Progressive Spasticity With a Single Magnetic Resonance Imaging Lesion

A 59-year-old White man with a history of excised basal and squamous cell skin cancers was evaluated for gait difficulties. He had erectile dysfunction but no bowel or bladder dysfunction. He also reported fatigue. He began using a cane for ambulation 2 weeks before evaluation at our facility. His medications included vitamin D and sildenafil. He was a lifelong nonsmoker and had no family history of multiple sclerosis. Neurologic examination at the time of our evaluation 3 years after onset was notable for a positive Hoffman sign on the right and mild weakness of the right triceps but preserved strength elsewhere. He had a spastic gait with moderate spasticity in both lower extremities, hyperreflexic patellar and ankle jerks bilaterally, and bilateral positive Babinski sign. The remainder of the examination was essentially normal. Magnetic resonance imaging of the brain showed a single lesion at the cervicomedullary junction and medullary pyramids, more prominent on the right. There was also some accompanying atrophy that was also visible on cervical spine magnetic resonance imaging. Results of cerebrospinal fluid analysis showed a normal white blood cell count, increased protein concentration (108 mg/dL), and positive oligoclonal bands. The progressive nature of his symptoms, spinal fluid results, and lesion appearance were all consistent with a diagnosis of progressive solitary sclerosis. At the time this patient was seen, no immunomodulatory medications for progressive solitary sclerosis were approved, so no immunomodulatory medication was tried. Ongoing symptomatic management was recommended. Progressive solitary sclerosis is a rare variant of multiple sclerosis in which patients have a single central nervous system demyelinating lesion and development of motor progression attributable to that lesion. Patients can initially have a clinical episode followed by progression or can have a progressive course without an initial relapse.