Treatment of Meningoencephalitis
The initial treatment of meningoencephalitis should include immediate administration of intravenous aciclovir at 10 mg/kg every 8 hours, along with appropriate antibiotics for bacterial meningitis, due to the high risk of mortality and neurological sequelae if treatment is delayed.
Initial Management
The management of meningoencephalitis requires urgent intervention due to its potentially fatal nature. Treatment should be initiated immediately after obtaining diagnostic samples, without waiting for results.
Empirical Treatment
- Aciclovir: 10 mg/kg IV every 8 hours (for adults with normal renal function) 1, 2
- Antibacterial therapy:
- Adults: Ceftriaxone 2g IV every 12-24 hours 3
- Add vancomycin if Streptococcus pneumoniae with resistance is suspected
- Add ampicillin in elderly or immunocompromised patients (for Listeria coverage)
- Dexamethasone: 0.15 mg/kg IV every 6 hours for 2-4 days, initiated with or before the first dose of antibiotics 1
Specific Treatment Based on Etiology
Viral Meningoencephalitis
- Herpes simplex virus: Continue aciclovir 10 mg/kg IV every 8 hours for 14-21 days 1, 2
- Varicella zoster virus: Aciclovir 10-15 mg/kg IV every 8 hours for 10-14 days 1
- Other viral causes: Most require supportive care only 1
Bacterial Meningitis
- Streptococcus pneumoniae: Ceftriaxone 2g IV every 12 hours for 10-14 days 1
- Neisseria meningitidis: Ceftriaxone 2g IV every 12 hours for 5-7 days 1
- Haemophilus influenzae: Ceftriaxone 2g IV every 12 hours for 7-10 days 1
Fungal Meningoencephalitis
- Cryptococcal meningoencephalitis:
Management of Complications
Increased Intracranial Pressure
- Therapeutic lumbar punctures should be performed daily until pressure normalizes 2
- Consider ventriculoperitoneal shunting for severe cases 2
- Mannitol or hypertonic saline may be considered, though evidence is limited 1
Seizures
- Administer antiepileptic drugs for patients presenting with seizures
- Prophylactic antiepileptics are not routinely recommended 1
Special Considerations
Immunocompromised Patients
- Broader antimicrobial coverage may be necessary
- In HIV patients with cryptococcal meningitis, initiate antiretroviral therapy 2-10 weeks after starting antifungal treatment 1, 2
- Consider longer treatment durations and maintenance therapy 2
Autoimmune Encephalitis
- Consider anti-NMDAR encephalitis, particularly in young patients or following HSV encephalitis 1
- High-dose corticosteroids, intravenous immunoglobulin, or plasma exchange may be indicated 2
Monitoring and Follow-up
- Monitor renal function, electrolytes, and complete blood count during treatment
- For cryptococcal meningitis, perform lumbar puncture after 2 weeks to verify CSF sterilization 1, 2
- For viral meningitis, if antibiotics were started empirically, they should be discontinued once a viral diagnosis is confirmed 1
Pitfalls to Avoid
- Delayed treatment: Do not wait for diagnostic confirmation before initiating therapy, as this significantly increases mortality 4
- Inadequate dosing: Ensure appropriate doses that achieve therapeutic concentrations in the CSF 5
- Premature discontinuation: Complete the full treatment course to prevent relapse
- Overlooking fungal causes: Consider cryptococcal meningitis in immunocompromised patients 1
- Missing autoimmune causes: Consider anti-NMDAR encephalitis, especially in young patients with behavioral changes 1
The key to successful management of meningoencephalitis is rapid diagnosis and immediate initiation of appropriate antimicrobial therapy, as delays can significantly worsen outcomes.