Corrections - Neurology Flashcards
Where do the pontine arteries radiate from?
What do they supply?
From the basilar artery on the brainstem.
They supply the pons.
Presentation of a pontine haemorrhage?
1) Pinpoint pupils: thought to be caused by irritation and stimulation of parasympathetic pathways in the pons
2) Paralysis: due to motor tracts in the pons that descend to supply the limbs
3) Low GCS
What structures are within the lateral medulla?
How does this explain features of a posterior inferior cerebellar artery lesion (i.e. lateral medullary syndrome)?
1) sympathetic tract: hence ipsilateral Horner’s syndrome
2) inferior cerebellar peduncle (connects medulla to cerebrum): ipsilateral ataxia
3) part of the trigeminal nerve nucleus: ipsilateral facial numbness
4) spinothalamic tract: contralateral body numbness
5) nucleus ambiguus (which gives rise to some vagus nerve and glossopharyngeal motor fibres): dysphonia and dysphagia
What should all TIA patients have?
an urgent carotid doppler unless they are not a candidate for carotid endarterectomy
What can be taken for 2ary prevention of stroke if clopidogrel is contraindicated?
Aspirin + dipyridamole
Role of dipyridamole in 2ary prevention of stroke?
Dipyridamole works synergistically with aspirin by inhibiting platelet activation and adhesion, as well as having vasodilatory effects.
How long should aspirin + dipyridamole be continued in 2ary prevention of ischaemic stroke?
lifelong
Causes of a brain abscess?
1) ascending infection from middle ear or from facial sinuses
2) trauma or surgery to the scalp
3) penetrating head injuries
4) embolic events from endocarditis
Presentation of brain abscess?
1) headache: often dull, persistent
2) fever: may be absent and usually NOT the swinging pyrexia seen with abscesses at other sites
3) focus neurology e.g. oculomotor nerve palsy or abducens nerve palsy 2ary to raised intracranial pressure
4) other features consistent with raised intracranial pressure e.g. nause, papilloedema, seizures
Management of brain abscess?
1) surgery: craniotomy
2) IV antibiotics: IV 3rd-generation cephalosporin + metronidazole
3) intracranial pressure management: e.g. dexamethasone
What can rapid correction of hyponatraemia cause?
Osmotic demyelination syndrome (central pontine myelinolysis)
Symptoms of osmotic demyelination syndrome?
How soon after correction of hyponatraemia do they occur?
Typically after 2 days.
Symptoms: dysarthria, dysphagia, paraparesis or quadriparesis, seizures, locked in syndrome, confusion, and coma.
These are usually IRREVERSIBLE.
Acute vs chronic management of migraine?
Acute: triptan + NSAID/paracetamol
Chronic: propanolol or topiramate
Features of a medication overuse headache?
- present for 15 days or more per month
- developed or worsened whilst taking regular symptomatic medication
- patients using opioids and triptans are at most risk
- may be psychiatric co-morbidity
Management of medication overuse headache?
simple analgesics and triptans should be withdrawn abruptly (may initially worsen headaches)
opioid analgesics should be gradually withdrawn
What 2 classes of drugs are at most risk of causing medication overuse headache?
triptans & opioids
What class of drug is metoclopramide?
Dopamine antagonist: blocking dopamine receptors in the chemoreceptor trigger zone of the CNS.
This can decrease N&V but increase EPSEs.
What is a Valsalva maneuver?
Performed by a forceful attempt of exhalation against a closed airway, usually done by closing one’s mouth and pinching one’s nose shut while expelling air out as if blowing up a balloon.
What do headaches that are worsened by alsalva manoeuvres associated with?
Raised ICP until proven otherwise