Progressive solitary sclerosis presented with diplopia: A case report.

To report a patient presented with diplopia followed by progressive quadriparesis in the setting of a solitary pontomedullary lesion.We report a 24-year-old woman presented with an attack of diplopia with full recovery, followed by progressive quadriparesis. The patient had a single pontomedullary lesion. Extensive diagnostic work up was negative. After follow up for 6 years, despite of clinical deterioration, the patient had the same pontomedullary lesion consistent with progressive solitary sclerosis. Corticosteroid pulse therapy and rituximab, didn't yield significant improvement, and the course was progressive, but after adding cyclophosphamide, partial improvement was seen.Progressive solitary sclerosis can cause progressive quadriparesis after an attack of diplopia without evidence of dissemination in time and space even after a prolonged period. This rare entity should be included in differential diagnosis of demyelinating lesions.