Teaching Video NeuroImage: Dramatic Response to Topiramate in Acquired Pendular Nystagmus From Multiple Sclerosis

A 41-year-old man with MS (Figure) experienced debilitating oscillopsia secondary to acquired pendular nystagmus (APN). Treatment with gabapentin and memantine (used individually and then in combination) were mildly effective, but he reported that the oscillopsia reduced dramatically after alcohol consumption. Given responsiveness to alcohol is a feature of essential tremor, we tried a similar therapeutic approach. Propranolol was ineffective, but topiramate 50 mg twice daily resulted in a dramatic improvement in oscillopsia and APN (Video 1). Gabapentin and memantine are commonly used treatments for APN,1 but understanding specific alleviating factors may shed light on pathophysiology and lead to novel therapeutic strategies.