What is the assessment and treatment approach for a patient with transverse myelitis?

Assessment and Treatment of Transverse Myelitis

Immediate Diagnostic Workup

Obtain urgent neurologic consultation and spine MRI with thin axial cuts through the suspected lesion to detect T2-weighted hyperintense lesions, which typically appear wedge-shaped on axial views and cigar-shaped on sagittal views. 1, 2, 3

Critical Imaging Features

• MRI of the entire spine is essential to identify the extent of spinal cord involvement and distinguish between short-segment (<3 vertebral segments) versus longitudinally extensive transverse myelitis (LETM, ≥3 segments) 1, 2
• LETM should raise immediate suspicion for neuromyelitis optica spectrum disorder (NMOSD), particularly if aquaporin-4 IgG is positive 4, 2
• The imaging must first exclude compressive myelopathy, as this requires emergent surgical intervention and is clinically indistinguishable from inflammatory transverse myelitis 5, 6

Laboratory Evaluation

Perform lumbar puncture to assess: 1, 2

• Cell count, protein, glucose
• Oligoclonal bands
• Viral PCRs
• Onconeural antibodies

Blood tests must include: 1, 2

• Vitamin B12
• HIV, RPR (syphilis)
• ANA, anti-Ro/La antibodies
• TSH
• Aquaporin-4 IgG (critical for NMOSD diagnosis)

Clinical Assessment

• Evaluate for spastic paralysis with increased deep tendon reflexes (upper motor neuron signs), which distinguishes transverse myelitis from conditions like Guillain-Barré syndrome that present with flaccid paralysis 2
• Assess for urinary retention and constipation, as autonomic dysfunction is common 1, 2
• Document the rapidity of symptom progression (typically hours to days, reaching maximal severity within 10 days) 3, 5

Treatment Algorithm

First-Line Therapy (Initiate Immediately)

Administer high-dose intravenous methylprednisolone 1g daily for 3-5 days as soon as the diagnosis is suspected. 1, 2

• Discontinue any potential causative agents (e.g., immune checkpoint inhibitors if applicable) 1
• For moderate to severe cases (significant weakness, sensory changes, or sphincter dysfunction), combine corticosteroids with IVIG 2g/kg over 5 days 1
• Early treatment (within 2 weeks of symptom onset) is associated with better outcomes; delays beyond 2 weeks predict poorer prognosis 1

Second-Line Therapy (For Refractory Cases)

If inadequate response to corticosteroids and IVIG after 5-7 days: 1

• Plasma exchange therapy should be initiated
• Consider rituximab for cases with positive autoimmune encephalopathy antibodies or continued treatment failure 1

Maintenance Immunosuppression

After acute treatment, initiate maintenance immunosuppressive therapy (such as azathioprine) to prevent relapses, which occur in 50-60% of cases during corticosteroid taper. 1

Special Clinical Scenarios

NMOSD-Associated Transverse Myelitis

• If aquaporin-4 IgG is positive, more aggressive immunosuppression is required 1, 2
• These patients typically have LETM (≥3 vertebral segments) on MRI 4, 2
• Long-term immunosuppression is mandatory to prevent devastating relapses 1

Antiphospholipid Antibody-Associated Cases

• Add anticoagulation therapy in addition to immunosuppressive treatment 1

Infectious Etiologies

• If infectious cause identified (e.g., schistosomiasis), administer appropriate antimicrobial therapy alongside corticosteroids 1
• However, ensure CSF studies demonstrate inflammation rather than direct infection before starting high-dose steroids 5, 6

Prognostic Indicators

Poor prognostic factors include: 1, 3

• LETM affecting ≥3 vertebral segments on MRI
• Reduced muscle strength or sphincter dysfunction at presentation
• Delay >2 weeks in initiating therapy

Approximately half of patients will have paraparesis at maximal clinical severity, and residual disability is divided equally between severe, moderate, and minimal categories 3

Critical Pitfalls to Avoid

• Do not delay MRI to rule out compressive myelopathy—this is a surgical emergency that mimics transverse myelitis clinically 5, 6
• Do not miss NMOSD—always check aquaporin-4 IgG, as these patients require different long-term management and have higher relapse rates 4, 1, 2
• Do not withhold IVIG in moderate-to-severe cases—combining it with corticosteroids upfront improves outcomes 1
• Do not stop immunosuppression prematurely—50-60% relapse during steroid taper without maintenance therapy 1