Neurology_Medicine & Surgery Flashcards

1
Q

Neuroanatomy - blood supply to the brain

A

Circle of Willis - perfuses brain

  • Cerebral arteries - anterior, middle, posterior (all bordering the circle)
    • ACA - supplies anterior & medial brain (frontal lobe + medial motor & somatosensory cortices) –> behavioural changes, weakness legs > arms, mild sensory defect
    • MCA - supplies the lateral brain (lateral motor & somatosensory cortices, language - Broca & Wernicke’s, optic tracts) –> weakness face > arms > legs, aphasia (expressive/receptive), hemisensory defect, homonymous hemianopia
    • PCA - supplies inferior & posterior brain (affecting visual cortex and tracts) –> homonymous hemianopia, visual agnosia/prosopagnosia
  • Major arteries giving rise to the circle of Willis:
    • Vertebral artery (from the spine)
    • Internal carotid artery (gives rise to A & M cerebral arteries)
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2
Q

UMN vs LMN:

  • Motorpathway name + route
  • UMN & LMN lesion causes and signs
A

Corticospinal tract = voluntary motor pathway for body:

  1. Cortex - primary motor cortex (posterior frontal cortex)
  2. Medulla - tracts from PMC converge and cross over = pyramids
  3. Spinal cord - UMN synapases with LMN
  4. Peripheral nerves - LMN innervates muscle

UMN lesions

  • Causes (anything affecting brain itself): stroke, SOL, MND, MS
  • Signs: hypertonia, hyperreflexia, spasticity (velocity/direction-dependent), upgoing plantars, pronator drift
  • NOTE: increased tone/reflexes as -ve feedback loop from the brain is removed

LMN lesions

  • Causes (affect peripheral nerves): MND, trauma, polio, GBS
  • Signs: hypotonia, hyporeflexia, muscle atrophy, fasciculations, fibrillations
  • NOTE: reduced tone/reflexes because no nerve supply
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3
Q

Intracranial bleeds - layers of the outer brain? types? Appearance on CT-head? Presentations?

A

Outer layers of the brain:

  • Skull > dura mater (adherent to inside of skull) > arachnoid mater > pia mater > brain parenchyma

Types:

  • Extradural haemorrhage- bleed between dura mater & skull
    • Most common = skull fracture of pterion (temple) –> trauma to middle meningeal artery
    • Hx: clear trauma –> transient LoC –> lucid interval –> ongoing headache –> reduced consciousness
    • Convex (EGG) appearance on CT-head as blood sealed in by dura ± soft-tissue oedema outside skull (trauma site)
    • Mx: A-E approach, refer to neurosurgery
      • Monitor GCS = deterioration
  • Subdural haemorrhage - bleed between dura & arachnoid mater
    • Tearing of bridging veins going from outer surface of brain to dura mater
    • Common in elderly + alcoholics (both have cerebral atrophy)
    • Types: both concave (SICKLE) appearance on CT-head
      • Acute - assoc w/ trauma + blood white (hyperdense) on CT-head
      • Chronic - little/no Hx of head trauma e.g. fall several weeks ago and then not been normal since (elderly) + dark (hypodense) blood on CT-head
      • Reduced consciousness, if severe = focal neurology (esp. if midline shift)
    • Mx: A-E, neurosurgery referral
      • Monitor GCS, reverse Warfarin
  • Subarachnoid haemorrhage - between arachnoid & pia matter
    • Caused by an aneurysm (berry) or trauma
    • Presentation: sudden-onset worst headache ever, photophobia, neck stiffness
    • LP 12hrs after Sx-onset (xanthochromia)
    • Mx: A-E approach
      • Monitor GCS and neuro obs
      • Discuss with neurosurgery
      • Other – fluids, monitor Na, nimodipine
    • Complications:
      • Vasospasm – presents like a stroke
      • Hyponatraemia – can be SIADH
      • Rebleed - coil ASAP if possible
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4
Q

Headache - types? Ix? Mx?

A

Types:

  • Tension - band-like, front of forehead, causes: dehydration, stress
  • Cluster - intense pain behind/around eye (worse @night + lacrimation & ptosis during attack), daily clusters for 4-6wks then nothing for months, M>F
    • Mx: 100% O2 + nasal triptans
  • Migraine - intense/throbbing, focal, aura, photophobia
    • Triggers: alcohol, chocolate, cheese, oestrogens (OCP)
    • Mx:
      • Acute - simple analgesia, dark room + Triptans (take as soon as Sx start)
      • Prevent - trigger avoidance + propranolol/ topiramate (anticonvulsant, terratogenic) /amitriptytline (TCA)
  • Meningitis - generalised, moves down neck, neck stiffness + fever + rash (meningococcal)
    • Ix: CT-head, LP (type of meningitis), BC (causative organism)
    • Mx:
      • Suspected in primary care - IM/IV Benzypenicillin
      • Secondary care - IV Ceftriaxone ± Amoxicillin (infants/>50yrs)
      • If could be encephalitis (seizure/behavioural) - IV Aciclovir
  • SAH - sudden-onset, worst headache ever ± neck stiffness, can get preceding sentinel bleed (minor), assoc w/ PCKD (Berry aneurysm in Circle of Willis)/Marfan’s
    • Ix: non-contrast CT –> LP for xanthochromia (after 12hrs)
    • Mx: nimodipine (CCB, give every 4hrs, reduces vasospasm in cerebral arteries)
  • Giant cell (temporal) arteritis - vasculitis –> scalp tenderness, jaw claudication, vision loss, assoc w/ polymyalgia rheumatica (>50yrs)
    • Ix: ESR, temporal artery biopsy
    • Mx: high-dose Prednisolone (to prevent blindness, do not wait for biopsy)
  • ​Trigeminal neuralgia - electric shock-like pain on touching face (extremely tender)
    • Divisions of trigeminal nerve (V2&3)
    • Ix: MRI brain
    • Mx: Carbamazepine (for pain), neurology referral
  • Raised ICP - worse at night/on waking/coughing/straining ± N&V, visual disturbances
    • Mx: osmotic diuresis - mannitol/hypertonic saline
  • Cerebral Venous Sinus Thrombosis (VTE in the brain) - papilloedema, 6th nerve palsy, seizures, Cushing’s reflex (HTN, bradycardia, Cheyne-Stokes breathing)
    • Ix: MRI w/ MR venography
    • Mx: LMWH
  • Idiopathic intracranial HTN (IIH) - Obese, female, papilloedema, postural headache worse with straining, assoc w/ OCP
    • Ix: visual field testing, fundoscopy, MRI brain, LP (≥25 opening pressure)
    • Mx: acetazolamide (carbonic anhydrase inh), weight loss, LPs + VP/LP shunt, ophthalmology follow-up
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5
Q

Cardiovascular accident (CVA) - Def? Presentation? DDx? Classification? Ix? Mx?

A

Def: better to use cardiovascular accident (CVA)

  • Stroke ≥24hrs, TIA ≤24hrs

Presentation:

  • Pyramidal weakness (flexors stronger than extensors in upper limb, opposite in lower limb), hypertonia, hyperreflexia
  • Hemiplegic/scissor gait –> circumduction
  • TIA: Amaurosis Fugax (black curtain)
    • If ≥2 in 1wk = high risk of stroke –> ADMIT
    • Aspirin 300mg + secondary prevention (as for stroke)

DDx:

  • Cerebral lesion - 80% ischaemic, 20% haemorrhagic (reduced GCS & raised ICP)
  • Neoplastic - SOL
  • Rare: syphilis, Todd’s paralysis (post-ictal), migraine, MS, cerebral abscess, rheumatological (arteritis)

Classification: Bamford aka Oxford

  • Total anterior circulation stroke: hemiplegia, homonymous hemianopia, higher cortical dysfunction
  • Partial anterior circulation stroke: 2/3
  • Lacunar circulation stroke: hemi-motor OR hemi-sensory stroke only
  • Posterior stroke: cranial nerve problems, eye-movement disorder, cerebella presentation
    • Weber’s & Wallenberg’s (lateral medullary syndrome = posterior cerebellar artery infarct)

Ix:

  • BEFORE Tx = CT-head - 80% strokes ischaemic, 20% haemorrhagic (wrong Tx will make it much worse) –> haemorrhage has an area of hyperdense (white) bleeding
  • After initial Mx –> identify cause:
    • ​​Structural heart defect - echocardiogram
    • AF - ambulatory ECG (24hr tape if no obv sign of AF as outpatient)
    • Carotid atherosclerosis - carotid doppler –> carotid artery stenosis (70-99%) = carotid endarterectomy

Mx: A-E approach + URGENTLY contact stroke team –> dedicated stroke unit, if ischaemic:

  • Immediately:
    • Aspirin 300mg OD + STOP anticoagulants (high risk of haemorrhagic transformation in first 2wks)
    • <4.5hrs since Sx onset: thrombolysis (Alteplase = tPA)
      • C/I: any sign of active bleeding, very high BP, recent surgery, raised ICP
    • >4.5hrs since Sx onset: conservative Mx:
      • BM - keep controlled <11 (sliding scale insulin)
      • NG tube (nutrition)
      • MDT - dietician, SALT, PT/OT
    • < 6hrs (sometimes up to 24hrs, depending on size, area, damage) –> thrombectomy (neurosurgery)
  • After 2wks:
    • STOP aspirin –> start clopidogrel 75mg OD + consider anticoagulation (e.g. if AF) - DOAC/Warfarin
    • Manage vascular RFs (DM, HTN, QRISK etc.)
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6
Q

Parkinson’s disease definition? Cardinal Sx? DDx? Ix? Mx? Complications?

A

Def: a neurodegenerative disease of dopaminergic neurones of substantia nigra (part of basal ganglia in the midbrain)

Cardinal Sx (from extrapyramidal involuntary dysfunction): resting tremor, rigidity (cogwheeling due to superimposed tremor), bradykinesia, postural instability

+ insomnia, hypomimia (mask face), depression, autonomic dysfunction

DDx:

  • Benign essential tremor - bilateral, postural, FHx, alcohol improves it (in 50%)
  • Drug-induced (anti-psychotic, metoclopramide) - drug chart
  • MSA (multisystem atrophy) incl Shy-Drager (autonomic) - cerebellar signs
  • PSP (progressive supranuclear palsy) - loss of downward gaze
  • LBD (Lewy body dementia) - visual hallucinations
  • Normal-pressure hydrocephalus - gait disturbance, cognitive impairment, impaired bladder control
  • Other:
    • Corticobasal degeneration - single-arm signs, alien limb syndrome (myoclonus)
    • Wilson’s disease (copper) - motor

Ix: clinical Dx –> dopaminergic agent trial ± MRI scan/DAT scan

Mx: problem = lack of dopamine in substantia nigra –> aim of Tx is to increase dopamine here

  • Dopamine agonist (cross BBB):
    • Good for younger patients to reduce time on levodopa (as get very sensitised)
    • Types:
      • Non-ergot - ropinirole, pramipexole - avoid below SEs = 1st line but still get dopamine dysregulation syndrome (hypersexuality & gambling)
        • SC Apomorphine for advanced disease
      • Ergot - cabergoline, bromocriptine –> retroperitoneal/pulmonary fibrosis
  • L-DOPA (levodopa) AND peripheral DOPA-decarboxylase enzyme (Carbidopa)’ = Sinemet/Medapar
    • Relevant physiology:
      • Substantia nigra contains dopaminergic neurones with DOPA decarboxylase (converts L-DOPA –> dopamine) - not happening as normal in Parkinson’s
      • Peripheral DOPA-decarboxylase in body
      • Chemoreceptor trigger zone (CTZ) –> triggers nausea & vomiting
    • Drug explanation:
      • If give L-DOPA by itself it will be broken down by peripheral DOPA-decarboxylase into dopamine - this can’t cross BBB to reach substantia nigra but can reach CTZ –> nausea/vomiting
      • Instead, give L-DOPA with peripheral DOPA-decarboxylase inhibitor to allow more L-DOPA to cross BBB to reach dopaminergic neurones in substantial nigra to be converted to dopamine (some still reaches CTZ –> SE of nausea/vomiting)
    • Other SEs: dyskinesia, on-off phenomena, postural hypotension
      • Amantadine - for dyskinesia secondary to levodopa
      • COMT inhibitors e.g. entacapone for tailing off betw/ doses of levodopa

Complications:

  • Falls, cognitive impairment, depression
  • Drool (SALT/glycopyrronium)
  • Meds SEs (e.g. vomiting)
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7
Q

Rigidity vs Spasticity

A

Rigidity (in Parkinson’s disease) = increased muscle tone, that is not velocity or direction-dependent

  • In Parkinson’s get Cogwheeling = rigidity overlayed by tremor

Spasticity (in Stroke) = increased muscle tone, that is velocity or direction-dependent

  • Flexors/extensors become imbalanced in strength - certain directions have increased muscle tone (not all) AND worse stiffness if move arm more quickly
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8
Q

Dementia - Types?

A

Types:

  • Alzheimer’s disease
    • ​Progressive decline in cognitive function
    • Tx: Acetylcholinesterase inhibitors (Donepezil)/NMDA receptor antagonists (Memantine)
  • Vascular dementia
    • A stepwise decline in cognitive function
    • Background of vascular disease (IHD, PVD)
  • Dementia with Lewy Bodies
    • ​Triad - dementia, hallucinations, parkinsonism
    • Balance - Parkinsonism = dopamine def vs hallucinations = dopamine excess
  • Frontotemporal - personality changes, early onset
  • Depressive pseudodementia - disinterested, low mood
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9
Q

What are the nerve innovations for deep tendon reflexes in upper and lower limb neuro examination?

A

Nerve innovations:

  • S1,2 - buckle my shoe - ankle jerk (Achilles tendon)
  • L3,4 - kick the door - knee jerk (patellar tendon)
  • C5,6 - pick up sticks - biceps, brachioradialis reflex
  • C7,8 - lay them straight - triceps reflex
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10
Q

MRC Power Scale

A
  • 1 flicker
  • 2 is moves with gravity removed
  • 3 is movement against gravity
  • 4 is reduced power against resistance
  • 5 is normal
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11
Q

Gait abnormalities vs normal

A

SUMMARY:

  • Normal gait cycle: 1) heel strike 2) foot flat 3) mid stance 4) heel off 5) toe-off
  • Antalgic gait - limping due to pain e.g. osteoarthritis, inflammatory joint disease, fracture, sciatica
  • Hemi/Diplegic gait - uni/bilateral circumduction of leg - CNS lesion (bilateral is called a ‘scissoring gait’)
  • Parkinsonian gait - shuffling gait, no arm swing - Parkinson’s/DLB/Antipsychotics
  • Ataxic gait - wide/broad-based stance & imbalance - Cerebellar/Vestibular/Sensory neuropathy
    • NOTE: can’t do tandem walk
  • Neuropathic gait - high-step gait (from foot drop) - motor neuropathy e.g. L5 radiculopathy (e.g. herniated disc), common peroneal neuropathy, MS, Charcot-Marie-Tooth disease
    • Can’t walk on heels
  • Myopathic gait - waddling/Trendelenburg gait (hip sways to one/both sides - hip abductor muscles weak) - muscular dystrophy/myopathy
  • Choreiform gait - involuntary movements - Basal ganglia disease e.g. Parkinson’s meds, Huntington’s, Wilson’s, Cerebral Palsy
  • Stomping gait - sensory neuropathy (loss of proprioception & vibration sense = dorsal column disease)
    • Vibration –> proprioception (Romberg’s +ve) –> light touch (in order lost)
    • Causes: SACD (subacute combined degen cord - B12), Friedrich’s ataxia, Tabes/taboparesis & tabes dorsalis (syphilis),
  • Marche à petit pas - small steps = normal pressure hydrocephalus

IN-DEPTH:

Normal gait cycle: 1) heel strike 2) foot flat 3) mid stance 4) heel off 5) toe off

Antalgic gait - limping due to pain

  • Causes: osteoarthritis, inflammatory joint disease, lower limb fracture, nerve entrapment (sciatica)

Hemiplegic gait - unilateral circumduction of leg to prevent dragging foot

  • CNS lesion –> unilateral weakness & spasticity (spastic flexion of upper limb vs extension of lower limb)
  • Causes - UMN lesion:
    • Unilateral cerebral lesion e.g. stroke, SOL, trauma, MS
    • Hemisection of spinal cord (trauma)

Diplegic gait - bilateral circumduction of legs (scissoring gait_)_

  • CNS lesion as above but bilateral clinical findings - spasticity worse in lower limbs vs upper limbs ± hyperreflexia, clonus, Babinski +ve, reduced power, sensory level if spinal cord pathology
  • Causes:
    • Spinal cord lesion e.g. prolapsed intervertebral disc, spinal spondylosis, spinal tumour/infarct, transverse myelitis
    • Bilateral brain lesion - cerebral palsy, MS, bilateral brain infarcts, midline tumour (paraspinal meningioma)
    • MND - if also LMN findings (wasting, fasciculations)

Parkinsonian gait - shuffling gait

  • Loss of dopaminergic neurones in substantia nigra of basal ganglia –> extrapyramidal dysregulation = rigidity, bradykinesia, resting tremor, postural instability
  • Features of parkinsonian gait:
    • Initiation - slow to start walking
    • Step length - shuffling gait (short steps) & festinant gait (progressively smaller steps)
    • Arm swing - reduced (early feature)
    • Posture - flexed trunk & neck = stooped
    • Turning - postural instability
  • Causes: Parkinson’s, Dementia w/ LBs, Parkinson’s plus syndromes (Multisystem atrophy & progressive supranuclear palsy), drug-induced (antipsychotics/emetics)

Ataxic gait - wide/broad-based stance (to maintain balance)

  • Assoc w/:
    • Midline cerebellar disease (alcoholism/B12 def, MS, cerebellar stroke) - DANISH (dysdiadokokinesia, ataxia, nystagmus, intention tremor, slurred speech, hypotonia)
    • Vestibular disease (labyrinthitis, Meniere’s, acoustic neuroma) - vertigo, N&V
    • Sensory ataxia (peripheral neuropathy e.g. DM) - +ve Romberg’s, impaired proprioception, impaired vibration sense, lack of other cerebellar signs
  • Features of ataxic gaint:
    • Stance - broad-based ataxic gait
    • Stability - staggering, slow, unsteady –> veer towards side of lesion
    • Turning - very difficult

Neuropathic gait - high-step gait (from foot drop)

  • Weakness in muscles of distal limb (foot dorsiflexors) - damage to peripheral nerves providing motor innervation –> foot drop & dragging toes –> knee & hip flex excessively to compensate
  • Other features: peripheral vascular disease, peripheral sensory impairment, reduced/absent reflexes
  • Causes: motor neuropathy
    • Isolated common peroneal nerve palsy (trauma/compression)
    • L5 radiculopathy (disc prolapse)
    • Generalised polyneuropathy involving multiple nerves (DM, MND, Charcot-Marie Tooth disease)

Myopathic gait - waddling/Trendelenburg gait (hip sways to one/both sides)

  • Weakness of hip abductors –> can’t stabilise pelvis –> tilts down towards unsupported side
  • Assoc features: hard to stand from seat/squat/lying without arms, +ve trendelenburg’s sign (stand on one leg - if the hip on the side of the raised leg drops = +ve)
  • Causes: muscular dystrophy, myopathy (e.g. in hyperthyroidism, Cushing’s, acromegaly, Polymyalgia rheumatica)

Choreiform gait - involuntary movements

  • Oro-facial dyskinesia (grimacing/lip-smacking) & choreic mov of upper/lower limbs = dance-like/writhing @rest/mov
  • Causes: Basal ganglia disease
    • Huntington’s, Sydenham’s chorea, Cerebal palsy (Choreiform type), WIlson’s disease, Dopaminergic meds (e.g. Parkinson’s)
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12
Q

Cerebellar syndrome causes?

A

MAVIS:

  • MS - eye (RAPD, INO), spastic paraparesis, catheterised
  • Alcohol - peripheral neuropathy, liver signs
  • Vascular (thromboembolic/haemorrhagic)
  • Inherited (Friedrich’s ataxia)
  • SOL
  • Other: hypothyroidism & paraneoplastic syndrome
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13
Q

MS - def? key features? DDx? Clinical courses? Ix? Mx? Poor prognostic features?

A

Def: evidence of damage to CNS that is separated in time & space

Key features:

  • Profile: young, female (catheter & walking aid/wheelchair), eye & cerebellar signs
  • Initial:
    • Ipsilateral visual disturbance - greying/blurring ± pain on eye mov/loss of red colours
    • Sensory phenomena - wetness/burning, uncomfortable band around the chest
      • Lhermitte’s sign - electric shock down neck and along spine & may radiate along limbs
      • Uthoff’s - neuro Sx worsen with increased temperature (hoff = hot)
  • UMN Sx: hyperreflexia, hypertonia, pyramidal pattern (arm flexors stronger, leg extensors stronger)
  • Dorsal column disease - reduced vibration, proprioception, Romberg’s +ve
  • Eyes:
    • Internuclear ophthalmoplegia
      • Adduction paralysis and abduction nystagmus
      • From lesion in medial longitudinal fasciculus
    • Optic nerve damage:
      • Colour & visual acuity loss, RAPD
      • Central scotoma (central blindspot), optic atrophy
    • CN palsy (most commonly 6th - as longest)
  • Cerebellar signs (imbalance, can’t tandem walk)

DDx:

  • Cervical spondylosis - wo/ UMN signs but no cerebellar signs
  • Subacute combined degeneration of the cord (SACD) - dorsal columns & cerebellar - if low B12
  • Neuromyelitis optica aka Devic’s disease (IgG against aquaporin-4 channel) - optic neuritis & transverse myelitis but no cerebellar Sx

Clinical courses/patterns:

  • Relapsing-remitting - steady decline + strong flair
  • Primary progressive - steady decline without attacks
  • Secondary progressive - initial relapsing-remitting becoming primary progressive
  • Marburg variant - very severe, rapidly progressive

Ix:

  • Bedside:
    • Fundoscopy (optic neuritis), full functional assessment (physio, OT)
    • Nerve conduction studies - visual evoked potentials (VEPs) - if single nerve lesion, delayed response
  • Bloods - B12 (SACD), TFTs
  • Imaging:
    • MRI (T2) head (lesions disseminated in time & space) - McDonald’s criteria
      • ​Periventricular white matter lesions
    • LP: IgG oligoclonal bands, high protein

Mx:

  • Acute relapse: high-dose methylprednisolone (shortens acute attack) e.g. optic neuritis (painful eye mov + reduced visual acuity)
  • Long-term - MDT approach (physio, OT, SALT)
    • Mobility - mobility aids, physio, OT
    • INF-beta = disease modifying
    • Spasticity –> Baclofen/Gabapentin (Dantrolene if CKD)
    • Bowel (laxatives) & bladder (oxybutynin, LT catheter)
    • Fatigue –> Amantadine
    • Emotional lability –> Amitriptyline

Poor prognostic features:

  • Brainstem/cerebellar disease at onset
  • >40yrs at onset
  • Primary progressive MS (no resolution
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14
Q

Wernicke’s encephalopathy - Def? Sx triad? Mx - in hypoglycaemia and without? Complication?

How does delirium tremens present?

A

Def: Acute presentation of thiamine (B1) def

Triad: confusion, ataxia, nystagmus

Complication = Korsakoff syndrome (chronic & permanent memory problems)

Delirium tremens: confusion, visual hallucinations, tachycardia, pyrexia

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15
Q

Spinal cord injury - RFs? Ix? First Mx?

A

RFs: atherosclerosis, hypotension, aortic aneurysm, aortic dissection

Ix:

  • Traumatic - CT-spine (bony injury/fracture)
  • Non-traumatic - MRI spine (soft tissue injury)

Mx: spinal immobilisation, manage in tertiary neurosurgical centre

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16
Q

What is Cushing’s triad? Indicates? Mx?

A

HTN, bradycardia, Cheyne-Stokes breathing

Indicates raised ICP (likely form herniation through foramen magnum)

Urgent referral to tertiary neurosurgical centre

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17
Q

Most common cause of SAH?

High SAH suspicion but normal CT - Ix?

How do you reduce risk of ischaemia afterwards?

A

Berry aneurysm (85%)

LP in 12hrs for xanthochromia (yellow from bilirubin in CSF - RBC breakdown)

Nimodipine

18
Q

Neurology Ix depending on UMN/LMN signs?

A

ALL: involve MDT for full functional assessment (physio & OT)

UMN:

  • Imaging (brain ± spinal cord)
  • CSF (LP)
  • Brain biopsy

LMN:

  • Nerve conduction studies & electromyography (NCS & EMG)
  • Bloods (metabolic, abs)
  • Muscle/nerve biopsy
19
Q

GBS Ix? Mx?

A

Ix:

  • Bloods (metabolic, abs), CT –> LP ± MRI spine (exclude other causes)
  • Nerve conduction studies

Mx: ADMIT suspected cases - normally self-limiting course

  • MDT - psychologist, SALT (if speech muscles affected)
  • Plasmapheresis (plasma exchange)
  • High-dose IVIG
  • DVT prophylaxis
20
Q

MND - Presentation? DDx? Types of MND? Dx? Mx? Complications?

A

Presentation: mixed UMN/LMN (no sensory deficits, no eye involvement)

  • UMN in lower limbs (spasticity, hyperreflexia, upgoing plantars)
  • LMN in upper limbs (hypotonia, hyporeflexia, fasciculations, wasting)
  • Bulbar/pseudo-bulbar tongue/speech (tongue fasciculations, palatal paralysis, nasal speech)
  • NORMAL SENSORY EXAM

DDx mixed signs:

  • Dual pathology (stroke + peripheral neuropathy)
  • Conus medullaris lesion - painful, assoc with traumatic spinal injury/higher up mets)
  • B12 def (subacute combined degen of spinal cord) = cofactor in myelination (as is folate)

Types:

  • Amyotrophic lateral sclerosis (60%) - classic (UMN & LMN)
  • Progressive Bulbar Palsy (30%) - CN 9-12 –> dysarthria (speech), dysphagia (swallowing)
  • Primary Lateral Sclerosis - pure UMN onset
  • Progressive Muscular Atrophy - pure LMN onset, ‘flail limb’ appearance

Dx: clinical, exclude other causes

  • EMG/NCS (nerve conduction study) - chronic nerve root denervation
  • Imaging - MRI (cervical, thoracic, lumbar spine) - exclude other causes

Mx: no cure - MDT approach

  • Conservative - SALT (swallowing), physio & OT
  • Sx-control:
    • Quinine - muscle cramp
    • Anticholinergics e.g. hyoscine patches - drooling
    • Exercise & nutrition
  • Prognostic:
    • Riluzole - glutamate antagonist (extend life expectancy by 3-5 months)
    • NIV - if respiratory muscles no longer functioning

Complications: resp compromise, frontal lobe dementia (2%)

21
Q

How to remember nerve innervation of the diaphragm? Nerve associated?

A

C3,4,5 keep the diaphragm alive

Phrenic nerve

22
Q

Raised ICP - what is the Monro-Kellie Doctrine? Causes? Signs? Mx?

A

Monro-Kellie Doctrine: skull is a closed box, the sum of volumes of brain, CSF & IC blood is constant - increase in one should cause a decrease in one/both of others

  • In brain there is little wiggle-room, the only weak point is the foramen magnum –> herniation = coning –> death

Causes: IC haemorrhage (IC blood), tumour, (brain vol), cerebral oedema (CSF)

Signs:

  • Acute (pressure on brainstem): CUSHING’S TRIAD (HTN, bradycardia, irregular breathing) + reduced GCS
  • Chronic: long-term headache

Mx:

  • Conservative: sit up, hyperventilated (if intubated –> reduce pCO2 –> reduce vasodilation in brain)
  • Medical: mannitol (osmotic diuretic), hypertonic saline –> both draw fluid out of brain –> reduce ICP
  • URGENT neurosurgical input –> Burr hole surgery
23
Q

Cauda equina - def? Sx? Causes? Key Ix? Mx?

A

Def: compression of Cauda Equina (nerve fibres below L1-2)

Sx: can you feel it while you urinate/when you tug on catheter?

  • Severe back pain
  • Saddle anaesthesia (numb around the anus)
  • Bladder/bowel dysfunction (urinary retention, faecal incontinence)
  • Lower limb weakness
  • Reduced anal tone (on PR exam)

Causes: large disc herniation, cancer, trauma, abscess, haematoma

  • NOTE: if likely mets e.g. background of prostate cancer –> 16mg Dexamethasone (reduces swelling)

Ix: urgent MRI scan (+ PR exam)

Mx:

  • In normal disc herniation (above cauda equina):
    • Get the patient to keep moving (or muscles will seize up)
    • Analgesia - PR Diclofenac (neuropathic pain) + Diazepam
  • In cauda equina –> urgent referral to neurosurgery for decompression/laminectomy
24
Q

Spinal cord compression Ix & Mx for malignancy?

A

Ix: MRI whole spine (often multifocal lesions)

Mx:

  • 1st line = surgical decompression (if localised, fit enough)
  • 2nd line = radiotherapy (external beam radiotherapy)
25
Q

Meningitis & encephalitis - presentation? causes? Ix? Mx?

A

Meningitis:

  • Presentation: headache, fever, photophobia, neck stiffness
  • Causes:
    • Bacterial – N. meningitides, S. pneumo (TB; neonates/elderly – GBS/Listeria/E.coli) – Listeria also more common in alcoholics
    • Viral – enterovirus (Coxsackie, echovirus), mumps, HSV2
    • Fungal – cryptococcus neoformans (chr)
  • Ix: A-E, BC, CT head, LP (CT first, if raised ICP –> LP would cause coning)
    • Kernig sign - flex knee & hip to 90 degrees –> extend knee (painful & limited extension)
    • Brudzinski sign - raise head while flat –> hip & knee flexion
  • Mx: bacterial – IV ceftriaxone ± amoxicillin (Listeria - neonate/elderly)
    • IM BenPen for possible meningococcal infection (rash) in GP setting before sending to the hospital
    • Viral – supportive (self-limiting)
    • Altered consciousness (encephalitis?) –> add IV acyclovir

Encephalitis:

  • Presentation: headache, fever, seizures, drowsiness, confusion (viral HSV1 affects temporal lobes –> affecting consciousness)
  • Ix: BC, CT head, LP
  • Mx: IV acyclovir ± anti-convulsants
26
Q

Sensory ataxia vs Cerebellar ataxia based on Romberg’s test?

A

Postural imbalance/swaying:

  • When eyes open & closed = Cerebellar ataxia
  • When eyes are closed = sensory ataxia (somatosensory nerve affected)
    • Dorsal column loss: Tabes dorsalis (syphilis), SCDC (B12), MS
    • Sensory peripheral neuropathy
27
Q

Spinal cord anatomy

A

Dark matter middle (cell bodies = synapses) –> white matter on the outside (neurone tracts)

Sensory pathways (ascending - goes up):

  • Dorsal columns (posterior) - fine touch, vibration, proprioception
    • Sensory receptors - 1st order neurone up spinal column along ipsilateral side
    • At the medulla oblongata - synapses with 2nd order neurone that crosses the midline (decussation)
    • At the thalamus synapses with 3rd order neurone to the Primary Somatosensory cortex
  • Spinothalamic tracts (anterior) - pain & temperature
    • Nociceptors (pain) - 1st order neurone to Substantia Gelatinosa within grey matter of spinal cord
    • Synapses with 2nd order neurone & immediately crosses midline (decussation) to ascend spinothalamic tract
      • NOTE: spinothalamic tracts decussate at the level the neurone enters the spinal cord
    • At the thalamus synapses with 3rd order neurone to the Primary Somatosensory cortex
  • (Spinocerebellar tracts (lateral) - proprioceptive info to cerebellum)

Motor pathways (descending - goes down):

  • Corticospinal tracts (anterior = trunk, neck, shoulders; lateral - limbs) - voluntary motor control (from primary motor cortex)
    • From the Primary Motor Cortex - UMN goes to the Medulla and crosses over (decussation)
    • At the anterior horn for each spinal level synapses with LMN–> muscle
    • NOTE: at any spinal level will be LMNs exiting the spine and UMNs that travel down further before synapsing with their respective LMN
      • SO cord pathology above the level of Cauda Equina –> some UMN & LMN signs
28
Q

Epilepsy - def? types & Tx? Status epilepticus def & Mx?

A

Def: tendency to have recurrent, unprovoked seizures

  • Seizure = episodes of abnormal uncoordinated excessive brain activity
    • Provoked seizures = consequence of inf/drugs
    • Unprovoked = epilepsy

Types:

  • Generalised (whole brain):
    • Tonic-clonic, Tonic, Atonic, Myoclonic –> Tx: Na Valproate (AVOID in girls/women of childbearing age)
    • Absence –> Tx: Ethosuximide/Na Valproate
  • Focal - aware (conscious) OR impaired awareness (impaired consciousness)
    • Tx: Lamotrigine

Status epilepticus = >5mins/repeated seizures without full recovery in between

  • 1st - IV lorazepam 4mg –> repeat
  • 2nd - phenytoin infusion
  • 3rd - general anaesthesia
  • If no IV access –> rectal diazepam/buccal midazolam
29
Q

Lumbar disc herniation vs lumbar spinal stenosis - presentation? Ix? Mx?

A

Presentation

  • Disc herniation - acute unilateral radiculopathy (pain & numb in specific dermatome/weakness in muscle group)
    • Straight leg raise +ve
    • Worse on flexion (bending over/sitting)
  • Spinal stenosis - insidious neurogenic claudication (intermittent back pain worse on walking/standing) ± pain radiating down leg/leg paraesthesia
    • RFs: rev back injury/surgery, manual labour
    • Worse on extension (standing/walking)

Ix:

  • Disc herniation - erect lumbar x-ray & MRI spine
  • Spinal stenosis - plane x-ray, MRI (T2-weighted)

Mx: surgical decompression

30
Q

Brain anatomy “rules” summary - cerebellar, motor nerves, dorsal columns, spinothalamic tract

Clues to localisation - cortical, basal ganglia, cerebellar, nerve root

A

Cerebellar signs ipsilateral

Motor nerves travel laterally in brainstem & cross @medulla

Dorsal columns are posterior & cross @medulla

Spinothalamic tract is anterior in spinal cord & cross in spinal cord

Localisation:

  • Cortical - UMN pyramidal signs (hypertonia, hyperreflexia, babinski)
  • Basal ganglia - rigidity, tremor, bradykinesia
  • Cerebellar - DANISH
  • Nerve root (dermatome/myotome)/single nerve - LMN signs (hypotonia, hyporeflexia, fasciculations, wasting, sensory loss)
31
Q

Myotonic dystrophy - presentation? Assoc? Ix? Mx?

A

LMN presentation = muscle pathology

  • Face:
    • Myopathic facies (sunken cheeks, bilateral ptosis, expressionless)
      • Wasting of facial & muscles of mastication
    • Frontotemporal balding
  • Distal wasting, weakness w/ loss of ankle jerks
  • Associations: cataracts, dysphagia, cardiac (cardiomyopathy, heart block), DM, hypogonadism (gynaecomastia/testicular atrophy)
  • Exam - failure of immediate relaxation after voluntary contraction
    • Percussion myotonia - tap thenar eminence and thumb contracts
    • Slow-releasing grip - SHAKE HANDS (or make a fist and then spread fingers quickly or squeeze eyes shut and open quickly)

Ix:

  • Conservative: full functional assessment (incl. SALT), lung function tests (NM resp insufficiency), ECG/echo (CMO/HB), slit lamp (cataracts)
  • Bloods - BM (DM assoc), CK, genetic testing
  • Imaging & invasive:
    • Electromyography (EMG) - ‘dive-bomber’ potentials
    • Muscle/nerve biopsy

Mx: MDT approach

  • Phenytoin for myotonia, weakness has no Tx
  • Genetic counselling - AD w/ genetic anticipation (trinucleotide repeat - worse severity/earlier presentation with each generation)
  • Avoid statins (can cause myopathy)
32
Q

Ptosis causes?

A

Bilateral:

  • MG
  • Myotonic dystrophy
  • Tabes dorsalis (syphilis) = Argyll-Robertson pupil

Unilateral:

  • 3rd nerve palsy (down & out, dilated, ptosis)
  • Horner’s syndrome (ptosis, meiosis, anhydrosis)
33
Q

Myasthenia Gravis Vs Lambert-Eaton Myasthenic Syndrome (LEMS)

Def? presentation? Assoc? Ix? Mx?

A

Myasthenia Gravis

  • Def:
    • Chr AI disorder of post-synaptic membrane of NMJ in skeletal muscle
    • Abs to AChR on post-synaptic membrane
  • Presentation:
    • Muscle fatiguability incl dysphagia, rarely SoB
    • Eyes - bilateral ptosis (and compensatory increased frontalis muscle activity = raised eyebrows), diplopia
    • Face - dysarthria (slurred speech), facial paresis
    • Curtain sign - when raising one upper eyelid the other one drops down
    • Assoc: thymomas (in the chest)
  • Ix:
    • Abs: AChR (on post-synaptic membrane), MUSK abs
    • Serial pul funct tests (FVC & negative inspiratory force)
      • NOTE: do not wait for ABG findings - late in course
    • CT-chest (for thymoma)
  • Mx:
    • Acetylcholinesterase inhibitors (Pyridostigmine) + IS (azathioprine)
    • IVIG/Plasmapheresis
    • Surgery - thymectomy
  • Myasthenic crisis = acute respiratory failure - FVC <1L, negative inspiratory force (NIF) ≤20cm H2O, need mechanical ventilatory support
    • Accessory muscle use indicates sign inspiratory muscle weakness
    • Weak cough indicates sign expiratory muscle weakness
    • ABG often shows hypercapnia before hypoxia
    • Low threshold for endotracheal intubation (rapid deterioration of bulbar & resp muscles)
    • Mx: intubation + mechanical ventilation (& Mx above)

Lambert-Eaton Myasthenic Syndrome (LEMS)

  • Def: rare AI disorder of NMJ
    • Pre-synaptic membrane Ab to voltage-gated Ca-channel receptors
    • 40% occur as paraneoplastic disorder assoc w/ SCLC
  • Presentation:
    • Limb weakness - proximal legs –> proximal arms e.g. waddling gait
      • STRONGER WITH USE (vs MG get’s weaker with use)
    • Hyporeflexia, NO eye involvement (compared to MG)
    • Autonomic disturbance - dry mouth (& orthostatic hypotension, sweating, GI & urinary problems, visual blurring, sexual dysfunction)
    • Associated with: small cell lung cancer (SCLC)
  • Ix:
    • Nerve conduction studies, EMG, serial PFTs
    • Ab testing (Voltage-gated Ca-channels & AChR-abs)
    • CT chest (SCLC)
  • Mx: MDT support
    • Tx underlying cause, Amifampridine
    • IVIg/plasma exchange
    • Supportive care
34
Q

Hammertoes can be seen in what condition? Presentation? What do I need to check for to exclude DDx? DDx? Types? Ix? Mx?

A

Hammertoes - bilateral, symmetrical, distal wasting of small muscles of feet

  • Advanced = dorsal guttering from distal wasting, wasting of extensor digitorum brevis at inferior border of lateral malleolus
  • Similar can be seen in the hands = wasting of first dorsal interosseus

Sign of Charcot-Marie-Tooth disease aka hereditary motor & sensory neuropathy (HMSN)/peroneal muscular atrophy (PMA)

  • Hx ankle sprains & scoliosis
  • Motor & sensory losses (sensory milder) = classic peripheral neuropathy
    • LMN pattern of weakness:
      • Motor loss in anterolateral compartments of legs (ankle dorsiflexion & toe extension)
      • Absent reflexes (plantar reflexes show no response)
    • Sensory loss in glove & stocking distribution bilaterally
  • Pes cavus ± palpable common peroneal nerve, thickened nerves @medial malleolus
  • High stepping (foot drop) & ataxic gait
    • Test for foot drop = heel walking

What do I need to check for? NO scars over fibula (would indicate peroneal nerve damage from trauma e.g. car accident)

DDx:

  • Common peroneal nerve palsy (inversion of foot normal)
  • Sensory peripheral neuropathy: B12-def (SACD), Alcohol, DM, Hypothyroid (vitiligo?), HIV, drugs
  • Motor peripheral neuropathy: lead poisoning

Types:

  • Type 1 - demyelination, AD
  • Type 2 - axonal, AD/AR
  • Type 3 - demyelination, AR & presents as infant

Ix: full functional assessment, FHx, nerve conduction studies, genetic testing

Mx:

  • Physio, walking aids with ankle & foot supports (e.g. foot splint)
35
Q

Wasting of hand muscles - distinguishing different nerves?

A

Hand muscle wasting - dorsal guttering = first to be affected in ulnar lesions

  • First dorsal interosseous (next to thumb) = ulnar nerve
  • Abductor policies brevis (thenar eminence) = median nerve
  • Weakness of both - suspect T1 radiculopathy
  • NOTE: ulnar nerve innervates most of the intrinsic muscles of hand except median nerve serves LOAF: 2 radial Lumbricals, Opponenes pollicis, Abductor pollicis brevis & Flexor pollicis brevis

Ulnar nerve palsy = claw hand @rest (4th & 5th fingers in extension at MCP, flexion at PIP/DIP)

  • Commonest site of lesion = elbow (arthritis @wrist & elbow)
  • Froment’s sign (weak adductor pollicis brevis –> thumb flexion) = +ve if thumb arches to hold paper = ulnar nerve palsy
  • Ulnar paradox - higher lesion causes lesser deformity as lower lesions spares flexor digitorum profundus (causes flexion at DIP)

Median nerve palsy = sign of benediction on asking to close hand (thumb, index finger can’t close, middle finger can close partially)

  • Look for sensation over thenar eminence –> if lost can’t be carpal tunnel syndrome (still median nerve palsy but arises proximally to carpal tunnel)
  • Bilateral carpal tunnel syndrome causes: Acromegaly, Amyloid (periorbital purpura after sneezing), DM, Hypothyroid, pregnancy
36
Q

Muscle weakness causes by location?

A

Brain: stroke, SOL, MS

Spinal cord: MS, trauma, disc herniation/spinal stenosis, spinal cord infarct, syringomyelia

  • MS - weakness & paraesthesia based on UMN demyelination, disseminated in time & space
    • Optic neuritis, periorbital pain, RAPD, INO (damage to medial longitudinal fasciculus)
    • Ataxia, vertigo, chr constipation, blaadder dysfunct
    • Lhermitte’s sign - electric shock down back on neck flexion
    • Unhthoff’s phenomenon - worsening of Sx with increased body temp e.g. exercise, hot shower
    • Ix: MRI (brain & spinal cord) + LP (oligoclonal bands), nerve conduction study (evoked potential)
    • Mx: methypred for flare, INF-b long-term
  • Trauma - extremity weakness wo/ cortical signs/facial weakness e.g. hemisection of spinal cord (Brown-Sequard syndrome) - below level of lesion:
    • Ipsilateral hemiparesis & loss of vibration/proprioception
    • Contralateral loss of pain & temperature
    • At level of lesion - loss of sensation + flaccid paralysis of muscles supplied by this spinal cord segment
  • Herniated disc/spinal stenosis - weakness at level of lesion & lower extremities + bladder/bowel dysfunction + sciatica
  • Spinal cord infarct - occlusion of anterior spinal artery (complication of aortic surgery)
    • Affects anterior 2/3 spinal cord in affected segment
      • Sudden-onset bilateral flaccid paralysis –> developing into spastic paralysis after several days
      • Loss of pain & temp
      • Light-touch, vibration & proprioception-sense spared (dorsal columns not involved)
  • Syringomyelia - developmental disorder
    • Syrinx (cavity) grows from centre of spinal cord & spreads outwards
    • Normally affects cervical cord but can extend into brainstem
    • Early - bilateral loss of pain & temp in cape-like distribution affecting neck, shoulders, upper arms
    • Late - as syrinx expands anterior horn cells affected –> bilateral flaccid paralysis

Anterior horn (motor neurone lesions): MND, poliomyelitis

  • Poliomyelitis - enterovirus infection attacking anterior horn cells
    • 1-2wks prodrome (fever, headache, N&V)
    • Asymmetrical weakness + can develop years after inf (post-polio syndrome) + can take place after taking live-attenuated polio vaccine
  • MND
    • Mixed UMN/LMN presentation
    • Ix (exclude other causes): EMG/NCS, MRI - whole spine
    • Mx: no cure - MDT approach (SALT (swallowing), physio & OT)
    • Sx-control:
      • Quinine - muscle cramp
      • Anticholinergics e.g. hyoscine patches - drooling
    • Prognostic:
      • Riluzole - glutamate antagonist (extend life expectancy by 3-5 months)
      • NIV - if respiratory muscles no longer functioning

Neuropathy: diabetic neuropathy

  • Polyneuropathy (multiple nerves): DANG My THeRAPIST
    • Diabetic neuropathy (most common, T1/2)
      • Sensory - glove & stocking loss of sensation/paraesthesia
      • Motor - same distribution as above + CN palsies (3rd - pupil-sparing)
      • Autonomic - orthostatic hypotension, constipation, erectile dysfunction
    • Alcoholic neuropathy (2nd most common)
    • Nutritional (B1/6/12 def)
    • GBS (AIDP - acute inflam demyelin polyneuropathy)
      • AI demyelination of peripheral nerves
      • 2-4wks post-inf e.g. diarrhoea with C. jejuni
      • Ascending weakness in distal lower extremities over hrs/days (worst after 4wks)
      • Flaccid paralysis with reduced/absent deep tendon reflexes
        • Can involve diaphragm –> resp failure
        • Bilateral facial nerve palsy
        • Difficulty swallowing –> aspiration
      • Autonomic dysfunction - sweating, orthostatic hypotension, urinary retention
      • NOTE: sensory Sx rare
      • Ix:
        • LP (high protein, normal WCC)
        • NCS & EMG (reduced conduction velocity)
        • Serum abs (anti-glycolipid abs)
      • Mx:
        • Monitor FVC <1L, NIF <20cm H2O –> intubate + mechanical ventilation
        • Monitor BP –> IV fluids for hypo, Labetalol for hyper
        • IVIG, plasma exchange
    • M(y)-edications (colchicine, cisplatin, isoniazid –> niacin def)
    • Toxins (lead)
    • Hereditary - HMSN (CMT)
      • Progressive hereditary (AD) motor & sensory neuropathy (HMSN)
      • Distal back & lower extremity weakness:
        • Foot drop (damage to common peroneal nerve)
        • High-arch foot (pes cavus) - does not flatten with weight-bearing
        • Scoliosis
      • ± pain & sensory loss (can lead to foot ulcers)
      • Ix: nerve conduction study + EMG, genetic testing (electrophoresis/FISH)
      • Mx: physio, walking aids, foot & heel-support
    • Renal failure (uraemic nephropathy)
    • Amyloidosis
    • Porphyrias
    • Inf (HIV, syphilis)
    • Systemic (hypothyroidism)
    • Tumours (multiple myeloma)
  • Mononeuropathy (one nerve):
    • Facial nerve palsy - not forehead-sparing, crying/sensitive to noise/abnormal taste (ant 2/3 tongue)
      • Idiopathic = Bell’s palsy
      • Secondary:
        • Lyme disease
        • Ramsay-Hunt syndrome - HZV reactivation in the geniculate ganglion, causes painful eruption in auditory canal
        • Tumours - acoustic neuroma, parotid
        • Bilateral palsy - Sarcoidosis, GBS
      • Tx: treat cause or if Bell’s palsy –> pred within 72hrs Sx onset + eye protection
    • Carpal tunnel syndrome - entrapment of median nerve in flexor retinaculum
      • Repetitive use of wrist –> numbness & tingling in lateral 3 fingers (& 1/2 4th finger) –> weakness of thenar muscles
      • Tinel’s sign - tap nerve at wrist
      • Phalen’s sign - reverse prayer sign for 60s
      • Ix: EMG, wrist USS, MRI wrist (imaging to detect SOL e.g. ganglion cyst)
      • Tx: immobiliser wrist (splint), CS injection, carpal tunnel release

Neuromuscular junction: MG/LEMS

  • Myasthenia gravis (MG) - AI condition where Abs attach to NMJ post-synaptic nicotinic AChR in skeletal muscle
    • FATIGUABILITY with use
    • Initial - oculobulbar weakness (diplopia, ptosis, dysphagia, nasal voice)
    • Chr:
      • Asymmetrical proximal limb muscle weakness
      • Resp muscle failure
    • Assoc w/ thymic hyperplasia/thymoma
    • NOTE: normal sensation, normal deep tendon & pupillary reflexes
    • Ix:
      • Serological testing: AChR, MUSK abs
      • Repetitive nerve stimulation (CMAPs decrease)
      • CT chest - thymoma
      • Monitoring with serial pul funct tests (FVC & negative inspiratory force) if suspect myasthenic crisis
    • Mx:
      • Acetylcholinesterase inhibitors (Pyridostigmine) + IS (azathioprine)
      • Surgery - thymectomy
    • Myasthenic crisis = acute respiratory failure - FVC <1L, negative inspiratory force (NIF) ≤20cm H2O
      • Often trigger - meds/inf
      • Accessory muscle use/weak cough = sign. exp muscle weakness
      • Mx: intubation + mechanical ventilation (& Mx above)
        • IVIG/Plasmapheresis
        • Stop pyridostigmine (increases secretions –> aspiration risk), stop trigger (meds)
    • Cholinergic crisis - same presentation as above (resp muscle weakness) BUT cause = excess pyridostigmine –> overstimulation of AChR –> eventually stop working
      • Pyridostigmine also binds to nicotinic receptors –> cholinergic Sx - SLUDGE (Salivation, Lacrimation, Urination, Diarrhoea, GI cramps, Emesis)
      • Mx: intubation + mechanical ventilation
        • Atropine (anti-muscarinic) for Sx but does not address resp weakness
        • Reduce dose of pyridostigmine
  • Lambert-Eaton myasthenic syndrome (LEMS) - AI condition where Abs target pre-synaptic voltage-gated Ca channels –> reduces release of ACh from presynaptic vesicles
    • Proximal muscle weakness - IMPROVES with use
    • Reflexes reduced/absent, ± autonomic Sx
    • Assoc w/ SCLC, Hodgkin’s lymphoma
    • Ix:
      • NCS, repetitive nerve stimulation (CMAPs increase)
      • Serological testing: VGCC abs
      • CT chest (SCLC)
    • Mx: Tx underlying cause, Amifampridine
      • IVIg/plasma exchange
      • Supportive care incl. intubation + mech ventilation (if resp compromise)

Myopathy: dermatomyositis

  • Inflammatory: proximal muscle weakness & pain
    • Dermatomyositis - skin rash (heliotropic rash & Gottron’s papules)
    • Polymyositis
    • Assoc: ILD - in 10% patients
    • Ix: CK, ab panel (anti-Jo-1, ANA)
      • EMG, muscle MRI + muscle biopsy
    • Mx:
      • Induction: CS (PO/IV) ± IVIg
      • Maintenance: IS (methotrexate/azathioprine) ± IVIg
  • Inherited:
    • X-linked - Duchenne’s & Becker’s muscular dystrophy
    • AD - Myotonic dystrophy
      • Myopathic facies (facial wasting) + frontal balding
      • Distal wasting & weakness + loss of ankle jerk
      • Assoc: cataracts, dysphagia, cardiac, DM, hypogonadism
      • Exam - failure of immediate relaxation after voluntary contraction
        • Percussion myotonia - thumb contracts tapping thenar eminence
        • Slow releasing grip on shaking hands
      • Ix: CK, genetic testing, EMG ‘dive-bomber’ potentials, muscle biopsy
      • Mx: MDT approach
        • Phenytoin for myotonia, weakness has no Tx
        • Genetic counselling - trinucleotide repeat -severity/earlier with each generation
        • Avoid statins (can cause myopathy)
  • Endocrine:
    • Hypothyroidism - proximal muscle weakness & pain, deep tendon reflexes decreased, myoedema (swelling on percussion)
    • Also possible in Addison’s Cushing’s, Vit D def
  • Meds - statins (proximal muscle weakness & pain), glucocorticoids (muscle weakness)
  • Ix: serum CK, TSH lvls, EMG
37
Q

Idiopathic inflammatory myopathies (IIMs) - RFs? Presentation by type? Ix? Mx?

A

RFs:

  • Exposure to high-intensity global UV radiation
  • Treatment w/ lipid-lowering agents, D-penicillamine (Tx for RA)
  • HIV, prev inf/vaccine

Presentation:

  • Overall: insidious/acute symmetrical muscle weakness of proximal arm & leg –> difficulty getting out of chair/climbing stairs
  • Dermatomyositis - acute, proximal muscle weakness + rash:
    • Heliotropic rash (purple discolouration of upper-eyelids)
    • Gottron’s papules (erythema over knuckles)
  • Polymyositis - subacute, proximal muscle weakness, no rash
  • Inclusion body myositis (IBM) - slowly, proximal & distal muscle weakness + muscle atrophy (quadriceps, distal wrist & finger flexor)
  • Assoc:
    • ILD - in 10% patients with dermatomyositis/polymyositis
    • Malignancy (ovarian, pancreatic, NH lymphoma, lung, bladder)
    • AI disease

Ix:

  • Bloods: CK, ANA/myositis ab panel (anti-Jo-1)
  • Imaging: MRI of involved muscle, electromyogram (EMG), muscle biopsy

Mx:

  • Induction: CS (PO/IV) ± IVIg
  • Maintenance: IS (methotrexate/azathioprine) ± IVIg
38
Q

Proximal muscle weakness causes?

A

CONGENITAL MIND

  • CONGENITAL - mitochondrial
  • Metabolic - Cushing’s, hypothyroidism
  • Inflammatory - dermato/poly/inclusion body myositis
  • Neuromuscular - MG/LEMS
  • Dystrophy - Becker
39
Q

UMN pattern of weakness - causes?

A

Bilateral = 3Ms

  • MS
  • MND (normal sensation)
  • Myelopathy (sensory level) - SOL, cervical myelopathy, disc prolapse, transverse myelitis, syringomyelia

Unilateral:

  • Intracranial - CVA, SOL, MS
  • Brainstem - MS
  • Spinal cord - trauma, SOL, haemorrhage
40
Q

Mononeuritis multiplex causes?

A

Vasculitis - GPA, EGPA, microscopic polyangiitis, polyarteritis nodosa

Rheum - RA, SLE, Sjogren’s, Sarcoidosis

41
Q

Causes of absent ankle jerk reflex AND extensor plantar response?

A

MND

B12 - SCDC (subacute combined degeneration of the spinal cord)

Friedrich’s ataxia (cause of cerebellar syndrome)

Syphilitic tabo-paresis