Stroke Flashcards
what is a TIA
temporary neurological deficit due caused by focal brain, spinal cord or retinal ischaemia (vascular cause) without acute infarction
- typically lastig less than an hour
what are possible features of a TIA
- unilateral weakness or sensory loss.
- aphasia or dysarthria
- ataxia, vertigo, or loss of balance
- visual problems e.g. sudden transient loss of vision in one eye (amaurosis fugax), diplopia, homonymous hemianopia
what 2 things should be done for patients with suspected TIA
- aspirin 300mg immediately unless contraindicated
- assessed urgently within 24hrs by stroke specialist
what are conditions that might mimic TIA that need to be excluded
- hypoglycaemia
- ICH
all patients on anticoagulants or with similar risk factors should be admitted for urgent imaging to exclude haemorrhage
what imaging shoud be done to assess suspected TIA
MRI - preferred to determine the territory of ischaemia, or to detect haemorrhage or alternative pathologies
what immediate antithrombotic therapy should be given to patients presenting within 24hrs of TIA and are at low risk of bleeding
- clopidogrel (300mg inital + 75mg OD) + aspirin (300mg initaly + 27mg OD for 21 days)
DAPT (dual antiplatelet therapy)
if a patient is not appropriate for DAPT in suspected TIA, what should be given
clopidogrel 300mg loading dose + 75mg OD
what is the aim of statin in the context of treating stroke
reduce non-HDL cholesterol by more than 40%
what further investigation might be necessary in TIA
atherosclerosis in carotid artery may be source of emboli so patients who are candidates for carotid intervention should have imaging within 24hrs of assessment
1. carotid duplex USS or CT/MR
2. carotid endarterectomy if stenosis >50%
what do ACA strokes present with
- contralateral hemiparesis and sensory loss
- lower extremity > upper
what do MCA strokes present with
- contralateral hemiparesis and sensory loss
- upper extremity > lower
- contralateral homonymous hemianopia
- aphasia
what do PCA strokes present with
- Contralateral homonymous hemianopia with macular sparing
- Visual agnosia
how does basilar artery occlusion present
locked in syndrome
what are common sites of lacunar strokes
basal ganglia
thalamus
internal capsule
how do lacunar strokes present
- isolated hemiparesis
- hemisensory loss or hemiparesis with limb ataxis
strong association with HTN
what are the 2 main types of stroke
- ischaemic (85%)
- haemorrhagic
what are subtypes of ischaemic stroke
- thrombotic stroke: thrombosis from large vessel e.g. carotid
- embolic stroke: AF, blood clot
- systemic hypoperfusion
- cerebral venous sinus thrombosis
what are subtypes of haemorrhagic stroke
- intracerebral haemorrhage
- subarachnoid haemorrhage
what criteria are assessed in the Oxford/Bamford stroke classification
- unilateral hemiparesis and/or hemisensory loss of the face, arm & leg
- homonymous hemianopia
- higher cognitive dysfunction e.g. dysphasia
what is the bamford/oxford classification of stroke
what are 2 main investigations for emergency neuroimaging and what is the main concern
CT/MRI
- see whether the patient may be suitable for thrombolytic therapy to treat early ischaemic stroke
if imaging identifies the cause of the stroke as ischaemic, what therapy should be offered
thrombolysis if:
- pt presents within 4.5hrs of stroke symptoms
- pt has not had previous ICH, uncontrolled HTN or pregnant
alteplase of tenecteplase
what are absolute contraindications for thrombolysis
- previous ICH
- seizure at onset of stroke
- active bleeding
what are relative contraindications to thrombolysis
- pregnancy
- concucrrent anticoag (INR >1.7)
- major surgery/trauma in preceding 2 weeks
what is a key risk factor for ischaemic stroke
AF
what is the mechanism of alteplase
tissue plasminogen activator that rapidly breaks down clots
- may be given within 4.5hrs of symptom onset
when might thrombectomy be considered
in pt w confirmed blockage of proximal anterior or posterior circulation
- may be considered within 24hrs of the symptom onset and alongisde IV thrombolysis
is BP treatment indicated in ischaemic stroke
no, lowering BP can worsen the ischaemia and is only indicated in hypertensive emergency or to reduce risks when giving IV thrombolysis
Blood pressure is aggressively treated in patients with a haemorrhagic stroke
