Ischemic Stroke: Evaluation and Acute Management
Core concepts
Acute ischemic stroke care begins with last known well, not symptom discovery, and a focused NIHSS. Obtain noncontrast CT to exclude hemorrhage, then CTA and perfusion imaging when they will alter reperfusion decisions. Intravenous thrombolysis is considered within 4.5 hours for disabling deficits after excluding hemorrhage, recent surgery, active bleeding, severe uncontrolled hypertension, and other contraindications. Tenecteplase or alteplase may be used per protocol; do not delay for a mild or rapidly improving deficit if it remains disabling. Endovascular thrombectomy benefits selected large-vessel occlusions in the anterior circulation up to 24 hours when imaging supports salvageable tissue; posterior circulation and basilar occlusion require urgent individualized decisions. Before lysis, lower blood pressure only to below 185/110 mmHg; after lysis keep below 180/105 mmHg. Avoid treating hypertension aggressively in non-lytic candidates unless above 220/120 mmHg or another emergency exists. Check glucose, temperature, oxygen saturation, and swallowing. Start antiplatelet therapy after hemorrhage is excluded and usually after 24 hours post-lysis. Do not treat fever or hyperglycemia with extremes.
Traps
A normal early CT does not exclude ischemia. Wake-up stroke may still qualify if MRI DWI-FLAIR mismatch or perfusion criteria are met. Posterior circulation strokes can have low NIHSS and high risk. Seizure, hypoglycemia, and migraine can mimic stroke.
Worked example
A patient with sudden dense left hemiparesis, last known well 6 hours ago, right MCA occlusion, and small core on CTP: proceed to thrombectomy rather than stopping at the IV lytic window. Imaging and time window, not the clock alone, drive the decision.