Fever, neck stiffness, confusion — bacterial meningitis; ceftriaxone before CT/LP delays. Bacterial meningitis (fever + neck stiffness + altered consciousness — Kernig's/Brudzinski's; pneumococcus/meningococcus: LP — neutrophils, low glucose, high protein; blood cultures): ceftriaxone + vancomycin (+ dexamethasone) immediately — don't wait for LP if delayed. Encephalitis (HSV — temporal lobe: fever, confusion, seizures — acyclovir urgently; MRI temporal). GBS (ascending paralysis post-diarrhea — Campylobacter: areflexia; IVIG/plasma exchange; monitor respiration — ventilate if needed). Myasthenia gravis (fatigable — ptosis, diplopia worse evening: pyridostigmine + steroids; thymectomy; crisis — ICU). The stiff neck with fever is meningitis — antibiotics first.