Cerebrovascular Disease and Stroke
Cerebrovascular Disease and Stroke
Acute ischemic stroke is a time-critical emergency. Know the eligibility windows: intravenous thrombolysis (alteplase or tenecteplase) generally within 4.5 hours of last known well, with selected patients treatable after wake-up stroke if advanced imaging shows salvageable tissue. Endovascular thrombectomy is offered up to 6 hours for large-vessel occlusion and up to 24 hours in selected patients with favorable imaging. Blood pressure thresholds matter: below 185/110 mmHg before thrombolysis, below 180/105 after, while thrombectomy candidates may tolerate higher pressures. Avoid aspirin for 24 hours after thrombolysis; start antiplatelet therapy for non-thrombolysed patients early.
Intracerebral hemorrhage management focuses on rapid reversal of anticoagulation, blood pressure lowering to a systolic target around 130–150 mmHg, and neurosurgical consultation for cerebellar hemorrhage, hydrocephalus, or lobar clots with mass effect. Do not give steroids for cerebral edema in stroke. Subarachnoid hemorrhage requires aneurysm securing, nimodipine for 21 days, monitoring for vasospasm and delayed cerebral ischemia, and treatment of hydrocephalus.
Common question traps: confusing wake-up stroke eligibility, missing posterior circulation symptoms such as diplopia or ataxia, withholding thrombectomy because of a low NIHSS but disabling deficit, overtreating blood pressure in ischemic stroke, or overlooking cerebellar infarction with brainstem compression. Always reassess for worsening exam and repeat imaging when the patient deteriorates.
Rule of thumb: a negative noncontrast CT within 6 hours of thunderclap headache has very high negative predictive value, but many protocols still require lumbar puncture; beyond 6 hours, lumbar puncture is needed to exclude xanthochromia.