Neuro Complications of CNS Infection

• Suspected meningitis: blood cultures and treatment straight away. CT before LP only with risk factors — marked drowsiness, focal deficit, papilloedema, recent seizure, immunocompromise or relevant CNS disease — and never delay antibiotics for imaging.
• Empiric ceftriaxone + vancomycin ± ampicillin, with dexamethasone alongside the first dose.
• On CSF check opening pressure (cryptococcus!), cell count, protein, glucose, Gram/culture, PCRs (HSV!).
• Aciclovir empirically until HSV is ruled out; think fungal CNS disease if immunocompromised/HIV.

Meningitis

First tests: Blood cultures, Full blood count, Sodium, potassium, bicarbonate, urea and creatinine, Blood glucose.

Only if indicated: Lumbar puncture and CSF studies, Noncontrast CT head, HIV testing.

Repeat monitoring: Neurological and systemic reassessment.

Encephalitis

First tests: Blood glucose, Sodium, potassium, bicarbonate, urea and creatinine, MRI brain.

Only if indicated: Lumbar puncture and CSF studies, EEG, Autoimmune encephalitis studies.

Repeat monitoring: Serial neurological assessment.

• Treating Suspected Central Nervous System Infection