In a 43-year-old man with a 3‑day history of progressive lower‑limb weakness, urinary incontinence, difficulty walking, and a well‑defined sensory level at T10, what is the most likely diagnosis?

Transverse Myelitis

The most likely diagnosis is C - Transverse myelitis. This 43-year-old man presents with the classic triad of acute bilateral lower limb weakness, urinary incontinence, and a well-defined T10 sensory level evolving over 3 days—all hallmark features of transverse myelitis 1.

Why Transverse Myelitis is Most Likely

The absence of back pain is the critical distinguishing feature that points away from spinal cord compression and toward transverse myelitis 1. Compressive myelopathy typically presents with significant, often severe back pain as a prominent early symptom, which is notably absent in this case 1.

The clinical presentation fits the established diagnostic criteria for transverse myelitis:

• Bilateral motor weakness developing acutely over hours to days 2, 3
• Sensory level at T10 indicating focal spinal cord involvement 1, 4
• Autonomic dysfunction manifested as urinary incontinence 2, 3
• Progression to maximal severity within days (3 days in this case), consistent with the typical 4 hours to 21 days timeframe 4, 5

Why Other Diagnoses Are Less Likely

Spinal Cord Compression (Option A)

• Back pain is typically severe and prominent in compressive myelopathy, which is absent here 1
• While compression must always be excluded urgently with MRI, the clinical picture without back pain makes this less likely 3, 4

Guillain-Barré Syndrome (Option B)

• GBS presents with ascending weakness starting in the legs and progressing upward, not a defined sensory level 1, 6
• Areflexia is characteristic of GBS, not mentioned in this presentation 6
• A clear T10 sensory level is uncommon in early GBS 1
• Urinary retention is unusual in early GBS presentation 1

Cauda Equina Syndrome (Option D - assuming "Spina cuda symptom" refers to this)

• The T10 sensory level indicates spinal cord involvement, not cauda equina nerve roots which are below L1-L2 1, 6
• Cauda equina typically presents with lower motor neuron signs and severe back pain, both absent here 1

Immediate Management Priorities

High-dose intravenous methylprednisolone 1g daily for 3-5 days should be initiated immediately once imaging excludes compression 7, 1. Outcomes are time-dependent, and delay beyond 2 weeks is associated with poor prognosis 7.

Urgent Diagnostic Workup Required

• MRI of the spine with thin axial cuts to detect T2-weighted hyperintense lesions and exclude compression 7, 6
• Lumbar puncture for cell count, protein, glucose, oligoclonal bands, and infectious workup 7
• Blood tests including B12, HIV, RPR, ANA, Ro/La, TSH, and aquaporin-4 IgG 7

Treatment Algorithm

1. First-line: High-dose IV methylprednisolone 1g daily for 3-5 days 7, 1
2. For moderate-severe cases: Combine corticosteroids with IVIG 2g/kg over 5 days 7
3. Second-line (refractory): Plasma exchange therapy 7, 8
4. Maintenance: Immunosuppressive therapy (azathioprine) to prevent relapses, which occur in 50-60% during steroid taper 7

Critical Pitfall to Avoid

Do not delay MRI to exclude spinal cord compression, as this requires urgent surgical intervention if present 6, 3. However, the absence of back pain in this case makes compression significantly less likely 1.