Neuro2 Flashcards
Cranial nerves and ophthalmology
What are the common pathologies which can affect a cranial nerve?
Diabetes mellitus MS Tumours Sarcoid Vasculitis SLE Syphilis
What should you look for on general inspection when performing a cranial nerve exam?
Dysarthria Asymmetry Ptosis Horner's/Bell's Glasses Hearing aids Eye patch Walking stick
What is the medical term for a loss of sense of smell?
Anosmia
What can cause anosmia?
Ageing Traumatic brain injury Parkinson's Alzheimer's Tumour
What should you assess for in the optic nerve?
Acuity Fields Reflexes Ophthalmoscope Colour
How should you assess the Pt’s acuity?
Using a Snellen Chart from 6m away
What are the causes of a loss of acuity?
Refractive error Ocular media -cataracts -diabetes Retina -age related macular degeneration -diabetic retiniopathy Optic neuropathy -MS -ischaemia
What is conjunctivitis?
Inflammation of the conjunctiva
What are the symptoms of conjunctivitis?
Conjunctival hyperaemia Chemosis (conjunctival swelling) Crust/discharge Foreign body sensation Photophobia
What are the causes of conjunctivitis?
Bacterial
Viral
Allergic
How can you typically differentiate a bacterial conjunctivitis from viral conjunctivitis?
B- unilateral, thick discharge, reduced vision, ?urethritis/vaginal discharge
V- bilateral, watery discharge, normal vision, signs of viral infx
What is allergic conjunctivitis?
Type 1 hypersensitivity reaction
What are the common triggers of allergic conjunctivitis?
Pollen, dust, chemical scents
What are the clinical features of allergic conjunctivitis?
Conjunctivitis
Itching
Sneezing
Red, watery, oedematous eye
What are cataracts?
Clouding of the lens of the eye
What are the clinical features of cataracts?
Visual impairment
Glare/halos around light
Painless
Reduced red reflex
What are the risk factors for cataracts?
Old age
Congenital
Diabetes
Steroids
What is glaucoma?
Vision loss from optic nerve damage due to raised intraocular pressure
2nd leading cause of blindness
In an acute red painful eye, you need to rule out closed-angle glaucoma
What is affected in open-angle glaucoma?
Dysfunction of trabecular meshwork
What is affected in closed-angle glaucoma?
Compression of trabecular meshwork
What are the differences between open-angle and closed-angle glaucoma?
OA- 90%, bilateral, progressive vision loss, initially asymptomatic, non specific symptoms
CA- 10%, unilateral, sudden onset, severe pain, N+V, cloudy cornea, headache, dilated pupil
What are the investigations for glaucoma?
Fundoscopy
Gonioscope
Slit lamp
Tonometry
What is the uvea made up of?
Choroid
Ciliary body
Iris
What is uveitis?
Inflammation of the uvea
Can be anterior, posterior, complete, and intermediate
What are the causes of uveitis?
Systemic inflammation
Infection
What is affected in anterior uveitis?
Iris
Ciliary body
Most common
What is affected in posterior uveitis?
Vitreous body
Choroid
Retina
What are the investigations for uveitis?
Fundoscopy
slit lamp examination
What visual defect will present in a chiasmal lesion?
Bitemporal hemianopia
What visual defect will present in a pre-chiasmal lesion?
Ipsilateral monocular loss
What are the causes of a pre-chiasmal lesion?
Ischaemia- TIA (amaurosis fugax)
Inflammation- MS
What are the causes of a chiasmal lesion?
Pituitary adenoma
Chraniopharyngioma
A lesion in which part of the optic pathway can cause a contralateral homonymous hemianopia?
Optic tract lesion
A lesion in which part of the optic pathway can cause a contralateral homonymous superior quadrantanopia?
Lateral optic radiation lesion
A lesion in which part of the optic pathway can cause a contralateral homonymous inferior quadrantanopia?
Medial optic radiation lesion
A lesion in which part of the optic pathway can cause a macular sparing contralateral homonymous hemianopia?
Occipital visual cortex lesion
What is the cause of visual neglect?
Damage to the contralateral parietal lobe
What are some causes of Marcus Gunn pupil (RAPD)?
Optic neuritis
Retrobulbar optic neuritis
What is anisocoria?
Unequal size of the pupils
What does Horner’s syndrome consist of?
Ptosis
Miosis
Anhydrosis
What are some causes of Horner’s syndrome?
Loss of sympathetic innervation due to either: Carotid artery dissection Pancoast tumour SOL/stroke MS Cavernous sinus thrombosis
What is the sympathetic pathway that supplies the eye?
Hypothalamus T1 Superior cervical ganglion Carotid artery Cavernous sinus Target sites (dilator pupillae, lacrimal gland)
What are the investigations for Horner’s syndrome?
CXR (Pancoast)
CT Head (stroke)
MRI/MRA (tumour/dissection)
Refer
What signs may you see on fundoscopy?
Diabetic retinopathy
Hypertensive retinopathy
Papilloedemea
How will a Pt with a CN3 palsy present?
Ipsilateral pupil looking down and out
Ipsilateral ptosis
Mydriasis (as pSymp fibres run with CN3)
Why doesn’t every patient with a CN3 palsy present with both mydriasis and ophthalmoplegia?
The parasympathetic fibres run outside the nerve, whereas the oculomotor fibres run on the inside. Usually only one is affected, causing mydriasis (surgical palsy) or ophthalmoplegia (medical palsy)
What are the causes of a medical CN3 palsy?
DM
Vasculitis
What are the causes of a surgical CN3 palsy?
Raised ICP
Aneurysm rupture
How may a Pt with a CN4 palsy present?
Ipsilateral pupil looking up and in
Tilted head to contralateral side
What are the commonest causes of a CN4 palsy?
Idiopathic
Head trauma
Diabetes
How may a Pt with a CN6 palsy present?
Failure to abduct ipsilateral eye
What are the causes of a CN6 palsy?
Stroke Trauma Viral illness SOL Inflammation
How does a Pt with internuclear ophthalmolegia present?
Ipsilateral eye has an inability to adduct, and contralateral eye elicits horizontal nystagmus upon abduction
What are the causes of internuclear ophthalmoplegia?
If young and bilateral, MS
If old and unilateral, stroke
What are the pathways for the corneal reflex?
V1 -> VII
What are the pathways for the jaw jerk reflex?
V3 -> V
Which part of the trigeminal nerves would be affected if there was a higher central lesion?
Contralateral nerves
What are the causes of a higher central trigeminal lesion?
Stroke
Which part of the trigeminal nerves would be affected if there was a brainstem lesion?
Ipsilateral nerves
What are the causes of a brainstem trigeminal lesion?
Stroke
Raised ICP
Which part of the trigeminal nerves would be affected if there was a peripheral lesion?
Branch distribution
What are the causes of a peripheral trigeminal lesion?
Raised ICP
Trauma
What are the branches of the facial nerve?
Two Zebras Bit My (Massive) Cock
Temporal Zygomatic Buccal Marginal mandibular Cervical
What is Bell’s palsy?
Facial paralysis of the ipsilateral side
What are the causes of Bell’s palsy?
Idiopathic
Compression of the facial nerve
Inflammation (eg. viral)
-herpes simplex type 1, varicella zoster
What are the risk factors for Bell’s palsy?
Diabetes
What are the investigations for Bell’s palsy?
Serology
-Lyme, herpes, zoster
What is the management for Bell’s palsy?
Prevent corneal abrasions- wear an eye patch
Steroids- prednisolone
What is Ramsay Hunt syndrome?
LMN facial palsy due to varicella zoster
What are the features of Ramsay Hunt syndrome?
Pain
Vesicles in ipsilateral ear, hard palate, anterior tongue
Deafness/vertigo/other CN features
If the forehead is spared in a CN7 pathology, where is the lesion?
UMN lesion
What is Weber’s test assessing for?
Sensorineural and conductive hearing loss
What is Rinne’s test assessing for?
Conductive hearing loss
What is a Rinne’s positive sign?
Air is louder than bony conduction
What is the diagnosis:
Weber’s: lateralises to the left
Rinne’s L: negative
Rinne’s R: positive
Left conductive hearing loss
What is the diagnosis:
Weber’s: lateralises to the right
Rinne’s L: negative
Rinne’s R: positive
Mixed hearing loss
What is the diagnosis:
Weber’s: lateralises to the left
Rinne’s L: positive
Rinne’s R: positive
Right sensorineural hearing loss
What is the diagnosis:
Weber’s: no lateralisation
Rinne’s L: positive
Rinne’s R: positive
No abnormality
What are the causes of conductive hearing loss?
EAM: -wax -foreign body -otitis externa Drum: -perforation Middle ear: -acute/serous otitis media Oval window: -otosclerosis
What are the causes of sensorineural hearing loss?
Inflammation: -meningitis -MMR Tumour: -acoustic neuroma (neurofibromatosis T2) Ototoxic drugs: -aminoglycoside ABx -aspirin overdose -loop diuretics Trauma Meniere's disease
What are the inheritance patterns for neurofibromatosis type 1 and 2?
Autosomal dominant
What is the gene and chromosome affected in NF1?
NF1 Chr 17 (neurofibromatosis: 17 letters)
What is the gene and chromosome affected in NF2?
NF2
Chr 22
What is the presentation of NF1?
Cafe-au-lait spots Freckling in skin folds Neurofibromas Lisch nodules spinal scoliosis Short stature Mild intellectual disability
What is the presentation of NF2?
Sensorineural hearing loss
Bilateral acoustic neuromas
Symptomatic at the age of 20
Possible tinnitus/vertigo
What can you do/look at to assess CN IX and X?
Soft palate and uvula Gag reflex Cough Swallow Assess speech quality and hoarseness
What two muscles are supplied by CN XI?
Sternocleidomastoid
Trapezius
What are you looking for when assessing CN XII?
Wasting
Fasciculations
Deviation of the tongue
Power of the tongue
What is a bulbar palsy?
Lesion affecting the medulla oblongata and its associated cranial nerves IX-XII
What are the clinical features of a bulbar palsy?
Absent gag reflex Wasting/fasciculation of the tongue Absent palatal movement Absent/normal jaw jerk Nasal speech Normal emotions Signs of underlying cause eg. limb fasciculations
(UMN signs)
What is a pseudobulbar palsy?
Lesion affecting the UMN supplying the medulla oblongata
What are the clinical features of a pseudobulbar palsy?
Increased/normal gag reflex Spastic tongue Absent palatal movement Increased jaw jerk Monotonous, slurred, high-pitched Donald Duck dysarthria Labile emotions Bilateral UMN limb signs
(LMN signs)
What are some causes of a bulbar palsy?
MND
Guillain-Barre
What are some causes of a pseudobulbar palsy?
Stroke
MND
MS
A 24 year old woman presents to her GP with a red painful eye with blurry vision. She has noticed a lot of clear discharge coming from her eye. She has otherwise been well, apart from some recent diarrhoea. What is the most likely diagnosis?
A. Viral conjunctivitis B. Bacterial conjunctivitis C. Anterior uveitis D. Posterior uveitis E. Closed angle glaucoma
C. Anterior uveitis
Firstly, because this is not an acute presentation (she’s presented to her GP), we can rule out closed angle glaucoma.
Posterior uveitis and viral conjunctivitis are usually painless making them unlikely.
Although bacterial conjunctivitis is painful, it normally gives thick muculopurent discharge.
The clear discharge is most likely to be increased lacrimation, which is in keeping with anterior uveitis.
A 50 year old patient presents to A&E with diplopia. The doctor examines their cranial nerves and finds a palsy in the oculomotor nerve. Peripheral nerve exam demonstrated a length dependent sensory neuropathy. What did the doctor most likely see during the cranial nerve examination:
A. Internuclear ophthalmoplegia B. Anhidrosis, miosis and ptosis C. Down and out pupil D. Mydriasis E. Down and out pupil with mydriasis
C. Down and out pupil
The palsy is why the patient has diplopia. The length dependent sensory neuropathy is indicative of diabetes, and if the peripheral sensory nerves are affected then a cranial nerve may be affected.
DM can cause a medical palsy, so the oculomotor nerve is affected first before the sympathetic, therefore will see down and out pupil. Wont see mydriasis yet until parasympathetic is affected, ruling out D and E.
A is not associated with DM, and B is describing Horner’s.
A 28 year old lady presents to A&E thinking she is having a stroke, worried as she cannot move the right side of her face. On examination, the patient cannot smile, puff up her cheeks or wrinkle her forehead on the right side. Serology comes back positive for herpes simplex virus 1. What is the most likely diagnosis?
A. Stroke B. Bell’s Palsy C. MS D. Ramsay Hunt syndrome E. Horner’s
B. Bell’s Palsy
As the patient is young a stroke is very unlikely, given she cannot wrinkle her forehead. This also makes MS unlikely.
MS also unlikely as there is an infective cause, but not Ramsay Hunt since this would normally be varicella zoster, not HSV1.
A 20 year old lady sees her GP after having some hearing difficulties in the last week. On examination, Weber’s test lateralises to her left ear. Rinne’s test is negative in her left ear also, but positive in the right ear. She reported having a cold at the start of the month. Which of these is most likely?
A. Meningitis B. Otitis media C. Foreign body D. Meniere's disease E. Neurofibromatosis type 2
B. Otitis media
As Rinne’s test is negative in the left ear we know it is a conductive problem in left ear, further supported by fact Weber’s lateralises to the left as well. This rules out meningitis and NF2 as they are a sensorineural problem, as is Meniere’s – Meniere’s is triad of sensorineural hearing loss, vertigo and tinnitus.
the fact they had a cold earlier points more towards B as this is an inner ear infection.
A 60 year old man presents to his GP with dysphagia. The GP notices he speaks with a nasally voice. Examination demonstrates a reduced gag reflex, as well as fasciculations and wasting of the tongue. Jaw jerk is normal. Which of these is the most likely cause of their dysphagia?
A. Stroke B. Parkinson’s C. Motor neuron disease D. MS E. Achalasia
C. Motor neuron disease
With this question the patient is old, making MS and achalasia unlikely – this is further supported by the LMN signs.
Stroke and Parkinson’s would give UMN signs, although both can cause dysphagia. The jaw jerk is normal suggesting that CNV is not affected, as is the case with a bulbar palsy.
A 66 year old woman presents with left sided upper and lower facial weakness as well as vertigo, which has worsened over the past few days. She is also suffering from a burning sensation over the left side of her face . This morning, she noticed a new rash in her left ear. On examination, clusters of vesicles on an erythematous base are noted in the patient’s left ear.
A. Bells Palsy
B. Ramsay Hunt syndrome
C. NF T2
D. Stroke
B. Ramsay Hunt syndrome
