Treatment Challenges in a Severe Case of Syphilitic Myelitis With a Longitudinally Extensive Spinal Cord Lesion.

Syphilitic myelitis is an unusual manifestation of neurosyphilis, rarely reported in the literature. The best management approach remains unclear in severe cases with longitudinally extensive spinal cord lesions. We describe a 29-year-old man with a history of incompletely treated syphilis after a high-risk sexual encounter, who presented two years later with several weeks of progressive numbness and weakness in both legs. MRI spine showed significant cord expansion from the craniocervical junction to T6 with patchy cord enhancement. He was diagnosed with syphilitic myelitis given his history of inadequately treated syphilis, positive serum rapid plasma reagin at a high titer, and CSF pleocytosis with elevated protein along with a reactive CSF Venereal Disease Research Laboratory test. Alternative infectious or immunological etiologies were excluded. He was treated with IV penicillin and pulse steroid therapy with IV methylprednisolone 1 g daily for 3 days with improvement. However, he was soon readmitted with recurrent weakness requiring an additional course of pulse steroid therapy followed by a short prednisone taper. Afterward, his symptoms recurred with worsened cord expansion on imaging. He was re-treated with IV penicillin and pulse steroid therapy with a more prolonged prednisone taper. The patient subsequently improved and had no further recurrent symptoms on extended outpatient follow-up. This report illustrates the importance of keeping syphilitic myelitis on the differential as a treatable cause of longitudinally extensive myelopathy. The patient may have benefited from high-dose IV steroids with a prolonged taper while waiting for the full treatment effect of antibiotics.