What is the treatment for myelitis caused by infection?

Treatment of Infectious Myelitis

Initiate antimicrobial or antiviral therapy immediately upon suspicion of infectious myelitis while simultaneously pursuing diagnostic workup, as delays beyond 2 weeks significantly worsen neurological outcomes. 1

Immediate Diagnostic Actions

Obtain Urgent Imaging

• Perform contrast-enhanced spinal cord MRI immediately to detect T2-weighted hyperintense lesions (sensitivity 70-93%) and exclude cord compression, which requires emergent surgical intervention 1
• Order brain MRI when other neurological symptoms coexist to differentiate demyelinating disorders from infectious causes 1

Collect Microbiological Specimens Before Treatment

• Obtain cerebrospinal fluid (CSF) analysis with microbiological studies including bacterial cultures, viral PCR panels (HSV, VZV, enterovirus, West Nile virus), and fungal/mycobacterial cultures to identify the causative pathogen 1, 2, 3
• Draw at least 2 sets of blood cultures before initiating antimicrobials 4
• Measure baseline inflammatory markers (ESR, CRP) for monitoring treatment response 4

Empiric Antimicrobial Therapy

When to Start Immediately

Begin empiric therapy without waiting for culture results if:

• Intensely inflammatory CSF resembling bacterial or HSV meningitis is present 1
• Patient exhibits hemodynamic instability, sepsis, or progressive neurological symptoms 1
• Neurological deterioration is occurring 4

Empiric Regimen Selection

• For suspected bacterial myelitis: Initiate vancomycin (for MRSA coverage) plus third- or fourth-generation cephalosporin (ceftriaxone or cefotaxime) or carbapenem for gram-negative coverage 1, 4
• For suspected viral myelitis: Start intravenous acyclovir immediately if HSV or VZV is suspected based on clinical presentation or CSF findings 5, 3
• For suspected tuberculous myelitis: Consider anti-tuberculous therapy if CSF shows caseating necrosis, giant cells, or acid-fast bacilli, particularly with paraspinal abscess formation 1

Pathogen-Specific Treatment

Viral Myelitis

• Administer high-dose intravenous acyclovir for HSV and VZV myelitis upon virus isolation or PCR confirmation 5, 3
• Continue antiviral therapy for 14-21 days depending on clinical response 3
• For enterovirus-71, West Nile virus, and other non-herpetic viruses, treatment is primarily supportive as specific antivirals are unavailable 3

Bacterial Myelitis

• Adjust antimicrobials based on culture results and susceptibility testing once available 1, 4
• Continue antibacterial therapy for minimum 4-6 weeks for associated osteomyelitis or epidural abscess 6, 4
• Total duration should be at least 6 weeks for spinal infections 4

Mycobacterial and Fungal Myelitis

• For tuberculous myelitis, initiate standard anti-tuberculous therapy with rifampin, isoniazid, pyrazinamide, and ethambutol 1
• For fungal myelitis (Candida, Aspergillus, endemic fungi), obtain infectious disease consultation for appropriate antifungal selection 1, 6

Adjunctive Corticosteroid Therapy

Administer high-dose intravenous methylprednisolone early (within first few hours) while awaiting MRI confirmation, and continue if infection is ruled out. 1

• The combination of IV methylprednisolone with antimicrobials can be effective when used promptly, with neurological response occurring within days to 3 weeks 1
• For confirmed infectious myelitis with inflammatory component, continue corticosteroids alongside antimicrobials 5, 7
• Monitor closely for relapses (50-60% occurrence) during corticosteroid dose reduction 1

Surgical Intervention

Indications for Urgent Surgery

Obtain immediate neurosurgical or orthopedic spine consultation if:

• Epidural abscess is present on imaging 4
• Cord compression is identified 1
• Progressive neurological deterioration occurs despite medical therapy 4

Surgical Procedures

• Perform surgical decompression and drainage for epidural abscess to prevent irreversible neurological damage 4
• Consider debridement of infected tissue with or without spinal stabilization based on extent of involvement 4

Monitoring and Follow-Up

Clinical Assessment

• Evaluate neurological status daily including motor strength, sensory function, and sphincter control 1, 4
• Monitor for signs of treatment failure: persistent fever, pain, or worsening neurological deficits 4

Laboratory Monitoring

• Repeat inflammatory markers (ESR, CRP) after approximately 4 weeks of therapy 4
• Serial CSF analysis may be needed if clinical improvement is inadequate 1

Imaging Follow-Up

• Obtain follow-up MRI at 3 months to assess response to therapy and extent of residual cord involvement 6
• Earlier repeat imaging is indicated if neurological deterioration occurs 4

Maintenance Therapy

• Implement maintenance immunosuppressive therapy (typically azathioprine) after initial treatment to prevent relapses, particularly in autoimmune-mediated infectious myelitis 1
• Consider plasma exchange therapy in severe cases not responding to initial treatment 1

Critical Pitfalls to Avoid

• Never delay antimicrobial therapy beyond 2 weeks from symptom onset, as this is associated with severe neurological deficit and poor outcomes 1
• Do not withhold empiric therapy while awaiting culture results in patients with progressive symptoms or hemodynamic instability 1, 4
• Avoid removing in situ neuraxial catheters without immediate antimicrobial coverage if infection is suspected 1
• Do not rely solely on clinical improvement without monitoring inflammatory markers, as this may miss early treatment failure 4