Treatment of Infectious Myelitis

Diagnostic Approach

The American College of Rheumatology recommends initiating 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, 2
Perform contrast-enhanced spinal cord MRI immediately to detect T2-weighted hyperintense lesions and exclude cord compression, which requires emergent surgical intervention 1, 2
Obtain cerebrospinal fluid (CSF) analysis with microbiological studies, including bacterial cultures, viral PCR panels, and fungal/mycobacterial cultures to identify the causative pathogen 1, 2

Begin empiric therapy without waiting for culture results if intensely inflammatory CSF resembling bacterial or HSV meningitis is present, or if the patient exhibits hemodynamic instability, sepsis, or progressive neurological symptoms 1, 2, 4
For suspected bacterial myelitis, initiate vancomycin plus third- or fourth-generation cephalosporin or carbapenem for gram-negative coverage 5, 3

Adjust antimicrobials based on culture results and susceptibility testing once available, and continue antibacterial therapy for a minimum of 4-6 weeks for associated osteomyelitis or epidural abscess 5, 3, 6
For tuberculous myelitis, initiate standard anti-tuberculous therapy with rifampin, isoniazid, pyrazinamide, and ethambutol 4

Administer high-dose intravenous methylprednisolone early while awaiting MRI confirmation, and continue if infection is ruled out, with the combination of IV methylprednisolone with antimicrobials being effective when used promptly 1, 2

Obtain immediate neurosurgical or orthopedic spine consultation if epidural abscess is present on imaging, cord compression is identified, or progressive neurological deterioration occurs despite medical therapy 3, 1, 2

Evaluate neurological status daily, including motor strength, sensory function, and sphincter control, and monitor for signs of treatment failure: persistent fever, pain, or worsening neurological deficits 7, 3
Repeat inflammatory markers after approximately 4 weeks of therapy, and obtain follow-up MRI at 3 months to assess response to therapy and extent of residual cord involvement 3, 6

Implement maintenance immunosuppressive therapy, typically azathioprine, after initial treatment to prevent relapses, particularly in autoimmune-mediated infectious myelitis 1, 2

Never delay antimicrobial therapy beyond 2 weeks from symptom onset, as this is associated with severe neurological deficit and poor outcomes 1, 2
Do not withhold empiric therapy while awaiting culture results in patients with progressive symptoms or hemodynamic instability 4, 3