Neurology
Stroke
Time is brain. Check glucose immediately - hypoglycemia mimics stroke. Get a noncontrast head CT to exclude hemorrhage; an early normal CT does not exclude ischemia. Thrombolysis is offered up to 4.5 hours in eligible patients with blood pressure below 185/110, and mechanical thrombectomy for large vessel occlusion up to 6 hours (selected patients to 24 hours). Start antiplatelet therapy and risk-factor modification; anticoagulation timing after cardioembolic stroke is delayed.
Seizures and headache
Status epilepticus: benzodiazepine first, then a second-line agent such as levetiracetam. A thunderclap headache suggests subarachnoid hemorrhage - CT first, then lumbar puncture for xanthochromia if CT is negative and suspicion remains. New headache in a patient over 50 with jaw claudication or visual symptoms suggests giant cell arteritis; start steroids immediately. Positional vertigo with a positive Dix-Hallpike is benign paroxysmal positional vertigo, treated with repositioning.
Neuromuscular and cognitive
Myasthenia gravis causes fatigable ptosis and diplopia; avoid aminoglycosides and other agents that worsen crisis. Guillain-Barré is ascending, areflexic weakness with albuminocytologic dissociation; monitor vital capacity and treat with IVIG or plasma exchange, not steroids. Parkinson disease is treated with levodopa-carbidopa; avoid metoclopramide and typical antipsychotics. Distinguish delirium (acute, fluctuating, inattentive) from dementia (chronic, progressive).
Worked example
A patient arrives 2 hours after sudden right-sided weakness with a normal CT and glucose of 100 mg/dL: proceed to thrombolysis if blood pressure and contraindications allow.