Stroke and TIA Flashcards
Pathophysiology of Stroke
(1. ) Acute neurological deficit lasting more than 24 hours (stroke) and caused by cerebrovascular aetiology.
(2. ) Interruption of blood flow leads to deprivation of oxygen and glucose to the brain territory.
(3. ) If circulation is not re-established in time, will lead to cell death and necrosis.
(4. ) The aetiology of stroke can affect prognosis, outcome and management.
Aetiology of ischaemic stroke
- Most common type
- Blood supply is reduced due to occlusion or critical stenosis of a cerebral artery.
- This narrowing + occlusion may be due to: fatty deposits, blood clots
Aetiology of haemorrhagic stroke
- Most haemorrhagic strokes are due to intra-cerebral haemorrhage (vascular rupture into brain parenchyma), with the rest being due to SAH
- Other causes (or inc risk): uncontrolled high BP, anticoag tx, aneurysms, trauma, ischemic stroke can lead to haemorrhagic
What is TIA and aetiology?
(1. ) TIA can last a few min or persist UP TO 24HRS
(2. ) Temporary period of Sx similar to a stroke, but does not cause permanent damage.
(3. ) Aetiology: Occlusion of blood vessel for short period of time + resolves itself
(6. ) Within 30d, there is a high risk of vascular event. This is assessed with ABCD2 and secondary prevention is required
What is a Lacunar Strokes?
- One modality effected e.g. just sensory in a limb or ataxia or speech difficulty etc, usually due to subcortical regions
Rf for stroke
- Older ages: >55yrs
- HTN
- AF
- DM
- Dyslipidemia
- Lifestyle: overweight, sedentary lifestyle, alcohol, smoke
- Fx: Stroke/TIA, MI
What would you consider in your Hx and Ex of stroke? (3)
(1. ) Establish time of Sx onset or last time pt was seen well
(2. ) Determine cause: is there a hx of recent stroke?, seizure, epilepsy? MI? AF? HTN? DM? anticoag?
(3. ) Determine location of stroke:
- Is it an anterior or a posterior circulation event? ischemic or haemorrhagic?
- Haemorrhagic: headache of increasing intensity, neck stiffness, photophobia, sudden onset etc
What makes up the posterior and anterior circulation in brain?
- Anterior = ACA, MCA (PCA)
- Posterior = (PCA) Cerebellar and basilar arteries
What may you see in an ACA stroke?
(1. ) ACA supplies the medial aspect of the brain
(2. ) Signs:
- Leg weakness
- Sensory disturbance in legs
- Gait apraxia
- Incontinence
- Stuporous state (mental state where people don’t respond to normal conversation
What may you see in an MCA stroke?
(1. ) MCA supplies lateral aspects of the brain
(2. ) Contralateral arm weakness
- Contralateral sensory loss
- Hemianopia (loss of half of visual field)
- Aphasia (inability to comprehend or formulate language)
- Dysphasia
- Facial droop
What may you see in an PCA stroke?
(1. ) PCA supplies posterior medial aspect -> occipital affected
(2. ) Signs:
- lack of ability to interpret visual info e.g. knowing difference between a face and a plant pot
- distinguish one persons face from another persons face
- dyslexia
- headaches unilateral
What may you see in Posterior Circulation Strokes?
(1. ) These are as devastating as the MCA strokes.
(2. ) MRI scans are better for posterior fossa visualisation + maps water contents in brain.
(3. ) Motor deficits: such as hemiparesis or tetraparesis and facial paresis
(4. ) Dysarthria and speech impairment
(5. ) Vertigo, N + V
(6. ) Visual disturbances
(7. ) Altered consciousness
Acute Mx of ISCHAEMIC Stroke
(1. ) FAST: Face, arms, speech, time
- Facial asymmetry?, Arm/leg weakness?, Speech difficulty?, Time to call 999
(2. ) CT: rule out haemorrhagic before tx
(3. ) Monitor and manage deterioration (ABCs)
(4.) IV Alteplase no haemorrhage present
- If ischemic and sx onset within 4.5hrs
- this dissolves clots (thrombolysis)
- CI: recent surgery last 3m,
malignancy, brain aneurysms, anticoag, clotting disorder
(5. ) Thrombectomy
- If onset was 6-24hrs ago
- Surgical procedure to remove the clot
- Give thrombolysis alongside
Secondary Prevention, Risk Mx of Stroke (6)
(1. ) Important to manage stroke and CVD risks especially in pts outside 4hr window
(2. ) Assess risk of stroke with ABCD2
(3. ) Platelet Tx: Aspirin, Clopidogrel
(4. ) Statins
(5. ) AF Tx i.e. anticoags - Warfarin, NOAC’s
(6. ) BP Tx: Antihypertensives
(7. ) Early mobilisation, prevent dvt
Mx of TIA
(1.) Aspirin 300mg (CI: bleeding disorder, need to exclude haemorrhage, on low-dose aspirin already, other CI)
(2. ) Specialist review
- Seen within 24hrs if TIA onset <7d
- Seen within 7d if TIA onset >7d
(3. ) Advise not to drive until seen by specialist
- Imaging: diffusion weighted MRI (GOLD), carotid USS
- Carotid endarterectomy/stenting if USS +ve, stenosis >70%
(4.) Further Mx: Clopidogrel (1st line) or aspirin + dipyridamole (2nd line)
