Neurology — stroke, seizure, MS, neurodegenerative
**Stroke:** • **Ischemic (87%)** — thrombotic, embolic, lacunar. tPA if <4.5 hr, thrombectomy up to 24 hr for LVO by imaging. Secondary prevention: antiplatelet, statin, BP control, AFib → anticoag. • **Hemorrhagic** — intracerebral (HTN, amyloid), SAH ('worst headache', CT → LP if xanthochromia). BP control; surgical evacuation selective. • **Vascular territories** — MCA (face/arm > leg, aphasia if dominant, neglect if non-dominant), ACA (leg > arm), PCA (homonymous hemianopia), lacunar (pure motor/sensory).
**Seizures:** • **Generalized tonic-clonic** — both hemispheres. Levetiracetam, valproate, lamotrigine, phenytoin. • **Focal** — with/without awareness. Carbamazepine, levetiracetam. • **Absence** — 3 Hz spike-wave, ethosuximide. • **Status epilepticus** (>5 min) — lorazepam IV → fosphenytoin → intubate + propofol/midazolam.
**Multiple sclerosis:** young women, relapsing-remitting most common. Dx: dissemination in space + time on MRI (McDonald 2017). CSF oligoclonal bands. DMT: B-cell depleters (ocrelizumab), S1P modulators, natalizumab. Acute flare — IV methylprednisolone × 3-5 d.
**Neurodegenerative:** • **Alzheimer** — gradual; episodic memory first. CSF Aβ42↓, tau↑; amyloid-PET. Donepezil, memantine; lecanemab/donanemab (anti-Aβ monoclonals) slow decline in early disease. • **Parkinson** — resting tremor, bradykinesia, rigidity, postural instability. Levodopa-carbidopa; MAO-B (rasagiline), dopamine agonists. • **ALS** — upper + lower motor neuron; riluzole, edaravone. • **Huntington** — AD, CAG repeats in HTT, chorea + psych.
**Meningitis:** adult bacterial — ceftriaxone + vanco + steroid (dexa) if pneumococcal; add ampicillin if >50 or immunocompromised (Listeria).