Neurology Flashcards
How are seizures defined?
Transient episode of symptoms due to abnormally excessive or synchronous neuronal activity in the brain
Define epilepsy
Neurological disorder characterised by recurring seizures
At least two unprovoked seizures occurring more than 24 hours apart OR
One unprovoked seizure and a probability of further seizures similar to the general recurrence risk (at least 60%) after two unprovoked seizures, occurring over the next 10 years OR
Diagnosis of an epilepsy syndrome
Define status epilepticus
Prolonged convulsive seizure lasting for 5 minutes or longer, or recurrent seizures one after the other without recovery in between
List causes of epilepsy and risk factors for epilepsy
Structural – stroke, trauma, malformation (genetic or acquired)
Genetic
Infectious – due to infection in which seizures are a core symptom (not seizure due to acute infection e.g., meningitis) e.g., tuberculosis, cerebral malaria, HIV
Metabolic – porphyria, pyridoxine deficiency
Immune – anti-NMDA encephalitis
Risk factors:
Prematurity
Complicated febrile seizures
FHx
Head trauma, infections, traumas
Cerebrovascular disease
Dementia and neurodegenerative disorders
Describe the classification of seizures
By area of onset:
Focal – start in a specific area, in one hemisphere
Generalised – involve both hemispheres
Focal to bilateral – begin in one hemisphere but spread to both
Level of awareness – aware, impaired awareness, loss of consciousness (all generalised)
Motor and non-motor
Specific types:
Generalised tonic-clonic – increased tone then jerking, with tongue biting, incontinence, groaning, irregular breathing
Myoclonic – brief, rapid muscle jerks
Atonic – ‘drop attacks’, brief lapses in muscle tone
Absence – brief episodes, blank, staring into space and then abruptly returns to normal, unaware of surroundings and don’t respond
Describe the rules for driving with epileptic seizures
First seizure:
Can’t drive for at least 6 months, 12 months if high-risk for another seizure
Established epilepsy:
Can drive if 12 months seizure-free, or 6 months if seizure was due to medication change
If seizures only during sleep can drive if only had seizures during sleep for past 3 years
Describe the pharmacological management of epilepsy
Generalised tonic-clonic:
Sodium valproate first line in males or women unable to have children
Lamotrigine or levetiracetam first line for women and girls able to have children, and second line for men
Focal seizures:
Lamotrigine or levetiracetam first line
Second line – carbamazepine
Absence seizures:
Ethosuximide first line
Sodium valproate second line
Myoclonic seizures:
Sodium valproate first line for males or women unable to have children
Levetiracetam first line in women able to have children
Atonic/tonic seizures:
Sodium valproate first line for males and women unable to have children
Lamotrigine for women able to have children
Describe the mechanism of action of anti-epileptic drugs
Sodium valproate – increases GABA activity
Carbamazepine – increases refractory period of sodium channels
Lamotrigine – sodium channel blocker
Levetiracetam – binds to SV2A protein to modulate neurotransmitter release (unknown exact mechanism)
List the major side effects of anti-epileptic drugs
Sodium valproate:
Increased appetite, weight gain
Alopecia, curly regrowth
P450 enzyme inhibitor
Ataxia
Tremor
Hepatitis
Pancreatitis
Thrombocytopaenia
Teratogenic – neural tube defects (do not used in women of childbearing age)
Carbamazepine:
P450 enzyme inducer
Dizziness and ataxia
Leucopaenia, agranulocytosis
SIADH
Visual disturbance – diplopia
Lamotrigine:
Stevens-Johnson syndrome
Which antiepileptic drugs are safe in pregnancy?
Lamotrigine and levetiracetam are safest
How is status epilepticus managed?
A-E assessment
Oxygen
Check BM
IV benzodiazepines – lorazepam or diazepam
(pre-hospital – PR diazepam or buccal midazolam)
Can repeat once after 10-20 minutes
If ongoing can start second-line agent e.g. phenytoin or phenobarbital
If no response within 45 minutes from onset best way to control is with induction of general anaesthesia
Describe the aetiology of cerebrovascular accidents
Ischaemic (85%):
Thrombotic
Embolic – AF
Hypoperfusion – cardiac arrest
Cerebral venous sinus thrombosis – venous congestion causes hypoxia
Haemorrhagic:
Intracerebral
Subarachnoid
Risk factors:
General risk factors for CVD – smoking, obesity, hypertension, diabetes
Embolic – AF, carotid artery disease
Thrombosis – COCP, hereditary thrombophilia, malignancy
Haemorrhagic – AV malformation, anticoagulation, hypertension, trauma
Describe the classification of ischaemic strokes
Bamford/Oxford classification
Total anterior circulation stroke – middle and anterior cerebral arteries, need to have all of:
Unilateral weakness/sensory loss of face, arm and leg
Homonymous hemianopia
Higher cerebral dysfunction – dysphagia, visuospatial disorder
Partial anterior circulation stroke – smaller divisions of anterior circulation (e.g. upper or lower middle cerebral artery), two of:
Unilateral weakness/sensory loss of face, arm and leg
Homonymous hemianopia
Higher cerebral dysfunction – dysphagia, visuospatial disorder
(or higher dysfunction alone)
Posterior circulation stroke – vertebrobasilar arteries (cerebellum and brainstem), one of:
Cranial nerve palsy and contralateral motor/sensory deficit
Bilateral motor/sensory deficit
Conjugate eye movement disorder
Cerebellar dysfunction e.g. vertigo, nystagmus, ataxia
Isolated homonymous hemianopia
Lacunar stroke – small vessel disease, one of:
Pure sensory or pure motor
Sensorimotor
Ataxic hemiparesis
(no higher dysfunction)
Describe the presentation of strokes by vessel affected
Anterior cerebral artery – contralateral hemiparesis and sensory loss, legs affected more than arms
Middle cerebral artery – contralateral hemiparesis and sensory loss, arms affected more than legs, contralateral homonymous hemianopia, aphasia
Posterior cerebral artery – contralateral homonymous hemianopia with macular sparing, visual agnosia
Weber’s syndrome (midbrain branches of posterior cerebral artery) – ipsilateral CN III palsy, contralateral weakness of upper and lower extremity
Posterior inferior cerebellar artery (lateral medullary/Wallenberg syndrome) – ipsilateral facial pain and temperature loss, contralateral limb/torso pain and temperature loss, ataxia, nystagmus
Retinal/ophthalmic artery – amaurosis fugax
Basilar artery – ‘locked-in’ syndrome
Describe the initial assessment of suspected stroke
Exclude hypoglycaemia
ROSIER score – stroke likely if >0
Non-contrast CT head 1st line investigation (exclude haemorrhage)
Investigations – ECG, U+Es, LFTs, cholesterol, FBC, ESR, coagulation
Swallow assessment within 4 hours – before oral medications, fluid, diet
Describe the presentation of haemorrhagic stroke compared with ischaemic stroke
Abrupt onset symptoms and decompensation
Reduced level of consciousness
Headache
Nausea and vomiting
Seizures
Describe the initial management of strokes
O2 as required
Withhold platelets and anticoagulants until CT excluded haemorrhage
If BM low correct, if high can give insulin but avoid hypoglycaemia
IVF as required
Haemorrhagic stroke excluded – give aspirin 300mg orally (if swallow safe) or rectally ASAP
If presenting less than 4.5 hours since symptom onset, symptoms still present and haemorrhage ruled out may be suitable for thrombolysis with alteplase
If presenting within 6 hours of symptom onset offer thrombectomy for confirmed occlusion of proximal anterior circulation on CTA or MRA (with thrombolysis)
Can also give if known to be well between 6-24 hours previously if confirmed proximal anterior circulation occlusion and potential to salvage brain tissue (on CT perfusion or diffusion-weighted MRI)
If not suitable for either give 300mg aspirin for 14 days then 75mg once daily
Aspirin and clopidogrel given for non-cardioembolic minor ischaemic stroke or high risk TIA (ABCD >4), for 21 days then clopidogrel 75mg long term
If haemorrhage on CT – check coagulation screen, stop anticoagulants (consider reversal), neurosurgery referral?
List indications for urgent CT in suspected stroke
Reduced GCS or coma
On anticoagulants
Brainstem signs, bilateral signs, ‘locked-in’
Cerebellar stroke signs with headache or raised ICP symptoms
Severe headache
Stuttering onset
Immunocompromised
Unexplained fever
Signs of raised ICP
List contraindications to thrombolysis for management of stroke
Define TIA and stroke
Transient ischaemic attack – transient episode (less than 24 hours) of neurologic dysfunction caused by focal brain, spinal cord or retinal ischaemia, without acute infarction (no longer purely time based, even short ischaemia can result in pathological changes)
Stroke – clinical syndrome of presumed vascular origin characterised by rapidly developing signs of focal or global disturbance of cerebral functions which persist (longer than 24 hours) or leads to death
Describe initial assessment and management of TIA
Immediate management:
No longer use ABCD2 score
Give aspirin 300mg immediately, unless patient has bleeding disorder or is taking anticoagulant, patient is already taking low-dose aspirin regularly (continue this until reviewed by specialist) or aspirin is contraindicated
Specialist review:
If more than one TIA (crescendo TIA) or suspected cardioembolic source or severe carotid stenosis discuss need for admission or observation urgently with stroke specialist
If suspected TIA in past 7 days – assessment within 24 hours by specialist stroke physician
If suspected TIA over a week ago – specialist assessment within 7 days
CT brain not recommended unless suspicion of another diagnosis
MRI (including diffusion weighted and blood-sensitive sequences) preferred, on same day as specialist assessment
Urgent carotid doppler (unless not a surgical candidate)
Driving rules for TIA/stroke
TIA
Don’t drive until seen by specialist
1 TIA – don’t drive for 1 month, no need to inform DVLA
Multiple TIAs – don’t drive for 3 months, need to notify DVLA
Stroke
Don’t drive for at least 1 month, may not need to inform DVLA
Can start driving after 1 month if made adequate clinical recovery, only need to inform DVLA if residual neurological deficit (particularly visual field defect, cognitive defect, impaired limb function)
Describe secondary prevention for TIA/stroke
Lifestyle modification
Ischaemic stroke/TIA:
Clopidogrel first-line (without AF)
Aspirin and modified release dipyridamole if clopidogrel contraindicated or not tolerated
Given long-term
High-intensity statin (e.g. atorvastatin)
Anti-hypertensives – target SBP less than 130mmHg (or 140-150 if severe bilateral carotid artery stenosis)
Anticoagulation in AF – DOAC (non-valvular) or warfarin (valvular)
Optimise management of comorbidities e.g. diabetes
Carotid artery stenosis:
Carotid artery endarterectomy recommended if patient has had stroke or TIA in carotid territory (extracranial internal carotid, ophthalmic artery, middle cerebral artery or anterior cerebral artery) and is not severely disabled
Considered if stenosis more than 70% according to European trial or 50% according to North American trial
Describe the cause and presentation of a subarachnoid haemorrhage
Causes:
Traumatic
Spontaneous –
Intracranial aneurysm (85%), associated with hypertension, PKD, Ehlers-Danlos, coarctation of the aorta
AV malformations
Pituitary apoplexy
Mycotic (infective) aneurysm
‘Thunderclap’ headache – acute onset, reaches peak intensity within seconds-minutes, occipital, severe (worst headache of life)
Nausea and vomiting
Photophobia
Neurological symptoms – dysphasia, weakness, visual disturbance, seizures
Reduced consciousness
Neck stiffness
Kernig’s sign – pain with passive knee extension when lying supine and hips and knees flexed
May have ECG changes e.g. ST elevation
How are subarachnoid haemorrhages assessed initially?
Investigation:
Non-contrast CT head first-line – hyperdense blood in basal cisterns, sulci, ventricular system
If CT head done within 6 hours of symptom onset and is normal, consider alternative diagnosis
If CT head done more than 6 hours after symptom onset and is normal – do an LP at least 12 hours after symptom onset
LP – xanthochromia, normal/raised opening pressure
If CT shows evidence of SAH immediate referral to neurosurgery
Further investigation:
CT angiogram to identify vascular lesion +/- digital subtraction angiogram (catheter angiogram)
Describe management of confirmed subarachnoid haemorrhage
Supportive:
Bed rest
Analgesia
VTE prophylaxis
Discontinuation of anti-thrombotics (reversal or anticoagulation if present)
Antiepileptics for seizures
Nimodipine – prevent vasospasm
Aneurysms are at risk of rebleeding, intervention within 24 hours – interventional radiology coiling (minority get craniotomy and clipping)
List potential complications of subarachnoid haemorrhage
Re-bleeding – 10%, most commonly within first 12 hours, should repeat CT if suspected
Hydrocephalus – can treat with temporary drain or permanent ventriculoperitoneal shunt
Vasospasm
Hyponatraemia – SIADH
Seizures
List red flags for headaches
Infection – immunocompromised, fever, photophobia, neck stiffness
Vomiting
Thunderclap headache
New-onset neurological deficit/cognitive dysfunction
Change in personality
Impaired consciousness
Recent (within 3 months) head trauma
Worse with cough, Valsalva
Changes with posture
Visual disturbance
Substantial change in characteristics of headache
Wakes from sleep
Pregnancy – pre-eclampsia
Papilloedema on fundoscopy
Describe the presentation and management of tension headaches
Recurrent
Mild ache across forehead, band-like
Come on and resolve gradually
No other symptoms, don’t interfere with ADLs
Associated triggers – stress, alcohol, skipping meals, dehydration
Management:
Simple analgesia – aspirin, paracetamol, NSAID
Acupuncture
Amitriptyline for prophylaxis (not recommended by NICE)
Describe the presentation and management of cluster headaches
Unilateral, excruciating/stabbing/burning pain
Ipsilateral to pain – conjunctival injection, lacrimation, nasal congestion, rhinorrhoea, ptosis/miosis
Last 15 minutes – 3 hours, 1-2x per day for 4-12 weeks (clusters)
MRI with contrast for investigation
Neurology referral
Acute management – 100% oxygen, SC triptan
Prophylaxis – verapamil (?prednisolone)
Describe the presentation of migraines
Severe, unilateral, throbbing headache
Associated with nausea, photophobia and phonophobia
Can last up to 72 hours
Classically have aura before migraine – visual, 5-60 minutes of hemianopic disturbance or spreading scintillating scotoma
Can have hemiplegic migraines – exclude stroke
Triggers – stress, alcohol, lack of food or dehydration, food (cheese, chocolate), menstruation, bright lights
Describe the management of migraines
Acute treatment:
1st line – oral triptan + NSAID/paracetamol
(in 12-17 year olds consider nasal triptan)
If not effective or tolerated give non-oral metoclopramide or prochlorperazine + non-oral NSAID or triptan
Prophylaxis:
Given if migraines are having significant impact on QOL and daily function e.g., frequent (more than once per week) or are prolonged and severe despite acute treatment
One of – propranolol, topiramate (avoid in women of childbearing age), amitriptyline
Other options – acupuncture, riboflavin, candesartan, Erenumab (MAB against calcitonin gene-related peptide)
Predictable menstrual migraines – frovatriptan or zolmitripan as ‘mini-prophylaxis’
Describe the mechanism of action, adverse effects, and contraindications to triptans
5-HT1 agonists
Available as oral, nasal, SC
Adverse effects – tingling, heat, chest/throat tightness
Contraindications – history of or significant risk factors for ischaemic heart disease or cerebrovascular disease
Describe the presentation and management of medication overuse headaches
Present for 15 days or more per month (more than every other day)
Medications which can trigger – triptans, opioids, paracetamol
Management – abruptly withdraw simple analgesics, withdraw opioids gradually
Headaches may initially worsen, withdrawal symptoms e.g., vomiting, hypotension, tachycardia, restless, sleep disturbance, anxiety
Describe the presentation, cause, and management of trigeminal neuralgia
Compression of trigeminal nerve roots – usually idiopathic, can be tumour/vascular cause
Unilateral, brief electric shock-like pain, abrupt onset and termination
Limited to one or more division of trigeminal nerve
Commonly triggered by light touch, cold, caffeine, citrus fruits or spontaneous
Management – carbamazepine first-line
Describe the risk factors for and presentation and management of idiopathic intracranial hypertension
Risk factors
Obesity
Female sex
Pregnancy
Drugs – COCP, steroids, tetracyclines, retinoids/vitamin A, lithium
Presentation – headache, blurred vision, papilloedema, enlarged blind spot, CN VI
Management
Weight loss
Diuretics – acetazolamide
Topiramate
LP for temporary reduction in ICP
Surgery – ventriculoperitoneal shunt, optic nerve sheath decompression to prevent damage
What are the indicators of secondary headaches?
Thunderclap – reaches maximal intensity within 1-5 minutes of onset
Associated focal neurological deficit
Associated systemic features – fever, weight loss, night sweats
Age >50
Describe the initial assessment of transient loss of consciousness
History – patient and witnesses
Circumstances, prodromal symptoms, appearance during event, duration, recovery after event
Previous TLoC, PMHx, DHx, FHx
Lying and standing BP
ECG
Cardiovascular or neurological signs
Referral for neurological assessment if seizure suspected and cardiovascular assessment if cardiovascular cause suspected
List the differential diagnosis of loss of consciousness
Syncope – vasovagal, cardiovascular, orthostatic
Seizures
Head injury
Psychogenic – psychogenic pseudosyncope, psychogenic non-epileptic seizures
Rare causes – vertebrobasilar TIA, SAH, cyanotic breath holding spell, subclavian steal syndrome
Describe the most common disease patterns in multiple sclerosis
Relapsing-remitting (most common) – episodes of exacerbations of symptoms followed by recovery and periods of stability
Secondary progressive – gradual accumulation of disability unrelated to relapses, which become less frequent or stop
2/3 with relapsing-remitting progress to secondary progressive
Primary progressive – steady progression and worsening from onset, without remission
How is an MS relapse defined?
Onset or new symptoms or worsening of pre-existing symptoms
Attributable to demyelinating disease
Lasting more than 24 hours
After stable period of at least a month
Describe the pathophysiology of multiple sclerosis
Largely unknown, risk factors:
Genetics
Vitamin D deficiency
Smoking
EBV
Female
Immune-mediated inflammation in response to environmental triggers in genetically predisposed
T-cells attack oligodendrocytes, damaging axons
May initially have some re-myelination of axons, eventually irreversible loss of function of affected nerves
Describe the presentation and diagnosis of multiple sclerosis
Typical presentation 20-50
Presenting features:
Optic neuritis
Unthoff’s phenomenon – worsening of symptoms with increase in body temperature (e.g. taking hot bath)
Internuclear opthalmoplegia – ipsilesional adduction deficit and contralateral abducting saccade/nystagmus on gaze to contralateral side
Sensory – paraesthesias, numbness, trigeminal neuralgia, Lhermitte’s syndrome
Spastic weakness
Ataxia
Tremor
Urinary incontinence
Sexual dysfunction
Diagnosis:
Requires evidence of two or more relapses
Clinical evidence of two or more lesions or evidence of one lesion and reasonable historical evidence of previous relapse
MRI evidence of two lesions (e.g., Dawson fingers)
If not enough evidence – CSF for oligoclonal bands
Describe the pathophysiology and presentation of internuclear ophthalmoplegia
Lesion involving medial longitudinal fasciculus in paramedian area of midbrain and pons – controls horizontal eye movements via CN III, IV and VI
Features – impaired adduction in ipsilateral eye, horizontal nystagmus of abducting eye on contralateral side
Describe the management of multiple sclerosis
Acute relapse:
High dose steroids (e.g., oral or IV methylprednisolone) for 5 days, shortens length of relapse but does not alter degree of recovery
Disease modifying drugs:
Typically if 2 relapses in past 2 years and able to walk 100m (if relapsing-remitting) or 10m (in secondary progressive)
Options e.g.
Natalizumab (alpha-4 beta-1 integrin antagonist)
Ocrelizumab (anti-CD20)
Fingolimod
Beta-interferon
Management of complications:
Fatigue – amantadine, CBT
Spasticity – baclofen, gabapentin, physiotherapy
Bladder dysfunction – US, self-catheterisation (if significant residual volume), anticholinergics (if no significant residual volume)
Describe the pathophysiology and presentation of Parkinson’s disease
Loss of dopaminergic neurones in the substantia nigra of the basal ganglion
Clinical features:
Classic triad is bradykinesia, tremor, and rigidity
Asymmetrical
Bradykinesia/hypokinesia – short, shuffling steps, reduced arm swinging, difficulty initiating movement
Tremor – resting, 3-5 Hz, improved with voluntary movement, typically ‘pill-rolling’
Rigidity – lead pipe, cogwheel
Reduced dexterity
Mask-like face
Stooped posture
Festinating gait
Anosmia
Psychiatric features – depression, dementia, psychosis, sleep disturbance
Autonomic dysfunction – postural hypotension, constipation, excessive salivation or sweating, urinary dysfunction, sexual dysfunction
How can drug-induced Parkinsonism be differentiated from Parkinson’s disease?
Drug-induced:
Rapid onset, bilateral
Rigidity and rest tremor uncommon
How is Parkinson’s disease diagnosed?
Clinical diagnosis
If unclear – single photo emission computerised tomography (SPECT)
Describe the strategy for management of Parkinson’s disease
First-line:
If motor symptoms are affecting quality of life – levodopa
If motor symptoms are not affecting quality of life – dopamine agonist, levodopa or monoamine oxidase B inhibitor
If continuing to have symptoms with levodopa add dopamine agonist, MAO-B inhibitor or catechol-O-methyl transferase (COMT) inhibitor as an adjunct
Levodopa nearly always given with decarboxylase inhibitor (e.g., carbidopa) – prevents peripheral metabolism of levodopa to dopamine outside brain to reduce side effects
List adverse effects of levodopa
Dry mouth
Anorexia
Palpitations
Postural hypotension
Psychosis
Difficult to achieve steady dose – end-of-dose wearing off, on-off phenomenon, dyskinesias at peak dose (dystonia, chorea, athetosis)
Important to take consistently
List adverse effects of dopamine receptor agonists and give examples
Examples – bromocriptine, ropinirole, cabergoline
Ergot-derived (bromocriptine, cabergoline) – associated with pulmonary, retroperitoneal and cardiac fibrosis, perform baseline tests and monitor closely
Impulse control disorders
Excessive daytime somnolence – may not be able to drive
Hallucinations – higher risk than levodopa in older patients
Nasal congestion
Postural hypotension
Describe the mechanism of action of monoamine oxidase B inhibitors in Parkinson’s disease and give examples
Selegiline
Inhibits breakdown of dopamine by monoamine oxidase B
Describe the mechanism of action of COMT inhibitors in Parkinson’s disease and give examples
Entacapone, tolcapone
COMT is involved in breakdown of dopamine – inhibit breakdown
Used in conjunction with levodopa in patients with established Parkinson’s disease
List causes of Parkinsonism/differential diagnosis of Parkinson’s disease
Parkinson’s disease
Drug induced – antipsychotics, antiemetics (metoclopramide)
Progressive supranuclear palsy – unsteadiness, dysphagia, gaze palsies
Multiple system atrophy – unsteadiness, falls, autonomic dysfunction
Wilson’s disease
Lewy body dementia
Essential tremor – increases on action, improved at rest, improved with alcohol, bilateral, not confined to hands
Why is it important to avoid missing doses of anti-Parkinsonian medications?
Missing doses can cause akinesia (freezing) and can precipitate neuroleptic malignant syndrome
List causes of peripheral neuropathy
Predominantly motor loss:
Guillain-Barre syndrome
Poryphria
Lead poisoning
Hereditary sensorimotor neuropathies – Charcot-Marie-Tooth
Diphtheria
Predominantly sensory loss:
Diabetes
Uraemia
Leprosy
Alcoholism
Vitamin B12 deficiency
Amyloidosis
Describe the functions of the spinal tracts
Ascending tracts:
Anterior spinothalamic tract – touch and pressure
Lateral spinothalamic tract – pain and temperature
Spinocerebellar tracts – proprioception
Descending tracts:
Pyramidal tracts – voluntary control of muscles
Extrapyramidal tracts – involuntary and automatic control of muscles (tone, balance, posture)
Causes of mononeuropathies
Most common – injury/compression
More rarely toxic/metabolic – tend to be mononeuritis multiplex, multiple single nerves affected sequentially
Diabetes
Drugs
Vasculitis
Infection – HIV/Lyme
What is the most common compression neuropathy? How does it present?
Radial nerve – ‘Saturday night palsy’
Presentation – wrist/finger drop, usually painless
Sensory loss in radial nerve distribution (proximal half of thumb, 1st, 2nd and lateral half of 3rd finger)
Which nerve palsy causes foot drop?
Common peroneal nerve
How should peripheral neuropathies be investigated?
Bloods –
Glucose, FBC, U&Es, LFTs, TFTs, B12, folate, protein electrophoresis
LP – not routine in length dependent neuropathy
Nerve conduction studies
Describe the presentation, diagnosis, and management of Guillain-Barre syndrome
Acute rapidly progressive flaccid paralysis
Weak proximally and distally
Prominent pain/sensory symptoms
+/- respiratory, bulbar, autonomic involvement
Areflexic
Post-infective - classically campylobacter jejuni
Diagnosis – clinical + raised protein in CSF (normal WCC), nerve conduction studies
Treatment – IV Igs or plasma exchange
Describe the pathophysiology and clinical presentation of myasthenia gravis
Antibodies to acetylcholine receptors
Muscle fatigability – weaker during activity, improve with rest
Extraocular muscle weakness – diplopia
Proximal muscle weakness – face, neck, limb girdle
Ptosis – exacerbated by repeated blinking
Dysphagia
Associations:
Thymoma – 15%
Autoimmune disorders – pernicious anaemia, autoimmune thyroid disorders, rheumatoid, SLE
How is myasthenia gravis diagnosed and managed?
Diagnosis:
Single fibre electromyography
CT thorax to exclude thymoma
CK normal
Antibodies to acetylcholine receptors
Tensilon test – IV edrophonium reduces muscle weakness temporarily (not done anymore)
Management:
Long-acting acetylcholinesterase inhibitors – pyridostigmine first-line
Longer term often need immunosuppression with prednisolone, azathioprine, cyclosporine etc.
Thymectomy
Management of myasthenic crisis:
Plasmapheresis
IV Igs
List drugs which can exacerbate symptoms of myasthenic gravis
Penicillamine
Quinidine
Beta-blockers
Lithium
Phenytoin
Antibiotics – gentamicin, macrolides, quinolones, tetracyclines
