Neuro Complications of CNS Infection

• Fever + headache + altered mental status: only focal signs, seizures, immunocompromise, or papilledema require CT before LP.
• 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.

Treating Suspected Central Nervous System Infection

• Fever, headache, nuchal rigidity ± altered mental status
• Obtundation, focal neurologic signs, or immune system compromise?
• Obtain CT or MRI
• Mass effect or posterior fossa mass?
• No lumbar puncture; empiric antibiotic coverage; neurosurgical consult
• Perform lumbar puncture; obtain blood cultures
• Perform lumbar puncture; obtain blood cultures
• Start empiric antibiotic coverage (may begin 4 hours before lumbar puncture if the procedure cannot be done sooner)
• PRESUMPTIVE BACTERIAL MENINGITIS: vancomycin 20 mg/kg q8 and ceftriaxone 2 g q12 hours IV · dexamethasone 10 mg IV q6 hours for 4 days for Streptococcus · add ampicillin 2 g q4 hours IV for Listeria coverage in elderly, alcohol abusers, immunocompromised · complete the full antibiotic course even if no organism is recovered · monitor for hydrocephalus, seizures, DIC, SIADH, venous sinus thrombosis
• PRESUMPTIVE VIRAL MENINGITIS: keep IV acyclovir 10 mg/kg q8 hours going for 14–21 days if HSV PCR is positive · stop when HSV or VZV PCR is negative · monitor for seizure