Oscillopsia is the subjective perception of visual motion. A physical examination typically reveals nystagmus, opsoclonus, or saccadic dysmetria. More cases of oscillopsia have been reported as an ocular presentation of multiple sclerosis (MS), with fewer cases in NMOSD. Medications such as memantine, gabapentin, and topiramate have been explored for treating oscillopsia in MS patients. Among the extremely limited published cases of oscillopsia associated with NMOSD, only high-dose steroids and plasmapheresis were administered, leaving the role of other medications largely unexplored.

A 19-year-old African American female presented with three days of progressively blurry vision, ocular oscillation, and retroorbital pain in the left eye. Symptoms rapidly began to affect the right eye as well. The physical examination was remarkable for bilateral ptosis, strabismus, and pendular nystagmus, with the left eye showing greater involvement than the right. No intracranial or spinal cord lesions were found on imaging. Aquaporin-4 antibody was positive in the serum. High-dose steroid showed no benefit, and plasmapheresis eventually stabilized the progression. Inebilizumab infusion was started after discharge. The patient continued to experience significant oscillopsia at the three-month follow-up. Inspired by a case report describing a dramatic response of pendular nystagmus to topiramate in an MS patient, we prescribed topiramate 50mg twice daily. The patient reported remarkable improvement one week later, and near-resolution of oscillopsia was observed in the follow-up visit.

Topiramate demonstrated efficacy in NMO-associated oscillopsia in our case, along with the case recently published on Neurology reporting dramatic response of oscillopsia to topiramate in a MS patient, suggesting it could be a promising medication for this debilitating condition.