What is the treatment approach for meningoencephalitis?

Treatment Approach for Meningoencephalitis

The treatment of meningoencephalitis requires immediate empirical antimicrobial therapy with intravenous acyclovir plus appropriate antibiotics (typically a third-generation cephalosporin such as ceftriaxone), with therapy later targeted based on identified pathogens. 1

Initial Management

Immediate Empiric Therapy

• Administer intravenous acyclovir (10-15 mg/kg every 8 hours) immediately upon suspicion of meningoencephalitis to cover possible herpes virus infections 1
• Simultaneously administer empiric antibacterial therapy with a third-generation cephalosporin (ceftriaxone 2g IV every 12-24 hours in adults; 100 mg/kg/day in children with meningitis) 2
• Initiate treatment as soon as possible after diagnosis is suspected, as delayed therapy is associated with increased mortality and worse neurological outcomes 1, 3
• Obtain blood cultures and perform lumbar puncture before antimicrobial administration if possible, but do not delay treatment if procedures will be delayed 1

Diagnostic Workup

• Perform neuroimaging (MRI preferred over CT) to identify complications and guide management 1
• Analyze CSF for cell count, glucose, protein, Gram stain, culture, and appropriate PCR tests 4
• Consider additional testing based on epidemiological and clinical clues 1

Pathogen-Specific Treatment

Bacterial Meningoencephalitis

• Once bacterial etiology is confirmed, target therapy to the specific pathogen 1
• For pneumococcal meningitis: ceftriaxone plus vancomycin until susceptibilities are known 2
• For meningococcal meningitis: ceftriaxone (2g IV daily in adults) 2
• For Haemophilus influenzae: ceftriaxone (2g IV daily in adults) 2
• Continue antibacterial therapy for 7-14 days depending on the pathogen 2

Viral Meningoencephalitis

• For confirmed HSV encephalitis: continue acyclovir (10-15 mg/kg every 8 hours) for 14-21 days 1
• For enterovirus meningitis: supportive care only, as no specific antiviral therapy is available 5
• For VZV meningoencephalitis: acyclovir, although evidence supporting treatment is limited 5
• For most other viral causes: primarily supportive care with analgesia and fluids 5

Autoimmune Encephalitis (ADEM)

• High-dose intravenous corticosteroids (methylprednisolone, 1g IV daily for 3-5 days) are recommended 1
• Consider plasma exchange in patients who respond poorly to corticosteroids 1
• Intravenous immunoglobulin may be considered as an alternative therapy 1

Management of Complications

Increased Intracranial Pressure

• Monitor for signs of increased intracranial pressure (decreased consciousness, focal neurological deficits) 1
• Consider neurosurgical intervention for hydrocephalus or space-occupying lesions 1
• In severe cases with refractory intracranial hypertension, decompressive craniectomy may be considered 6

Seizures

• Treat clinical seizures with appropriate antiepileptic medications 1
• Consider EEG monitoring in patients with altered mental status to detect subclinical seizures 1

Supportive Care

• Ensure adequate hydration with intravenous or oral fluids 5
• Provide analgesia for headache and other symptoms 5
• Monitor for and treat systemic complications (respiratory failure, cardiovascular instability) 3, 7

Prognosis and Follow-up

• Assess for potential long-term sequelae before discharge 5
• Common sequelae include hearing loss, seizures, motor deficits, and cognitive impairment 1, 5
• Arrange appropriate follow-up care as many issues only become apparent after discharge 5

Important Considerations and Pitfalls

• Do not delay antimicrobial therapy while waiting for diagnostic results, as this increases mortality 1, 3
• Discontinue antibiotics once viral diagnosis is confirmed and bacterial infection is excluded 5
• Be aware that bacterial meningoencephalitis can have high mortality (up to 30%) without prompt treatment 8, 7
• The time between hospital admission and ICU admission >1 day is associated with poor outcomes, suggesting early aggressive management is crucial 3
• Recognize that immunocompromised patients have worse outcomes and may require more aggressive management 3, 7