Neurologic Emergencies
Core concepts
Acute ischemic stroke is time-critical: check glucose first, obtain noncontrast CT within 20 minutes of arrival, and calculate the NIHSS. Intravenous thrombolysis is offered within 4.5 hours when blood pressure is below 185/110 (and maintained below 180/105 afterward) and there is no hemorrhage; thrombectomy extends to 6 hours for large-vessel occlusion and up to 24 hours in selected patients. Do not lower blood pressure aggressively in ischemic stroke unless thrombolysis is planned or there is a hypertensive crisis. Intracerebral hemorrhage: reverse anticoagulants, control blood pressure, stop antiplatelets, and involve neurosurgery for cerebellar or hydrocephalus-threatening bleeds. Subarachnoid hemorrhage presents with thunderclap headache; CT within 6 hours is nearly 100% sensitive, otherwise proceed to lumbar puncture after 12 hours looking for xanthochromia. Status epilepticus: benzodiazepines first, then a second-line anticonvulsant, then a continuous infusion with intubation. Meningitis: do not delay antibiotics for lumbar puncture, and give dexamethasone with the first antibiotic dose when pneumococcal disease is suspected. In acute vertigo, HINTS (head impulse, nystagmus pattern, test of skew) distinguishes central from peripheral causes better than symptoms alone.
Traps
Posterior circulation strokes present with dizziness, diplopia, dysarthria, or ataxia and slip past fast stroke screens. Giving thrombolytics to a hypoglycemic patient, or to one with a seizure at onset, is a classic error. A normal CT does not exclude SAH, an isodense subdural in anemia, or posterior stroke. A first-ever "migraine" in an older patient deserves imaging.
Rule of thumb
Time is brain: glucose, then CT, then decision - never let a blood pressure target delay thrombolysis-eligible care. Get the scan, then treat.