Neurology Flashcards
what area of the brain is involved with comprehension and understanding of speech? where in the brain is this? what is its main blood supply?
Wernicke’s area.
superior temporal gyrus of the dominant hemisphere.
middle cerebral artery.
what area of the brain is involved with the production of speech? where in the brain is this? what is its main blood supply?
Broca’s area.
frontal lobe of the dominant hemisphere.
middle cerebral artery.
how would an ischaemic stroke of the anterior cerebral artery present?
tends to affect feet, legs, up to bowel problems.
leg weakness, sensory disturbance in leg, gait apraxia, truncal ataxia, incontinence, drowsiness, akinetic mutism
what is akinetic mutism?
worst form of ACA stroke - decrease in spontaneous speech, stuporous state, completely mute and don’t move.
a patient presents with leg weakness, incontinence, drowsiness, and some missing sensations in his legs. in what artery is the ischaemic stroke likely to have occurred?
anterior cerebral artery
how would an ischaemic stroke of the middle cerebral artery present?
tends to be more arm and face.
contralateral arm and leg weakness, contralateral sensory loss, aphasia, dysphasia, facial droop.
how would a posterior cerebral artery stroke present?
contralateral homonymous hemianopia, cortical blindness with bilateral involvement of the occipital lobe branches.
visual agnosia (can see, but can’t interpret visual information).
prospagnosia - can’t recognise faces (parietal lobe).
dyslexia, anomic aphasia, colour naming and discrimination problems.
what clinical features might a patient have with a posterior circulation stroke (vertebral/basilar arteries)?
motor deficits e.g. hemiparesis or tetraparesis and facial paresis.
dysarthria and speech impairment.
vertigo, nausea and vomiting.
visual disturbances.
altered consciousness.
at what point do symptoms become a stroke, rather than a TIA?
if they last over 24h.
name 2 causes of a TIA, other than atherosclerosis/emboli
vasculitis, sickle cell anaemia, polycythaemia, myeloma - causes of hyperviscosity!
what specific investigation would you carry out if you suspected that atherosclerosis had caused your patient’s TIA? what treatment would you consider?
carotid Doppler and carotid endarterectomy.
name 3 risk factors for a TIA
hypertension, smoking, obesity, diabetes, high alcohol intake
what is amaurosis fugax?
progressive loss of vision in one eye - “like a curtain descending over my field of view” - due to emboli passing into the retinal artery
name 2 differential diagnoses of a TIA
hypoglycaemia, migraine aura, focal epilepsy, hyperventilation, retinal bleeds
what is the ABCD2 score and what is it used for?
used to predict progression to full stroke:
Age >60yo
BP >140/90
Clinical features - unilateral weakness, speech disturbance without weakness.
Duration of symptoms - >1h or 10-59min.
Diabetes.
how would you treat a TIA?
control hypertension/hyperlipidaemia/diabetes.
smoking cessation.
antiplatelet drugs - clopidogrel/aspirin/warfarin.
± carotid endartectomy.
how does warfarin work to reduce platelet aggregation?
inhibits vitamin K dependent synthesis of clotting factors 2, 7, 9 and 10
list 4 risk factors for stroke
hypertension, smoking, diabetes, heart/peripheral vascular disease, past TIA/stroke, hyperlipidaemia, alcohol, increased clotting/clotting disorders, the Pill, syphilis, carotid bruit
what are the 2 main types of stroke?
ischaemic and haemorrhagic
list 5 causes of haemorrhagic stroke
hypertension, trauma, aneurysm rupture, anticoagulation, thrombolysis, carotid artery dissection, subarachnoid haemorrhage
what might be some pointers in the presentation of stroke, to whether it is due to haemorrhage or ischaemia?
haemorrhagic - meningism, severe headache, coma within hours.
ischaemic - carotid bruit, AF, past TIA, IHD.
what would be the clinical features of a brainstem infarct?
quadriplegia, disturbances of gaze and vision, locked-in syndrome
what are the 5 different syndromes produced by lacunar infarcts?
ataxic hemiparesis, pure motor, pure sensory, sensorimotor, dysarthria/clumsy hands
if a patient presented with vertigo, headache, ataxia and vomiting, what structure has been affected and what vessel has caused it?
cerebellar syndrome - due to occlusion of superior, anterior inferior or posterior inferior cerebellar artery
what is the essential investigation to carry out before you start specific stroke treatments?
urgent CT head
give 3 differential diagnoses of stroke
head injury, hypo/hyperglycaemia, subdural haemorrhage, intracranial tumours, hemiplegic migraine, epilepsy, CNS lymphoma, pneumocephalus, Wernicke’s encephalopathy, hepatic encephalopathy, mitochondrial cytopathies, abscesses, mycotic aneurysm
if CT showed that the stroke was caused by an infarct, how would you treat it?
thrombolysis - aspirin and alteplase - recombinant tissue plasminogen activator (tPA)
give 2 examples of primary prevention of stroke
treat hypertension, control DM, statins for hyperlipidaemia, regular physical exercise, smoking cessation, anticoagulation of patients with rheumatic/prosthetic heart valves on left
give 2 examples of secondary prevention of stroke
control risk factors (hypertension, diabetes, hyperlipidaemia).
aspirin or clopidogrel (unless haemorrhagic stroke)
list the causes of subarachnoid haemorrhage
rupture of saccular (Berry) aneurysms - 80%.
AV malformations - 15%.
idiopathic.
list 3 risk factors for subarachnoid haemorrhage
smoking, alcohol misuse, hypertension, bleeding disorders, mycotic aneurysm
what are some common sites for Berry anuerysms?
junction of posterior communicating artery with internal carotid.
junction of anterior communicating artery with anterior cerebral artery.
bifurcation of middle cerebral artery.
what 3 things are Berry aneurysms associated with?
polycystic kidneys, coarctation of the aorta, Ehlers-Danos syndrome
describe the symptoms of subarachnoid headache
THUNDERCLAP HEADACHE.
sudden, devastating occipital headache (I thought I’d been kicked in the head).
vomiting, collapse, seizures, coma.
give some signs of subarachnoid haemorrhage
neck stiffness, Kernig’s sign (inability to straighten knee with flexed hip).
retinal, subhyaloid and vitreous bleeds.
give 2 differential diagnoses of subarachnoid haemorrhage
meningitis, migraine, intracerebral bleeds, cortical vein thrombosis
what would you see on CT head in a subarachnoid haemorrhage?
no clear bleed - blood pools in available spaces, showing up white.
“star sign” - blood pooled in ventricles appears as white star.
what clinical features would indicate you should avoid doing a lumbar puncture and why?
headache, unilateral pupillary dilatation, vomiting, papilloedema, reduced mental state.
these are signs of raised ICP - risk herniation of brain and coning leading to death.
how would the CSF look if you performed a lumbar puncture on a person with subarachnoid haemorrhage?
CSF is bloody early on, then becomes yellow due to bilirubin - finding xanthochromia (yellow CSF) confirms SAH
how would you manage a subarachnoid haemorrhage?
hydrate, aim for systolic BP of 160 in order to maintain cerebral perfusion.
nimodipine - CCB, reduces vasospasm.
endovascular coiling, surgical clipping, intracranial stents, balloon remodelling.
give 2 possible complications of SAH
rebleeding.
cerebral ischaemia due to vasospasm - permanent CNS deficit.
hydrocephalus due to blockage of arachnoid granulations.
explain the process behind subdural haemorrhage
bleeding from bridging veins between cortex and venous sinuses - accumulating haematoma between dura and arachnoid - ICP gradually rises - midline structures shifted away from side of clot - eventual tentorial herniation and coning unless treated
who is at risk of subdural haemorrhage?
(those with small brains) - trauma patients, the elderly.
those prone to falls (epileptics, alcoholics).
those on anticoagulants.
how would a subdural haemorrhage present?
fluctuating consciousness level ± insidious physical/intellectual slowing.
sleepiness, headache, personality change, unsteadiness.
raised ICP, seizures.
what would you see on head CT/MRI of a patient with a subdural haemorrhage?
clot ± midline shift.
crescent shaped collection of blood over one hemisphere.
how would you manage a subdural haemorrhage?
mannitol for ICP.
irrigation/evacuation - burr twist drill/burr hole craniostomy.
craniotomy.
what causes an extradural haemorrhage?
MIDDLE MENINGEAL ARTERY most common.
any tear in dural venous sinus.
fractured temporal or parietal bone - causes laceration of middle meningeal artery and vein, typical after trauma to temple just lateral to eye.
what is a common clinical presentation of extradural haemorrhage?
‘lucid interval’ - walks away from road traffic accident seeming fine, then after a few hours/days, there’s a decrease in GCS from rising ICP.
after a lucid interval, what will be the clinical features of an extradural haemorrhage?
increasingly severe headache, vomiting, confusion, fits ± hemiparesis.
then - ipsilateral pupil dilates, coma deepens, bilateral weakness develops, deep and irregular breathing (brainstem compression)
how would an extradural haematoma appear on head CT?
round shape, rather than the sickle shape seen in subdural haematoma.
how would an extradural haematoma be treated?
mannitol for ICP.
neurosurgery - clot evacuation ± ligation of bleeding vessel
what treatment is contraindicated in all cerebral haemorrhages?
antiplatelets and anticoagulants
what 2 medical treatments can help reduce the risk of complications in intracranial haemorrhages?
dexamethasone (glucocorticoid) - reduces cerebral oedema, stabilises BBB.
nimodipine - CCB, reduces vasospasm
define a seizure, and define epilepsy
seizure = convulsion or transient event caused by a paroxysmal discharge of cerebral neurones.
epilepsy = continued tendency to have seizures.
what do the terms tonic, myoclonic and akinetic mean in terms of seizures?
tonic = intense stiffening of body with no convulsions.
myoclonic = isolated muscle jerking (rapid repetitions of this = clonic).
akinetic = cessation of movement, falling and loss of consciousness
what may be features of the post-ictal state?
headache, confusion, myalgia, sore tongue.
temporary weakness following focal seizure in motor cortex / dysphasia following seizure in temporal lobe.
list 4 causes of epilepsy
idiopathic/familial - 2/3rds!
cortical scarring, developmental, space-occupying lesion, stroke, hippocampal sclerosis, vascular malformations, tuberous sclerosis, sarcoidosis, SLE, PAN
list 4 non-epileptic causes of seizures
trauma, stroke, haemorrhage, raised ICP, alcohol/benzodiazepine withdrawal, metabolic disturbance, liver disease, fever.
infection - HIV, meningitis, encephalitis, syphilis.
drugs - tricyclics, cocaine, tramdol, theophylline
describe the features of a simple partial seizure
awareness unimpaired.
focal motor, sensory, autonomic or psychic symptoms.
no post-ictal symptoms.
describe the features of a complex partial seizure
impaired awareness.
may have simple partial onset (aura).
arise from temporal lobe.
post-ictal confusion.
what happens in a partial seizure with secondary generalisation?
electrical disturbance that began focally spreads widely causing a secondary generalised seizure - usually convulsive
what occurs in the brain during a primary generalised seizure?
simultaneous onset of electrical discharge throughout cortex with no localised features
describe the features of absence seizures
brief pauses, e.g. stops mid-sentence then carries on - presents in childhood
describe the features of tonic-clonic seizures
loss of consciousness.
limbs stiffen (tonic) then jerk (clonic).
may have one without the other.
post-ictal - confusion, drowsiness.
describe the features of myoclonic seizures
sudden jerk of a limb, face or trunk.
patient may be thrown to the ground suddenly, or have a violently disobedient limb.
describe the features of atonic (akinetic) seizures
sudden loss of muscle tone causing a fall, no loss of consciousness
list some features of a focal seizure that would localise it to the temporal lobe
automatisms - motor phenomena with impaired awareness and no recollection afterwards - lip smacking, chewing, fumbling, fiddling - even complex acts - singing, kissing, driving a car, violence.
abdo rising sensation/pain.
dysphasia.
memory phenomena (deja vu/jamais vu).
hippocampal involvement = emotional disturbance.
uncal involvement = hallucinations of smell or taste.
auditory cortex involvement - auditory hallucinations.
give some features of a focal seizure that would localise it to the frontal lobe
motor - posturing, versive movements of head and eyes, peddling of legs.
jacksonian march.
motor arrest.
subtle behaviour disturbances.
dysphasia or speech arrest.
give some features of a focal seizure that would localise it to the parietal lobe
sensory disturbances - tingling, numbness, pain.
motor symptoms - spread to pre-cental gyrus.
give some features of a focal seizure that would localise it to the occipital lobe
visual phenomena - spots, lines, flashes
how would you diagnose an epileptic seizure?
clinically - detailed description of attack from eye witness.
EEG - electroencephalogram and CT/MRI.
how would you treat generalised tonic-clonic seizures?
sodium valproate or lamotrigine.
2nd line - carbamazepine or topiramate.
how would you treat absence seizures?
sodium valproate or lamotrigine or ethosuximide
how would you treat tonic, atonic and myoclonic seizures? what should be avoided?
as for tonic-clonic but avoid carbamazepine.
so, sodium valproate/lamotrigine, with topiramate as 2nd line.
how would you treat partial seizures ± secondary generalisation?
carbamazepine.
give a side effect for each of the main 3 anti-epileptic drugs
sodium valproate - nausea, diarrhoea, weight gain.
lamotrigine - Stevens-Johnsons syndrome, diplopia, blurred vision.
carbamazepine - Stevens-Johnson syndrome, hyponatraemia, impaired balance.
what is the cardinal Parkinsonism triad comprised of?
bradykinesia (Parkinsonian gait), cogwheel rigidity, pill-rolling tremor
explain the pathophysiology of Parkinson’s disease. the presence of what feature in the brain is diagnostic?
degeneration of dopaminergic neurons in the substantia nigra pars compacta, associated with presence of Lewy bodies.
causes decrease in striatal dopamine levels leading to cell loss and akinesia.
give 3 non-motor symptoms of Parkinson’s disease
depression, dementia, dribbling, anosmia, hallucinations, constipation, dysphagia, heartburn, urinary difficulties, micrographia.
what one main risk factor for other diseases, is protective in Parkinson’s disease?
smoking
explain what you are likely to observe if you were to ask a Parkinson’s patient to walk up and down for you
stooping, shuffling gait. struggles to start walking. narrow base making falls common. obstacles, doors etc make them freeze and struggle to restart.
what is the typical age of onset of Parkinson’s disease?
65yrs
describe the medical management of Parkinson’s disease
dopamine agonists (ropinirole, pramipexole) and MAO-B inhibitor (rasagiline, selegiline) allows delay of starting L-Dopa.
start levodopa late - becomes ineffective after several years so start late and at a low dose then increase as needed.
prescribe with a decarboxylase inhibitor (carbidopa, besnerazide) to reduce peripheral side effects (esp. nausea).
why can’t Parkinson’s patient just be treated with dopamine?
it cannot cross the blood-brain barrier - levodopa is a precursor of dopamine and is able to cross the BBB and the be converted to dopamine within the brain.
what non-pharmacological treatment options are available for Parkinson’s?
deep brain stimulation, surgical ablation of overactive basal ganglia circuits.
what is Huntington’s chorea?
autosomal dominant, incurable, progressive, neurodegenerative disease.
define chorea
abnormal involuntary movements - brief, abrupt, irregular, unpredictable, non-stereotyped - may appear purposeful - patient appears fidgety/clumsy
describe the features of the prodromal phase of Huntington’s disease
irritability, depression, incoordination - personality changes, self-neglect (doesn’t wash, doesn’t care about work), fidgeting, tic.
describe the features of Huntington’s chorea
chorea, dementia ± fits and death.
what is the underlying pathology of Huntington’s chorea?
atrophy and neuronal loss of striatum and cortex.
what are the changes in neurotransmitters seen in Huntington’s chorea?
reduced ACh synthesis, depleted GABA and ACE in substantia nigra.
high somatostatin levels in corpus striatum.
dopamine remains normal.
what would an MRI scan of the brain of a patient with Huntington’s chorea show?
caudate nucleus atrophy
how would you treat Huntington’s chorea?
nothing will stop progression - symptomatic treatment only.
phenothiazines - sulpiride - antipsychotic drug, selective dopamine antagonist against receptors D2 and D3.
Tetrabenazine - used in hyperkinetic movement, promotes degradation of dopamine, helps chorea.
name 3 precipitating factors of a tension headache
loud noise, worry, fumes, concentrated efforts
how might a patient describe the pain of a tension headache?
bilateral, ‘tight band’, non-pulsatile, scalp tenderness.
how would you manage a patient with tension headaches?
reassurance. stress relief.
can prescribe NSAIDs, paracetamol or aspirin - watch for analgesic overuse headache
what causes tension headaches?
neurovascular irritation, referred to scalp muscles and soft tissues.
what other symptoms may accompany the pain of a tension headache?
vomiting, sensitivity to head movement
what are the clinical features that affect the eye in cluster headaches?
lacrimation, transient ipsilateral Horner’s, lid swelling, unilateral eye pain
describe the timeline of cluster headaches
recurrent bouts of the headache a couple of times a day, coming on a few times a month, then disappears for a few months and then returns unexpectedly
describe the pain of a cluster headache
rapid onset excrutiating pain around one eye. strictly unilateral - affects same side each time.
how would you treat an acute attack of a cluster headache?
100% O2 for 15min via non-rebreathe mask.
sumatriptan (SC) - 5HT receptor agonist, acts on serotonin receptors.
what preventatives are available to be used for cluster headaches?
suboccipital steroid injections.
intranasal civamide.
both are controversial.
also verapamil (CCB)
give 4 migraine triggers
chocolate, cheese, oral contraceptives, caffeine, alcohol, anxiety, travel, exercise, lie ins, loud noise
give 3 possible features of a migraine aura
flashing lights, tingling and weakness down one side, visual disturbance, ataxia, dysphasia
give 2 possible features of a migraine prodrome
yawning, cravings, mood/sleep change
describe the pain of migraine
severe unilateral throbbing headache, with nausea, vomiting ± photophobia/phonophobia.
what are the diagnostic criteria for migraine without aura?
> 5 headaches lasting 4-72h + nausea/vomiting (or photo/phonophobia) + 2 of:
unilateral, pulsating, impairs (or worsened by) routine activity.
give 3 differential diagnoses of migraine
cluster or tension headache, cervical spondylosis, hypertension, intracranial pathology, sinusitis/otitis media, TIA (may mimic migraine aura)
how might you pharmacologically treat a migraine?
NSAIDs - ketoprofen, aspirin.
triptans (5HT agonists) - riztriptan, sumatriptan.
what drugs might be used to prevent migraines?
1st line - propranolol, amitriptyline, topiramate, CCBs.
2nd line - valproate, pizotifen, gabapentin, pregabalin.
what rheumatological disease is giant cell arteritis associated with?
polymyalgia rheumatica
describe the 3 main clinical features of giant cell arteritis, and what causes them
headache - inflamed superficial temporal/occipital artery that hurts to touch and can become tortuous and thickened (I can’t even comb my hair!)
facial pain - inflammation of facial maxillary and lingual branches of external carotid artery, worse on eating (jaw claudication) - I can’t eat steak anymore!
visual disturbance - arterial inflammation and occlusion causing monocular painless visual loss (amaurosis fugax).
what is the risk if treatment of giant cell arteritis is delayed?
irreversible bilateral visual loss.
how would you diagnose giant cell arteritis? what should be done first?
raised ESR/CRP.
temporal artery biopsy - start steroids first!!
how would you treat giant cell arteritis?
immediate high dose oral prednisolone.
list 3 secondary causes of trigeminal neuralgia
compression of trigeminal root by anomalous/aneurysmal intracranial vessels or a tumour.
chronic meningeal inflammation.
MS.
herpes zoster.
skull base malformation.
describe the clinical features of trigeminal neuralgia
paroxysms of intense, stabbing pain, lasting seconds in the trigeminal nerve distribution.
unilateral, affecting mandibular or maxillary divisions.
face screwed up in pain.
give 2 examples of triggers of trigeminal neuralgia
washing affected area, shaving, eating, talking, dental prostheses
how would you treat trigeminal neuralgia?
carbamazepine, lamotrigine, phenytoin or gabapentin.
some surgical options.
give 3 causes of spinal cord compression
secondary malignancy - breast, lung, prostate, thyroid, kidney.
TB - Pott’s disease (destruction of vertebral bodies and disc spaces).
epidural haemorrhage or haematoma
prolapsed disc.
where do the corticospinal tracts decussate? what do they control?
85% - pyramids of medulla - lateral corticospinal tract, muscles of arms and legs.
15% - at the spinal level they leave at - control postural muscles, only present in thoracic levels.
which tract controls pain and temperature? where does it decussate?
spinothalamic - goes up 2-3 levels, then decussates
what tract controls “nice sensations” where does it decussate?
dorsal columns - touch, vibration, proprioception.
gracile fasciculus - legs, cuneatus fasciculus - arms.
decussate in upper medulla.
what imaging would you use to investigate the cause of the symptoms in spinal cord compression?
MRI
in Brown-Sequard syndrome, there is a hemisection of the spinal cord, on what side is there a loss of proprioception, vibration, power, pain and temperature?
contralateral loss of pain and temperature.
ipsilateral loss of proprioception, vibration and power.
what is the T10 dermatome?
umbilical level
what is the L1 dermatome?
inguinal ligament
what is the L2-3 dermatome?
anterior and inner leg
what is the C3-4 dermatome?
clavicles
what is the C6-7 dermatome?
lateral arm/forearm
what is the T1 dermatome?
medial side of the arm
what is the T4 dermatome?
nipple level
how would you treat spinal cord compression due to malignancy?
dexamethasone IV ± radio/chemotherapy
what is the cauda equina?
a bundle of spinal nerves and spinal nerve roots that consists of L2-5 and S1-5, they innervate the lower limbs and pelvic organs.
they also supply the sensory innervation to the perineum and parasympathetic supply to the bladder.
what causes damage to the cauda equina?
damage to spine at or distal to L1
what are the clinical features of cauda equina syndrome?
flaccid leg weakness and areflexic paralysis of legs.
back pain, radicular pain down legs, sensory loss in a root distribution, decreased sphincter tone
how would you manage cauda equina syndrome?
surgical decompression within 48h
explain the pathogenesis of multiple sclerosis
inflammatory process in the white matter of the brain and cord mediated by CD4 T cells.
there are discrete plaques of demyelination at multiple CNS sites.
demyelination leads to axonal damage.
heals incompletely causing relapsing and remitting disease.
describe the 4 possible disease courses in MS. what is necessary for diagnosis?
need lesions disseminated in time and space.
relapsing and remitting - disease relapses followed by full recovery, or at least partial recovery - clear period of time with no disease activity, followed by another relapse.
primary progressive - disease progresses from onset, with occasional plateaus/temporary improvements.
secondary progressive - initially relapsing/remitting, then following progressive phase.
progressive/relapsing - progressive disease from onset, with clear acute relapses that recover then continue to progress.
describe the epidemiology of MS
prevalence increases with distance from equator - possible role of vitamin D?
more common in women, mean age of onset 30yrs.
give some clinical features of MS
unilateral optic neuritis - pain on eye movement, rapid worsening of central vision.
numbness or tingling limbs.
leg weakness.
brainstem/cerebellar symptoms (diplopia, ataxia).
sensory - paraesthesiae, trigminal neuralgia.
motor - spastic weakness, myelitis.
GU - ED, urine retention, incontinence.
GI - swallowing disorders, constipation.
eye - diplopia, hemianopia, visual phenomena, pupil defects.
cognitive decline - amnesia, mood swings, decreased executive functioning.
what commonly makes symptoms of MS worse?
raised body temp - HOT BATHS
what 2 investigations would you carry out in MS and what would you expect to see?
MRI - visible plaques.
CSF - oligoclonal IgG bands on electrophoresis.
lesions disseminated in time and space
how would you treat MS?
acute - IV methylprednisolone (doesn’t affect prognosis, just treats relapse symptoms).
prevention of relapses - beta-interferon, azathioprine.
what is the gold standard investigation for stroke?
CT
why do you get a lucid interval in extradural haematomas?
because the patient is bleeding very slowly - due to how tightly the dura mater is adherent to the skull.
venous bleed.
what is the genetic basis of Huntington’s chorea? how many repeats may a patient have before they develop Huntington’s?
expansion of CAG repeat on chromosome 4 - overexpression of the huntingtin gene.
> 27 repeats is abnormal.
40 almost definitely will get Huntington’s.
the more repeats, the worse the symptoms.
what is giant cell arteritis?
systemic immune mediated vasculitis affecting medium and large sized arteries
what 3 clinical features make up Cushing’s triad of signs of raised ICP?
irregular resps.
bradycardia.
hypertension.
explain the pathophysiology of myasthenia gravis
an autoimmune disease, producing antibodies to nicotinic ACh receptors, which interfere with neuromuscular transmission by depleting receptor sites.
immune complexes of anti-ACh receptor IgG and complement are deposited at the post-synaptic membranes.
what drug can cause a transient form of myasthenia gravis?
penicillamine
what is the main clinical feature of myasthenia gravis?
increasing muscular fatigue - weakness on sustained/repeated activity, that improves after rest
which muscle groups are affected by mysathenia gravis, in order of most affected
extra-ocular, bulbar (swallowing, chewing), face, neck, limb girdle, trunk
give some examples of things you can look for to assess mysathenia gravis
ptosis (eyelid droop), diplopia, mysathenic snarl on smiling.
voice fades when asked to count to 50.
what specific test would you carry out to investigate myasthenia gravis?
tensilon test - IV edrophonium given, shows improvement in weakness for about 5 minutes
what might you seen on serology of a patient with myasthenia gravis?
anti-AChR and anti-MUSK antibodies
what eye test might you perform to confirm a diagnosis of myasthenia gravis?
see if ptosis improves by >2mm after ice applied to affected lid for >2 mins
how would you treat myasthenia gravis?
symptom control - anticholinesterase (pyridostigmine).
immunosuppression - prednisolone for relapses ± azathioprine/methotrexate.
thymectomy may be considered.
how does pyridostigmine help treat symptoms of myasthenia gravis? name a possible side effect and how you would treat it.
inhibits acetylcholinesterase enzyme from breaking down ACh - thereby increasing level and duration of action of ACh.
colic, diarrhoea - atropine.
name a gene that causes MND. is this the usual cause?
SOD1.
causes rare familiar MND - most cases are sporadic.
what distinguishes motor neurone disease from MS/polyneuropathies?
NO sensory loss or sphincter disturbance in MND.
affects upper and motor neurones.
what happens to the nervous system in MND? what is the prognosis?
selective loss of neurones in motor cortex, cranial nerve nuclei and anterior horn cells.
relentless and unexplained destruction of these neurones.
most die in 3yrs from respiratory failure due to bulbar palsy and pneumonia.
how could you distinguish MND from myasthenia gravis?
MND never affects eye movement, myasthenia gravis will.
name the 4 clinical patterns of MND
ALS (amyotrophic lateral sclerosis).
progressive bulbar palsy.
progressive muscular atrophy.
primary lateral sclerosis.
describe the features of ALS MND and what part of the CNS it affects.
disease of lateral cortiospinal tracts.
causes weakness with UMN signs and LMN wasting.
progressive spastic tetraparesis with LMN signs and fasciculation.
who should you suspect MND in?
> 40yrs.
stumbling spastic gait, foot drop ± proximal myopathy.
weak grip and shoulder abduction.
give some UMN and LMN signs that may feature in MND
UMN - spasticity, brisk reflexes, upgoing plantars.
LMN - wasting, fasciculation of tongue, abdomen, back, thigh
how would you treat a patient with MND?
antiglutamatergic drugs - riluzole - only drug that slows progression.
for drooling - amitriptyline.
muscle spasticity - beclofen.
give 3 organisms that can trigger Guillain-Barre syndrome
Campylobacter jejuni, CMV, mycoplasma zoster, HIV, EBV
describe the pattern of disease progression seen in Guillain-Barre syndrome
a few weeks after infection, symmetrical ascending muscle weakness starts.
advances quickly - affects all limbs, can lead to paralysis.
progressive phase of up to 4 weeks, followed by recovery
describe the clinical features seen in Guillain-Barre
symmetrical ascending muscle weakness.
proximal muscles more affected e.g. trunk, respiratory, cranial nerves.
pain common (e.g. back limb), but no sensory signs.
autonomic dysfunction - sweating, raised pulse, BP changes, arrhythmias.
if you were to perform lumbar puncture on a patient with Guillain-Barre syndrome, what might you see?
increased protein
how would you treat a patient with Guillain-Barre syndrome?
IV immunoglobulin/plasmapharesis.
heparin to prevent DVT.
give 3 possible clinical features of dementia besides memory loss
agitation, aggression, apathy, depression, wandering, hallucination, slow repetitive speech, mood disturbance
list some possible causes of dementia
alzheimer’s.
vascular dementia.
Lewy body dementia.
Fronto-temporal dementia.
explain how vascular dementia arises
cumulative effects of many small strokes.
sudden onset, with stepwise deterioration.
what are the features of Lewy body dementia?
fluctuating cognitive impairment, detailed visual hallucinations, Parkinsonism.
histology = Lewy bodies in brainstem and neocortex.
what are the features of fronto-temporal (Pick’s) dementia and what causes it?
frontal and temporal atrophy without Alzheimer’s histology.
genes on chromosome 9.
executive impairment, behavioural/personality change, preservation of episodic memory, disinhibition, hyperorality, stereotyped behaviour, emotional unconcern
how would you diagnose dementia?
clinical history + timeline of progression - ask relatives/spouse!
cognitive testing - AMTS/TYM (dementia screens), mental state examinations.
CT/MRI.
how would you manage dementia?
develop routines early on - retained until later, prolongs independence.
trazodone, lorazepam.
watch for depression - SSRIs (citalopram).
what genetic disorder is associated with Alzheimer’s disease?
Down’s syndrome - will inevitably progress to Alzheimer’s
describe the pathology behind Alzheimer’s disease
accumulation of beta-amyloid peptide (a degradation product of amyloid precursor protein) results in progressive neuronal damage, neurofibrillary tangles, raised numbers of amyloid plaques and loss of ACh.
neuronal loss is selective - hippocampus, amygdala, temporal neocortex and subcortical nuclei.
give 3 risk factors for Alzheimers disease
1st degree relative with AD.
Down’s syndrome.
homozygous for apolipoprotein e (ApoE) 4 allele, vascular risk factors, decreased physical/cognitive activity, depression, loneliness
give some clinical features of Alzheimers disease
general dementia features.
plus - enduring, progressive and global cognitive impairment, loss of visuo-spatial skill.
memory, verbal abilities and executive function affected.
late features - irritability, mood changes, behavioural change, psychosis, agnosia.
anosognosia - lack of understanding of the problems caused by the disease.
how might you treat Alzheimer’s disease dementia?
acetylcholinesterase inhibitors (rivastagmine, donezepil, galantamine).
antiglutamatergic treatment (memantine).
folic acid and B vits.
give 2 mechanisms by which you can develop neuropathy
demyelination - Schwann cell damage.
Axonal degeneration - axon damage, conduction remain intact.
Wallerian degeneration - follows nerve section.
Compression - disruption of myelin sheath.
Infarction - microinfarction of vasa nervorum.
Infiltration - by inflammatory cells, granulomas and neoplastic cells.
what are Tinel’s sign and Phalen’s test and what are they used for?
Tinel’s - lightly tap over a nerve to induce irritation in it e.g. over the wrist.
Phalen’s - ask patient to hold wrists in full flexion (reverse prayer position) for 30-60s, press on wrist if needed, should get tingling sensation/pain.
they are diagnostic for carpal tunnel.
give 3 diseases carpal tunnel is associated with
diabetes mellitus, acromegaly, hypothyroidism, amyloidosis, rheumatoid disease.
what is otherwise known as ‘Saturday night palsy’?
radial nerve compression - causes wrist drop and weakness of brachioradialis and finger extension, sensory loss in anatomical snuff box
what nerve controls the ankle jerk reflex?
S1
a slim female yoga instructor comes to see her doctor complaining that her left foot keeps dragging on the floor, what do you think could be causing her problem?
common peroneal palsy - her symptoms are due to weakness of ankle eversion and extension, she probably also has numbness over anterolateral border of dorsum of foot and lower shin
a patient comes in having had an accident on the rugby pitch with a suspect elbow fracture, he’s now complaining of sensory loss over his little finger and medial side of his hand, what do you think could be causing his symptoms and if left untreated, what could he go on to develop?
ulnar nerve compression, could go on to develop weakness/wasting of medial wrist flexors, interossei, medial 2 lumbricals and hypothenar eminence
what changes in the spine could there be in cervical/lumbar degeneration?
osteophytes, thickening of spinal ligaments, narrowing of spinal canal, disc degeneration and protrusion, vertebral collapse, ischaemic changes
what would be felt in the myotome and dermatome affected by a spinal nerve root lesion?
myotome - pain of root compression.
dermatome - tingling discomfort.
give 2 causes of nerve root lesions
spondylosis, herpes zoster, tumours, meningeal inflammation.
give 2 causes of anosmia caused by an olfactory nerve palsy
respiratory tract infection, olfactory groove tumour, meningitis
if someone is referred to you with suspected Horner’s syndrome, what do you expect to find on examination?
unilateral pupillary constriction with slight ptosis and enophthalmos, loss of sweating on same side
a patient comes to see you complaining of visual loss at the ‘sides of his eyes’ on both sides and has some vague endocrine symptoms, what are you thinking is the cause, what kind of visual loss does he have and where is the lesion?
pituitary neoplasm pressing on the optic chiasm causing bitemporal hemianopia.
you are performing a cranial nerve examination on a patient who has an oculomotor nerve lesion (CN3), what would you see?
ptosis, large pupil, eye down and out.
what kind of visual symptoms would you get with a trochlear nerve lesion?
diplopia on looking down and in
complete external opthalmoplegia is due to palsy of which nerves and what does it cause?
palsy of the oculomotor, trochlear and abducens (III, IV and VI) nerves causing complete paralysis of the eye
what is the corneal reflex and what nerve controls it?
trigeminal nerve.
involuntary blinking of eye when the cornea is stimulated by something such as cotton wool.
a small child presents to you with a vesicular rash on the side of their face, their mother says they’ve been struggling to eat recently as well - what do you suspect is the cause and how would you treat it?
Ramsay Hunt syndrome caused by herpes zoster/shingles, treat with fanciclovir
name a drug that can cause sensorineural deafness?
gentamicin, furosemide
what symptoms are caused by vestibular nerve palsy?
vertigo, loss of balance and nystagmus
why do lesions of the glossopharyngeal and vagus appear together?
they both leave the skull through the jugular foramen
a patient is struggling to turn their head to the right - they think the’ve slept on it in a weird position. what nerve could have been damaged?
left hand side acessory nerve
you ask a patient to stick their tongue out and it immediately deviates to the right and is very stiff to move, what do you suspect?
UMN lesion affecting the right hypoglossal nerve
what is mononeuritis multiplex? give 3 examples of causes
2+ peripheral nerves affected, causes tend to be systemic - WARDS PLC:
Wegener’s
AIDs/Amyloid
Rheumatoid
Diabetes mellitus
Sarcoidosis
PAN
Leprosy
Carcinomatosis
list the muscles involved in precision grip. what nerve controls us, and what are its spinal roots?
median nerve - C6-T1.
LOAD:
2 Lumbricals
Opponens pollicis.
Abductor pollicis brevis
Flexor pollicis brevis
describe the patterns of sensory loss seen in the hand
median nerve damage - loss of radial 3.5 fingers and palm.
ulnar - medial/ulnar 1.5 fingers.
give a sign of radial nerve damage and an example of how this may occur
wrist and finger drop - compression against humerus
give a sign of ulnar nerve damage and how it may occur
weakness/wasting of ulnar side wrist flexors, interossei (can’t cross fingers) and medial two lumbricals (claw hand).
hypothenar eminence wasting.
how would brachial plexus damage present?
pain/paraesthesiae and weakness in affected arm.
how would phrenic nerve (C3-5) damage present?
orthopnoea with raised hemidiaphragm on CXR.
how might damage to the lateral cutaneous nerve of the thigh present (L2-L3)?
meralgia paraesthetica - anterolateral burning thigh pain from entrapment under inguinal ligament
how would sciatic nerve damage present (L4-L5)?
affects hamstrings and all muscles below the knee - foot drop.
loss of sensation below the knee laterally.
pelvic tumours/fractures.
give 2 signs of damage to the common peroneal nerve (L4-S1)
foot drop, weak ankle dorsiflexion/eversion, sensory loss over dorsum of foot
how would tibial nerve damage present (L4-S3)?
unable to stand on tiptoe, invert foot or flex toes.
originates from sciatic nerve just above the knee.
describe the clinical features of carpal tunnel syndrome
aching pain in hand and arm, esp at night.
paraesthesiae in thumb, index and middle fingers.
relieved by dangling hand over edge of bed and shaking it - wake and shake.
list 3 causes of carpal tunnel syndrome
MEDIAN TRAPS:
Myxoedema.
Enforced flexion (Colles’ splint).
Diabetic neuropathy.
Idiopathic.
Acromegaly.
Neoplasms e.g. myeloma.
benign Tumours.
Rheumatoid arthritis.
Amyloidosis.
Pregnancy/premenstrual oedema.
Sarcoidosis.
how might you manage carpal tunnel syndrome?
splinting, local steroid injection, decompression surgery.
describe the features of a UMN lesion
pyramidal weakness - arm extensors, small muscles of hand and lower limb flexors.
no muscle wasting.
spasticity in stronger muscles.
hyperreflexia.
upgoing plantars.
describe the features of a LMN lesion
damage to anterior horn cells, nerve roots, plexi or peripheral nerves.
distribution of weakness corresponds to those muscles supplied by the involved cord segment etc.
muscles show wasting ± fasciculation.
hypotonia/flaccidity - limb feels soft and floppy.
reduced/absent reflexes.
plantars remain flexors.
give the 2 subtypes of gliomas
astrocytoma and oligodendroglioma
name 3 types of primary malignant brain tumour
glioma, embryonal tumours, lymphoma
name 2 types of benign brain tumour
meningioma, neurofibroma (e.g. from Schann cells)
what is the most common cause of brain tumours?
metastases:
bronchus, breast, stomach, prostate, thyroid, kidney.
what are the common sites of meningiomas?
parasagittal region, sphenoidal region, subfrontal region, pituitary fossa and skull base
what are the 4 main classes of symptoms you can get from a brain tumours?
raised ICP, seizures, focal neurology, personality change
what investigation would you use to stage a brain tumour?
CT/MRI + CXR etc to look for primary
how would you manage a brain tumour?
surgical removal if possible.
IV/PO dexamethasone to reduce cerebral oedema.
phenytoin to treat epileptic seizures.
radiotherapy.
name 3 organisms that commonly cause meningitis
Neisseria meningitides, Streptococcus pneumoniae, H influenzae, Listeria monocytogenes.
immunocompromised - CMV, cryptococcus, TB.
list some clinical features of meningitis
neck stiffness (Brudzinski’s neck sign), headache, fever.
cold hands and feet.
photophobia, Kernig’s sign (pain + resistance on passive knee extension when hip fully flexed).
non-blanching petechial rash.
vomiting, rigors, irritability, papilloedema.
give 3 differential diagnoses of meningitis
malaria, encephalitis, septicaemia, subarachnoid haemorrhage, dengue, tetanus
what antibiotics would you give to a patient presenting with meningitis?
cefotaxime - 3rd gen cephalosporin
what would you need to do, apart from treat them, if you were presented with a patient with meningitis?
contact tracing for prophylaxis.
inform local officer/PHE.
what drugs would you give for meningitis prophylaxis?
rifampicin or ciprofloxacin.
give 2 viral causes of encephalitis
(viral is more common than bacterial)
herpes simplex, coxsackie, EBV, mumps, CMV, VZV, measles, rabies
give 2 non-viral causes of encephalitis
bacterial meningitis, TB, malaria, listeria, lyme disease, Legionella, leptospirosis, aspergillosis, typhus
what is encephalitis?
inflammation of brain parenchyma
what clinical features would make you suspect encephalitis?
(can be mild, self-limiting - fever/headache/drowsiness)
odd behaviour, decreasing consciousness, seizures, focal neurology, headache, fever, history of travel/animal bite
if you performed a lumbar puncture on a patient with encephalitis, would would you expect to see?
increased WCC, increased protein
how would you treat a patient with viral encephalitis?
IV acyclovir, phenytoin for seizures
what is the primary infection in shingles?
chicken pox - reactivation of herpes zoster/varicella zoster virus
what are the clinical features of shingles?
dermatome distribution of rash (papules and vesicles), pain and tingling.
most common in lower thoracic dermatomes and ophthlamic division of trigeminal nerve.
how would you treat shingles?
oral acyclovir or valaciclovir as early as possible
what is the main complication of shingles and how would you treat it? how is it prevented?
post-herpetic neuraligia - pain in distribution of affected nerves.
treat with carbamazepine or phenytoin.
prevented by prompt antiviral treatment.
how do anti-epileptic drugs work?
they work on sodium channels to inhibit action potentials to stop continuous firing of neurones
pyridostigmine is used in a neurotransmitter disease, which one and how does it relieve symptoms?
myasthenia gravis - acetylcholinesterase inhibitor, which means ACh is around longer to attach to the post-synaptic membranes
baclofen is used for muscle spasticity in what disease, and how does it work?
Huntington’s chorea - GABA agonist.
what type of drug do you prescribe in trigeminal neuralgia?
anti-epileptic, carbamazepine
ceftriaxone is prescribed in bacterial meningitis, what class of antibiotic is it?
3rd generation cephalosporin
give 2 examples of benzodiazepines. what are they used for?
diazepam, lorazepam, chlordiazepam - first line management of seziures and status epilepticus, management of alcohol withdrawal rections.
how do benzodiazepines work?
target the gamma-aminobutyric acid type A (GABA-a) receptor, which is a chloride channel that opens in response to binding by GABA (main inhibitory neurotransmitter) - opening the channel makes the cell more resistant to depolarization.
benzodiazepines facilitate and enhance binding of GABA to GABA-a receptors and have a widespread depressant effect on synaptic transmission - cause reduced anxiety, sleepiness, sedation, anti-convulsion.
what is carbamazepine used to treat?
epilepsy - focal seizures ± secondary generalisation and for primary generalised.
trigeminal neuralgia.
how does carbamazepine work?
inhibits neuronal sodium channels, stabilising resting membrane potentials and reducing neuronal excitability.
this may inhibit spread of seizure activity, and control spread of neuralgic pain by blocking synaptic transmission.
what are valproates used for? name one.
epilepsy - 1st choice for generalised/absence seizures and focal seizure treatment.
sodium valproate, valproic acid.
what are gabapentin/pregabalin used to treat?
focal epilepsies as an addition to carbamazepine.
also for neuropathic pain and migraine prophylaxis.
how does gabapentin work?
closely related to GABA - binds to voltage sensitive calcium channels, preventing inflow of calcium and thus inhibiting neurotransmitter release, interfering with synaptic transmission and reducing neuronal excitability.
give some examples of dopaminergic drugs
levodopa (as co-careldopa, co-beneldopa), ropinirole, pramipexol
how do dopaminergic drugs work to treat Parkinson’s?
there’s a dopamine deficiency in Parkinson’s - treatment increases dopaminergic stimulation to the basal ganglia.
levodopa = dopamine precursor that is able to cross the BBB.
ropinirole and pramexipol = selective agonists for the D2 receptor, which predominates in the basal ganglia - used to delay starting levodopa.
what is levodopa always given with? why?
a peripheral dopa-decarboxylase inhibitor e.g. carbidopa - combined preparations (co-careldopa, co-beneldopa).
this is to reduce conversion to dopamine outside the brain, reducing SE of nausea, and lowering the dose.
what are triptans used to treat?
migraines and cluster headaches - not preventative/curing though.
e.g. sumatriptan, rizatripan.
how do triptans work?
agonist effects on serotonin 5-HT-1b and d receptors in cranial blood vessels - causes their constriction, and subsequent inhibition of pro inflammatory neuropeptide release.
may also work on serotonin receptors in nerve endings to relieve pain through decrease in levels of substance P.
what class of drug do rivastigmine and neostigmine belong to? what are they used to treat?
acetylcholinesterase inhibitors.
Alzheimer’s disease, Lewy body dementia and Parkinson’s disease. also myasthenia gravis.
how do acetylcholinesterase inhibitors work as neurological drugs?
inhibit ACh break down. in neurodegenerative disorders they are used to treat memory and learning deficit symptoms - improve due to role of ACh in cognition.
in myasthenia gravis there are too few ACh receptors, so with greater ACh availability, symptoms improve.
list 3 things that can worsen the weakness of myasthenia gravis
pregnancy, hypokalaemia, infection, over-treatment, change of climate, emotion, exercise
what would you see in a patient with an abducens nerve (CNVI) lesion?
horizontal diplopia on looking out
what might patients complain of in mysathenia gravis?
“stairs, chairs and hair”
can’t get up out of chairs, can’t walk up the full flight of stairs, can’t brush their hair.
