Stroke and TIA Flashcards
What is a TIA?
New passmed defintion:
A transient episode of neurologic dysfunction caused by focal brain, spinal cord, or retinal ischaemia, without acute infarction.
Old definition we have been taught:
A sudden onset of a focal neurologic symptom and/or sign lasting less than 24 hours, brought on by a transient decrease in blood flow.
Presentation of TIA?
Similar to stroke but features resolve, usually within 1 hour.
- unilateral weakness or sensory loss
- aphasia or dysarthria
- ataxia, vertigo, loss of balance
- visual problems
—> sudden transient loss of vision in one eye (amaurosis fugax)
—> diplopia
—> homonymous hemianopia
What is aphasia?
Inability to produce or understand speech / language
What is dysarthria?
Difficulty speaking, inability to control muscles used in speech
What is amaurosis fugax?
Transient loss of vision in one eye
Immediate management of suspected TIA?
Aspirin 300mg immediately unless contraindicated
Need specialist review - by stroke specialist (within 24hrs if possible).
Advise pt not to drive until they have been seen by specialist (usually within 24hrs-7days)
Reasons for 300mg aspirin being contraindicated for immediate management of TIA?
Pt has bleeding disorder.
Pt is taking anticoagulant
Pt is already on low dose aspirin
Allergy/ other contraindication
Investigations for TIA?
Neuroimaging:
- MRI is preferred to see area of ischaemia/detect haemorrhage area. Should be done on the same day
- CT = NICE says that CT shouldn’t be done unless there is a clinical suspicion of an alternative Dx that a CT could detect.
Carotid imaging = urgent carotid doppler
- look for atherosclerosis as may be source of emboli.
Management of TIA?
(assume you have already done immediate management)
Note: immediate management is 300mg aspirin.
1) Prescribe clopidogrel. If contraindicated, give aspirin + dipyridamole.
2) If suffered TIA in carotid territory and aren’t severely disabled, consider a carotid artery endarterectomy
Risk factors for a TIA?
DM
hyperlipidaemia
HTN
Smoking
Hx of CVD/stroke
A fib
Differentials for TIA?
Stroke
Hypoglycaemia
MS
SOL
BPPV - differential for potential posterior circulation infarct
Pathophysiology of haemorrhage stroke?
Weakening of cerebral vessels —> cerebral vessel rupture —> haematoma formation —>reduction in blood flow —> cause clinical deficit.
Clinical deficit is caused directly by neuronal injury.
Clinical deficit is caused indirectly by cerebral oedema
Risk factors for haemorrhagic stroke?
Age
Male
FHx of haemorrhagic stroke
Haemophillia
Anticoag therapy
Drug use - cocaine, amphetamines
Vascular malformations e.g AVM
Weaker RFs:
NSAIDs
Heavy alcohol use
Thrombocytopenia
Management of haemorrhagic stroke?
Neurosurgery and critical care evaluation - may need surgery e.g. decompressive hemicraniectomy
Admit to neuro ICU / stroke unti
Manage BP <140/80 - poor BP control = poor outcomes later on.
May need to stop anticoagulants and antithrombotic meds - minimise further bleeds.
What are the two main types of stroke?
Ischaemic
Haemorrhagic
What is an ischaemic stroke?
Get a blockage in the blood vessels supplying the brain -> stops blood flow.
What are subtypes of ischaemic stroke?
Thrombotic - thrombosis from a large vessel e.g. carotid.
Embolic - blood clot, fat, air can act as embolus
Name an important cause of embolic stroke?
AF!!
Forms blood clot in heart —> can go up to brain
What are the subtypes of haemorrhage stroke?
Intracerebral haemorrhage = bleed within the brain
Subarachnoid haemorrhage = bleed on the surface of the brain
Risk factors for ischaemic stroke?
Age
HTN
Smoking
Hyperlipidaemia
DM
AF (if cardioembolism)
Presentation of stroke?
Motor weakness
Dysphasia
Swallowing problems
Visual field defects - homonymous hemianopia
Balance problems
Presentation of stroke with cerebral hemisphere infarcts?
Contralateral hemiplegia - flaccid at first, then spastic
Contralateral sensory loss
Homonymous hemianopia
Dysphasia
Presentation of stroke with brainstem infarction?
Severe symptoms:
Lock-in-syndrome
Quadriplegia
Presentation of stroke with lacunar infarcts?
Could be:
- purely motor
- purely sensory
- mixed motor and sensory
- ataxia
Where are lacunar infarcts?
Around basal ganglia, internal capsule, thalamus and pons
What classification system is used for stroke?
Oxford Stroke Classification (aka Bamford classification)
This classifies stroke based on initial symptoms
What criteria are assessed in Oxford stroke classification?
- unilateral hemiparesis and/or hemisensory loss of the face, arm and leg
- homonymous hemianopia
- higher cognitive dysfunction e.g. dysphasia
What blood vessels are involved in Total Anterior Circulation Infarct (TACI)?
Middle cerebral artery
AND
Anterior cerebral artery
on the affected side
What blood vessels are involved in partial anterior circulation infarct (PACI)?
Smaller arteries of anterior circulation e.g. upper or lower division of the MCA on the affected side.
What features of Oxford criteria are present in TACI?
All three!! :
Unilateral hemiparesis and/or hemisensory loss of face, arm and leg
Homonymous hemianopia
AND higher cognitive dysfunction
What features of Oxford criteria are present in PACI?
2 of the following:
Unilateral hemiparesis and/or hemisensory loss of face, arm and leg
Homonymous hemianopia
Higher cognitive dysfunction
What blood vessels are involved in LACI?
LACI = lacunar infarct
Perforating arteries around the internal capsule, thalamus and basal ganglia
What features are present in LACI?
Presents w/ 1 of the following:
- unilateral weakness of face and arm, arm and leg or all three
- pure sensory stroke
- ataxic hemiparesis
What blood vessels are involved in POCI?
POCI = posterior circulation infarct
Vertebrobasilar arteries
What features are present in POCI?
Presents w/ 1 of the following:
- cerebellar or brainstem syndromes
- conjugate eye movement disorder
- LOC
- isolated homonymous hemianopia
- bilateral motor/sensory deficit
- ipsilateral cranial nerve palsy with contralateral motor/sensory deficit
What features is a pt with a haemorrhage stroke more likely to have (compared to a pt presenting with ischaemic stroke)?
Reduced level of consciousness
Headache
N+Vom
Seizures
Describe FAST campaign mnemonic
Face - has face fallen on one side? Can they smile?
Arms - can they raise both arms and keep them there?
Speech - is speech slurred?
Time - call 999 if you see any of these signs
What investigations would you do for presentation of suspected stroke?
Emergency neuroimaging = CT, diffusion weighted MRI
How are ischaemic strokes managed?
Once established it is ischameic, give 300mg aspirin asap rocky.
Alteplase within 4.5hrs of symptom onset
Anterior circulation stroke = mechanical thrombectomy within 6hrs of symptom onset.
Posterior circulation stroke = mechanical thrombectomy within 12 hrs of symptom onset.
Rehab and supportive management - MDT needed for physio, OT, speech and language therapy, neurorehab.
Why is neuroimaging v important to do in pts with presentation of stroke?
Can see if it is ischameic or haemorragic. This will then decide treatment needed.
If ischameic = need thrombolysis as blood flow is blocked by clot.
If haemorrhagic = they are already bleeding!!! so giving thrombolysis would just make it worse.
Further investigations for ischaemic stroke, after initially managing it?
- Carotid ultrasound = to find carotid artery stenosis
- CT/MRI angiography = to find any intracranial and extra cranial stenosis
- Echocardiogram = if cardio-embolic stroke is suspected
- Vasculitis screen or thrombophilia screen = if young pt.
Serum glucose, serum lipids
Further investigations for haemorrhagic stroke?
Serum toxicology screen - for drugs, cocaine is a strong RF.
Serum glucose, serum lipids
What is involved in secondary stroke prevention?
HALTSS
H = HTN. Prescribe anti-HTN, start 2weeks post stroke
A = Antiplatelet therapy. Prescribe Clopidogrel 75mg OD. If stroke was secondary to AF, may need DOAC or warfarin - start this 2 weeks post stroke
L = Lipid lowering therapy. Prescribe atorvastatin 20-80mg OD.
T = Tobacco = smoking cessation support
S = Sugar. Screen for DM and manage if necessary
S = Surgery. If pt has ipsilateral carotid artery stenosis more than 50% —> refer for carotid endarterectomy
Tool used to differentiate stroke between stroke mimetics?
Recognition of Stroke in the Emergency Room (ROSIER) scale
