Cranial Nerve Vivas Flashcards
Features of Horners syndrome
Miosis (small pupil)
Ptosis
Anhidrosis (loss of sweating one side)
What is seen in congenital Horners?
Heterochromia: difference in iris colour
What characterises Horners caused by central lesions? List 5 causes
Anhidrosis of FACE, ARM + TRUNK
Stroke
Syringomyelia
MS
Tumour
Encephalitis
What characterises Horners caused by pre-ganglionic lesions? List 4 causes
Anhidrosis of FACE
Pancoast’s tumour
Thyroidectomy
Trauma
Cervical rib
What characterises Horners caused by post-ganglionic lesions? List 4 causes
NO anhidrosis
Carotid artery dissection
Carotid aneurysm
Cavernous sinus thrombosis
Cluster headache
Ix for Horners syndrome
CT head: ?CVA
CT angiography: ? Carotid artery dissection
CXR: ? Pancoast tumour
Third nerve palsy
Eye deviated down + out
Ptosis
Surgical third nerve palsy
Eye deviated down + out
Ptosis
Mydriasis
Medical causes of third nerve palsy
DM
GCA
SLE
MS
Surgical causes of third nerve palsy
Posterior communicating artery aneurysm
Cavernous sinus thrombosis
Tumour
What causes mydriasis in surgical CNIII palsy?
Compression of external parasympathetic fibres
What is strabismus?
misalignment of the visual axes, eyes do not properly align with each other when looking at an object
Most common cause of CN IV palsy
Trauma
UMN facial nerve palsy
Stroke
LMN facial nerve palsy
Bells palsy
What is Bells palsy?
Acute, unilateral, idiopathic, facial nerve paralysis
Peaks at 20-40y
Other than unilateral facial paralysis, list 4 S/S of Bells palsy
Post-auricular pain (may precede paralysis)
Altered taste
Dry eyes
Hyperacusis
Mx of Bells palsy
<72h: Prednisolone PO
Artificial tears
Eye lubricants
Microporous tape for sleep
Describe follow up in Bells palsy
If no improvement after 3w, refer urgently to ENT
If long standing (months) weakness: refer to plastics
2 causes of bilateral ptosis
Myasthenia gravis
Myotonic dystrophy
Describe Argyll Robertson Pupils (ARP)
Accommodation Reflex Present (ARP) but Pupillary Reflex Absent (PRA)
Small, irregular pupils
No response to light but there is a response to accommodate
Name 2 causes of Argyll Robertson Pupils
DM
Syphilis
What is Myasthenia Gravis?
AI disorder characterised by muscle fatiguability
Abs to ACh receptors
S/S of myasthenia gravis
Extraocular muscle weakness: diplopia
Proximal muscle weakness: face, neck, limb girdle
Ptosis
Dysphagia
3 associations to myasthenia gravis
Thymoma (CT thorax)
AI disorders: Thyroid, RhA, SLE
Thymic hyperplasia
Ix for myasthenia gravis
SINGLE FIBRE EMG
CT thorax
CK normal
Abs to ACh receptors
Mx of myasthenia gravis
Pyridostigmine
Later: Prednisolone/ Azathioprine/ MM
Thymectomy
Mx of myasthenic crisis
Plasmapheresis
IVIG
4 drugs that exacerbate myasthenia gravis
B-blockers
Lithium
Phenytoin
Abx: Gentamicin, Macrolides
Tool to measure resp function in GBS and MG
FVC
5 causes of sudden visual loss
CRAO
Retinal detachment
Vitreous haemorrhage
GCA
Optic neuritis
4 causes of gradual visual loss
Diabetic retinopathy
Cataract
Glaucoma (open angle)
Dry age-related macular degeneration (AMD)
