrosal nerve
D. Pharyngotympanic tube
E. Processus cochleariformis
F. Promontory
G. Pyramid
H. Tensor tympani
I. Tympanic canaliculus
J. Stapedius muscle
Select the MOST RELEVANT structure from the list of options above.
Neutralises the pressure between the middle ear and nasopharynx
D
Eustachian / Pharyngotympanic / Auditory tube
- Anterior wall of middle ear
[PP]
Structures related to the middle ear
A. Chorda tympani
B. Fenestra cochlea
C. Greater petrosal nerve
D. Pharyngotympanic tube
E. Processus cochleariformis
F. Promontory
G. Pyramid
H. Tensor tympani
I. Tympanic canaliculus
J. Stapedius muscle
Select the MOST RELEVANT structure from the list of options above.
Is the origin of stapedius muscle
G
Pyramid
- bony projection at posterior wall of middle ear
[PP]
The arcuate eminence is part of the petrous bone and located at the roof the middle ear. What structure is found directly beneath the arcuate eminence?
A. Anterior semicircular canal
B. Cochlea and utricle
C. Lateral semicircular canal
D. Posterior semicircular canal
E. Promontory
A
Arcuate eminence
- small upwards projection of petrous temporal bone into cranial cavity above
[PP]
Mr. Choi, an 83-year-old, was diagnosed with early Alzheimerâs disease six years ago. Rivastigmine patch was prescribed to him. However, his functional abilities (activities of daily living, communication and memory) have significantly declined in the past year. During his recent routine check-up, the doctor decided to add another medication memantine.
State the classes of the drugs rivastigmine and memantine, respectively.
Rivastigmine - acetylcholinesterase inhibitor (AChE I)
Memantine - uncompetitive NMDA glutamate receptor antagonist
Grandma Doesnât Remember Me Man
G: Galantamine
D: Donepezil
R: Rivastigmine
M: Memantine
[PP]
Describe how how rivastigmine and memantine work, respectively.
- MOA of rivastigmine
- increase the amount of acetylcholine (AChE) available
- by preventing its breakdown by acetylcholinesterase in synaptic cleft - MOA of memantine
- improve cognitive ability
- by protecting CNS neurons from the excitotoxic effects of glutamate due to sustained activation
[PP]
Name one COMMON adverse (side) effect of rivastigmine.
Nausea, vomiting, diarrhoea, anorexia
[PP]
Mrs. Chao was an 83-year-old woman when she was diagnosed with early Alzheimerâs disease (AD). Rivastigmine patch was being prescribed. Another 6 years have passed and Mrs. Chaoâs functional abilities (activities of daily living, communication and memory) have significantly declined. During her recent routine check-up, which of the following drugs would MOST LIKELY be added by the doctor?
A. Amantadine
B. Benztropine
C. Bromocriptine
D. Memantine
D
Others: Parkinson disease
[PP]
Mr. Lam is a 78-year-old male who was diagnosed with Parkinson disease 8 years ago. He was started on levodopa / carbidopa 3 years ago. During his current visit, he complained about tremor worsened and feels that the improvement he gained from a dose of levodopa / carbidopa does not last until the time that next dose is due. As a result, benztropine is added.
State the mechanism of action of levodopa.
Levodopa is a metabolic precursor of dopamine
-> decarboxylated via DOPA decarboxylase in the periphery and the brain to dopamine
-> as dopamine canât cross the blood brain barrier (BBB) but levodopa can
[PP]
What is the rationale for adding carbidopa to levodopa?
Carbidopa is a peripheral DOPA decarboxylase inhibitor that does not cross BBB
-> increase availability of levodopa to CNS
-> by reducing the metabolism of levodopa in the periphery
[PP]
What is benztropine?
A central anticholinergic agent to block ACh receptors in the brain
[Old PP]
Dick Wong, a 78-year-old patient with Parkinsonâs disease is currently being treated with carbidopa/levodopa, but his Parkinsonâs symptoms are worsening. Selegiline is added to his regimen. How does selegiline work in Parkinsonâs disease?
A. Inhibition of acetylcholinesterase
B. Inhibition of catechol-O-methyl transferase (COMT)
C. Inhibition of DOPA decarboxylase
D. Inhibition of monoamine oxidase B (MAO-B)
E. Stimulation of dopamine release
D
COLD SALAD
COMT inhibitors: entacapone, tolcapone
Selegiline: selective irreversible MAO-B inhibitor (also Rasagiline)
Anticholinergics: BBB (Benztropine, Benzhexol, Biperidine)
L-Dopa (+ Carbidopa / Benserazide)
Amantadine: dopamine facilitator
Dopamine receptor agonists: bromocriptine, pergolide, pramipexole, ropinirole, rotigotine
[PP]
How does benztropine work?
After binding to ACh receptors
-> benztropine blocks the action of ACh
-> reduction of cholinergic output in the striatum
-> reduce tremor
[Old PP]
A 71-year-old man with impaired short-term memory and speech is thought to have Alzheimerâs disease. Doctor gives rivastigmine. What is mechanism of action of rivastigmine?
A. Increases dopamine
B. Inhibits acetylcholinesterase
C. Selectively inhibits monoamine oxidase B (MAOB)
D. Stimulates acetylcholine receptor
E. Stimulates dopamine receptor
B
[Old PP]
What kind of neurons does drug act on to improve memory function in Alzheimerâs disease?
A. Adrenergic
B. Cholinergic
C. Dopaminergic
D. Serotonergic
E. Histaminergic
B
[Old PP]
A 60-year-old male presents with cogwheel rigidity, tardive dyskinesia and resting tremor: He is suspected to have Parkinsonâs disease. Treatment with levodopa seems to improve his symptoms. What is mechanism of levodopa in treating Parkinsonâs disease?
A. Increase production of dopamine
B. Stimulate dopaminergic receptor
A
[Old PP]
Which of the following may be the side effect on a Parkinsonâs subject taking dopaminergic drugs?
A. Cheese reaction
B. Depression
C. Discoloration of skin
D. Excess sleepiness
E. Hypertension
D
E.g. ropinirole (dopamine receptor agonist)
Cheese reaction: MAO-A I
Orthostatic / Postural hypotension
[Old PP]
DOPA is a drug often used in treating Parkinsonism. A patient suffering from this condition was found not to respond to this drug and vitamin deficiency is suspected. Which specific vitamin would you prescribe to patient?
A. Vitamin A
B. Vitamin B1
C. Vitamin B2
D. Vitamin B6
E. Vitamin B12
E
X Pyridoxine (vitamin B6)
-> increase peripheral breakdown of L-dopa
[Old PP]
Which naturally occurring substance is MOST LIKELY to decrease storage of synaptic transmitters:
A. Adrenaline
B. Dopamine
C. Noradrenaline
D. Serotonin
E. Reserpine
E
Drug-induced Parkinsonism (antipsychotics)
1. Reserpine (deplete dopamine store)
2. Haloperidol (dopaminergic blocker)
[Old PP]
Why does long-term use of levodopa decrease its effectiveness?
- Progressive loss of dopaminergic neurons for decarboxylation
- Decreased number and sensitivity of dopamine receptors
- Overstimulation of central dopamine receptors -> motor complications e.g. dyskinesia
[PP]
A 35-year-old lady presented with an enlargement of the left parotid gland. Fine needle aspiration showed cytologically benign spindle cells in a myxoid stroma together with small duct-like spaces. What is the MOST LIKELY diagnosis?
A. Adenoid cystic carcinoma
B. Mucoepidermoid carcinoma
C. Pleomorphic adenoma
D. Sialadenitis
E. Warthinâs tumour
C
[PP]
In the multistep progression to the development of nasopharyngeal carcinoma, which of the following factors is regarded as being important for the progression from early premalignant change of the epithelium to irreversible malignant transformation?
A. DNA repair damage
B. Epstein-Barr virus
C. Exposure to salted fish
D. Genetic susceptibility
A
[PP]
A 25-year-old lady presented with an enlargement of the right parotid gland. Fine needle aspiration showed cytologically benign spindle cells in a myxoid stroma plus small duct like spaces. What is the MOST LIKELY diagnosis?
A. Adenoid cystic carcinoma
B. Mucoepidermoid carcinoma
C. Pleomorphic adenoma
D. Sialadenitis
C
[PP]
A 45-year-old Chinese man presented with a 4-month history of post-nasal drip. On examination, the nasopharynx contained a granular lobulated mass.
What are the two MOST COMMON malignancies that may account for this mass?
- Nasopharyngeal carcinoma (esp. non-keratinising undifferentiated)
- NK/T cell lymphoma
[PP]
A 45-year-old Chinese man presented with a 4-month history of post-nasal drip. On examination, the nasopharynx contained a granular lobulated mass.
Biopsy of the mass is performed and the histopathology shows sheets of tumours. Neither squamous nor glandular cells were found. The report states that âThe cells stain positive for epithelial markers and are negative for CD3 and CD56.â Based on these findings, what is your MOST LIKELY diagnosis?
Non-keratinising undifferentiated nasopharyngeal carcinoma
CD3: T cell marker
CD56: NK cell marker
[PP]
A 45-year-old Chinese man presented with a 4-month history of post-nasal drip. On examination, the nasopharynx contained a granular lobulated mass.
In-situ hybridisation of the lesion indicates the presence of viral RNA. What virus is this MOST LIKELY to be?
Epstein-Barr virus (EBV)
[Old PP]
A 45-year-old Chinese man presented with a 4-month history of post-nasal drip. On examination, nasopharynx contained a granular lobulated mass.
Biopsy of mass is performed. Report states that âcells stain negative for epithelial markers and positive for CD3 and CD56â. In-situ hybridisation of the lesion indicates presence of viral RNA. Based on these findings, is surgery indicated?
No
Extranodal NK/T cell lymphoma, nasal type (malignant)
-> chemotherapy
[Old PP]
Name the most common viral etiology of laryngeal neoplasms.
Human Papillomavirus (HPV)
[Old PP]
Name a common risk factor of laryngeal neoplasms.
Smoking
[Old PP]
A male presents with laryngeal polyps. Give two possible differential diagnoses of it.
- Benign vocal cord polyps (singersâ nodules)
- Laryngeal neoplasm
[Old PP]
A male presents with laryngeal polyps. Biopsy shows increased pleomorphism and other malignant features. What is your diagnosis?
Laryngeal squamous cell carcinoma
[Old PP]
A 50-year-old man had nasopharyngeal carcinoma 20 years ago, was treated by radiotherapy, had no lymph node metastasis. He now suffers from progressive swallowing difficulty. No sign of recurrence of tumour. What is the most likely cause of his symptoms?
A. Occult mediastinal metastasis
B. Parkinson disease
C. Progressive fibrosis of superior pharyngeal constrictor muscles due to previous radiation
D. Recurrent cerebrovascular events
E. Senile degeneration
C
[Old PP]
A 4-year-old girl visited ENT OPD and was referred by her GP. She presented with a 2-month history of difficulty of breathing when sleeping and swallowing. ENT surgeon found multiple small outgrowths on vocal cord. Biopsy shows squamous cell with clearing of cytoplasm. What is the most likely viral aetiology?
A. Epstein-Barr virus
B. Herpes simplex virus
C. Human metapneumovirus
D. Human papillomavirus
E. Respiratory syncytial virus
D
Juvenile squamous papillomas of larynx:
- multiple, wide area
- soft, mobile
- high recurrence
- disappear after puberty
[Old PP]
A 42-year-old male came to see a general practitioner for tinnitus and loss of hearing for 2 months. He also reported epistaxis for 1 month. Left neck lymph node was also enlarged. He was referred to a specialist. At specialist clinic endoscopy was performed. Epithelial neoplasm was suspected. What is the most likely histology of the neoplasm?
A. Adenocarcinoma
B. Lymphoepithelioma
C. Non-keratinising undifferentiated carcinoma
D. Transitional cell carcinoma
E. Well-differentiated squamous cell carcinoma
C
S/S:
1. Tinnitus, deafness
2. Epistaxis
3. Headache, facial pains
4: Neck LN
Squamous cell carcinoma is NOT common
[Old PP]
A person presented with hoarseness and dysphagia with laryngoscopy finding as left vocal cord paralysis and swollen vocal cord mucosa. Which of the following diagnoses is likely?
A. CA larynx
B. CA lung
C. Subglottic CA of larynx
A
[Old PP]
51-year-old male, presents with painless progressive swelling on his right face for 3 months. Physical exam shows 2.5cm firm mass on right parotid gland, branches of facial nerve are intact. No cervical lymphadenopathy. What is the MOST COMMON parotid malignancy?
A. Acinar cell carcinoma
B. Adenocarcinoma
C. Liposarcoma
D. Mucoepidermoid carcinoma
E. Squamous cell carcinoma
D
Benign: pleomorphic adenoma, Warthinâs tumour
Malignant: Mucoepidermoid carcinoma, adenoid cystic carcinoma
[Old PP]
A patient waiting for investigations developed stridor. List three treatment options
Airway protection
1. Tracheostomy
2. Intubation
3. Cricothyroidotomy (coniotomy)
- Steroids
[Old PP]
A 60-year-old man noticed hoarseness for 2 months and this was associated with dysphagia. There was no cervical lymphadenopathy node, no pain and no fever.
Name three likely diagnoses.
Name one predisposing factor for each condition.
- Squamous papillomas of larynx: HPV
- Invasive squamous cell carcinoma of larynx: heavy smoking
- Vocal cord polyps (singersâ nodules): chronic laryngitis due to mechanical injury e.g. misuse of voice
(4. Goitre: iodine deficiency / ingestion of goitrogens - Aortic aneurysm
- Glottic tumour)
[Old PP]
A 60-year-old man noticed hoarseness for 2 months and this was associated with dysphagia. There was no cervical lymphadenopathy node, no pain and no fever.
Name two investigations for this patient.
- Laryngoscopy
- CT scan of neck and chest
- Blood test of iodine level
[Old PP]
A 60-year-old man noticed hoarseness for 2 months and this was associated with dysphagia. There was no cervical lymphadenopathy node, no pain and no fever.
A 2cm diameter irregular growth with contact bleeding was seen over the left vocal cord.
Name one investigation which will give you the diagnosis.
Biopsy
[Old PP]
Oral squamous cell carcinoma of tongue
When a biopsy is done, what cells are expected to be seen?
Squamous epithelial cells with
1. Keratinisation within cells
2. Intercellular bridges
3. Extracellular keratin pearls
4. Increased mitosis
5. Increased N/C
[Old PP]
Name 6 clinical features to support your diagnosis of SCC of tongue.
- Ulceration of tongue
- Dysphagia
- Numbness of tongue, loss of taste
- Pain of tongue
- Cervical LN
- Mass in tongue
[Old PP]
Anatomy of middle ear
A. Chorda tympani
B. Fenestra vestibuli
C. Greater petrosal nerve
D. Pharyngotympanic tube
E. Processus cochleariformis
F. Promontory
G. Stapedius
H. Stapes
I. Tensor tympani
J. Tympanic canaliculus
It originates from posterior wall of middle ear and inserts at handle of stapes
G
Tensor tympani
- from anterior wall of middle wall
- inserts at malleus
[Old PP]
Anatomy of middle ear
A. Chorda tympani
B. Fenestra vestibuli
C. Greater petrosal nerve
D. Pharyngotympanic tube
E. Processus cochleariformis
F. Promontory
G. Stapedius
H. Stapes
I. Tensor tympani
J. Tympanic canaliculus
It is a bony projection that arises from anterior wall.
E
[Old PP]
Anatomy of middle ear
A. Chorda tympani
B. Fenestra vestibuli
C. Greater petrosal nerve
D. Pharyngotympanic tube
E. Processus cochleariformis
F. Promontory
G. Stapedius
H. Stapes
I. Tensor tympani
J. Tympanic canaliculus
It carries parasympathetic fibres to nasal cavity.
C
[Old PP]
Anatomy of middle ear
A. Chorda tympani
B. Fenestra vestibuli
C. Greater petrosal nerve
D. Pharyngotympanic tube
E. Processus cochleariformis
F. Promontory
G. Stapedius
H. Stapes
I. Tensor tympani
J. Tympanic canaliculus
A branch of CN IX passes through this structure in the floor of middle ear.
J
[Old PP]
Anatomy of middle ear
A. Chorda tympani
B. Fenestra vestibuli
C. Greater petrosal nerve
D. Pharyngotympanic tube
E. Processus cochleariformis
F. Promontory
G. Stapedius
H. Stapes
I. Tensor tympani
J. Tympanic canaliculus
It exits middle ear through petrotympanic fissure.
A
[Old PP]
Hyperacusis (complained of excessive acuteness of hearing)
A. Ossification of ossicles
B. Ossicles (stapes or malleus or something) too much vibration?
C. Immobility of ossicles
D. Hyperstimulation of tensor tympani
E. Paralysis of stapedius
E
Stapedius (CN VII) + tensor tympani (CN V3)
-> dampen loud sounds
-> paralysis => hyperacusis
[Old PP]
Which of the following structures is marked by auricular eminence of temporal bone?
A, Lateral SCC
B. Anterior SCC
C. Promontory
D. Posterior SCC
E. Arcuate eminence
B
At arcuate eminence (upward projection of petrous temporal bone into cranial cavity above)
[Old PP]
Middle ear
A. Chorda tympani
B. Fenestra vestibuli
C. Geniculate ganglion
D. Pharyngotympanic tube
E. Processus cochleariformis
F. Promontory
G. Stapedius muscle
H. Stapes
I. Tensor tympani
J. Tympanic canaliculus
Links between middle ear and nasopharynx
D
[Old PP]
Middle ear
A. Chorda tympani
B. Fenestra vestibuli
C. Geniculate ganglion
D. Pharyngotympanic tube
E. Processus cochleariformis
F. Promontory
G. Stapedius muscle
H. Stapes
I. Tensor tympani
J. Tympanic canaliculus
Passes behind handle of malleus
A
[Old PP]
Which cranial nerve involves spiral ganglion?
Vestibulocochlear nerve (CN VIII)
Special sensory (hearing)
Damaged => neurodeafness
[Old PP]
Why puncture tympanic membrane posteroinferiorly?
A. . Less vasculature structure and more easy to find
B. Avoid damage of ossicles and chorda tympani
C. Lowest point of middle ear cavity
D. Easy to insert a tympanostomy tube
B
Chorda tympani
- medial to tympanic membrane
- in supero-posterior quadrant
- best: puncture infero-anterior quadrant by the posterior end of cone of light (e.g. during myringotomy)
[Old PP]
Which cranial nerve supplies both a muscle in soft palate and in middle ear?
Trigeminal nerve
CN V3
Soft palate: tensor veli palatani
Middle ear: tensor tympani
[Old PP]
Which foramen allows exit of CN VII and VIII?
Internal acoustic meatus
[Old PP]
Middle ear
A. Auditory tube
B. Footplate of stapes
C. Geniculate ganglion
D. Head of malleus
E. Internal carotid artery
F. Long process of incus
G. Sigmoid sinus
H. Stapedius
I. Tensor tympani
J. Tympanic membrane
Match above structures to their locations in and around middle ear.
Epitympanic recess
D
[Old PP]
Middle ear
A. Auditory tube
B. Footplate of stapes
C. Geniculate ganglion
D. Head of malleus
E. Internal carotid artery
F. Long process of incus
G. Sigmoid sinus
H. Stapedius
I. Tensor tympani
J. Tympanic membrane
Match above structures to their locations in and around middle ear.
Lateral wall
J
[Old PP]
Middle ear
A. Auditory tube
B. Footplate of stapes
C. Geniculate ganglion
D. Head of malleus
E. Internal carotid artery
F. Long process of incus
G. Sigmoid sinus
H. Stapedius
I. Tensor tympani
J. Tympanic membrane
Match above structures to their locations in and around middle ear.
Posterior wall
H
[Old PP]
Middle ear
A. Auditory tube
B. Footplate of stapes
C. Geniculate ganglion
D. Head of malleus
E. Internal carotid artery
F. Long process of incus
G. Sigmoid sinus
H. Stapedius
I. Tensor tympani
J. Tympanic membrane
Match above structures to their locations in and around middle ear.
Fenestra vestibuli
B
[Old PP]
Middle ear
A. Auditory tube
B. Footplate of stapes
C. Geniculate ganglion
D. Head of malleus
E. Internal carotid artery
F. Long process of incus
G. Sigmoid sinus
H. Stapedius
I. Tensor tympani
J. Tympanic membrane
Match above structures to their locations in and around middle ear.
Medial wall
C
[Old PP]
A 6-year old boy developed acute right otitis media with effusion due to frequent upper respiratory infection. Otitis media progressed further with more severe complications. Which of following complications is highly probably to occur?
A. Loss of lacrimation on right eye
B. Loss of parotid function on right
C. Loss of sense of balance
D. Loss of sense of smell
E. Loss of taste from posterior â
of tongue
C
A: CN VII (Bellâs palsy)
B, E: CN IX
D: CN I
C: labyrinthitis (inflammation of inner ear), symptoms: vertigo, hearing loss, tinnitus, etc.
[Old PP]
A 65-year-old patient with history of heart problem visited a doctor to remove wax in ear. During procedures of syringing of external auditory meatus. Patient suddenly developed cardiac arrhythmia and collapsed. Which cranial nerve is most likely involved?
A. Facial nerve
B. Glossopharyngeal nerve
C. Trigeminal nerve
D. Vagus nerve
E. Vestibulocochlear nerve
D
[PP]
A previously healthy 34-year-old lady developed sudden severe headache and was admitted into hospital. There was no history of hypertension or prior head injury. A computed tomography scan of the brain was performed, and showed a thin film of blood in the subarachnoid space. The brain itself showed no additional abnormal bleeding site. What is the MOST LIKELY underlying pathology and their anatomical location?
A. Berry (saccular) aneurysm located at the bifurcation of the internal carotid artery into the middle cerebral and posterior communicating artery.
B. Berry (saccular) aneurysm located at the middle segment of the basilar artery.
C. Microaneurysm located at the deep penetrating arteries supplying the basal ganglia.
D. Microaneurysm located at the pontine arteries.
A
Rupture of berry aneurysm -> subarachnoid haemorrhage -> severe headache
Blood irritating meninges -> neck rigidity
Microaneurysm VS Berry (saccular) aneurysm
- Chronic HT VS Otherwise healthy individual (rarely with coarctation of aorta / adult polycystic kidneys)
- Microscopic VS Macroscopic (5mm or larger)
- Penetrating arteries (e.g. basal ganglia, pons, cerebellum) VS Bifurcation of arteries in Circle of Willis (90% anterior circulation)
- Intracerebral haemorrhage VS Subarachnoid haemorrhage
- Prevention: control of HT VS Neurosurgical (clip / embolise the aneurysm to prevent re-bleed)
[PP]
A 35-year-old man was brought into the Accident and Emergency Department after a car accident and sustained a skull fracture. He complained of right homonymous hemianopia and rapidly became comatose. An urgent computed tomography scan showed a large epidural haematoma on the left side of his brain. What is the MOST LIKELY cause of his visual problem?
A. Compression of the aqueduct of Sylvius causing obstructive hydrocephalus
B. Compression of the left occipital lobe
C. Compression of the left oculomotor nerve
D. Compression of the left posterior cerebral artery
E. Compression of the optic nerve
D
Epidural hematoma
=> Transtentorial herniation with midline shift
=> Compression of left PCA
=> infarction / ischemia of left occipital lobe
=> right homonymous hemianopia with macular sparing
[PP]
RAISED INTRACRANIAL PRESSURE CAUSED BY SPACE OCCUPYING LESION
A. Aqueduct of Sylvius
B. Fourth ventricle
C. Left middle cerebellar peduncle
D. Left motor cortex
E. Left posterior cerebral artery
F. Midbrain
G. Right middle cerebellar peduncle
H. Right oculomotor nerve
I. Right optic nerve
J. Right posterior cerebral artery
A 34-year-old taxi driver had a road traffic accident and sustained head injury with skull fracture. An urgent computed tomography (CT) scan upon admission to the Accident and Emergency Department showed a large epidural haematoma beneath the right temporal skull fracture, which compressed directly on the underlying right cerebral hemisphere including the right motor and sensory cortex, and resulting in midline shift to the left side. His Glasgow coma scale deteriorated rapidly with onset of the following neurological signs.
For each of the following neurological signs, select the structure in the brain from the list of options above which is MOST LIKELY to be compressed/damaged because of the space occupying lesion in the right cerebral hemisphere. Each option may be used once, more than once, or not at all.
Progressive deterioration in consciousness
F
Compress vital structures
- haemorrhage and infarction of midbrain and pons
-> loss of consciousness, depressed HR & respiration
-> increased BP due to sympathetic activity
[PP]
RAISED INTRACRANIAL PRESSURE CAUSED BY SPACE OCCUPYING LESION
A. Aqueduct of Sylvius
B. Fourth ventricle
C. Left middle cerebral peduncle
D. Left motor cortex
E. Left posterior cerebral artery
F. Midbrain
G. Right middle cerebral peduncle
H. Right oculomotor nerve
I. Right optic nerve
J. Right posterior cerebral artery
A 34-year-old taxi driver had a road traffic accident and sustained head injury with skull fracture. An urgent computed tomography (CT) scan upon admission to the Accident and Emergency Department showed a large epidural haematoma beneath the right temporal skull fracture, which compressed directly on the underlying right cerebral hemisphere including the right motor and sensory cortex, and resulting in midline shift to the left side. His Glasgow coma scale deteriorated rapidly with onset of the following neurological signs.
For each of the following neurological signs, select the structure in the brain from the list of options above which is MOST LIKELY to be compressed/damaged because of the space occupying lesion in the right cerebral hemisphere. Each option may be used once, more than once, or not at all.
Right hemiplegia
C
Right epidural haematoma
-> transtentorial herniation
-> compression of left cerebral peduncle against free edge of tentorium
-> right hemiplegia (corticospinal tract affected) (false localising sign)
[PP]
RAISED INTRACRANIAL PRESSURE CAUSED BY SPACE OCCUPYING LESION
A. Aqueduct of Sylvius
B. Fourth ventricle
C. Left middle cerebellar peduncle
D. Left motor cortex
E. Left posterior cerebral artery
F. Midbrain
G. Right middle cerebellar peduncle
H. Right oculomotor nerve
I. Right optic nerve
J. Right posterior cerebral artery
A 34-year-old taxi driver had a road traffic accident and sustained head injury with skull fracture. An urgent computed tomography (CT) scan upon admission to the Accident and Emergency Department showed a large epidural haematoma beneath the right temporal skull fracture, which compressed directly on the underlying right cerebral hemisphere including the right motor and sensory cortex, and resulting in midline shift to the left side. His Glasgow coma scale deteriorated rapidly with onset of the following neurological signs.
For each of the following neurological signs, select the structure in the brain from the list of options above which is MOST LIKELY to be compressed/damaged because of the space occupying lesion in the right cerebral hemisphere. Each option may be used once, more than once, or not at all.
Papilloedema
I
Compressed optic nerve, retinal vein
[PP]
A 76-year-old gentleman had long standing hypertension but often forgot to take his drug. One day he was found unconscious on the street and brought into the Accident and Emergency Department. An urgent computed tomography scan of the brain showed the presence of a 1x1x0.5 cm haematoma in his pons. He died shortly afterwards. Which of the following pathological changes is MOST LIKELY associated with the cause of his haematoma in the pons?
A. Berry (saccular) aneurysm in the posterior cerebral artery
B. Deposition of amyloid in the cerebral blood vessels
C. Emboli from the heart obstructing the pontine arteries
D. Lipohyalinosis with microaneurysm in the deep penetrating pontine arteries
D
[PP]
A 55-year-old man presented with a 16-month history of progressive loss of memory and cognitive ability, personality changes, unsteadiness and clumsiness and more recently myoclonic jerks. He has previously been well and has no known immunocompromised conditions. The cerebrospinal fluid examination revealed no increase of white cells or total protein. Which of the following aetiological agents would you consider to be the MOST LIKELY cause of his illness?
A. Cryptococcus
B. Cytomegalovirus
C. Herpes simplex type 1
D. John Cunningham (JC) virus
E. Prions
E
Spongiform encephalopathy
- X inflammation / immune response
- Long incubation period
- Progressive dementia, loss of memory / intellect, personality changes, unsteadiness / clumsiness, myoclonic jerks
- Accumulated Prion-related protein PrP^sc -> spongiform vacuolation of brain, loss of neurons
[PP]
Which of the following pathological changes and corresponding consequences is MOST COMMONLY observed in tuberculous meningitis?
A. Attack of myelin sheath by body immune system and demyelination
B. Fibrosis with obliteration of subarachnoid space and hydrocephalus
C. Lipohyalinosis of penetrating arteries and infarction of basal ganglia
D. Neuronophagia (engulfment of neurons by microglia) and loss of anterior horn cells
B
[PP]
Fungi can cause infection of the central nervous system. However, most fungal infections are opportunistic, affecting patients with underlying impaired cellular immunity. Which of the following fungi is MOST LIKELY to cause fungal meningitis in an otherwise healthy individual?
A. Aspergillus
B. Candida
C. Cryptococcus
D. Mucormycosis
C
A, B, D: opportunistic
[PP]
Different types of pathological damage can lead to different modes of cell injury and pathological reaction. Which of the following is the characteristic pathological change of an acute cerebral infarction of 1 to 2-week-old?
A. Formation of granuloma with caseous necrosis at the centre bordered by epithelioid cells
B. Healing by fibrosis with progressive transformation into a fibrous scar
C. Infiltration of lymphocytes and microglia that attack and engulf the neurons
D. Infiltration of macrophages with abundant foamy cytoplasm
D
A: mycobacteria
B: no fibroblasts in brain
Liquefactive necrosis
Macrophages -> engulf necrotic cell debris with high lipid content, forming foamy cytoplasm
[PP]
A 50-year-old poorly controlled diabetic patient presented with headache, night sweating, fever and weight loss for 3 months. His cerebrospinal fluid (CSF) also showed high protein, high sugar and lymphocytic pleocytosis. Bacterial, mycobacterial and fungal cultures were negative. His symptoms fully responded to a combination of anti-tuberculous drug treatment. Why were microbiological cultures for Mycobacterium tuberculosis negative in this patient?
A. Mycobacterium tuberculosis are often walled off by granulomatous reaction
B. Mycobacterium tuberculosis cannot spread through the subarachnoid space
C. Mycobacterium tuberculosis is partially suppressed by antibiotic from the family doctor
D. Obstruction of CSF circulation in the subarachnoid space from brain to spinal cord
E. The high sugar level in CSF suppressed the growth of Mycobacterium tuberculosis
A
Mycobacterium tuberculosis protein & mycolipid elicit a strong granulomatous inflammation (macrophages, epithelioid histiocytes)
-> Fibrosis walls off the granuloma
-> AFB cannot be shared in subarachnoid space
[PP]
Johnâs mother reports to the family doctor Dr. Wong on a visit that John has been frequently anxious and cannot get into sleep at night for more than 6 months. Dr. Wong decides to prescribe a short course of diazepam to him. How does diazepam work?
A. Activating GABAB receptors in the central nervous system.
B. Blocking glutamate receptors in hierarchical neuronal pathways in the brain
C. Increasing the frequency of Cl- channel opening which is coupled to GABAA receptors
D. Inhibiting GABA-transaminase leading to increased levels of GABA
C
[PP]
Dopamine receptors are widely expressed in different regions of the brain. Blockade of dopamine D2 receptors in the mesocortical and mesolimbic region of the brain is associated with antipsychotic efficacy. Which of the following is the major side effect of blocking the dopamine D2 receptors in the tuberoinfundibular region of the brain?
A. Acute dystonia
B. Akathisia
C. Gynecomastia
D. Increased risk of diabetes
E. Schizophrenia
C
Hyperprolactinemia:
- gynecomastia
- galactorrhoea
- sexual dysfunction: X ovulation, X menstruation
- reduced FSH, LH
- loss of libido
- pseudopregnancy
[PP]
Blockade of dopamine D2 receptors in different regions of the brain is associated with various side effects. What is the major side effect of anti-psychotics on blocking the dopamine receptor 2 receptors on the nigrostriatal region of the brain?
A. Galactorrhoea
B. Increased risk of diabetes
C. Manifestation of extrapyramidal symptoms
D. Sexual dysfunction
C
In basal ganglia
Acute dystonia, akathisia, Parkinsonism, tardive dyskinesia
[PP]
An increasing life expectancy at birth represents one of the two MOST IMPORTANT factors driving global population ageing. What is the second factor?
A. Decreasing age-standardised mortality rate
B. Decreasing fertility rate
C. Decreasing infant mortality rate
D. Increasing prevalence of infertility among women of child bearing age
B
[PP]
Functional capacity such as cardiac output, ventilatory capacity, and muscle strength generally peaks in early adulthood and declines afterwards. Exposure to various behavioural and environmental factors during which period of life may affect the rate of decline in functional capacity?
A. Early adulthood
B. Early childhood
C. Elderly years
D. Over the whole life course
D
[PP]
The incidence of traumatic brain injury in paediatric age group varies from birth to teenage years. In which gender(s) does/do this age-dependent incidence follow a positively skewed pattern?
A. In both genders
B. In females
C. In males
D. In neither gender
B
Age distribution:
- Male: bimodal distribution
- Female: positively skewed distribution
Sex distribution:
- M>F at all ages
- M VS F: 2X risk of TBI & 4X risk of fatal TBI
[Old PP]
What is most common cause of traumatic brain injury of a pre-school boy?
A. Child abuse
B. Fall at home
C. Motor vehicle accident
D. Sports injury
E. Unknown cause
B
[Old PP]
Define defensive medical practice.
- Tests and procedures primarily driven by fear of malpractice liability rather than medical indications
- Choosing an aggressive patient management style even though conservative treatment was considered medically acceptable by the experts
[Old PP]
List two potential consequences of defensive medical practice. (2 marks)
Bio: unnecessary additional health risks (radiation / contrast / invasive procedures)
Psycho: emotional and stress issues
Socio: costly (and opportunity cost) to healthcare system
[Old PP]
For a 30-year-old male patient suffering from a minor traumatic brain injury with a Glasgow Coma Scale of 15/15, list six criteria that indicate the need for a computed tomography (CT) according to New Orleans Criteria. (6 marks)
Headache
Emesis = Vomiting (+ another V = Visible trauma above Clavicle)
Age: Older than 60 years old (+another A = persistent Anterograde Amnesia, i.e. deficits in short-term memory)
Drug or alcohol intoxication
Seizure
HEADS
Any one -> CT
[Self-assessment]
Which are the two main at risk age-groups for traumatic brain injury?
Select one:
A. Children and working age adult
B. Children and elderly
C. Adult and elderly
B
[Self-assessment]
What is the underlying cause of a much higher incidence of traumatic brain injury in teenage male comparing to teenage female?
Select one:
A. Assault
B. Motor-vehicle accident
C. Contact sports
C
[Self-assessment]
What is the percentage of traumatic brain injuries that may have a consequence of persisting or lifelong disability?
Select one:
A. 0.1%
B. 2%
C. 10%
B
[Self-assessment]
Which of the following scenario is compatible with defensive medical practice?
Select one:
A. Defending oneâs clinical decision by quoting published evidence in medical literature
B. Refusing to prescribe antibiotics for the fear of contributing to antimicrobial resistance
C. Ordering a blood test to avoid the possibility of being sued
C
[Self-assessment]
What is the ratio of the proportions of positive testing result in patients versus the proportion of positive testing result in non-patients?
Select one:
A. Sensitivity
B. Positive likelihood Ratio
C. Positive predictive value
B
[Self-assessment]
When most people not having COVID-19 infection were having a negative result on undergoing a rapid test for COVID-19 infection, the test is said to be having a high:
Select one:
A. High negative predictive value
B. High specificity
C. High negative likelihood ratio
B
[Self-assessment]
Which clinical decision tool(s) for traumatic brain injury considered CT is necessary for those having a history of drug or alcohol intoxication?
Select one:
A. New Orleans Criteria
B. Both
C. Canadian Head CT rules
A
[Self-assessment]
What is the main clinical use of the New Orleans Criteria and Canadian Head CT rules in the management of traumatic brain injury (TBI)?
Select one:
A. To inform prognostic assessment of TBI patients
B. To inform neurosurgical planning of TBI patients
C. To identify TBI patients who may need neuroimaging
C
[PP]
A 40-year-old gentleman presented with a unilateral facial nerve palsy involving the lower face but not the upper face. His other cranial nerves were normal. There was no limb weakness. Where is the MOST LIKELY site of disease?
A. Caudate nucleus
B. Frontal lobe cortex
C. Medulla oblongata
D. Parietal lobe cortex
E. Parotid gland
B
UMN lesion of facial nerve
- Only lower but NOT upper face affected
LMN lesion of facial nerve
- BOTH upper & lower faces affected
Frontal lobe contains primary motor cortex (UMN)
D: Parietal lobe: mainly sensory
C: Facial nerve leaves the brainstem well above the medulla oblongata
E: facial nerve within the parotid gland is a LMN
[PP]
The patientâs tongue points to the left when protruding. Which nerve is MOST LIKELY damaged?
A. Left CN X
B. Left CN XII
C. Right CN IX
D. Right CN XII
B
[PP]
A 56-year-old man presents with a sudden onset of right upper and lower face weakness. His speech is normal. There is no limb weakness. Where is the MOST LIKELY site of disease?
A. Inferior frontal gyrus
B. Internal acoustic meatus
C. Internal capsule
D. Medulla oblongata
B
Internal acoustic meatus: CN VII, VIII
LMN lesion of CN VII
[PP]
The middle cerebral artery (MCA) is a major source of blood supply to the brain. Which of the following would MOST LIKELY be present following an acute right MCA occlusion?
A. Expressive dysphasia
B. Impaired conjugate eye movement
C. Lower facial weakness
D. Lower limb muscle fasciculation
C
UMN lesion
A: Right MCA affected, but Brocaâs area is mostly on the left
D: LMN lesion
[PP]
There are multiple descending pathways from the motor cortex and brainstem for the control of posture and movement. What is the major function of the vestibulospinal tract originating from the brainstem?
A. Controls axial muscles and posture
B. Controls movement of fingers on contralateral side of the body
C. Provides input to basal ganglia for planning complex movements
D. Provides input to cerebellum for feedback control of movement
A
[PP]
The vestibulospinal reflex coordinates head and body movements in maintaining an upright posture. Which brain region is involved in executing this reflex?
A. Cerebellar dentate nucleus
B. Medullary pyramids
C. Medullary reticular formation
D. Red nucleus
C
A: Cerebellar dentate nucleus: modify voluntary movements, NOT posture
B: Medullary pyramids carry pyramidal tracts from motor cortex
=> voluntary movements
C: Medullary reticular formation is closely linked with the vestibular nucleus to exert descending influences on vestibulospinal reflex
D: Red nucleus of midbrain: motor coordination, but NOT vestibulospinal reflex
[PP]
The vestibulo-ocular reflex stabilises gaze for clear vision during head movement. Which brain region in the diagram provides inhibitory input to the neural circuit mediating this reflex?
A. Cerebellar nodulus
B. Midbrain
C. Pontine reticular formation
D. Tectum
E. Tegmentum
A
[PP]
Inferior olivary nucleus conveys motor information to Purkinje cells. Which peduncles mediate the connection between inferior olivary nucleus to Purkinje cells?
A. Cerebral peduncles
B. Inferior cerebellar peduncles
C. Middle cerebellar peduncles
D. Superior cerebellar peduncles
B
[PP]
Cerebellum is one of the three main neural areas for voluntary motor control. What is the test for identifying cerebellar dysfunction?
A. Plantar response
B. Reaction time
C. Spiral analysis
D. Tandem walking test
D
[PP]
Basal ganglia, cerebellum and cerebral cortex are the three main neural areas for motor control. Which clinical test specifically identifies cerebellar dysfunction?
A. Neuropathy test
B. Plantar reflex test
C. Romberg test with eyes open
D. Tandem walking test
D
[PP]
Homeostasis is the maintenance of a constant internal environment. Which brain region is primarily responsible for homeostasis?
A. Amygdala
B. Hippocampus
C. Hypothalamus
D. Thalamus
C
[PP]
There are many connections of different brain regions in the Papez circuit. Which nucleus of the thalamus connects to the mammillary bodies via the mammillothalamic tracts?
A. Anterior nucleus
B. Ventral anterior nucleus
C. Ventral lateral nucleus
D. Ventral posterior nucleus
A
[PP]
Mr. Chan is a 70-year-old gentleman who has recently suffered from cerebrovascular accident and has been comatose for 4 days. After he has woken up from the coma, his relatives discover that he has difficulty in producing intelligible speech. His ability to understand speech and his voice are all normal. Which of the following structures is LIKELY to be damaged by the cerebrovascular accident?
A. Left inferior frontal gyrus
B. Left internal capsule
C. Left vagal nucleus
D. Right cerebellopontine angle
A
Left inferior frontal gyrus (e.g. Brocaâs area: Brodmann area 44, 45): language / speech
Damaged internal capsule => contralateral hemiparesis
Damaged vagal nucleus => gastroparesis, dysphagia, dysphonia
Cerebellopontine angle syndrome: unilateral hearing loss, vertigo, CN VII palsy, numbness
[ALW]
The allergic conditions, viz. hay fever or allergic rhinitis, cause irritation of pterygopalatine ganglion, which causes congestion of glands of the nose and palate, and lacrimal gland.
Which types of fibres may be affected by the irritation of pterygopalatine ganglion?
Lacrimal, nasal, palatine, (pharyngeal) mucous glands: parasympathetic secretory motor
Orbital branches (via infraorbital foramen): general sensory
(Posterior) Nasal branches: parasympathetic secretory motor + general sensory
Nasopalatine nerve (via incisive foramen): General sensory
Greater & lesser palatine nerve: special visceral sensory + general sensory + parasympathetic secretory motor
Pharyngeal branches: general sensory
[ALW]
What blood vessels are innervated by pterygopalatine ganglion neurons?
Blood vessels of eye, nasal cavity and palate
Cerebral and meningeal blood vessels
[ALW]
Which nerves provide sympathetic and parasympathetic input to pterygopalatine (sphenopalatine) ganglion respectively?
- Parasympathetic: greater petrosal nerve
Facial nerve -> geniculate ganglion -> greater petrosal nerve - Sympathetic: deep petrosal nerve
Superior cervical ganglion -> internal carotid plexus -> deep petrosal nerve
Join to give nerve of pterygoid canal (Vidianâs nerve)
[Old PP]
Ms. Chan, a 30-year-old lady, just underwent an operation to remove left lobe of thyroid. She found she had choking on drinking water and spoke with a weak voice on day 1 post-operation. Which of following is most likely explanation?
A. Excessive cough during recovery from anaesthesia
B. Inappropriate infiltration of local anaesthetics during operation
C. Surgical injury to left recurrent laryngeal nerve
D. General anaesthesia has not fully worn off
E. Trauma to larynx during intubation
C
[Old PP]
After left thyroidectomy. Choke on swallowing water, weak voice?
A. Left recurrent laryngeal nerve palsy
B. Wrong anaesthesia procedure or something
C. Anaesthesia
D. Cough too much or something
A
[Old PP]
During thyroidectomy or parathyroidectomy resection, patientâs neck is hyperextended and a mid-line incision is made. Which structures do surgeon need to dissect through, from superficial to deep, before being able to gain access to thyroid or parathyroid gland?
A. Subcutaneous fascia and platysma â Deep fascia â Sternocleidomastoid muscle â Sternothyroid muscle â Thyrohyoid muscle
B. Subcutaneous fascia and platysma â Deep fascia â Sternohyoid muscle â Sternocleidomastoid muscle â Thyrohyoid muscle
C. Subcutaneous fascia and platysma â Deep fascia â Sternohyoid muscle â Sternothyroid muscle â Thyrohyoid muscle
D. Subcutaneous fascia and platysma â Deep fascia â Thyrohyoid muscle â Sternohyoid muscle â Sternothyroid muscle
E. Subcutaneous fascia and platysma â Deep fascia â Sternothyroid muscle â Sternohyoid muscle â Thyrohyoid muscles
C
[PP]
A foreign body lodging at the piriform fossa causes irritation and coughing. What is the innervation at this site?
A. External laryngeal nerve
B. Glossopharyngeal nerve
C. Internal laryngeal nerve
D. Lingual nerve
C
[PP]
Stylopharyngeus muscle is one of the muscles of the pharynx. What is the function of this muscle?
A. Acts as the sphincter of lower end of the pharynx
B. Assists in closing the nasopharynx
C. Depresses the pharynx
D. Elevates the larynx during swallowing
D
Palatopharyngeus, stylopharyngeus, salpingopharyngeus = longitudinal pharyngeal muscles
- shorten and widen the pharynx
- elevate the larynx during swallowing
Superior, middle and inferior pharyngeal constrictors (inferior = thyropharyngeus + cricopharyngeus) = circular pharyngeal muscles
- constrict the pharynx -> push food into esophagus
- cricopharyngeus = sphincter of esophagus, relax during swallowing to admit food
All muscles of soft palate and pharynx: pharyngeal plexus (CN X)
- except tensor veli palatini (CN V3), stylopharyngeus (CN IX), cricopharyngeus (CN X)
[Old PP]
A 50-year-old man complained of severe pain triggered by swallowing. Pain was felt in back of throat, tongue, tonsil and extends up to ear.
Which cranial nerve is producing neuralgia? (2 marks)
Glossopharyngeal nerve (CN IX)
[Old PP]
Name one muscle innervated by branchial motor component of glossopharyngeal nerve. (2 marks)
Stylopharyngeus (longitudinal pharyngeal muscle)
[Old PP]
Name one structure supplied by visceral sensory component of glossopharyngeal nerve. (2 marks)
Carotid sinus and body
[Old PP]
Name one other cranial nerve that provides general sensation to external ear except glossopharyngeal nerve. (2 marks)
Mandibular / vagus / facial nerve
[Old PP]
Name the nerve that controls muscles involved in oesophageal stage of swallowing. (2 marks)
Vagus nerve
[Self-assessment]
Which structure demarcates the boundary between oral cavity and oropharynx?
A. Sulcus terminalis
B. Palatoglossal arch
C. Palatopharyngeal arch
B
Sulcus terminalis: boundary between anterior 2/3 and posterior 1/3 of tongue
Palatopharngeal arch: oropharynx
Between palatoglossal & palatopharyngeal arches: palatine tonsils
[Self-assessment]
Which part of the nasopharynx has a high propensity for malignant degeneration?
A. Pharyngeal recess
B. Salpingopharyngeal fold
C. Tubal elevation
A
Pharyngeal recess / Fossa of Rosenmuller: common site of NPC
- behind tubal elevation & salpingopharyngeal fold
[Self-assessment]
What is the main action of palatopharyngeus muscle?
A. Elevates the larynx
B. Elevates the tongue
C. Depresses the larynx
A
[Old PP]
A 10-year-old boy had tonsillectomy due to chronic tonsillitis. Which of following nerve closely accompanies tonsillar branches of facial artery and ascending pharyngeal arteries?
A. Glossopharyngeal nerve
B. Vagus nerve
C. Hypoglossal nerve
D. Lingual nerve
E. Inferior alveolar nerve
A
Prone to damage during tonsillectomy:
1. Glossopharyngeal nerve
2. Tonsillar artery
3. Internal carotid artery
[Old PP]
What is anterior attachment of superior pharyngeal constrictor muscle?
A. Buccopharyngeal fascia
B. Pharyngeal tubercle
C. Pharyngeal raphe
D. Pharyngobasilar fascia
E. Pterygomandibular raphe
E
Superior: pterygomandibular raphe (attaches to buccinator)
Middle: hyoid bone
Inferior: oblique line of thyroid cartilage
[Old PP]
Pharynx
A. Auditory tube
B. Cricoid cartilage
C. C3-C6
D. Epiglottis
E. Inferior pharyngeal constrictor muscle
F. Palatine tonsils
G. Pharyngeal recess
H. Soft palate
I. Thyroid cartilage
J. Tubal elevation
What is structure that communicates with middle ear
A
[Old PP]
Pharynx
A. Auditory tube
B. Cricoid cartilage
C. C3-C6
D. Epiglottis
E. Inferior pharyngeal constrictor muscle
F. Palatine tonsils
G. Pharyngeal recess
H. Soft palate
I. Thyroid cartilage
J. Tubal elevation
What is structure that can be found at level C3?
D
Also hyoid
[Old PP]
Pharynx
A. Auditory tube
B. Cricoid cartilage
C. C3-C6
D. Epiglottis
E. Inferior pharyngeal constrictor muscle
F. Palatine tonsils
G. Pharyngeal recess
H. Soft palate
I. Thyroid cartilage
J. Tubal elevation
What is depression found in nasopharynx?
G
[Old PP]
3X year old truck driver complained of waking up at night. He has a BMI of 32 kg/m2 and he was diagnosed obstructive sleep apnea. What is anterior attachment of superior pharyngeal constrictor?
A. Buccopharyngeal fascia
B. Pharyngeal raphe
C. Pharyngeal tubercle
D. Pharyngobasilar fascia
E. Pterygomandibular raphe
E
[Old PP]
There is one mucosal fold anterior to and one posterior to palatine tonsil. What is muscle deep to mucosal fold?
A. Genioglossus and hyoglossus
B. Genioglossus and styloglossus
C. Hyoglossus and styloglossus
D. Palatoglossus and palatopharyngeus
E. Tensor veli palatini and levator veli palatini
D
[Old PP]
Sensory innervation of pharyngeal constrictor muscle in oropharynx is supply by which cranial nerve?
A. Facial nerve
B. Glossopharyngeal nerve
C. Spinal accessory nerve
D. Trigeminal nerve
E. Vagus nerve
B
[Old PP]
A 40-year-old man complains of snoring loudly and waking up at midnight due to difficulty with breathing. He is hypertensive with a BMI of 32. Diagnosis is obstructive sleep apnoea with relaxed pharyngeal muscles. What statement about pharynx is correct?
A. Inferior pharyngeal constrictor muscle is attached to hyoid bone.
B. Middle pharyngeal constrictor muscle is one of longitudinal muscles.
C. Palatopharyngeus muscle elevates larynx.
D. Stylopharyngeus muscle is innervated by pharyngeal plexus.
E. Superior pharyngeal constrictor muscle is drained by pterygoid plexus.
C
Middle pharyngeal constrictor -> hyoid
Inferior pharyngeal constrictor -> oblique line of thyroid cartilage
- circular muscles
Stylopharyngeus: CN IX
Pharyngeal venous drainage: pharyngeal venous plexus (communicate with pterygoid plexus) -> IJV
[Old PP]
Which of following is not true?
A. Atlas and dens of axis is located at (anteroposterior?) level of open mouth.
B. Carotid artery bifurcates at C4.
C. Hyoid bone is at C5.
D. Larynx opens into trachea at C6.
E. Pharynx is connected to oesophagus at C6.
C
Laryngopharynx ends at C6 (D, E)
C6 is also lower end of cricoid cartilage
Hyoid bone: C3
All bifurcations: C4 (common carotid artery, trachea, abdominal aorta)
Hard palate: C1
[Old PP]
A man with hypertension and a BMI of 32 consulted a doctor because his wife complained
that he snored loudly at night. He was diagnosed with obstructive sleep apnoea due to pharyngeal
muscles. Which of following muscles elevate pharynx and larynx during swallowing and speaking?
A. Superior constrictor muscle
B. Palatoglossal muscle
C. Stylopharyngeus muscle
D. Inferior constrictor muscle
E. Tensor veli palatini muscle
C
[Old PP]
In which phase does epiglottis tips backward to close glottis?
A. Bolus touches vallecula
B. Bolus reaches cricopharyngeus
C. Pharyngeal phase
D. Oral phase
E. Oesophageal phase
C
Vallecula: posterior end of tongue -> more likely to have food dislodgement
Pharyngeal phase: shortest but most fatal
[Old PP]
Which of followings helps to raise larynx and pharynx in speech and swallowing?
A. Stylopharyngeus
B. Middle pharyngeal constrictor
C. Cricopharyngeus
D. Levator veli palatini
E. Palatoglossus
A
[ALW]
A 27-year-old male was stabbed in a fight. His left half of spinal cord was cut at T3 level.
What are the findings during physical examination?
Ipsilateral motor paralysis of lower limbs (below lesion)
Ipsilateral loss of proprioception, vibration and fine / discriminative touch in lower limbs (below lesion)
Contralateral loss of pain and temperature in lower limbs (a few levels below lesion)
[PP]
Structures related to the middle ear
A. Chorda tympani
B. Fenestra cochlea
C. Greater petrosal nerve
D. Pharyngotympanic tube
E. Processus cochleariformis
F. Promontory
G. Pyramid
H. Tensor tympani
I. Tympanic canaliculus
J. Stapedius muscle
Select the MOST RELEVANT structure from the list of options above.
Passes medial to the malleus
A
CT = only structure behind malleus
- arises at posterior wall of middle ear
- from main branch of CN VII before it exits stylomastoid foramen
-> courses anteriorly and passes behind malleus -> exit anterior wall through petrotympanic fissure
