Station 3: Neurology Flashcards
General inspection findings of isolated ulnar nerve neuropathy?
- wasting of the dorsal interossei “guttering” of the hands, and hypothenar eminence
- ulnar claw: flexion of the interphalangeal joints of the 4th and 5th digits
- sparing of the thenar eminence
cause: look for scars around the wrist or near the elbow
if suspecting ulnar neuropathy, what other important negatives?
rule out medial/ nerve palsies or C8/T1 nerve root problem
Power findings in ulnar neuropathy?
weak
- finger abduction (dorsal interossei)
- Froment’s sign positive (weakness of adduction of the thumb, adductor policis)
test finger flexion of the 5th finger for flexor digitorum profundus involvement (more proximal lesions may result in weakness of IP joint flexion)
test for wrist flexion at ulnar side (flexor carpi ulnaris)
ulnar paradox?
the higher the level of injury to ulnar nerve, the less obvious the “clawing”
if ulnar nerve injured more proximally, the ulnar half of the flexor digitorum profundus muscle may be affected. As a result, flexion of the IP joints of the 4th and 5th fingers is weakened, which reduces the claw-like appearance of the hand.
sensory testing in ulnar neuropathy?
medial 1.5 fingers affected
what is the anatomical course of the ulnar nerve?
begins from the medial cord of the brachial plexus (C8, T1)
enters the forearm via the cubital tunnel (medial epicondyle and olecranon proocess) and motor supply to the flexor carpi ulnaris and ulna half of the flexor digitorum profundus
gives off a sensory branch just above the wrist
and enters the Guyon’s canal and supplies the sensory medial 1.5 fingers and hypothenar as well as motor to all intrinsic muscles of the hands except LOAF (lateral two lumbricals, opponens pollicis, abductor pollicis brevis, flexor pollicis brevis)
what does ulnar nerve supply in terms of motor function?
motor to all muscles of the hands except the LOAF:
- lateral two lumbricals.
- opponens pollicis.
- abductor pollicis brevis.
- flexor pollicis brevis
forearm: flexor carpi ulnaris (wrist flexion and adduction) and flexor digitorum profundus to 4th/5th fingers
level of ulnar lesions and its clinical correlation?
wrist- hypothenar eminence wasting, froment’s positive, weakness of finger abduction, pronounced claw and loss of sensation
elbow- less pronounced claw, loss of terminal flexion of the DIPJ and loss of flexor carpi ulnaris tenon on the ulnar flexion of the wrist
how do you differentiate ulnar nerve palsy vs T1 lesion?
motor- wasting of the thenar eminence will be seen for T1
sensory- loss of T1 dermatomal distribution
what is the ulna claw hand?
- hyperextension of the 4th and 5th MCPJ associated with flexion of the IPJs of the 4th and 5th fingers
due to the unopposed long extensors of the 4th/5th fingers in contrast to the IF and MF
what is froments sign?
asked to grasp piece of paper between thumbs and the lateral aspect of the index finger
affected thumb will flex as the adductor policis muscles are weak
-> pt trying to compensate by using the flexor pollicis longus supplied by the median nerve
causes of ulnar nerve palsy?
- compression or entrapment (Cubital tunnel at elbow; Guyon’s canal at the wrist)
- trauma (fractures or dislocation- cubitus valgus leads to tardive ulnar nerve palsy)
- surgical
- mononeuritis multiplex
- infection: leprosy (thickened nerves, hypopigmented hypoaesthetic patches)
- ischaemia- vasculitis
- inflammatory -CIDP
ix of ulnar nerve palsy?
- blood ix to rule out DM if no obvious cause
- Xrays of the elbow and wrist KIV C spine
- EMG (axonal degeneration for chronic)
- Nerve conduction studies: can help to locate level and monitor
mx of ulnar nerve palsy?
education and avoidance of resting on elbow
PTOT
Medical: NSAIDs
Surgical decompression with anterior transposition of the nerve
causes of sensory predominant peripheral neuropathy?
DM
Alcohol
Metabolic: B1, B6, B12 deficiency
CKD
Infective: Leprosy
causes of motor predominant peripheral neuropathy?
inflammatory: GBS, amyloid, sarcoid, hiv
drugs: lead poisoning, dapsone, organophosphate
metabolic: DM, porphyria
Congenital: charcot-marie-tooth (HSMN type 1)
PAN
causes of mononeuritis multiplex? (ie involvement of 2 or more peripheral or cranial nerves by the same disease)
Endocrine: DM, Acromegaly
Infiltrative: Amyloidosis, Sarcoidosis
Autoimmune: RA/SLE, PAN, Sjogren, GPA, eGPA
Neoplastic: Carinomatosis
Infection: Leprosy, Lyme, HIV
causes of thickened nerves?
CIDP
Charcot-Marie Tooth Disease (HMSN)
Acromegaly
Amyloidosis
Others:
Sarcoidosis
Leprosy
Neurofibromatosis
Refsum Disease (Retinitis pigmentosa, optic atrophy, cerebellar and deafness, cardiomyopathy and ichthyosis)
Dejerene-Sottas disease (hypertrophic peripheral neuropathy)
Causes of sensorimotor peripheral neuropathy?
- DM
- Alcohol
- Endocrine: Hypothyroidism
- Uraemia (CKD)
- Sarcoidosis
- Inflammatory: Vasculitis
- Paraneoplastic
- Immune mediated: CIDP
- Congenital: HSMN
- Drugs: Vincristine, Cisplatin, Gold, Amiodarone
Drugs causing sensory peripheral neuropathy?
isoniazid, chloroquine, metronidazole
causes of peripheral neuropathy with autonomic dysfunction?
GBS
infection: botulism, Chagas disease, HIV
porphyria
paraneoplastic
DM
Amyloidosis
Demyelinating causes of peripheral neuropathy?
CIDP
Multiple myeloma
HSMN Type 1 and 3
HIV
POEMs disease
Multifocal motor neuropathy
Hereditary neuropathy with pressure palsy
Screening for causes of peripheral neuropathy during neuro examination?
- features of DM: diabetic dermopathy
- thickened nerves or hypopigmentation patches (leprosy)
- parotidomegaly, dupuytrens (ETOH)
- sallow (uraemia)
- pallor (B12 deficiency)
- cachexia, toe clubbing (paraneoplastic)
- symmetrical deforming polyarthropathy (RA)
- clinical features of acromegaly, hypothyroidism
gait in peripheral neuropathy?
sensory ataxic gait
- may be high stepping
causes of peripheral neuropathy (mixed/ sensory/ motor)
DAMIT BICH
Drugs: Isoniazid, chloroquine, nitrofurantoin, gold, penicillamine, cyclosporin A, phenytoin, vincristine
Alcohol
Metabolic: DM, uraemia (CKD), porphyria
Infectious: Leprosy, HIV, botulism
Inflammatory: GBS, CIDP
Tumour: paraproteinaemia (MM), Paraneoplastic (Lung Ca)
B12, B6, B1
Infiltrative: Amyloid, sarcoid
Congenital: HMSN, porphyria
Hormonal: Acromegaly, Hypothyroidism
causes of a painful peripheral neuropathy?
DM, Alcohol, B12 deficiency
Carcinoma, Porphyria, Arsenic
types of neuropathy in DM?
- glove and stocking symmetrical sensory neuropathy
- predominantly motor, asymmetrial (DM amyotrophy)
- mixed motor and sensory peripheral neuropathy
- mononeuropathy
- mononeuritis multiplex
- autonomic neuropathy
neurological complications of alcohol?
wernicke’s (Confusion, ophthalmoplegia, ataxia)
korsakoffs psychosis (anterograde amnesia, confabulation)
cerebellar degeneration
central pontine myelinolysis
epilepsy
myopathy and rhabdomyolysis
peripheral neuropathy
nerve conduction studies in diabetic peripheral neuropathy?
axonal loss
Further examination if patient presents with ptosis?
- visual acuity
- pupils: miosis (horners), mydriasis (CN III)
- EOM (down and out: CN III, complex: MG?)
- fatiguability: MG
DDx unilateral ptosis?
Horner’s syndrome
3rd Nerve Palsy
Myasthenia gravis
Previous tarsorraphy/ congenital ptosis
Muscle - local orbital infiltration/ pathology, dystrophia myotonica
DDx Bilateral ptosis?
Myasthenia gravis
Myotonia dystrophy
GBS/ Miller Fisher
Motor Neuron Disease
Oculopharygneal dystrophy
Thyroid eye disease
Senile ptosis/ congenital ptosis
Mitochondrial dystrophy e.g. CPEO, Kearn Sayre syndrome
Tabes dorsalis
Nuclear 3rd nerve palsy
Syringomyelia with bilateral Horner’s syndrome
Esotropia
6th nerve palsy
DDx exotropia
3rd nerve palsy
4th nerve palsy
DDx complex ophthalmoplegias?
Central cause:
Intranuclear ophthalmoplegia
Wernicke’s encephalopathy
Nerves: Miller Fisher
NMJ:
Myasthenia gravis
Myopathies:
Thyroid eye disease
CPEO/ Kearn-Sayre synrome or Ragged Red Fiber Myopathy
Glass eye/ trauma
cause of unilateral facial droop? + Long tract signs
UMN lesion
- pontine and above
unilateral facial droop + VIII nerve involvement?
neurolocalisation
Internal auditary canal
unilateral facial droop + 5th/6th/8th CN involvement
neurolocalisation?
Cerebellopontine angle lesion
unilateral facial droop + cerebellar involvement; neurolocalisation?
middle cerebellar peduncle
Approach to CN examination, if no obvious signs on general inspection. what to think of?
visual fields
RAPD (with fundoscopy)
EOM restriction
Myasthenia Gravis
Bulbar/ pseudobulbar palsy
Cranial nerve examination: general inspection. What can be suggestive of underlying defect?
- Ambulation aids: ?LL weakness
- Supplemental O2
- NG tube ?CN 9/10/12 lesion
- Urine catheters ?cauda equina, neurogenic bladder, myelopathy
- IV fluids/drugs
then look more closely:
any ophthalmoplegia?
ptosis?
facial asymmetry?
abnormal speech?
limb asymmetry/ posturing
tremors
fasciculations
CN exam: checking CN 1
olfactory nerve
- ask “any problems with your sense of smell?”
CN exam: checking CN 2?
optic nerve
- check visual acuity grossly (how many fingers?)
- pupillary reflexes (direct, consensual, accommodation)
- RAPD?
CN exam: checking CN 3/4/6?
Oculomotor, Trochlear, Abducens
- check ROM of eyes (diplopia, ophthalmoplegia)
- in presence of complex ophthalmoplegia or ptosis, check for fatiguability
CN exam: CN 5 testing?
Trigeminal nerve
- pin prick sensation over forehead, maxilla, chin
- “bite your teeth” -> feel for bulk masseters
- “open your mouth” -> feel for strength of pterygoids and see if jaw moves to one side (displaced to the side of weakness)
CN exam: CN 7 testing?
- “Look up” -> loss of wrinkling of forehead (frontalis) = LMN lesion
- “Close your eyes as tight as possible, don’t let me open them” -> bell’s phenomenon, unable to bury eyelashes
- “show me your teeth” -> facial droop, loss of nasolabial fold
- “puff out your cheeks”
additional:
lacrimation - lesion proximal to geniculate nucleus if affected
taste over tip of tongue
salivary gland
hyperacusis - paralysis of stapedius muscle
CN exam: CN 8 testing?
“I’m going to say something into your ear, please repeat the words after me”
- Rinne’s test: place 256Hz tuning fork on mastoid, then in line with ear
- Weber’s test: place 256Hz tuning fork on forehead
Rinne’s positive = AC>BC. negative: BC > AC (conductive HL)
Weber’s test: localizes to side with conductive HL, localizes away from side with SNHL
CN exam: testing for CN 9/10 nerves
Glossopharyngeal, vagus nerves
“open your mouth and say AH”
-> look for deviation of uvula and palatal weakness
CN IX: mainly sensory function
CN X: mainly motor function in the mouth
CN exam: testing CN XII nerve?
Hypoglossal nerve
stick out tongue (deviation, wasting, fasciculations)
move it left to right
CN exam: testing CN XI accessory nerve?
“push your head against my hand” test SCM ->feel for SCM contraction/bulk
shrug shoulder and feel for trapezius contraction/bulk
CN exam: how to screen for cerebellar and UL signs?
Cerebellar:
Nystagmus, finger-nose test (intention tremor), dysdiadochokinesia, upper limb rebound, heel shin test, toe finger test, gait (ataxia)
UL and LL:
Hemiplegia, pyramidal signs
CN exam: how to say you will complete your examination?
- fundoscopy
- visual field defect
- proper assessment of visual acuity with snellen’s chart
- check the corneal reflex: afferent CN V1, efferent VII
- check gag reflex: afferent CN IX, efferent X
CN II lesion: how may different pathologies present?
- homonymous hemianopia: optic tract/radiation lesion
- superior homonymous quadrantonopia: contralat temporal lobe lesion
- inferior homonymous quadrantonopia: contralat parietal lobe lesion
- bitemporal hemianopia: optic chiasm lesion
- monocular blindness: pre-chiasmal lesion
CN III: how may different pathologies present?
- pupils normal: ischaemic CN III palsy
- pupils fixed and dilated: PCOM aneurysm
- DDx OAS, SOFS, CSS, Benedikt’s syndrome, MG (excluded if pupillary reflex abnormal)
CN V lesion: how may different pathologies present?
ganglion/sensory root lesion: total loss of sensation in all 3 divisions
post-ganglionic lesion: total loss of sensation in 1 division (usually ophthalmic division a/w CN III, IV, VI palsies due to lesion in cavernous sinus)
Brainstem/upper cervical cord lesion:
- dissociated sensory loss of face: ie. loss of temp/sensation but retention of touch and propioception sensations of face
CN VI lesion: how may different pathologies present?
nerve tract:
- cavernous sinus (may p/w isolate CN VI if early)
- clivus lesino
- NPC/meningeal lesino
- GBS/MFS- check reflexes
- ischaemic
- false localising sign
NMJ: MG
Local/muscle: infiltrative orbital process, tumour thyroid eye disease
DDx: OAS, SOFS, CP angle
Causes of UMN CN VII lesion?
contralateral cortical or subcortical lesion:
vascular: stroke
Tumours
-> if detected, examine UL and look for hemiparesis on same side of facial weakness
-> check for xanthelasma, DM signs, BP
Causes of LMN CN VII lesions?
infection: HSV (bell’s palsy), zoster, lyme disease
Connective tissue/ infiltrative: sarcoid, amyloidosis, Sjogrens, behcets
Neoplasm
Brainstem (infarct/ haemorrhage) - a/w gaze palsy
MS
can organize by site of lesion:
brainstem: infarct/bleed, MS, abscess/tumour, syringobulbia
base of skull lesion: infective, tumour, infiltrative
CPA lesion:
Acoustic neuromas
Meningiomas
neurofibroma
Petrous temporal bone/ facial nerve canal:
Bells palsy
Ramsay Hunt syndrome
Fractures
otitis media
Parotid gland: tumour, surgery, sarcoidosis
mononeuritis multiplex
causes of isolated CN II palsy?
ischaemic
PCOM aneurysm
causes of isolated CN IV palsy?
trauma
decompensated squint
causes of single CN VI palsy?
- false localising
- ischaemic
- NPC
- meningeal
- cavernous sinus pathology
causes of CN VII isolated palsy?
Bells palsy
Parotid tumour
Middle ear disease
trauma: # to mastoid area
Causes of isolated CN XII palsy?
hypoglossal canal
base of skull pathology
carotid artery dissection
ALS (bilateral wasted tongue)
CN III palsy?
- abnormal EOM (down and out pupil)
- abnormal light reflex
- abnormal dilated pupils (may be normal in ischaemic CN III palsy)
causes of isolated CN III palsy?
- Posterior communicating artery aneurysm
- Medical CN III palsy
cavernous sinus syndrome?
CN III, IV, V1, V2, VI
superior orbital fissure syndrome?
CN III, IV, V1, VI
Orbital apex syndrome?
CN II, III, IV, V1, VI
CN III palsy + long tract signs?
midbrain pathology
CN III palsy + signs of peripheral neuropathy?
GBS/ Miller Fisher syndrome
Signs of Horner’s syndrome
miosis
partial ptosis
enophthalmos
slight elevation of lower eyelids
+/- anhidrosis depending on level of lesion
Causes of Horners syndrome + what to examine for?
- Pancoast tumour:
- tracheal deviation, supraclavicular dullness, wasting of small muscle of hands, clubbing, loss of pain sensation in UL
- scars of cervical sympathectomy
- enlarged LNs
- carotid and aortic aneurysms
- examine for signs of brainsteam vascular disease or demyelination
- nystagmus, cerebellar signs, cranial nerves, pale optic discs
Suspected myasthenia gravis: what to examine?
Test for fatiguability
- prolonged upward gaze
- superio-lateral gaze
-> Normal pupils, normal light reflex, EOM may be abnormal
Test for bulbar weakness
Test for proximal limb weakness
Examine for associated signs:
- thyroid goitre, retrosternal extension
- retrosternal thymoma
- RA hands
- vitiligo
Horner’s syndrome:
degree of anhidrosis according to location of lesion
central lesion (1st order neuron): anhidrosis over head, upper trunk and arm
proximal to superior cervical ganglion (2nd order neuron): anhidrosis over face only
distal to super cervical ganglion (3rd order neuron): none
approach to unilateral ptosis?
- rule out pseudoptosis
- droopy eyelids - muscle
- myotonic dystrophy - neuromuscular
- Myasthenia gravis - nerve
- III nerve palsy
- horner’s syndrome
approach to unilateral horner’s syndrome?
- examine the other cranial nerves
- cavernous sinus syndrome
- superior orbital syndrome
- lateral medullary syndrome
- syringobulbia
- multiple sclerosis (INO, cerebellar, RAPD) - neck
- scars: trauma/ surgery
- neoplasia
- carotid aneurysm
- cervical rib - upper limbs (examine in this sequence)
- pronator drift then cerebellar signs (lateral medullary syndrome)
- wasting of ipsilateral small muscles of the hands (T1)
- clubbing
- sensory loss T1
- dissociated sensory loss (syringomyelia)
- contralateral loss to pain and temp (lateral medullary syndrome)
- axilla (trauma to brachial plexus) - chest
- pancoast tumour: tracheal deviation, dullness, auscultation
- ask for loss of sweating and level
what medications can help to delineate the site of lesion clinically?
adrenaline 1:1000 to both eyes (denervation hypersensitivity)
- abovev the superior cervical ganglion (peripheral) = dilates the affected eye
- below/ proximal to superior cervical ganglion or a normal eye = no effect
cocaine 4%
- dilates normal eyes
- no effect on the affected side if above/ distal to superior cervical ganglion
how do you delineate the site of lesion clinically via loss of sweating?
central lesion (1st order): loss of sweating in head, upper trunk and arm
neck, proximal to superior cervical ganglion (2nd order): loss of sweating in face
neck, distal to superior cervical ganglion: sweating intact (3rd order)
causes of horner’s syndrome?
Hypothalamus/ brainstem:
stroke, pontine glioma, coning of temporal lobe
cervical cord (C8-T2: intermediolateral column):
syringomyelia, multiple sclerosis, tumour
superior mediastinum (2nd order nerves exixt the spinal cord and synapses at the superior cervical ganglion):
pancoast lesion (SCC lung), trauma to brachial plexus
neck (carotid sympathetic plexus and superior cervical ganglion):
neoplasia, trauma, surgery (cervical sympathectomy), carotid aneurysm, carotid dissection (triad of pain, ipsilateral horner’s, cerebral/retinal ischaemia)
idiopathic
congenital - heterochromia of iris (grey blue on affected side)
migraine- causes intermittent horner’s syndrome
approach to bilateral ptosis?
muscular (usually no wrinkling of the forehead):
myotonic dystrophy
ocular myopathy
oculopharyngeal dystrophy
chronic progressive external ophthalmoplegia (mitochondrial/Kearns sayre)
Neuromuscular:
myasthenia gravis
Nerve:
bilateral 3rd CN palsy (rare)
bilateral Horners’ (syringomyelia)
tabes dorsalis
miller fisher syndrome
examination approach in bilateral ptosis?
- general screen for myotonic dystrophy, fascioscapular dystrophy
- screen for myasthenia gravis
- check CNs:
> III, Horner’s
> Argyll Robertson pupils (Tabes)
> Ophthalmoplegia (kearns sayre)
> bulbar palsy (syringomyelia) - Neck
- Upper Limbs:
> ataxia (kearns sayre, miller fisher)
> Syringomyelia: flaccid and wasted ULs, dissociated sensory loss, spastic paraparesis
> Areflexia (miller fisher) - complete examination by fundoscopy for retinitis pigmentosa (CPEO)
Examination of myasthenia gravis, sequence?
- eyes
- ptosis with fatiguability
- variable strabismus and diplopia that occurs after some time
- check for hyperthyroid and thyroid eye disease
- check for anaemia
- check for malar rash of SLE
- face
- VII power
- assessment of speech: count to 1 to 20, nasal voice (bulbar palsy)
- masseter weakness but pterygoids normal
- check neck for goitre and scars
- ULs
- normal deep tendon reflexes (Miller fisher/ lambort eaton are reduced)
- normal sensation
- fatiguability with weakness
- RA and SLE features - Thymectomy scar and plasmapheresis line
associations of Myasthenia gravis:
endocrine: Thyroid, DM, pernicious anaemia
CTD: RA, SLE, polymyositis
Request for:
negative inspiratory force
drug history: antibiotics/ drugs that can worsen MG
temperature chart for fever - can ppt weakness
what is myasthenia gravis?
- autoimmune condition with antibodies targeting the post synaptic Ach receptors of the neuromuscular junction
- resulting in progressive muscle weakness with use of the muscle and recovery of strength after a period of rest
- weakness experienced once number of receptors is 30% or less
how common is the thymus involved in myasthenia gravis ?
75% of cases:
of which 15% are thymomas and 85% are thymic hyperplasia
usual age for myasthenia gravis?
2 peaks
20 to 30 years old with female predominance
> 50 years old with male predominance
features of myasthenia gravis on presentation
ptosis, diplopia
dysarthria, difficulty swallowing (isolated bulbar muscle involvement in ~20%)
generalised weaness or reduced exercise tolerance
respiratory failure in 1%
tends to affect extra ocular muscles first then facial to bulbar and then limbs and truncal
what may exacerbate myasthenia gravis or precipitate a crisis?
- non compliance to meds
- infection
- emotions/ stress
- drugs
what drugs may exacerbate MG crisis?
antibiotics: aminoglycosides, tetracyclines, macrolides, fluoroquinolones
cardiac: BBs, CCBs (verapamil)
others: chloroquine, procainamide, Lithium, Mg, prednisolone, quinine, penicillamine
what is a cholinergic crisis?
not the same as myasthenic crisis
results from excess of cholinesterase inhibitors such as neostigmine and pyridostigmine
causes flaccid paralysis and SLUDGE (miosis, salivation, lacrimation, urinary incontinence, diarrhoea, GI hypermotility and emesis)
ix to do for suspected myasthenia gravis?
Bloods:
- AChR Ab (+ve in 80% with generalised MG, only +ve in 50% with ocular involvement only, also present in 90% of patients with penicillamine induced MG)
- anti striated muscle Ab
- Anti MUSK Ab (muscle specific kinase)
- FBC to rule out infection
Imaging:
- CXR: thymus (Anterior mediastinal mass), aspiration pneumonia
- CT for thymus
Tensilon test: for diagnosis
Ice pack test
Electrodiagnostic studies:
- repetitive nerve stimulation test
- single fibre nerve EMG
what is the ice pack test in myasthenia gravis?
ice applied with glove to eyelids for 2 mins
improvement in ptosis (positive in 80%)
what is the tensilon test in myasthenia gravis?
can help to distinguish from cholinergic crisis
- edrophonium (half life 10 min)
- look for objective improvement in ptosis
- cardiac monitoring for bradycardia and astystole (Rx with atropine if any)
- 1mg test dose and up to 10mg
- in cholinergic crisis, will get increased salivation etc
repetitive nerve stimulation test in myasthenia gravis?
shows a decrease in the compound muscle action potential by 10% in the 4th to 5th response to a train of nerve stimuli
single fibre nerve EMG in myasthenia gravis?
evidence of neuromuscle blockade with increased jitter
how do you grade the severity of weakness in myasthenia gravis?
Myasthenia Gravis Foundation of America
- Grade 1: affects ocular muscles only
- Grade 2: mild weakness affecting muscles other than ocular muscles
> 2A: limbs/ axial muscles
> 2B: respiratory and bulbar muscles
- Grade 3: moderate weakness
- Grade 4: severe weakness
- Grade 5: intubation required
Osserman’s grading
I: ocular
II A: mild generalised with slow progression
II B: Moderate generalised
III: acute fulminant MG
IV: late severe MG (Takes 2 years to progress from I to II)
Management of myasthenia gravis?
crisis: ABC approach
tx exacerbating factor:
stop exacerbating medications, treat infection if any, treat fever with antipyretics
oral pyridostigmine
steroids, azathioprine, cyclosporine (to maintain remission)
plasmapheresis
IVIG
Thymectomy
complications of myasthenia gravis?
myasthenic crisis
- severe exacerbation of MG
- 10% require intubation
treatment complications
- cholinergic crisis
- cx of medications
what is Lambert Eaton syndrome?
myasthenic disorder associated with malignancy such as small cell Lung Ca
affects the proximal (thigh/pelvic girdle) and truncal musculature, bulbar muscles rarely involved
improves with exercise
presence of Abs to calcium channels
approach to examination upon detection of facial asymmetry (CN VII palsy)
- test CN VII functions:
> look up (frontalis)
> close eyes (orbuclaris oculi) attempt to open
> look for exposure keratitis, tarsorraphy
> nasolabial fold, show teeth, blow against closed lips
> look for drooling of saliva - determine LMN or UMN, unilateral or bilateral
2A UMN unilateral:
examine UL and look for hemiparesis on same side of the facial weakness
check for xanthelasma, DM signs and BP
2B LMN unilateral
- examine other CN
- VI nerve and contralateral weakness in brainstem lesions
- CPA lesion (V, VI, VII, VIII with cerebellar)
- other CN involvement non comforming type: mononeuritis multiplex, MG
- look at palate for vesicles
- examine the parotids and for surgical scars
- mastoid tenderness
- examine neck for cervical LNs
- Upper limbs: contralateral hemiparesis, ipsilateral cerebellar
ask to examine:
otoscopy for vesicles in ear canal and otitis media
for hyperacusis
for loss of taste in anterior 2/3 of tongue
urine dip for glucose and BP (mononeuritis multiplex)
if noted to have bilateral rather than unilateral facial weakness?
rule out MG
rule out myotonic dystrophy or fascio scapular humeral dystrophy
bilateral LMN VII:
> look for V VI VIII
> examine parotids (sarcoidosis, amyloidosis)
> examine tongue (scrotal tongue for MR syndrome)
> examine UL for GBS, MND, leprosy, lyme (radiculopathy) and bilateral cerebellar signs if suggestive of bilateral CPA tumours
rare: melkerssson rosenthal syndrome, mobius syndrome
what is the course of the facial nerve?
VII nerve nucleus lies in the pons in close proximity to VI nerve nuclei
VII leaves the pons with VIII via cerebellopontine angle
VII enters facial canal and enlarges to become the geniculate ganglion
A branch is given off to the stapedius muscle and the greater superficial petrosal branch goes to the lacrimal glands
the chorda tympani which supplies taste sensation to anterior 2/3 of tongue joins the VII nerve in the facial canal
VII nerve exits the skull via stylomastoid foramen through the parotids and branches into 5: temporalis, zygomatic, buccal, mandibular, cervical
what are the causes of bilateral LMN VII nerve palsies?
after ruling out MG and myopathies
bilateral CPA tumour as in NF type 2
Bilateral Bell’s palsy
bilateral parotid enlargement (Sarcoidosis- uveoparotid fever or Heerfordt’s fever)
GBS, MND, Lyme disease
Rare: Rosenthal Melkersson syndrome (triad of VII palsy with facial oedema and plication of the tongue), Mobius syndrome (congenital facial diplegia, oculoparalysis from III and VI and infantile nuclear hypoplasia)
what is Bell’s phenomenon?
refers to the upward movement of the right eyeball with incomplete closure of the right eyelid in an attempt to close the right eye
why are the muscles of the upper face spared in an UMN lesion?
the upper facial muscles are preserved in an UMN lesion as there are bilateral cortical representations of these muscles
what is bell’s palsy?
an idiopathic facial paralysis, believed to be due to viral-mediated cranial neuritis from HSV
typically presents with abrupt onset weakness with worsening the following day, associated with facial or retroauricular pain, hyperacusis and excessive tearing
what is ramsay hunt syndrome?
- herpes zoster infection of the geniculate ganglion
- presents with vertigo, hearing loss, facial weakness, pain in the ear with vesicles seen on the external auditory meatus and palate
what is facial synkinesis?
attempt to move one group of facial muscles results in movement of another group
occurs as a result of anomalous regeneration of the facial nerve
e.g nerve fibres that innervate facial muscles innervating lacrimal glands -> tearing on mastication (crocodile tears)
ix of facial nerve palsy?
target ix according to history and physical examination
bloods e.g. Lyme disease
Imaging
Management of Bell’s palsy?
- educate
- lubricating eye drops, eye patch, taping eyes closed
- physiotherapy
Meds:
PO pred 1mg/kg/d for 7-10 days and PO aciclovir 400mg 5x/d for 7 days (within first 72h)
regular follow up to look for resolution and exclude new developing signs suggestive of other conditions
surgical (tarsorraphy) for chronic non resolving cases
how would you educate or counsel patient with Bell’s palsy?
common condition
course:
improvement onset 10d - 2mo
plateau 6w-9mo
residual signs
- synkinesis in 50%
- face weakness 30%
- contracture 20%
- blepharospasm: may occur years after paralysis
synkinesis in facial nerve - can be treated with?
synkinesis may be due to anomalous regeneration of nerve
may be treated with botulinum
what are associated signs with better prognosis in bells palsy?
incomplete paralysis
early improvement
slow progression
younger age
normal salivary flow
normal taste
normal NCS, electrogustometry
examination approach to visual field defects
general inspection:
acromegaly
hemiparesis
dysphasia
visual fields
- introduce
- sit about arms length
- “can you see my whole face”
- test gross VA- counting fingers (wear specs!)
- test gross visual fields using finger movements as well as for visual inattention
- test using white hat pin from all quadrants
if single eye defect for visual field, examination approach?
proceed with fundoscopy:
BRAO, haemorrhages, chorioretinitis
optic atrophy, glaucoma, RP
single eye visual defect with constricted field (tunnel vision)
> chronic papilloedema
chronic glaucoma
retinitis pigmentosa
chorioretinitis
hysteria (visual field does not widen as object is brought further away from the patient compared to organic cause)
single eye visual field defect: scotoma? causes
retinal haemorrhage or infarct (paracentral or peripheral scotomas)
- does not cross the horizontal midline
optic nerve (pale in atrophy, normal in retrobulbar neuritis, pink/swollen in papillitis) resulting in central scotoma
- compression: tumour, aneurysm, paget’s
- glaucoma
- neuritis: MS, ischaemia (temporal arteritis, idiopathic, C/BRAO), toxic (methanol), B12 deficiency, Hereditary (Friedrich’s ataxia, LHON), 2’ retinitis pigmentosa
totally blind in one eye causes?
retina
optic nerve lesion
single eye altitudinal visual field defect (ie. superior or inferior)?
retinal infarcts
ischaemic optic neuropathy
bitemporal visual field defect causes
upper > lower= inferior chiasmal
- pituitary tumour
- suprasellar meningioma
lower > upper
- craniopharyngioma
others: aneurysm, metastasis, glioma
homonymous hemianopia - causes?
infarcts/ haemorrhages/ tumour
left homonymous hemianopia = right cerebral lesion and vice versa
incongruous: optic tract
congruous:
upper quadrantonopia: temporal lobe
lower quadrant: parietal lobe
macula sparing (test with red hat pin):
occipital cortex
no macula sparing: optic radiation
note any DM dermopathy, xanthelasma. AF. hemiparesis (causes / RF for stroke)
ix of bitemporal hemianopia?
- lateral skull XR: enlarged sella turcica, calcification for craniopharyngioma
- CT or MRI head
- formal field perimetry
- serum prolactin
- screen for hypopituitarism
- IGF1: screen for acromegaly if suspected
what signs to mention when patient has a unilateral homonymous hemianopia?
incongruous/ congruous
macula sparing or not
if any: hemiparesis,
dysphasia, visual inattention
look for CVRF- DM dermopathy, xanthelasma, AF
tumour - cachexia, clubbing for metastatic disease
request for full neurological examination to evaluate for stroke/ SOL
ix of homonymous hemianopia?
CT head
formal field testing, perimetry
examination findings for right INO?
left eye can abduct with nystagmus, right eye fails to adduct on leftward gaze
right eye is able to independently adduct
saccadic eye movement - horizontal saccade is abnormal with the right eye lagging behind the left eye
Internuclear ophthalmoplegia:
what examination finding can help to neurolocalise?
convergence intact: pons
convergence not intact: midbrain
what else to examine for if internuclear ophthalmoplegia is picked up?
eye movements
convergence
proceed with other CN examination:
- multiple sclerosis (RAPD)
- myasthenia gravis
limbs:
- multiple sclerosis: may have cerebellar signs
- CVA: DM dermopathy, xanthelasma, AF
request for fundoscopy: optic atrophy
what causes a right INO?
lesion is in the right medial longitudinal fasciculus that connects the ipsilateral third nerve innervation to the right medial rectus to the left gaze center
causes of INO?
multiple sclerosis
brainstem infarction
pontine glioma
infections: Lyme disease, syphilis, viral
drug intoxication: TCAs, phenytoin, CMZ
trauma
myasthenia gravis (pseudo INO due to EOM weakness)
ix of internuclear ophthalmoplegia?
as per possible aetiologies:
MG
MRI brain
Lipid panel, fasting glucose
Lyme disease titre
VDRL
drug levels
what is wall eyed bilateral INO? (webino syndrome)
- due to bilateral MLF damage
- bilateral INO with exotropia and failure of convergence
- lesions in the pons and midbrain
- due to MS/ brainstem infarct, gliomas, wernicke’s
what is fisher’s one and a half syndrome?
ipsilateral horizontal gaze palsy (ie. both eyes can’t look right) and ipsilateral INO (ie. left eye can look left, right eye cannot adduct)
- due to lesion in MLF and adjacent gaze center
causes of conjugate upward vertical gaze palsy?
midbrain lesion:
MS (demyelination), vascular (infarct, haemorrhage, aneurysm), tumour
causes of conjugate downward vertical gaze palsy?
lesion in midbrain or foramen magnum
- arnold chiari malformation, dandy walker
- acquired lesion (tumour, vascular, demyelination, abscess)
features of parinaud’s syndrome?
loss of vertigal gaze (usually upward gaze affected)
+
nystagmus on convergence (particularly with upward gaze and saccades upward)
+
light near dissocation (poor bilateral pupillary constriction in response to light, but preserved constriction with convergence)
+ bilateral lid retraction
parinaud syndrome -causes?
lesions affecting structures in the dorsal midbrain
most often: pineal region tumors, brainstem hemorrhage, and ischemic infarction
MS
features of progressive supranuclear gaze palsy in parkinsons plus disease?
loss of downward gaze, then upward gaze then horizontal gaze
can be overcome by doll’s reflex
loss of saccadic (frontal lobe) and pursuit movements (occipital lobe)
isolated CN III palsy - what to examine for upon completion of eye/ CN examination?
look for intortion of the affected orbit by asking patient to look down and medially of affected eye (if affected, implies 4th nerve palsy)
rule out:
thyroid eye disease, MG
Superior orbital syndrome and cavernous sinus syndrome
proceed with
- neck for LNs
- examine upper limbs for cerebellar, hemiplegia, EPSE, areflexia
- look for DM dermopathy
isolated CNIII palsy: what to request for on completion of examination?
- corneal reflex (Reduced or absent)
- visual fields (bitemporal hemianopia)
- fundoscopy for optic atrophy (MS), DM or hypertensive changes
- visual acuity
- blood pressure
- urine dipstick
- temperature chart
- headache or pain
what is the course and anatomy of the 3rd CN?
- nuclear portion at the midbrain
- fasicucular intraparenchymal portion: close to the red nucleus, emerges from the cerebral peduncle
- fascicular subarachnoid portion: meninges, PCA aneurysm
- fasiculular cavernous sinus portion: sella turcica between the petroclinoid ligament below and interclinoid above
- fascicular orbital portion: superior orbital fissure
what are the causes of an isolated 3rd nerve palsy?
Brainstem:
- infarct, haemorrhage, tumour, abscess, MS
peripheral:
- subarachnoid portion: PCA aneurysm, meningitis, infiltrative
- cavernous sinus lesions
- orbital
- mononeuritis multiplex, MG, Miller fischer
features of a third nerve nucleus lesion?
will also have contralateral ptosis and elevation palsy
as axons from the third nerve nucleus also innervate the contralateral superior rectus and the contralateral levator palpebrae
emergency causes of third nerve palsy?
coning (raised ICP)
giant cell arteritis
aneurysm
how would a patient present with thrid nerve palsy? (symptoms)
diplopia
ptosis
symptomatic glare from failure of constriction of pupil
blurring of vision on attempt to focus of near objects due to loss of accommodation
pain in certain aetiologies: DM, PCA aneurysm, migraine
causes of a dilated pupil?
- III nerve palsy
- optic atrophy (direct light and accommodation absent with intact consensual reflex)
- Holmes Adie Pupil (myotonic pupil)
- Mydriatic eye drops
- Sympathetic overactivity
why does a PCA aneurysm result in pupillary involvement whereas conditions such as DM or hypertension spares the pupil?
the pupillary fibres are situated superficially and prone to compression whereas ischaemic lesions tends to affect the core of the nerve thus sparing the pupillary fibres
ix of isolated CN III palsy?
imaging: CT, MRI
Angiogram
Bloods:
Fasting blood glucose
ESR
TFT
screen for myasthenia if suspected
LP
mx of 3rd nerve palsy?
medical third nerve palsy
- education: watchful waiting, avoid driving/ heavy machinery/ climbing high places
- treat underlying conditions such as DM/ hypertension
- most spontaneously recover within 8 weeks
- symptomatic treatment: NSAIDs for pain, eye patch for severe diplopia and prism glasses for mild diplopia
surgical 3rd nerve palsy - surgery
Bilateral foot drop in examination, with UMN pattern of weakness. Causes?
Cord lesion
Parasagittal lesion
ACA territory stroke
Bilateral cortical / sub cortical lesion
Bilateral foot drop in examination, with LMN pattern of weakness. Causes?
Peripheral neuropathy
Multifocal motor neuropathy
HSMN/ Charcot Marie tooth
Unilateral foot drop on examination, UMM pattern of weakness. Causes?
Cortical or hemicord lesion
Unilateral foot drop, LMN pattern of weakness.
Causes?
Need to differentiate between
Common peroneal nerve palsy
L5 plexopathy
Sciatic nerve palsy
Unilateral foot drop with LMN pattern of weakness -> what to assess for next?
Knee flexion
-> if weak knee flexion: sciatic neuropathy
* beware complex polyradiculopathy, lumbosacral plexopathy, polyneuropathy, myopathy, peripheral neuropathy
-> if knee power normal, then move on to differentiate between common peroneal nerve palsy and L5 radiculopathy
Features of sciatic neuropathy?
Weak knee flexion (hamstrings)
- knee extension and hip adduction normal
Weak ankle dorsi and plantar flexion-> foot drop
Weak foot inversion and eversion
Wasting of peroneus and anterior tibialis muscle
Loss of ankle reflex and plantars absent, knee jerk intact
Everything below knee except medial aspect of leg and foot may be numb
Unilateral foot drop with LMN pattern of weakness, knee flexion normal. What to examine for next?
Hip abduction
Hip internal rotation
Foot inversion
-> if weak: L4-5 radiculopathy
-> if normal: peroneal nerve
general features of Parkinsonism in UL and general inspection?
mask like facies, monotonous speech, dyskinesias
resting tremors which disappears with use of hand
bradykinesia
leadpipe rigidity and cogwheeling
acute dystonia or alien limb syndrome
pronator drift and cerebellar signs
features of parkinsonism in the face?
- eye movements, vertical dolls if vertical gaze impaired
- close eyes for blepharospasm
- feel for seborrhoea
- KF rings
- count 1-20
features of parkinsonism in gait?
shuffling gait with festination
stooped posture
parkinsonism: how to test for function on examination?
unbutton shirt, cap a pen, comb hair
parkinsonism: how to request to complete examination?
speech if not done
swallowing
handwriting
postural BP
AMT
Parkinonism: what important negatives to present?
Parkinsons Plus features
- no evidence of Supranuclear gaze palsy ie. vertical gaze palsy
- no evidence of cerebellar signs to suggest multisystem atrophy
- no evidence of corticobasal ganglia degeneration such as dystonic arm or alien limb syndrome
- no evidence of dyskinesias which can result from L-dopa therapy
what is parkinson’s disease?
it is a progressive neurodegenerative disorder associated with degeneration of the dopaminergic nigostriatal neurons
- clinical diagnosis with 2 out of 3 signs comprising of resting tremors, bradykinesia and rigidity. 4th sign of postural instability occurs later in the course of disease
causes of Parkinsonism?
- Parkinson’s disease
- Parkinson Plus syndrome
- Drugs: Dopamine antagonists, antiemetics
- Anoxic brain damage (post cardiac arrest, CO, Manganese)
- Post encephalitis
- Tumour such as giant frontal meningioma
pathological findings of Parkinsons disease
loss of pigmented dopaminergic neurons in the substantia nigra
presence of lewy bodies (eosinophilic cytoplasmic inclusions)
What are the Parkinsons plus syndromes
- Progressive supranuclear palsy
- Multiple system atrophy
- Corticobasalganglionic degeneration (fronto parietal lobe)
- Diffuse Lewy Body disease
- Parkinonism -dementia-ALS complex
features of progressive supranuclear palsy?
vertical gaze palsy
- downgaze affected first, then upgaze, then horizontal
- can be overcome by vertical Doll’s
- other features such as blepharospasm, slow pursuit, saccadic eye movements
postural instability and axial rigidity with falls early in the course of the disease
frontal lobe signs
features of multiple system atrophy?
MSA-P (Parkinsonism features)
MSA-C (Cerebellar features)
- Cerebellar signs
- Autonomic features: orthostatic hypotension, urinary dysfunction, erectile dysfunction
- Corticospinal signs: hyperreflexia and extensor plantar response
features of corticobasal degeneration
limb apraxia or alien limb syndrome
dystonia
what is the significance of diagnosing parkinson plus syndrome?
poorer prognosis
poor response to L dopa therapy
what features suggest that patient may have parkinson plus syndromes?
- early onset dementia
- presence of hallucinations or psychosis
- early onset of postural instability
- truncal symptoms more prominent than appendicular symptoms
- marked symmetry of signs early in the stage of the disease
- lack of response to levo dopa therapy in the early stage of the disease
- presnce of signs and symptoms suggestive of parkinson plus syndrome
what are the stages of parkinson’s disease?
staged via the Hohen and Yahr staging system
1: symptoms and signs unilateral and mild
2: bilateral, mild disability
3: generalised dysfunction with significant bradykinesia and gait impairment
4: rigid and bradykinesia, severe symptoms with limited walking
5: completely invalid and requires nursing care
ix of parkinsonism
MRI brain:
to rule out NPH, multi infarct syndromes, frontal meningiomas, parkinson plus syndrome
if patient is young ie <50, rule out wilson’s disease:
- slit lamp examination
- serum caeruloplasmin and 24h urinary copper
features of multiple system atrophy on MRI brain
atrophy of the cerebellum, brainstem
“hot cross bun” sign: cruciform hyperintensity within the pons
features of progressive supranuclear palsy on MRI brain?
atrophy and hyperintensity of the midbrain and red nucleus
“hummingbird” sign: atrophy of the midbrain results in a profile of the brainstem (in the sagittal plane) in which the preserved pons forms the body of the bird, and the atrophic midbrain the head, with beak extending anteriorly towards the optic chiasm.
features of corticobasal degeneration in MRI brain?
frontoparietal cortical atrophy
Mx of parkinsonism?
MDT approach
Education and counselling, PTOTST
Medications: e.g. L dopa combined with peripheral decarboxylase inhibitor, Dopamine agonist
Surgical
Surgical options in Parkinon’s?
Deep brain stimulation: for all features especially tremors
Lesion surgery: thalomotomy for tremors or pallidotomy (may help reduce tremors, stiffness)
medical management of parkinons?
dopamine agonist e.g. pramipexole or ropinirole
- use in younger patients or early in course of disease
- delay onset of motor fluctuations and dyskinesias
L dopa therapy + peripheral decarboxylase inhibitor (Madopar)
- should be used if there is disability
Tremors: can consider anticholinergics e.g. benztropine
Rigidity: can use MAO-B inhibitors
COMT inhibitors
side effect of dopamine agonists e.g. ropinirole, pramipexole
nausea, orthostatic hypotension, hallucinations, somnolence, oedema
side effect of L dopa therapy?
peak dose dyskinesia and end of dose rigidity
nausea, orthostatic hypotension, hallucinations
how to manage peak dose dyskinesia?
- reduce the dose and increase frequency of L dopa
- add on COMT inhibitors e.g. entacapone which increases half life of L dopa therapy
- initiating with dopamine agonist and adding on L dopa therapy resulting in less motor fluctuations
how to manage end of dose L dopa dyskinesia?
- increase dose, frequency
- switch to CR formulations
- add dopamine agonist, MAO-b Inhibitor or COMT inhibitor
what is the prognosis of Parkinsons disease?
chronic progressive disease
- some will have mild, while others will have severe symptoms
- some will be troubled by tremors, others by rigidity and bradykinesia
what is the abbreviated mental test?
used as a screening for possible dementia in the elderly
a score of less than 6 warrants further assessment
includes:
age
DOB
remembering an address- 40 west street
time
year
recognition of 2 people
place
prime minister
first year of WW1
count backwards from 20 to 1
features of ataxia telangiectasia?
auto recessive
childhood onset with death by 20s or 30s
ataxia, slurred speech, choreathetosis, telangiectasia on face, ears, conjunctiva and skin crease
low IgA with recurrent sinopulmonary infections and lymphoreticular malignancy
what strokes can cause cerebellar symptoms?
can be bleed or infarct
ataxic hemiparesis: lacunar stroke
cerebellar, posterior circulation stroke
lateral medullary syndrome: ipsilateral horners, CN V, IX, X, cerebellar signs/ nystagmus, contralateral spinothalamic tract deficits
Benedikt’s syndrome (midbrain stroke): ipsilateral CN III + contralateral hemiparesis, cerebellar ataxia and choreiform movements
what SOL may cause cerebellar signs
primary or secondary
malignancy, abscess
at the CPA (+/- neurofibromatosis) or cerebellum
what congenital lesions may cause cerebellar signs?
arnold chiari malformation: downward displacement of cerebellar tonsils through the foramen magnum, which may cause CSF outflow obstruction and hydrocephalus
dandy walker syndrome: congenital brain malformation with partial/complete agenesis of cerebellar vermis, and cystic dilatation of 4th ventricle
parkinsonism + cerebellar signs?
multiple system atrophy
findings of peripheral neuropathy, how to complete your examination?
gait if not already done: high steppage gait (sensory ataxia)
UL for distal sensory impairment
urine dipstick for glycosuria (DM)
ask history: drug history, chronic ETOH ingestion
approach to examination of patient with hemiparesis?
examine UL and LL
aim is to locate the lesion of stroke: brainstem, subcortical, cortical
- EOM
- cortical signs: gaze preference, sensory or visual neglect, hemianopia and dysphasia if dominant lobe involved
causes or risk factors:
- pulse, carotid bruit, heart murmur
- signs of hyperlipidaemia (xanthelasma, xanthomas)
- DM dermopathy
- tar stains
- bruising, telangiectasia (?brain bleed)
function and complications:
- gait
- pressure sores, NG tube, urinary catheter
presentation of patient with hemiparesis?
this patient has a L/R hemiparesis as evidence by
- state UL and LL findings
- state level of lesion (brain stem, subcortical, cortical) and justify
- causes/ risk factors
- functional status and complications
types of lacunar strokes (subcortical)?
pure motor (50%)
pure sensory (5%)
mixed motor and sensory (35%)
ataxic hemiparesis (10%)
dysarthria clumsy hand syndrome (rare)
What is webers syndrome?
midbrain stroke
ipsilateral CN III palsy and contralateral hemiplegia
what is millard gubler syndrome
ventral pons lesion
ipsilateral CN VI, VII palsy
+ contralateral hemiplegia
+/- contralateral loss of propioception and light touch with medial lemniscal damage
what to request for at end of examination of patient with hemiparesis?
- CBG reading
- BP
- ECG
- fundoscopy for papilloedema (to rule out SOL which is a potential differential)
DDx of patient with unilateral hemiparesis?
Vascular: ischaemic (80%): intracranial thrombosis, embolic, lacunar strokes, dissection; haemorrhagic
Space occupying lesion: primary/ secondary malignancy
Infective: abscess, meningoencephalitis
seizures with Todd’s paresis
Toxic/metabolic: hypoglycaemia, hyponatraemia
causes of ischaemic stroke?
intracranial atherosclerotic disease (ICAD)
extracranial atherosclerotic disease (ECAD): stenosis of internal/common carotid artery
small vessel disease (SVD): common for lacunar strokes
embolic:
- cardioembolic (LV thrombus, AF)
- septic (IE)
- paradoxical embolus
Embolic stroke of undetermined source (ESUS)
dissection e.g. vertebral artery dissection
how does an anterior cerebral artery stroke present?
affects frontal lobe function:
AMS, impaired judgment
contralateral lower extremity weakness
gait apraxia
how does MCA stroke present
contralateral hemiparesis involving face/UL > LL with reduced sensation
ipsilateral hemianopsia (blindness in one half of visual field)
gaze preference towards lesion
receptive or expressive aphasia if lesion in dominant hemisphere
presentation of PCA stroke?
homonymous hemianopia
cortical blindness (loss of vision due to problem with visual cortex rather than eyes)
visual hallucinations
visual agnosia
altered mental status
how does vertebrobasilar artery stroke present?
varied depending on CN, cerebellar, brainstem area affected
vertigo, nystagmus, diplopia, VF defects, dysphagia, dysarthrits, ataxia
contralateral hemiparesis
ipsilateral pain and temp loss in face
ix of stroke?
confirm the diagnosis:
CT brain to rule out bleed +/- Angiogram
MRI brain stroke protocol: to look for restricted diffusion on DWI (diffusion weighted imaging) sequence
-> and to look for complications e.g oedema
Bloods:
FBC Coagulation, renal panel, liver function, CK
CVRF Lipid panel, Hba1c, fasting glucose
CYP2C19 if planning for long term clopidogrel use
ECG: AF, MI
24h holter
CXR: enlarged mediastinum suspicious of aortic dissection
Echo: cardioembolic cause
US carotids to look for ipsilateral stenosis >70%
ix for young stroke workup?
transcranial doppler bubble study: to look for right to left shunts
TTE with bubble
Autoimmune/inflammatory screen:
ANA, dsDNA, ANCA, ESR
Antiphospholipid syndrome: anticardiolipin antibodies, LAC, anti-B2 glycoprotein
Homocystine
Infective screen:
Syphilis HIV screen
Thrombophilia screen:
Thrombophilia:
Protein C, S deficiency
Anti Thrombin III
Factor V Leiden
D Dimer
CT TAP / malignancy workup in selected cases
What are the limitations of the CT brain for evaluation of acute stroke?
may be normal up to 6 hours of onset
unable to visualise the posterior fossa structures such as brainstem and cerebellum well
early signs on CT brain scan of stroke
loss of grey white differentiation
insular ribbon sign
sulcal asymmetry
hyperdense MCA sign
Management of stroke?
MDT approach: neuro, PTOTST
Education and counselling
Driving restrictions!
Medications: antiplatelets, anticoagulation if cardioembolic
Treat CVRF: HTN, DM, HLD
Smoking cessation
Surgical: intracranial bleeds, hydrocephalus
carotid endarterectomy
management of patient in acute stroke?
ABC approach
If bleed, control BP. otherwise allow permissive hypertension up to 220/110
rule out bleed
maintain euglycaemia, normothermia
if ischaemic stroke, assess for possibility of thrombolysis or mechanical thrombectomy with use of NIHSS
treat complications e.g. seizures, raised intracranial pressure, haemorrahagic transformation
IV hydration
neurological mimics of stroke?
seizures: todds paralysis
migraine with aura: hemiplegic migraine
structural lesion: subdural haematoma, tumour, AVM
trauma/ head injury
infection: abscess, encephalitis
multiple sclerosis
non neurological mimics of stroke?
metabolic: hypoglycaemia, uraemia, CO2 narcosis, electrolyte imbalances
sepsis
drugs: intoxication/withdrawal
syncope
labyrinthine disorder: vestibular neuritis
traumatic/ musculoskeletal: hip/ knee contusion or fracture
Rare causes of young strokes?
MELAS/ CADASIL/ CNS vasculitis: history of migraines
SLE: malar rash, alopecia, joint pains
Sjogrens
Behcets: mouth ulcers
Fabrys disease: Angiokeratomas, acroparesthesia, kidney disease
malignancy: constitutional symptoms
Recent neck trauma or manipulation: cervical artery dissection
Young onset TIAs, strokes: moyamoya
utility of NIHSS scoring
estimates stroke severity
guides treatment decision
enables uniform monitoring for progression
features of higher cortical dysfunction
aphasia, visual/sensory neglect, apraxia, agnosia
why is US carotid arteries not required for most posterior circulation strokes?
posterior circulation is supplied by vertebrobasilar system
- exception would be presence of foetal origin of the PCA
management of hyperacute stroke
stroke activation if within 6 hours of symptom discovery
- thrombolysis if symptoms <4.5h ago
- EVT (endovascular therapy) if <6h clinical and radiological criteria fulfilled
BP management after thrombolysis/ EVT?
usually IV labetalol or nicardipine
aim <180/105 post rTPA
AIm SBP <160 post EVT
antiplatelet therapy in stroke? when to consider DAPT
CHANCE trial: for mild strokes NIHSS <4, or high risk TIAs ABCD2 score 4 or more
- DAPT 3/52 then lifelong SAPT
SAMMPRIS trial: for ICAD, DAPT 3 months then lifelong SAPT
when to delay starting antiplatelet therapy or anticoagulation therapy in stroke?
ischaemic stroke with parenchymal haemorrhage
Malignant MCA infarct
large stroke with surgical decompression
when is carotid artery intervention indicated?
symptomatic carotid artery stenosis of >70%
-> carotid artery endarterectomy, carotid artery stenting
bilateral LL weakness, UMN pattern of weakness, normal sensation. causes?
MND
subcortical (multiple strokes)
parasagittal lesions (meningioma)
hereditary spastic paraparesis
Bilateral LL weakness, UMN pattern of weakness (Spastic paraparesis) with abnormal sensation (glove and stocking)
causes
cervical myelopathy
medical myelopathy (SACD, Tabes dorsalis)
spastic paraparesis with cerebellar signs?
causes
demyelinating disease: Multiple sclerosis
Friedrich’s ataxia
Spinocerebellar degeneration
Cervicomedually junction lesion
spastic paraparesis with abnormal sensation but not glove and stocking?
test for sensory level:
myelopathy, myelitis
spastic paraparesis, UL normal, where is the lesion?
lesion between T1-L2
- look at back for scars
- test for sensory level
- test abdominal reflexes
- Beevor’s sign
how to complete examination for spastic paraparesis?
Gait and assess function
DRE for anal tone and saddle anaesthesia
Scars and deformities of cervical spine
UL, CN examination and examine for cerebellar signs
causes of lesion between T1-L2?
compressive cord lesion (malignancy, infective, trauma)
transverse myelitis (demyelinating, infective, inflammatory)
anterior spinal artery occlusion: spinal infarct
Subacute combined degeneration of the cord
Tabes dorsalis
spastic paraparesis + spastic UL,
where is the lesion?
above C5
-> can do jaw jerk next
if jaw jerk normal: lesion is between pons and C5
if exaggerated, lesion is above mid pons
then ideally check CN, cerebellar signs
causes of spinal cord lesion above mid pons? with exaggerated jaw jerk
pseudobulbar palsy
MND
bilateral CVA
SOL
demyelinating disease
syringobulbia
causes of spinal cord lesion mid pons-C5 causing spastic paraparesis in all four limbs, with normal jaw jerk?
compressive cord lesions (malignancy, infection, trauma)
cervical myelopathy
transverse myelitis
syringomyelia
Subacute combined degeneration of the cord
tabes dorsalis
spinal infarct (anterior spinal artery occlusion)
Friedreich’s ataxia
spastic paraparesis + UL flaccid, where is the lesion?
LMN lesion at cervical cord
-> check CN for palsies
causes of spastic paraparesis with flaccid UL (ie. LMN lesion at cervical cord)?
MND
Cervical myeloradiculopathy
Syringomyelia
Cervicomedullary lesion
neuro examination: how to comment on one’s functional status?
use of mobility aids: wheelchair, stick
orthotic shoes
gait
what is Friedreich’s ataxia?
autosomal recessive disease hereditary ataxia causing spinocerebellar degeneration
- usually present as teens, inability to walk by 20s
- pes cavus, distal wasting, spastic LL (pyramidal weakness pattern)
- gait and limb ataxia, dysarthria (Cerebellar signs)
- loss of ankle +/- knee reflexes (degeneration of peripheral nerves)
- dorsal column loss (marked loss of cells in the dorsal root ganglion)
- scoliosis
spastic paraparesis with absent ankle +/- knee jerks
causes
fasciculations: MND
Cerebellar: Spinocerebellar degeneration (Friedreich’s ataxia)
Dorsal column loss: SACD, taboparesis
conus medullaris lesion
combined pathologies: cord compression + pre-existing peripheral neuropathy e.g. DM and cervical myelopathy
spastic paraparesis + dorsal column loss (loss of propioception and vibration sense), causes?
spinocerebellar degeneration
multiple sclerosis
SACD, taboparesis
features of MS to examine for if you suspect Multiple sclerosis
RAPD, INO, Optic neuropathy
Spastic paraparesis and inverted supinator jerk positive in UL?
C5-6 lesion
what is spinocerebellar ataxia?
inherited disorder with multiple subtypes >20
cx by cerebellar and spinal degeneration, slowly progressive with atrophy of cerebellum
Friedreichs ataxia- complications?
spine - scoliosis
Cardio: HOCM, AF
Fundoscopy: optic atrophy
Urinalysis for glycosuria
intellectual deterioration
Friedreich’s ataxia; differential diagnosis for spasticity, cerebellar and dorsal column loss?
multiple sclerosis
- usually has inceased reflexes compared to friedreich’s ataxia which has absent reflexes
what is subacute combined degeneration of the cord?
progressive disorder due to Vit B12 deficiency with degeneration of the corticospinal tracts and dorsal column of the spinal cord
causes of B12 deficiency
low intake, vegan
impaired absorption:
- gastrectomy
- pernicious anaemia: anti-IF, anti-parietal cell antibody
- small intestines: crohns, coeliac, SIBO
ix of subacute combined degeneration of the cord?
FBC - macrocytic anaemia
B12, folate
Anti-IF, parietal cell antibodies
Schilling test
screen with OGD if pernicious anaemia, or higher risk of gastric Ca
MRI spinal cord- degeneration of lateral corticospinal tracts and dorsal columns
management of subacute combined degeneration of the cord?
B12 replacement
- symptoms may recover if treated early, otherwise damage is usually permanent
what is taboparesis?
neurosyphilis infection
- caused by treponema pallidum infection
features of taboparesis?
spasticity with dorsal column loss (high steppage gait)
absent ankle jerks
charcot joints, trophic ulcers
LL before UL affected
incontinence, constipation
argyll-robertson pupils
stages of syphilis infection?
primary: painless chancre
secondary: maculopapular rash, acute syphilitic meningitis
tertiary: neurosyphilis, cardio syphilis, gummatous syphilis
ix of taboparesis?
TPHA: specific
once positive, will remain positive even after treatment
RPR: non specific, more to monitor treatment and reinfection
management of taboparesis?
penicillin
symptomatic management:
parasthesiae: analgesia, carbamazepine
ataxia: PTOT
Bladder: avoid anticholinergics, self catheterisation
what does MND not involve?
no sensory deficit
no ccerebellar disorder
no ocular involvement
what is lhermittes phenomenon
tingling or electric sensation that passes down the spine with flexion of the neck
causes include: MS, cervical myelopathy (reversed lhermitte’s - occurs on extension of neck), SACD
what causes fasciculation?
sign of LMN disease with denervation
spontaneous firing of large motor units formed by branching fibres of surviving axons striving to innervate the muscles that have lost their nerve supply
clinical features of cervical myelopathy?
spasticity exceeds weakness, symptoms exceeds signs
look for wasting and weakness of C5/6 as this is the most common area for spondylosis
passive abduction of the little finger (myelopathy hand sign)
inverted supinator jerk
sensory - often no sensory loss, but may have loss of propioception and vibration
generic neurolocalisation groups
muscle
NMJ
nerve
anterior horn cell
spinal cord
brain/ brainstem
myopathies causing flaccid paraparesis?
inflammatory myopathy (poly, dermatomyositis)
rhabdomyolysis
periodic paralysis (hypoK)
metabolic derangements (hypomg, hypoCa, HypoPO4)
thyroid or steroid myopathy
acute alcoholic necrotizing myopathy
NMJ causes of flaccid paraparesis?
myasthenia gravis
botulism
tick paralysis
organophosphate toxicity
LEMS: lambert eaton
nerve causes of flaccid paraparesis?
GBS
multifocal motor neuropathy
Lyme disease, HIV
Sarcoidosis
drugs, toxins
vasculitis including lupus, polyarteritis nodosa
paraneoplastic, paraproteinaemias
Cauda equina syndrome
brachial, lumbosacral plexopathy
anterior horn cell disease causing flaccid paraparesis?
poliomyelitis
kennedys disease (spinobulbar atrophy)
MND
other spinomuscular atrophies
spinal cord lesions causing flaccid paraparesis?
Affecting anterior horn cells (LMN)
inflammatory: transverse myelitis
Spinal cord infarct
brain/brainstem causes of flaccid paraparesis?
pontine lesions e.g central pontine myelinolysis
Features of poliomyelitis?
Usually would present with the paralytic form in paces
Flaccid Paralysis and wasting in bulbar or spinal distribution
Pathophysiology of poliomyelitis
Polio virus is an enterovirus spread via oro faecal route or contaminated water
Replicates in the nasopharyngeal and GIT then haematological spread with predilection to the anterior horn cells of the spinal cord or brain stem with flaccid paralysis in spinal or bulbar distribution
Ix of polio
Viral cultures or PCR from stool, throat, csf
Poliovirus antibodies
Management of polio
Education and counselling
PTOT
Care of limbs
Medical: treat complications
Eg pain, respiratory failure, clear bowels
Management of polio
Education and counselling
PTOT
Care of limbs
Medical: treat complications of pain, respiratory failure, clear bowels
Prevention of polio
Inactivated polio vaccine- Salk vaccine which is administered parenteral
Oral live vaccine- can result in poliomyelitis so contraindicated in immunodeficient individuals
What is spina bifida?
Incomplete closure of the bony vertebral canal
Usually in lumbosacral region, can also involve the cervical region and associated with hydrocephalus
Features of spina bifida?
- scars, tufts of hair, dimples, sinus, naevus, lipoma
- asymmetric LMN signs of LLs
Features of spina bifida?
- scars, tufts of hair, dimples, sinus, naevus, lipoma
- asymmetric LMN signs of LLs
- L5, S1 dermatomal loss
- bladder involvement
Causes of spina bifida
Multifactorial aetiologies: folic deficiency, maternal use of sodium valproate, family history of spina bifida
Prevented with use of folic acid in early pregnancy
Features of cauda equina syndrome
Low back pain
Unilateral/ bilateral sciatica
Saddle anaesthesia
Bladder and bowel disturbances
Variable motor and sensory LL abnormalities
Features of cauda equina syndrome on examination?
Bilateral knee and ankle jerks absent
Flaccid paralysis, asymmetrical
Saddle anaesthesia
Sphincter disturbance occurs late
Features of conus medullary lesion on examination
Spastic paraparesis, symmetrical
More LBP
Knee jerks preserved, ankle absent
Perianal loss of sensation
Frequent impotence
Sphincter disturbance early
Features of guillain barre syndrome
Progressive ascending muscle weakness
Variable patchy sensory loss
Hyporeflexia
Autonomic disturbances such as tachycardia and labile bp
Complications:
Respiratory failure
Features of L5 radiculopathy?
Weakness of hip abduction and internal rotation,
Weak foot dorsiflexion (foot drop)
loss of foot inversion and eversion
plantar flexion preserved
Loss of ankle reflex
Sensory loss over dorsum of foot and lateral calf + big toe
Features of common peroneal nerve palsy?
Weak ankle and toe dorsiflexion, foot eversion
Wasting of anterior tibialis muscles
Foot inversion and plantar flexion normal (innervated by posterior tibial nerve)
Reflexes all normal
Sensory loss over lateral calf and dorsum of foot
Features of palsy of deep peroneal nerve
Deep branch supplies the ankle +
toe dorsiflexion (foot drop)
- eversion spared (supplied by superficial branch)
Normal reflexes
Sensory loss only over first interdigital web space
Causes of common peroneal nerve palsy?
Trauma
Surgery
Compression at fibula head
Mononeuritis multiplex
Leprosy
CIDP
Ischaemia/ vasculitis
How to complete examination in patient with foot drop?
Gait
Walking aids
Look for cause of foot drop (scars, fibular head lesion, spinal lesions)
Offer Dre to assess for anal tone and spinal anaesthesia
What motor function does the posterior tibial nerve control ?
Foot inversion and plantarflexion
In common peroneal nerve palsy, need to differentiate further how to differentiate between common peroneal nerve or deep branch only or superficial branch only
Superficial branch: weak foot eversion, sensation lost over lateral calf and dorsum of foot
Deep: weak ankle and big toe dorsiflexion, sensation lost over first interdigital web space
Ix common peroneal nerve palsy?
NCS and EMG
Mx of common peroneal nerve palsy?
PTOT- 90 degrees splint at night
Surgery: for severed nerve or excision of ganglion
How are reflexes affected in sciatic nerve palsy?
l4, L5, S1/2
Knee jerk intact
Ankle jerks and plantar response absent
How are reflexes affected in L5 radiculopathy?
Loss of ankle reflex
What differentiates L5 nerve root compression from common peroneal nerve palsy
l5 nerve root,
Hip abduction and IR affected
Foot inversion affected
Loss of ankle reflex
What differentiates sciatic nerve palsy from common peroneal nerve palsy?
Loss of ankle reflex and plantars absent
Knee flexion weak
Foot plantarflexion weak
Features of anterior cord syndrome?
Ventral 2/3 of spinal cord affected
Dorsal columns spared
Bilateral weakness with LMN signs at level of lesion and UMN signs distal to lesion
Bilateral loss of pin prick and temp sense
-> commonly seen in anterior spinal artery infarct
Features of complete transection of spinal cord eg cord trauma/ transverse myelitis
LMN signs at level of lesion
UMN signs caudal to level of lesion
dorsal columns + corticospinal tracts affected?
Subacute combined degeneration of the cord
Dorsal columns + corticospinal tracts + spinocerebellar tracts affected?
Spinocerebellar degeneration:
Proprioception and vibration sensory loss
weakness
Cerebellar dysfunction
Central cord syndrome eg syringomyelia, hydromyelia, tumour. Features
Usually bilateral weakness with LMN signs at level of lesion and UMM signs caudal to level of lesion (spastic paraparesis)
Loss of pin prick and temp sense with sparing of dorsal columns
Causes of dorsal column loss of function ?
Tabes dorsalis
DM
B12 deficiency
Local lesion trauma infarct tumour haemorrhage
Posterior spinal artery infarct-> would cause ipsilateral dorsal column dysfunction
Brown sequard syndrome features
Ipsilateral weakness
Ipsilateral loss of proprioception and vibration
Contralateral loss of pain and temp
Usually anaesthesia at level of lesion and area of hyperaesthesia just below level of lesion
Causes of brown sequard syndrome
Syringomyelia
Cord tumour
Trauma: Bullet/ stab wounds, haematomyelia
Degenerative disease of spine: cervical spondylosis
Multiple myeloma
Infection: abscess
Immune: MS
What are the different types of movement disorders?
Tremors
Chorea
Athetosis
Hemiballismus
Orofacial dyskinesias
What are the different types of tremors you may see?
Resting tremors in Parkinsonism
Intention tremor of cerebellar
Postural tremor of outstretched hands (anxiety, thyrotoxicosis, ETOH withdrawal, alcohol, drug induced ie salbutamol/ theophylline, Bzd withdrawal, familial)
Causes of hemiballismus
Subthalamic nucleus affected
- infarct
- abscess, tumour, AVM, MS
Chorea occurs when which part of the brain is affected?
Globus pallidus
Can be stroke/ SOL/ MS etc
spastic paraparesis - what are the 3 things to test?
1) sensation: normal? Glove and stocking loss? Sensory level?
2) cerebellar signs
3) UL: pronator drift, tone, reflexes
spastic paraparesis with dorsal column loss but pinprick sensation intact?
spinocerebellar degeneration
MS
SACD
taboparesis
young patient
pes cavus, distal wasting, spastic LL (pyramidal weakness pattern)
gait and limb ataxia
Friedreich’s ataxia
differential for spasticity, cerebellar, dorsal column loss
freidreichs ataxia: usually absent knee +/- ankle jerks
multiple sclerosis: usually assoc with increased reflexes
unilateral foot drop, LMN pattern of weakness, both knee flexion and extension are weak
Anterior horn cell
polyradiculopathy
lumbosacral plexopathy
how to differentiate between plexopathy and radiculopathy?
Nerve conduction studies and needle electromyography are particularly helpful in distinguishing radiculopathy from plexopathy. Sensory nerve action potentials are generally abnormal in plexopathy, but spared in most radiculopathies.
approach to a unilateral ptosis?
first to rule out pseudoptosis (droopy eyelids)
see if there is a horner’s syndrome (miosis)
unilateral Horner’s syndrome - examine the other cranial nerves to look for?
potential causes
Cavernous sinus syndrome
Superior orbital syndrome
Lateral medullary syndrome
Syringobulbia (V, VII, IX-> XII)
Multiple sclerosis (INO, RAPD, cerebellar)
unilateral horner’s syndrome
what to examine in the upper limbs?
- pronator drift then cerebellar signs (lateral medullary syndrome)
- Wasting of ipsilateral small muscles of hands (T1)
- Clubbing
- Sensory loss T1
- Dissociated sensory loss (syringomyelia)
- Contralateral loss to pain and temperature (lateral medullary syndrome)
- axilla: trauma to brachial plexus
unilateral horner’s syndrome: what to request for for patient history?
loss of sweating and level
main differentials for bilateral ptosis?
1) Muscle:
- Myopathy e.g. myotonic dystrophy, CPEO, ocular myopathy, oculopharyngeal myopathy
- Local infiltration
2) NMJ: Myasthenia gravis
3) III nerve bilaterally: GBS/ Miller fisher syndrome, Midbrain (Nuclear III)
bilateral horner’s (syringomyelia)
patient with suspected myasthenia gravis, what to examine for in the eyes?
ptosis with fatiguability
variable strabismus and diplopia that occurs after some time
check for hyperthyroid and thyroid eye disease
check for anaemia
check for malar rash of SLE
patient with suspected myasthenia gravis, what to examine for in the face?
VII- show teeth
assessment of speech: count 1-20, nasal voice (bulbar palsy)
masseter weakness but pterygoids normal
check neck for goitre and scars
patient with suspected myasthenia gravis, what to examine for in the ULs?
normal deep tendon reflexes (Lambert eaton and miller fisher assoc reduced reflexes)
normal sensation
fatiguability with weakness
signs of RA, SLE features
patient with suspected myasthenia gravis, what to examine for in the chest?
thymectomy scar
plasmapheresis line
associated conditions of myasthenia gravis
endocrine: thyroid, DM, pernicious anaemia
Connective tissue disorders: RA, SLE, polymyositis
myasthenia gravis: how to complete your examination?
checking negative inspiratory force, forced vital capacity
temperature chart
drug history
signs of a pancoast tumour causing ipsilateral horners syndrome
supraclavicular dullness
tracheal deviation
small muscles of hands -wasting
loss of pain sensation in UL
clubbing
features of isolated VI nerve palsy?
failure of abduction of affected eye
convergent strabismus at primary gaze
diplopi where image is side by side and further on gaze at affected size, with disappearance of the outer image on covering the affected eye
-> suggests lateral muscle weakness and VI nerve palsy
isolated CN VI nerve palsy? what to perform on examination
- eye examination: rule out MG, thyroid eye disease
- rule out cavernous sinus/ superior orbital fissure syndrome
- check other CN for CPA tumour (V, VII, VIII), base of skull lesions (XI, X, XI, XII)
examine upper limbs:
hemipleigia (long tract signs suggesting brainstem)
cerebellar signs (CPA lesion, Miller fisher usually truncal and gait ataxia)
reflexes for areflexia (miller fisher)
CN VI palsy what to request for on completion of examination?
fundoscopy: papilloedema from raised ICP, optic atrophy for MS, DM or hypertensive retinopathy
field testing (bitemporal hemianopia)
acuity (reduced in orbital lesions)
corneal testing for reduced sensation from V1 involvement (cavernous sinus/ superior orbital syndrome)
BP
urine dipstick
Fever chart- meningitis
Ask for retrobulbar pain
causes of unilateral VI nerve palsy?
brainstem (pons): infarct, haemorrhage, demyelination (MS), abscess
meningitis
CPA lesions
cavernous sinus / superior orbital syndrome
miller fisher syndrome
mononeuritis multiplex
DM, HTN
MG
raised ICP
most commonly: ischaemic CN VI palsy in adults
causes of bilateral CN VI nerve palsy?
leptomeningeal causes: leptomeningeal carcinomatosis, NPC with secondaries, lymphoma, radiotherapy
miller fisher syndrome
mononeuritis multiplex
MG
raised ICP
wernicke’s encephalopathy (opthalmoplegia, confusion, ataxia)
central syndromes associated with VI nerve palsy?
raymond’s syndrome: ipsilateral VI with contralateral hemiparesis
millard-gubler: ipsilateral VI and VII with contraleteral hemiparesis
peripheral syndromes associated with VI nerve palsy?
CPA (V, VI, VII, VIII + cerebellar)
superior orbital (III, IV, VI + V1)
Cavernous sinus (III, IV, VI + V1 and 2)
Gradenigo syndrome: inflammation of the tip of the petrous bone from mastoiditis; VI, V and VII
how to evaluate diplopia?
- double vision is maximal in the direction of gaze in the affected muscle
- false image is the outer image
- false image arises from the affected eye
what is cavernous sinus syndrome?
lesion in the cavernous sinus leading to:
ophthalmoplegia, V1, v2, Horners, proptosis, chemosis, pain
causes of cavernous sinus syndrome
carotid aneurysm, carotid-cavernous fistula, tumour, thrombosis, tolosa hunt syndrome
what is Miller fisher syndrome?
triad of ophthalmoplegia, ataxia, areflexia
- presence of antiGQ1B antibodies
- variant of GBS
causes of mononeuritis multiplex
endocrine: DM, HTN
Autoimmune: GPA, eGPA, PAN, Sjogrens, SLE, RA
Infective: lyme, leprosy
Infiltrative: amyloid, sarcoid
ix of VI nerve palsy?
Bloods: Fasting glucose, ESR, ANA, VDRL
Imaging; CT/MRI brain
vascular imaging if proptosis/chemosis looking for cavernous sinus thrombosis or dural carotid-cavernous fistula
LP: if bilateral/systemic illness
8-30% remain cryptogenic after workup
management of CN VI palsy?
education
avoid driving/ operating heavy machinery
treat underlying cause: e.g. DM/ HTN
symptomatic treatment:
patch, prism
if chronic, chemodenervation with botox, or strabismus surgery
prognosis for CN VI palsy
most either spontaneously improve or have underlying lesion found
ischaemic palsies almost always recover completely in 2-4 months while some recovery seen in half of traumatic cases
if no recovery over 3-6 months then suspect underlying lesion such as tumour
- > follow regularly looking for emergence of new localising signs, ensure adequate neuroimaging and ENT evaluation
“examine this patient’s speech”
-> what to look for
look for unilateral weakness
ataxia of UL (cerebellar)
tremors (Parkinsonism)
Dysphonia: recurrent laryngeal nerve involvement
- offer to examine left chest, radiation marks, enlarged cervical LNs, look for horners and wasting of T1
Dysarthria:
- British constitution, Bababa, lalala, kakaka
Dysphasia:
expressive, receptive (give 1,2,3 step instructions), conductive, global
if dysphasia found: demonstrate other cortical signs
-> visual fields, sensory or visual inattention, graphaesthesia, astereognosis
“examine this patient’s cortical function”
evaluate for obvious gaze preference or hemiparesis
test which side is affected with inattention:
visual inattention
sensory inattention
line bisection test
test visual fields for hemianopia
test for dysphasia
look for pronator drift
test functions of each lobe
aetiology: pulse, carotid bruit, murmur, hyperlipidaemia, DM dermopathy, tar stains
request for BP, urinary analysis for DM, fundoscopy (papilloedema)
test for occipital lobe function
cortical blindness
hemianopia with macula sparing
test for temporal lobe function
superior quadrantonopia
receptive dysphasia
short and long term memory
test for parietal lobe function
gerstmanns: acalculia (serial 7 subctraction),
agraphia (inability to write)
L-R disorientation
finger agnosia
constructional (copy a cub) and dressing apraxia, spatial neglect
test for frontal lobe function
expressive dysphasia
labile emotion, personality changes
gait apraxia
esotropia ->
6th nerve palsy
exotropia
3rd, 4th nerve palsy
complex ophthalmoplegia causes
central: INO, wernickes
nerves: miller fisher
NMJ: MG
Myopathies: thyroid eye disease, CPEO
LMN unilateral facial droop + CN 5th/ 6th and 8th involvement?
cerebellopontine angle lesion
LMN unilateral facial droop + 8th CN palsy?
internal auditory canal lesion
LMN unilateral facial droop + cerebellar signs
lateral medullary syndrome
or
middle cerebellar peduncle
LMN unilateral facial droop + long tract signs
pontine lesion
UMN facial droop + long tract signs, neurolocalisation
pontine and above
cranial nerve examination, how to complete examination
fundoscopy
visual field defect
proper assessment of visual acuity with snellen chart
check corneal reflex- afferent CN V1, efferent VII
check gag reflex- afferent CN IX, efferent X
CN palsies single or multiple: how to work through?
1) part of CN club? ie. cavernous sinus
2) base of skull/meningeal disease
3) polyneuropathy: GBS/ MFS
4) brainstem (except for II)
Unilateral CN III, IV, VI + V1 + II optic nerve palsy
orbital apex syndrome
Unilateral CN III, IV, VI + V1 palsy
superior orbital fissure syndrome
Unilateral CN III, IV, VI + V1 and V2 palsy
Cavernous sinus syndrome
Ipsilateral horners, CN V, IX, X, cerebellar, nystagmus
contralateral pain and temp
lateral medullary syndrome
ipsilateral CN XII palsy + contralateral dorsal column and pyramidal tract palsy
medial medullary syndrome
unilateral CN V, VI, VII, VIII, IX palsy + cerebellar?
cerebellopontine angle syndrome
unilateral CN IX, X, XI palsy +/- XII
jugular foramen
bilateral UMN CN IX, X, XI, XII palsy
pseudobulbar palsy
bilateral LMN CN IX, X, XI, XII palsy
bulbar palsy
what is part of the CN clubs
orbital apex
superior orbital fissure
cavernous sinus
lateral medullary syndrome
cerebellopontine angle
jugular foramen
base of skull /meningeal disease causing CN palsies?
NPC
meningitis - bacterial, TB
carcinomatous meningitis- melanoma, lymphoma, adenoCa
arnold chiari malformation
infiltrative- sarcoidosis, amyloidosis
Horner’s + CN V, VII, IX, X, XI, XII palsy
usually unilateral can progress to bilateral
syringobulbia
signs of bulbar palsy?
slurred / nasal bulbar speech, difficulty with consonants
atrophic tongue with fasciculations
palatal weakness
pooling/ dribbling of saliva
weakness/ wasting of SCM
jaw jerk normal or absent
weakness of soft palate
gag reflex absent
what signs to look for to suggest aetiology of bulbar palsy?
surgical and radiation scars (NPC)
UL and LL examination -look for signs of LMN lesion and fasiculations
what is bulbar palsy?
bilateral LMN CN IX, X, XI, XII palsy
-lesion at medulla or lower
what is pseudobulbar palsy?
UMN bilateral CN IX, X, XI, XII palsy
- usually in the internal capsule
signs of pseudobulbar palsy?
pseudobulbar “hot potato” speech
small spastic tongue
palatal weakness
pooling of saliva
brisk jaw jerk
gag reflex may be normal/ brisk
look for:
surgical and radiation scars (NPC)
UL and LL examination- look for signs of UMN lesion
AF, xanthelasma, DM dermopathy
causes of bulbar palsy?
MND
syringobulbia/myelia
brainstem tumour e.g. NPC
medullary infarct
poliomyelitis
GBS
MG
causes of pseudobulbar palsy?
MND/ALS
high brain stem lesion/ tumour e.g. NPC
MS
bilateral hemispheric infarct/ trauma
causes of jugular foramen syndrome?
ca of pharynx (most common)
basal meningitis
pagets disease
thrombosis of jugular vein
examination of a homonymous hemianopia?
lesion affecting optic radiation or visual cortex of occipital lobe
can start with visual fields to confirm
CN II- XII
- involvement of other CN palsies may be present in posterior circulation stroke causing brainstem pathology along w occipital lobe
screen for other long tract signs:
sensory or tactile neglect
pronator drift
UL weakness
babinkski for upgoing plantars
screen for cerebellar signs:
dysmetria
screen for cause of stroke:
cardiovasc: pulse, cardiac murmur, carotid bruit
