Cranial nerves + ophthalmology Flashcards
Name the cranial nerves and which ones are sensory and/or motor
I - olfactory (S) II - optic (S) III - oculomotor (M) IV - trochlear (M) V - trigeminal (S+M) VI - abducens (M) VII - facial (S+M) VIII - vestibulocochlear (S) IX - glossopharangeal (S+M) X - vagus (S+M) XI - accessory (M) XII - hypoglossal (M)
Potential ddx for cranial nerve palsy overall
Diabetes mellitus MS Tumours Sarcoid Vasculitis (temporal => blindness) SLE Syphilis
Anosmia ddx
Ageing (men>women)
Traumatic brain injury (cribiform plate damaged)
Tumour
Alzheimer’s
Parkinson’s (almost prodromal, first sx before motor start)
Kallman’s syndrome (RARE)
Acuity ddx
Optic neuropathy (ischaemia for old pts, MS for young pts)
Retina (age related macular degeneration, diabetic neuropathy)
Ocular media (cataracts, diabetes)
Refractive error
Compare bacterial and viral conjunctivitis
Bacterial
- unilateral
- thick discharge, ‘sticky eyes’
- reduced vision
- ?urethritis/vaginal discharge
Viral
- bilateral
- watery discharge
- normal vision
- signs of viral infection (fever, lymphadenopathy)
How may allergic conjunctivitis present?
‘Seasonal’ itchy, red, watery and oedematous eyes
Sneezing
Type I hypersensitivity (IgE)
How may cataracts present?
Older patient with painless visual impairment
O/E reduced red reflex and clouding of lens (halos around eyes)
Compare anterior and posterior uveitis
Anterior (iris + ciliary body)
- painful, ocular, hyperaemia (pink eye)
- blurry vision
- increased lacrimation and photophobia
- autoimmune conditions (RA, sarcoidosis, IBD, Bechet’s, SLE, seronegative spondyloarthropathies)
Posterior (vitreous body, choroid + retina)
- painless
- blurry vision w/ floaters and scotoma
- infective cause (Lyme disease, syphilis, TB, EBC, CMV, HSC, VZV)
Compare open and closed angle glaucomas
Open angle glaucoma (90% cases)
- bilateral
- initially asymptomatic then progressive vision loss
- mild, non-specific sx
- Closed angle glaucoma (10% cases)
- unilateral
- sudden onset, severely painful
- N&V, cloudy corners, headache, dilated pupils
- MUST rule out for any acute, red eye, glaucoma 2nd cause of blindness
- *Glaucoma = vision loss from CNII damage due to increased intraocular pressure
State the visual field disturbance and possible cause based on the sight of the lesion:
a) prechiasmal
b) chiasmal
c) post chiasmal
a) prechiasmal
- one eye only, ipsilateral side to lesion
- ischaemia (TIA), inflammation (MS)
b) chiasmal
- bitemporal hemianopia
- pituitary tumour, craniopharyngioma
c) post chiasmal
- homonymous, contralateral side to lesion
- ischaemia (stroke)
Which lobe is affected in a:
a) superior homonymous quadrantanopia,
b) inferior homonymous quadrantanopia?
a) Superior vision lost => temporal lobe
b) Inferior vision lost => parietal lobe
Both combine at occipital lobe so if occipital lobe affected, both lost
What type of visual loss would occur if the following had lesions?
a) optic nerve
b) optic chiasm
c) optic tract
d) optic radiation
a) ipsilateral monocular vision loss
b) bitemporal hemianopia
c) contralateral homonymous hemianopia
d) contralateral homonymous quadrantanopia
What is neglect syndrome?
Damage to right parietal love
Only do things on the right side of the body, ignores the left
Problem of attention, not blindness
What is tested in the swinging torch test?
RAPD (relative afferent pupillary defect)
- eye starts to constrict less between unaffected and affected eye, making it look like eye is dilating in affected eye
- seen in optic neuritis (this can occur in MS, will improve)
What causes pupil constriction and dilation?
Constriction due to parasympathetic
Dilation due to sympathetic
Patient presents with ptosis, miosis and anhydrosis, what do they have and what are three potential ddx?
Horner’s syndrome (constricted pupil, droopy eyelid, absence of sweating)
1) carotid artery dissection: blood in artery expanding and compressing nerve
2) pancoast tumour: sympathetic nerve pressed on at vertebrae at apex of lung
3) brainstem stroke/tumour: hypothalamus ischaemia/compression
Ix and mx of Horner’s syndrome
Ix = CXR, CT head, MRI/MR angiography Mx = referral asap
CNIII palsy / CNIV palsy / CNVI palsy
III:
Down and out
Ptosis
IV:
Up and in
Head trauma/microvasculopathy (DM, atherosclerosis, HTN)
VI:
Affected eye fails to abduct when looking laterally
Stroke, trauma, viral illness, tumour
Long course from brainstem so check for associated neuro sx depending on where lesion located
Compare surgical and medical CNIII palsy
Surgical: - compressing from outside - pupil dilation - raised ICP Medical: - blood supply problems within - no pupil dilation - diabetes mellitus
What is and does internuclear opthalmoplegia indicate?
Lesion in tract connecting CN3 and CN6
Occurs in stroke (unilateral, old) or MS (bilateral, young)
O/E pt looks to one side and fine, looks to the other side and affected eye fails to adduct so stops while the other eye looks to side but has nystagmus
How may a CNV palsy look O/E?
Absent sensation in sensory distribution
Absent corneal reflex
Weakness/wasting of muscles of mastication
What are possible causes of CNV palsy?
Higher central - MCA stroke (most common cause for deficient in face sensation) - contralateral side affected Brainstem - raised ICP, stroke Peripheral - trauma, raised ICP - lesion beyond trigeminal ganglion
What are the branches of the facial nerve?
Temporal Zygomatic Buccal Marginal mandibular Cervical
Bell’s palsy summary card
One side of face paralysed
- idiopathic, compression of facial nerve, viral infection, herpes simplex virus, varicellar zoster
- serology to check for virus
- prednisolone (speed up recovery), close eye at bedtime, wear sunglasses (prevent corneal abrasions)
Ramsay Hunt syndrome summary card
Type of Bell’s palsy more prominent due to varicella zoster
- ‘shingles in the cranial nerve’
- pain
- vesicles in ipsilateral ear, hard palate or 2/3 of anterior tongue
- includes deafness and vertigo
How do you differentiate between a LMN and UMN lesion of CNVII?
LMN = forehead affected so only one side crinkles UMN = forehead unaffected so both sides crinkle
CNVII has double innervation from each hemisphere for the foreheard so if one supply is knocked out, the other side still covers it, meaning a more local lesion will only affect one side but a central lesion will mean the forehead is spared
How do you test CNVIII?
Weber’s
- louder in good ear if sensorineural
- louder in affected ear if conductive
Rinne’s
- AC > BC +ve result => if Weber’s lateralised, suggests sensorinueral in other ear
- BC > AC -ve result => conductive hearing loss if not amplifying sound in air
Causes of conductive ear disease
Oval window - otesclerosis Middle ear - serous otitis media - acute otitis media Drum - perforation; infection/trauma External auditory canal - wax - foreign body - otitis externa
Causes of sensorineural ear disease
Meniere's disease Trauma Ototoxic drugs - loop diuretics (furosemide) - aspirin overdose - aminoglycosides (gentamycin) Tumour - acoustic neuroma (assoc. w/ neurofibromatosis type II)
Patient presents with diffifulty hearing and the room spinning when they get up from bed and tinnitus.
O/E Weber’s lateralises to left ear and +ve Rinne’s test.
Diagnosis?
Meniere’s disease
- typically occurs to young/middle-aged pts
Triad of sx
- sensorineural hearing loss
- vertigo
- tinnitus
Compare the types of neurofibromatosis
Type 1
- associated with ONE whole body problems
- AD, NF1, chr 17
- short stature, mild intellectual disability
- cafe au-lait spots
- spinal sclerosis, neurofibromes, Lisch nodules (eyes)
Type 2
- associated with TWO ear problems
- AD, NF2, chr 22
- sensorineural hearing loss, symptomatic by 20yo
- bilateral acoustic neuromas
- tinnitus/vertigo possible
Compare pseudobulbar and bulbar palsy
Pseudobulbar (corticobulbar supply)
- UMN
- V, VII, X, XI, XII affected
- spasticity, hyperreflexia
- ‘Donald Duck’ speech
- stroke of internal capsule, MS, motor neurone disease
Bulbar (medulla oblongata)
- LMN
- X, XI, XII affected
- fasiculations, wasting, hyporeflexia
- nasal speech
- motor neurone disease, Guillain-Barre syndrome
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
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
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
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
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
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. Neurofibromatosis Type 2
D. Stroke
B. Ramsay Hunt Syndrome
