Psych / Neuro 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)
2
Q
UMN vs LMN:
- Motorpathway name + route
- UMN & LMN lesion causes and signs
A
Corticospinal tract = voluntary motor pathway for body:
- Cortex - primary motor cortex (posterior frontal cortex)
- Medulla - tracts from PMC converge and cross over = pyramids
- Spinal cord - UMN synapases with LMN
- 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
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
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
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.)
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
-
Non-ergot - ropinirole, pramipexole - avoid below SEs = 1st line but still get dopamine dysregulation syndrome (hypersexuality & gambling)
- ‘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
- Relevant physiology:
Complications:
- Falls, cognitive impairment, depression
- Drool (SALT/glycopyrronium)
- Meds SEs (e.g. vomiting)
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
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
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
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
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)
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
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)
- Internuclear ophthalmoplegia
- 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
- MRI (T2) head (lesions disseminated in time & space) - McDonald’s criteria
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
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
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
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
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
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%)
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
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
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
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
- LMN pattern of weakness:
- 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)
- Affects anterior 2/3 spinal cord in affected segment
-
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)
-
Diabetic neuropathy (most common, T1/2)
- 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
-
Facial nerve palsy - not forehead-sparing, crying/sensitive to noise/abnormal taste (ant 2/3 tongue)
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
