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26 Cards in this Set
- Front
- Back
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Types of stroke |
Ischemic 85% Hemorrhagic 15% |
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Causes of stroke |
Ischaemia due to atherosclerosis A fib with clot embolism to brain Septic emboli from IE |
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Ischemic stroke/ cerebral infarction |
Leading cause of neurological disability |
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Classes of ischemic stroke |
Transient ischemic attack Reversible ischemic neurological deficit (>24 h but <2 weeks) Evolving stroke - worsening Completed stroke - maximal deficit has occured |
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TIAs |
Lasts for few min to <24 hrs though mostly > 30 min Symptoms are transient coz of collateral circulation or breaking up of an embolus. Blockage in BF doesn't last long enough to cause permanent infarction. Once patient has TIA, high risk of stroke in subsequent months |
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TIAs causes |
Usually embolism Transient hypotension in the presence of severe carotid stenosis |
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RFs stroke |
Age Htn Smoking DM Hyperlipidemia A fib CAD Fam hx of stroke Previous stroke/TIA carotid bruits Younger pts: oral contraceptives, hypercoagulable states(protein C n S def, antiphospholipid antibody syndrome), vasoconstrictive drug use(cocaine, amphetamine) polycythemia vera, SCD |
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Causes |
Emboli: MC Origins: heart mc, embolization of mural thrombi in A fib ICA Aorta Paradoxical... emboli arise from clots in peripheral veins and pass through dental defects is ASD, PFO, pulmonary AV fistula and reach the brain.
Thrombotic stroke: atherosclerotic plaque in large arteries of the neck (carotid, mostly at the bifurcation of common carotid) or medium sized arteries of the brain (esp MCA)
Lacunar strokes: small vessel thrombotic dx Affects subcortical structures is basal ganglia, thalamus, internal capsule, brainstem... not the cerebral cortex predisposing: Htn and Dm Narrowing of arterial lumen is due to thickening of vessel walls nt thrombosis Arteries: small branches of MCA, arteries of circle of Willis and vascular and vertebral arteries. When they occlude, small infects result, when they heal, are called lacunes. Non vascular causes : low cardiac output and anoxia (may cause global ischaemia and infarction) |
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Deficits seen in stroke |
ACA: contralateral lower extremity and face MCA:(mc location) aphasia, contralateral hemiparesis, sensory loss, hyperreflexia Vertebral/basilar: ipsilateral: ataxia, diplopia,dysarthria, vertigo Contralateral: homonymous hemianopsia with basilar-PCA lesions Lacunar : Internal capsule... pure motor hemiparesis Pons... dysarthria, clumsy hand Thalamus... pure sensory deficit |
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Diagnosis |
CT... diff ischemic(dark) from hrrgic(white) MRI... ID early infarcts ECG... acute MI and Afib may be cause of emboli Carotid duplex U/S... estimates degree of carotid stenosis if present MRArteriogram... identify stenosis and aneurysm in vessels of head and neck. |
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Complications |
Progression of neurological insult Cerebral oedema... 1-2days and can cause mass effect for upto 10 days. Hyperventilation and mannitol to reduce ICP Hrrge into infarction (rare) Seizures |
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Tx |
Thrombotic therapy: t-PA If pt presents within 3hrs Aspirin... within 24 hrs If cant take aspirin, give clopidogrel Anticoagulant(heparin and warfarin) BP control |
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Prevention |
Control RFs Aspirin Surgery... carotid endarterectomy Control htn (lacunar strokes) |
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Hrrgic stroke categories |
Intracerebral hrrge - bleeding into brain parenchyma SAH- bleeding into CSF, outside parenchyma |
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ICH causes |
Htn... mc Causes rupture of small vessels deep with in parenchyma Chronic htn causes degeneration of small arteries, causing micro aneurysms which cn easily rupture. Risk inc with age Ischemic stroke may convert into hrrgic Amyloid angiopathy, anticoagulant/antithrombotic use, brain tumors, AV malformations |
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Locations |
Basal ganglia... 66% Pons 10% Cerebellum 10% Other cortical areas |
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CF |
Abrupt FNDs that worsen steadily over 30 to 90 minutes Altered lvl of consciousness, stupor or coma Headache, vomiting Inc ICP |
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Diagn |
CT head Coag panel and platelets... evaluate bleeding diasthesis |
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Complications |
Inc ICP seizures Rebleeding Vasospasm Hydrocephalus SIADH |
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Tx |
ABC BP reduction... gradual not to induce hypotension. Nitroprusside agent of choice Mannitol (osmotic agent) and diuretics... reduce ICP Surgical evacuation of cerebellar haematoma |
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Subarachnoid hrrge location |
Saccular aneurysms at bifurcation of arteries at circle of Willis |
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Causes |
Ruptured berry/secular aneurysm Trauma AV malformations |
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CF |
Sudden, severe headache 'worst headache of my life' Sudden transient loss of consciousness Vomiting Meningeal irritation, nuchal rigidity, photophobia Retinal hrrges |
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Diagn |
CT LP : blood in CSF xanthochromia ( yellow color of csf due to rbc lysis. Blood has been in csf for several hrs and not due to traumatic tap.) After diagn, cerebral angiogram... site of bleed for surgical clipping |
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Complications |
Rerupture Vasospasm hydrocephalus Seizures SIADH |
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Tx |
Surgical clipping Bed rest Stool softener to avoid straining Analgesia for headache (acetaminophen) Cntrl htn .... gradual Calcium channel blockers (nifedipine) for vasospasm |
