Neurology
Core concepts
Stroke: sudden focal deficit; thrombolysis within 4.5 hours and thrombectomy up to 24 hours in selected large-vessel occlusion; exclude hypoglycaemia and haemorrhage first. Localise: anterior circulation (hemiparesis, aphasia, hemianopia), posterior circulation (vertigo, diplopia, ataxia, crossed signs), lacunar syndromes (pure motor, pure sensory, sensorimotor, ataxic hemiparesis). TIA needs urgent carotid imaging, antiplatelet and statin. Seizures: classify focal versus generalised; status epilepticus needs a benzodiazepine then phenytoin or levetiracetam; always check glucose, sodium, calcium and consider alcohol withdrawal. Headache red flags: thunderclap (subarachnoid), fever with neck stiffness (meningitis), papilloedema, position-dependent pain, new headache over 50 (giant cell arteritis), cancer or HIV. Neuromuscular disease: myasthenia gravis (fatigable weakness, ptosis, diplopia, anti-acetylcholine receptor antibodies, thymoma; worsened by aminoglycosides, quinolones, beta-blockers), Guillain-Barré (ascending areflexic weakness, albuminocytological dissociation, monitor vital capacity), motor neurone disease (upper and lower motor signs, no sensory loss, fasciculation). Multiple sclerosis: dissemination in time and space, oligoclonal bands, Uhthoff phenomenon.
Traps
Missing hypoglycaemia, or a seizure with Todd's paresis, as a stroke mimic. Diagnosing Bell's palsy when the forehead is spared - that is an upper motor neuron lesion. A third-nerve palsy with a dilated pupil suggests a compressive aneurysm, not diabetic microvascular disease.
Rule of thumb
In any acute neurological presentation, check the capillary glucose first. Nothing else you do matters if the brain is running on 1.5 mmol/L of glucose.