Chronic flaccid quadriparesis from tract specific myelopathy in neurosyphilis

Tract-specific myelopathies with distinctive imaging features are uncommon and typically occur with metabolic or paraneoplastic syndromes. We report a unique case of tract-specific myelopathy with neurosyphilis.

A 53-year-old male presented with a four-month history of flaccid quadriparesis, sensory loss, and bladder dysfunction. His MRIs revealed striking symmetric T2-weighted hyperintensities in the lateral corticospinal tracts and dorsal columns of the cervical spinal cord that extended rostrally into the pyramidal decussation and medial lemnisci of the medulla oblongata. Nerve conduction and needle electromyography studies excluded axonal or demyelinating lower motor neuron disorders. The patient reported previous untreated primary syphilis and was seropositive on the T.pallidum hemagglutination assay. Penicillin therapy resulted in substantial clinical improvement.

Although syphilitic meningomyelitis is well-reported, our patient was unique because of the persistent flaccidity (possibly suggesting prolonged spinal shock) and striking tract-specific MRI patterns. These features are novel in syphilitic myelitis and suggest unknown mechanisms of tract-specific tropism and neuronal injury.

"Tract-specific" complete transverse myelopathy with persistent flaccid weakness and areflexia is a novel presentation of neurosyphilis. Early recognition and crystalline penicillin therapy can alleviate morbidity. Our report describes this patient's findings and discusses the differential diagnoses of tract-specific myelopathies.