Neurology
Neurology questions reward time-based decision-making in stroke, correct drug sequencing in status epilepticus, and recognition of headache red flags.
Acute ischaemic stroke
Establish the last known well time. Non-contrast CT excludes haemorrhage before thrombolysis. Intravenous thrombolysis is given within 4.5 hours of onset in eligible patients; mechanical thrombectomy within 6 hours, and up to 24 hours with favourable perfusion imaging. Blood pressure must be below 185/110 mmHg before lysis. After thrombolysis, wait 24 hours and repeat imaging before starting antiplatelet therapy. Do not lower blood pressure in ischaemic stroke unless it exceeds 220/120 mmHg.
Status epilepticus
Define as a seizure lasting 5 minutes or more, or recurrent seizures without recovery. Give a benzodiazepine first - lorazepam 0.1 mg/kg intravenously - then a second-line agent such as levetiracetam, fosphenytoin or valproate. Refractory status requires intubation and a propofol or midazolam infusion. Always check glucose before sedating.
Headache red flags
Thunderclap onset, fever with neck stiffness, new headache over age 50, focal deficit, papilloedema, and headache that changes with posture.
Neuromuscular patterns
Guillain-Barré syndrome causes ascending, areflexic weakness; myasthenia gravis causes fatigable ptosis and diplopia.
Worked example
A patient arrives 2 hours after onset with a NIHSS of 12 and blood pressure 198/112 mmHg. Lower the pressure below 185/110, exclude haemorrhage on CT, then give thrombolysis; uncontrolled pressure above 185/110 is a contraindication.
Traps that cost marks
- Giving thrombolysis with blood pressure above 185/110.
- Starting aspirin immediately after lysis.
- Sedating a seizing patient before checking glucose.