Neurology_Medicine & Surgery Flashcards
Neuroanatomy - blood supply to the brain
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)
UMN vs LMN:
- Motorpathway name + route
- UMN & LMN lesion causes and signs
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
Intracranial bleeds - layers of the outer brain? types? Appearance on CT-head? Presentations?
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
Headache - types? Ix? Mx?
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
Cardiovascular accident (CVA) - Def? Presentation? DDx? Classification? Ix? Mx?
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.)
Parkinson’s disease definition? Cardinal Sx? DDx? Ix? Mx? Complications?
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)
Rigidity vs Spasticity
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
Dementia - Types?
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
What are the nerve innovations for deep tendon reflexes in upper and lower limb neuro examination?
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
MRC Power Scale
- 1 flicker
- 2 is moves with gravity removed
- 3 is movement against gravity
- 4 is reduced power against resistance
- 5 is normal
Gait abnormalities vs normal
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)
Cerebellar syndrome causes?
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
MS - def? key features? DDx? Clinical courses? Ix? Mx? Poor prognostic features?
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
Wernicke’s encephalopathy - Def? Sx triad? Mx - in hypoglycaemia and without? Complication?
How does delirium tremens present?
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
Spinal cord injury - RFs? Ix? First Mx?
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
What is Cushing’s triad? Indicates? Mx?
HTN, bradycardia, Cheyne-Stokes breathing
Indicates raised ICP (likely form herniation through foramen magnum)
Urgent referral to tertiary neurosurgical centre