Neurology Flashcards
What are the features of Horner Syndrome?
- Ptosis
- Anhidrosis
- Miosis
+ Flushing of the affected side of the case
What are the lesions that are associated with Horner Syndrome?
- *Any lesion of the spinal cord located above T1 level**
- Pancoast tumour
- Brown-Sequard syndrome
- Late-stage syringomyelia
Which cranial nerves have their nuclei in the midbrain?
- CN3 (Oculomotor nerve)
- CN4 (Trochlear nerve)
Which cranial nerves have their nuclei in the pons?
- CN5 (Trigeminal nerve)
- CN6 (Abducens nerve)
- CN7 (Facial nerve)
- CN8 (Vestibulocochlear nerve)
Which cranial nerves have their nuclei in the medulla?
- CN9 (Glossopharyngeal nerve)
- CN10 (Vagus nerve)
- CN12 (Hypoglossal nerve)
What are the vagal nuclei and what do they supply?
-
Nucleus solitarius
- Sensory to: taste, baroreceptors, gut distension
-
Nucleus ambiguus
- Motor to: pharynx, larynx and upper esophagus
-
Dorsal motor nuclei
- Autonomic to: heart, lungs and upper GI
Which important structures are located in the cavernous sinus?
Cranial nerves
- EOM nerves: 3, 4, 6
- Trigeminal nerve: V1 (ophthalmic) and V2 (maxillary)
Others
- Internal carotid artery
- Pituitary gland
In close proximity
- Optic chiasm
- Sphenoidal sinuses
Which muscles of mastication are involved in closing the jaw?
- Masseter
- Temporalis
- Medial pterygoid
Which muscles of mastication are involved in opening the jaw?
Lateral pterygoid
What diseases are associated with an increase in norepinephrine?
- Anxiety
- Mania
What diseases are associated with a decrease in norepinephrine?
Depression
What diseases are associated with an increase in dopamine?
- Huntington disease
- Schizophrenia
What diseases are associated with a decrease in dopamine?
- Parkinson disease
- Depression
What diseases are associated with an increase in serotonin (5-HT)?
Parkinson disease
What diseases are associated with a decrease in serotonin (5-HT)?
- Anxiety
- Depression
What diseases are associated with an increase of ACh?
Parkinson disease
What diseases are associated with a decrease of ACh?
- Alzheimer disease
- Huntington disease
What diseases are associated with a decrease in GABA?
- Anxiety
- Huntington disease
Where are the following neurotransmitters made?
- Norepinephrine
- Dopamine
- 5-HT
- ACh
- GABA
- Norepinephine: locus ceruleus
- Dopamine: substantia nigra pars compact and ventral tegmentum
- 5-HT: raphe nucleus
- ACh: basal nucleus of Meynert
- GABA: nucleus accumbens
What do muscle spindles monitor?
Length of the muscle
What do Golgi tendon organs monitor?
Tension of the muscle/tendon
What are the efferunt nerves of Golgi tendon organs called?
Ib fibres
What are the efferunt nerves of muscle spindles called?
Ia fibres
What is the gamma loop? What is its function?
- CNS-regulated gamma fibres send signals to the muscle spindles
- Causes muscle spindle contractions and thus increases the sensitivity of the reflex arc
Name the thalamus nucleus.
Somatosensory from body
>> Medial lemniscus (DCML)
>> Spinothalamic tract (STT)
Ventroposterolateral nucleus (VPL)
Name the thalamus nucleus.
Trigeminothalamic tract and taste pathways >> Somatosensory cortex
Ventroposteriomedial nucleus (VPM)
Name the thalamus nucleus.
Communications with prefrontal cortex
- Memory loss results if destroyed
Mediodorsal nucleus (MD)
Name the thalamus nucleus.
Cerebellum’s dentate nucleus and basal ganglia >> Motor cortex
Ventrolateral nucleus (VL)
Name the thalamus nucleus.
Cerebellum’s dentate nucleus and basal ganglia >> Supplementary motor cortex
Ventrolateral nucleus (VL)
Name the thalamus nucleus.
Basal ganglia >> Prefrontal, premotor and orbital cortices
Ventroanterior nucleus (VA)
Name the thalamus nucleus.
Mamillothalamic tract >> Cingulate gyrus
(Part of Papez circuit)
Anterior nucleus
Name the thalamus nucleus.
Integration of visual, auditory and somesthetic input
Pulvinar nucleus
Name the thalamus nucleus.
Retina >> Occipital lobe
Lateral geniculate body (LGN)
Name the thalamus nucleus.
Brachium of inferior colliculus (auditory information) >> Primary auditory cortex
Medial geniculate body (MGN)
What are the muscles that are innervated by the axillary nerve?
- Deltoid
- Teres minor
- Long head of the tricpes brachii
What are the muscles that are innervated by the radial nerve?
- All three heads (medial, lateral and long) of the triceps brachii
- Brachioradialis
- Supinator
- Extensors of the wrist and fingers
- Abductor pollicis longus
What are the muscles that are innervated by the median nerve?
- Pronator teres
- Flexor carpi radialis
- Palmaris longus
- Flexor digitorum superficialis
- Pronator quadratum
- Flexor pollicis longus
- Lateral half of the flexor digitorum profundus
- First and second lumbricals
- Thenar muscles
What are the muscles that are innervated by the ulnar nerve?
- Flexor carpi ulnaris
- Medial half of the flexor digitorum profundus
- 3rd and 4th lumbricals: IP joint extension
- All interossei: MCP flexion, finger abduction
- Adductor pollicis
- Hypothenar muscles
What are the muscles that are innervated by the musculocutaneous nerve?
- Biceps brachii
- Brachialis
- Coracobrachialis
What are the muscles that are innervated by the long thoracic nerve?
Serratus anterior
>> Winged scapula
What are the muscles that are innervated by the femoral nerve?
Hip flexors
- Psoas
- Iliacus
- Pectineus
- Sartorius
Knee extensors (Quadriceps)
- Rectus femoris
- Vastus lateralis
- Vastus medialis
- Vastus intermedius
What are the muscles that are innervated by the obturator nerve?
Hip adductors
- Adductor magnus (also innervated by the sciatic nerve partially)
- Adductor longus
- Adductor breview
Knee flexor
- Gracilis
What are the muscles that are innervated by the superior gluteal nerve?
Hip abductors
- Tensor fascia latae
- Gluteus medius
- Gluteus minimus
What are the muscles that are innervated by the inferior gluteal nerve?
Gluteus maximus
(Hip extension, hip medial rotation)
What are the muscles that are innervated by the tibial branch of the sciatic nerve?
Hip extensors (Hamstrings)
- Biceps femoris
- Semimembranosus
- Semitendinosus
+ Adductor magnus
What are the muscles that are innervated by the tibial nerve?
Plantar flexors of the foot
- Gastronemius
- Soleus
- Plantaris
Unlocking the knee from the locked position
- Popliteus
Toe flexors
- Flexor hallucis longus
- Flexor digitorum longus
Foot inversion
- Tibialis posterior
What are the muscles that are innervated by the deep peroneal nerve?
Dorsiflexors of the foot
- Extensor hallucis longus
- Extensor digitorum longus
- Tibialis anterior
Foot eversion
- Peroneus tertius
What are the muscles that are innervated by the superficial peroneal nerve?
Foot eversion
- Peroneus longus
- Peroneus brevis
What injury will lead to damage of the sciatic nerve?
- Intervertebral disc herniation
- Spinal stenosis
- Spondylolisthesis
What injury will lead to damage of the femoral nerve?
Pelvic fracture
What injury will lead to damage of the obturator nerve?
Anterior dislocation of the hip
What injury will lead to damage of the superior gluteal nerve?
Posterior dislocation of the hip
What injury will lead to damage of the inferior gluteal nerve?
Posterior dislocation of the hip
What injury will lead to damage of the tibial nerve?
Any general knee injury
What injury will lead to damage of the common peroneal nerve?
Lateral knee injury/Fibular neck fracture
What injury will lead to damage of the deep peroneal nerve?
Usually injury to the common peroneal nerve due to lateral knee injury or fibular neck fractures
What is the mechanism of action of dantrolene?
Inhibitor of ryanodine receptors in sarcomeres >> prevents release of calcium from the SR of the skeletal muscle
What are the clinical indications for use of dantrolene?
- Malignant hyperthermia (usually when inhaled GAs are used with succinylcholine in those with a RYR1 gene mutation)
- Neuroleptic malignant syndrome
>> Delirium
>> Muscle rigidity/contractions leading to myoglobinuria
>> Hyperthermia
>> Autonomic instability
What are the common underlying causes of cotton wool spots on the retina upon fundoscopic examination?
- Hypertension
- Diabetes mellitus
- AIDS
What are the underlying causes of a cherry red spot on eye examination?
- Central retinal artery occlusion
- Tay-Sachs disease
- Niemann-Pick disease
What are the syndromes associated with lens subluxation?
- Marfan syndrome
- Homocysteinuria
What pathology does a white reflex upon eye examination suggest?
Retinoblastoma
Describe the flow of aqueous humour.
- Produced by the ciliary epithelium at the ciliary body
- Secreted into the posterior chamber
- Passes into the anterior chamber via the angle between the iris diaphragm and the lens
- Secreted into the anterior chamber
- Leaves/reabsorbed from the anterior chamber via the Canal of Schlemm
What is the underlying pathophysiology of acute angle/closed angle/narrow angle glaucoma?
Obliteration/narrowing of the space between the iris diaphragm and the lens >> aqueous humour cannot pass into the anterior chamber >> accumulates in the posterior chamber
What is the underlying pathophysiology of open angle glaucoma?
Unknown
- Decreased reabsorption at the Canal of Schlemm
- Over-production at the ciliary epithelium
What is the function of aqueous humour?
- Maintains intraocular pressure
- Provides nutrition to cornea and lens
What are the presenting features of open angle glaucoma?
- Early: asymptomatic
- Late: gradual loss of vision, starting with the peripheral visual field and moving towards the centre
What are the presenting features of acute angle glaucoma?
- Sudden onset of pain
- Visual changes: halos, rainbows around lights
- Mid-dilated pupil, not responsive to light
- Red teary eyes with hazy cornea
- Eyeball firm on palpation
>> An emergency!!! Can damage the optic nerve by increased IOP
What are the main drugs used for treatment of glaucoma?
Increased reabsorption of aqueous humour
- Prostaglandins
- Alpha-agonists
- Cholinergic agonists
Decreased production of aqueous humour
- Beta-blockers
- Alpha-agonists
- Acetazolamide (carbonic anhydrase inhibitor)
In acute angle glaucoma
- Mannitol
What are the risk factors for open angle glaucoma?
- Increasing age
- African American
- Positive family history
- Diabetes
What are the presenting features of cataract?
- Painless gradual loss of vision, starting with difficulty in driving at night, reading signs and small print
- Near-sightedness
- Disabling glares
What are the risk factors for cataract?
- Diabetes mellitus
- Long term use of steroids
- Trauma
- Infection
- Galactosemia
What are the eye problems associated wtih DM?
- Cataract
- Glaucoma
- Retinal detachment
- Neovascularization and proliferative diabetic retinopathy
What are the two different types of age-related macular degeneration?
Dry (nonexudative) macular degeneration
- Characterized by drusen: yellowish extracellular material deposits in and between the Bruch membrane of the choroid and the retina
- GRADUAL loss of vision
- Most common: 80% of all age-related macular degeneration
Wet (exudative) macular degeneration
- Due to bleeding from neovascularization
- RAPID loss of vision
- 20% of all age-related macular degeneration
What is the treatment for dry age-related macular degeneration?
- Cessation of smoking
- Multivitamin and antioxidant supplements
>> Beta-carotene
>> Vitamin C
>> Lutein
>> Selenium
>> Zinc
What is the treatment for wet age-related macular degeneration?
- Anti-VEGF injection
- Laser surgery
What is the typical presentation of retinal detachment?
Sudden onset of flashing lights, immediately followed by poor vision — PAINLESS!!!
Describe the auditory pathway.
- Tympanic membrane
- Middle ear ossicles: malleus, incus and stapes
- Auditory hair cells (outer and inner) of the cochlea
- Cochlear/Spiral ganglion
- Cochlear nuclei in the brainstem
- Superior olivary nucleus (decussation)
- Lateral meniscus
- Inferior colliculus (midbrain)
- Medial geniculate body (thalamus)
- Primary auditory cortex (temporal lobe)
What are the common bacteria that cause otitis externa?
- Pseudomonas aeruginosa
- Staphylococcus aureus
What are the common bacteria that cause acute otitis media?
- Streptococcus pneumoniae
- Non-typable Hemophilus influenzae
- Moraxella catarrhalis
What are the presenting features of otitis externa?
Pain at pulling of the pinna/manipulation of the ear
What are the presenting features of acute otitis media?
- Fever
- Earache
- Inspection of the tympanic membrane
>> Bulging
>> Erythematous
>> Air/fluid level, pus or opacity
>> Immotile upon positive pressure from the pneumatic otoscope – almost entirely diagnostic
What is the treatment for otitis externa?
- Irrigation
- Topical antibiotics
What is the treatment for acute otitis media?
- Antibiotics
>> Amoxicillin
>> Amoxicillin + clavulanic acid
>> Cephalosporins - Tympanostomy tubes (gromett)
What is a cholesteatoma?
Overgrowth of desquamated keratin debris within the middle ear space that made eventually erode the ossicular chain and mastoid air cells
What are the possible causes of cholesteatoma?
- Negative pressure on the tympanic membrane due to Eustachian tube dysfunction
- Epithelial growth through a perforated TM
What is seen upon examination of a cholesteatoma?
- Pearly grayish-white lesion behind or involving TM
- Conductive hearing loss
- Vertigo
What is the treatment of cholesteatoma?
- Tympanomastoidectomy
- Reconstruction of ossicular chain
What is the common treatment for Eustachian tube dysfunction?
Intranasal steroids
>> Most are due to allergic rhinitis
What are the presenting features of Meniere disease?
Presentation triad
- Tinnitus
- Hearing loss
- Intermittent vertigo
What are the possible causes of vertigo?
- BPPV (Benign paroxysmal positional vertigo)
- Vestibular neuritis
- Meniere disease
- Central vertigo: brainstem/cerebellar lesions
What is the underlying pathophysiology of Meniere disease?
Imbalances of fluids and electrolytes of the endolymph
What is the underlying pathophysiology of BPPV (Benign Paroxysmal Positional Vertigo)?
Debris or misplaced otoliths in the vestibular apparatus
How does one diagnose BPPV?
Dix-Hallpike Test
How does one treat BPPV?
Epley maneuver
What is the cutaneous innervation of the peroneal nerves?
- Superficial peroneal nerve: majority of the dorsum of the foot
- Deep peroneal nerve: only between the first and second digitis of the foot
Name the neuronal pigment/inclusion.
Intranuclear inclusions seen in herpes simplex encephalitis
Cowdry type A bodies
Name the neuronal pigment/inclusion.
Cytoplasmic inclusions pathognomonic of rabies
Negri bodies
Name the neuronal pigment/inclusion.
Neuronal inclusions characteristic of Parkinson disease
Lewy bodies
Name the neuronal pigment/inclusion.
Cytoplasmic inclusion bodies associated with aging
Lipofuscin granules
Name the neuronal pigment/inclusion.
Dark cytoplasmic pigment in neurons of the substantia nigra and locus coeruleus, not seen in patients with Parkinson
Melanin
Name the neuronal pigment/inclusion.
Eosinophilic, rod-like inclusion in hippocampus of Alzheimer patients
Hirano bodies
Name the neuronal pigment/inclusion.
Diagnostic of Alzheimer disease
Neurofibrillary tangles
Name the neuronal pigment/inclusion.
Filamentous inclusions that stain with silver, do not survive neuronal death
Pick bodies
Name the neuronal pigment/inclusion.
Filamentous inclusions that stain with PAS and ubiquitin
Lewy bodies
Name the neuronal pigment/inclusion.
Extracellular amyloid deposits in the grey matter
Senile plaques of A-beta amyloid
Name the neuronal pigment/inclusion.
Intracellular spherical aggregates of tau protein seen on silver stain
Pick bodies
Name the neuronal pigment/inclusion.
Intracellular deposits of hyperphosphorylated tau protein
Neurofibrillary tangles of tau protein
What genes are associated with early-onset Alzheimer’s disease?
- APP gene on chromosome 21
- Presenilin-1 gene on chromosome 14
- Presenilin-2 gene on chromosome 1
What genes are associated with late-onset Alzheimer’s disease?
ApoE4 in chromosome 19
What gene is protective against Alzheimer’s disease?
ApoE2 on chromosome 19
What investigations/tests are performed for diagnosis of the cause of dementia?
- Mini-mental status examination – to confirm cognitive decline
- Rule out organic causes/other causes
>> RPR — neurosyphilis
>> HIV testing
>> TSH — hypothyroidism
>> Vitamin B12 levels
>> MRI brain — normal pressure hydrocephalus,
>> +/- serum copper/ceruloplasmin — Wilson disease
Name the major differential diagnoses for dementia.
- Alzheimer’s disease
- Vascular dementia
- Parkinson’s disease
- Lewy body dementia
- Pick disease/frontotemporal dementia
- Creutzfeldt-Jakob disease
- Neurosyphilis
- HIV
- Hypothyroidism
- Vitamin B12 deficiency
- Depression – pseudodementia
Name the cause of dementia.
- Dementia
- Parkinsonism features
- Visual hallucinations
- Recurrent syncopal episodes
Lewy body dementia
Name the cause of dementia.
- Dementia
- Aphasia
- Changes in personality
Frontotemporal dementia/Pick disease
Name the cause of dementia.
- Abrupt onset
- Myoclonus
- Spongiform cortex
- Beta-pleated sheets
Creutzfeldt-Jakob disease
Name the cause of dementia.
- Resting tremor
- Bradykinesia
- Postural instability
- Cogwheel rigidity
Parkinson’s disease
Name the cause of dementia.
- Urinary incontinence
- Magnetic gait
Normal pressure hydrocephalus
>> Reversible dementia
Name the cause of dementia.
- Dysarthria
- Liver disease
Wilson disease
Name the cause of dementia.
- Dementia
- Ataxia
- Loss of pupillary light reflex
Neurosyphilis
Name the cause of dementia.
- Dementia
- Megaloblastic anemia
- Peripheral neuropathy
Vitamin B12 deficiency
What are the questions to ask for a seemingly disoriented patient?
- Person: Who are you? What’s your name?
- Place: Where are you now? Which city are you in now?
- Time: What time is it now? What year is it now?
What are the common causes of delirium?
- Drugs
- Benzodiazepines
- Drugs with anticholinergic effects
>> Antimuscarinic agents: atropine etc.
>> First generation H1R blockers: diphenhydramine, chlorpheniramine
>> Neuroleptics: thioridazine, chlorpromazine, olanzapine, clozapine
>> Tricyclic antidepressants
>> Amantadine
- Urinary tract infections
What two arteries does the oculomotor nerve run through after exiting from the midbrain?
Posterior cerebral artery and superior cerebellar artery
What is the mechanism of action of opioids?
Agonists at opioid receptors
- G-protein-linked receptors
- Open K+ channels
- Close Ca++ channels
- Inhibit adenylate cyclase
- Inhibit transmitter release: acetylcholine, 5-HT, epinephrine, glutamate and substance P
>> Mu = Morphine
>> Kappa = Dynorphin
>> Delta =
Which opioid is used for cough suppression?
Dextromethorphan
Which opioid is used for diarrhea treatment?
- Loperamide
- Diphenoxylate
What is the most commonly injured nerve in the leg?
Common fibular nerve/Common peroneal nerve
- Courses laterally around the neck of fibula
- The location makes the nerve susceptible to trauma resulting from lateral blows to the knee as well as from tightly applied plaster casts and other devices.
