Diagnostic Approach to Transverse Myelitis

Imaging Studies

MRI of the spine with thin axial cuts through the region of suspected abnormality is essential to detect T2-weighted hyperintense lesions that may appear wedge-shaped on axial views and cigar-shaped on sagittal views 1, 2
MRI helps rule out compressive lesions and evaluate for nerve root enhancement/thickening 3
Brain MRI should be performed to evaluate for demyelinating lesions suggestive of multiple sclerosis or other CNS disorders 4
For patients with suspected neuromyelitis optica spectrum disorder (NMOSD), look for longitudinally extensive transverse myelitis (LETM) affecting ≥3 vertebral segments 5, 2

Lumbar puncture should be performed to analyze cell count, protein, glucose, oligoclonal bands, cytology, and viral PCRs 1, 3
Cell count often shows pleocytosis with elevated WBCs 3
Protein is typically elevated 3
Oligoclonal bands help distinguish from MS 1
Cytology is particularly important in patients with cancer 3
Viral PCRs should be performed 1

Aquaporin-4 IgG antibodies should be tested to evaluate for NMOSD 5, 1
MOG-IgG antibodies (myelin oligodendrocyte glycoprotein) should be tested 6, 5
Autoimmune panel, including antinuclear antibodies (ANA), anti-Ro/La antibodies, and antiphospholipid antibodies, should be performed 1, 2
Infectious disease screening, including HIV and RPR (for syphilis), should be performed 1, 2
Metabolic and nutritional screening, including vitamin B12 levels and thyroid function tests (TSH), should be performed 1, 7
In cases with suspected Guillain-Barré syndrome variants, test for serum antiganglioside antibodies (e.g., anti-GQ1b for Miller Fisher variant) 3

Electrodiagnostic studies (EMG/NCS) should be considered to evaluate for polyneuropathy and distinguish from peripheral nerve disorders 3

First-line testing should include MRI spine with and without contrast, lumbar puncture for CSF analysis, and basic blood tests (CBC, CMP, B12, folate, TSH) 1, 7
Second-line testing should include aquaporin-4 IgG and MOG-IgG antibodies, brain MRI with and without contrast, expanded autoimmune panel, and infectious disease screening 5, 1
Third-line testing should include electrodiagnostic studies, specialized antibody testing, and additional imaging as indicated 3, 1

The presence of increased deep tendon reflexes is a key distinguishing feature of transverse myelitis compared to conditions with flaccid paralysis (like Guillain-Barré syndrome) 2
Longitudinally extensive transverse myelitis (≥3 vertebral segments) should raise suspicion for NMOSD 5, 2

For patients with immune checkpoint inhibitor therapy, consider immune-related adverse events as a potential cause of transverse myelitis 3, 7
Evaluation for urinary retention and constipation is important as these are common autonomic manifestations of transverse myelitis 1, 2