What is the most likely diagnosis for a patient presenting with acute onset of lower limb weakness, urine incontinence, difficulty walking, and a T10 sensory level, without a history of previous infection?

Spinal Cord Compression is the Most Likely Diagnosis

The clinical presentation of acute-onset bilateral lower limb weakness, urinary incontinence, difficulty walking, and a T10 sensory level over 3 days is pathognomonic for spinal cord compression and requires emergency MRI and neurosurgical consultation. 1

Why Spinal Cord Compression is the Answer

The presence of a defined sensory level at T10 is the critical diagnostic feature that localizes pathology directly to the spinal cord itself, not to peripheral nerves or nerve roots. 1 This acute presentation with bilateral motor, sensory, and autonomic dysfunction (urinary incontinence) at a specific spinal level indicates an evolving compressive myelopathy requiring emergency imaging. 1

Key Distinguishing Features Supporting Compression:

• Acute onset over 3 days with progressive symptoms suggests a structural lesion causing mechanical compression rather than an inflammatory or demyelinating process 1
• Bilateral lower limb weakness with urinary incontinence represents both motor and autonomic dysfunction at the cord level 1
• T10 sensory level precisely localizes the lesion to the thoracic spinal cord 1
• The combination of all three features (motor, sensory, autonomic) at a specific level is diagnostic for cord pathology requiring urgent decompression 1

Why the Other Options Are Incorrect

B. Guillain-Barré Syndrome - Excluded

GBS presents with ascending weakness starting distally in the legs and progressing upward over days to weeks, causing areflexia due to peripheral nerve involvement. 1, 2 The hallmark features that exclude GBS in this case include:

• No defined sensory level: GBS causes distal paresthesias or sensory loss, not a sharp T10 sensory level 2
• Ascending pattern: Weakness begins in feet/ankles and ascends, not acute bilateral leg weakness 2
• Areflexia is mandatory: Diminished or absent reflexes are a key diagnostic feature of GBS 2
• Bladder dysfunction is rare at onset: Marked persistent bladder dysfunction at presentation should prompt reconsideration of GBS diagnosis 2
• Bilateral facial palsy is common: The facial nerve is the most frequently affected cranial nerve in GBS, not mentioned here 2

C. Transverse Myelitis - Less Likely

While transverse myelitis can present with similar features (bilateral weakness, sensory level, urinary retention), it is less likely due to the absence of back pain, which is typically present in transverse myelitis but is a prominent early symptom in spinal cord compression. 3 Additionally:

• Transverse myelitis typically follows a viral infection or immune-mediated process, and the absence of infectious prodrome makes structural compression more likely 1, 3
• The acute 3-day progression without preceding infection or back pain favors a compressive etiology 3
• Transverse myelitis characteristically presents without significant back pain, whereas this patient's presentation is more consistent with compression 3

Critical caveat: The question states "no history of previous infection mentioned," which makes transverse myelitis less likely but does not completely exclude it. However, the acute mechanical progression over 3 days with a precise sensory level strongly favors compression. 1, 3

D. Cauda Equina Syndrome - Anatomically Impossible

Cauda equina syndrome is anatomically excluded by the T10 sensory level. 1 The cauda equina consists of lumbosacral nerve roots below the L1-L2 level, and:

• A T10 sensory level is too high for cauda equina involvement 1
• Cauda equina causes lower motor neuron signs with areflexia, not upper motor neuron signs 1
• The sensory level indicates spinal cord involvement, not nerve root compression 1, 3

Immediate Management Algorithm

1. Obtain emergency MRI of the entire spine (without and with contrast) immediately to differentiate compressive lesions from non-compressive myelopathy 1

2. Do not delay imaging: Spinal cord compression requires urgent surgical decompression within hours to prevent permanent neurological deficit 1

3. Urgent neurosurgical consultation upon clinical suspicion, as timing of decompression is critical for neurological recovery 1

4. Early surgical decompression within 24 hours is associated with better functional outcomes in compressive myelopathy 1

Common Pitfalls to Avoid

• Do not assume lumbar pathology based on lower limb symptoms alone—lower limb sensory disturbance can be a false localizing sign of cervical or thoracic cord compression 4
• Do not delay imaging to pursue clinical observation or conservative management—permanent neurological deficit occurs rapidly without decompression 1
• Do not confuse with transverse myelitis based solely on the absence of back pain—the acute mechanical progression and precise sensory level favor compression 1, 3