Dalfampridine for Imbalance in Multiple Sclerosis

Study Summary

Dalfampridine is a new medication that was FDA approved in 2010 to improve walking speed in people with Multiple Sclerosis (MS). People with MS walk slowly in part because MS damages the myelin insulation around nerves which slows conduction of messages from the brain to the leg muscles. Dalfampridine works by improving conduction in nerves with damaged myelin. Recent research indicates that imbalance in MS is in large part caused by poor conduction by the nerves that transmit information about the position of the legs to the brain. It is therefore likely that, by improving nerve conduction, dalfampridine will also improve imbalance in people with MS. Dalfampridine will be administered in this study by the same route (oral), dosage (10mg), and frequency (every 12 hours) approved by the FDA to improve walking speed in people with MS. The proposed pilot study will examine the effects of dalfampridine on imbalance in 24 subjects with Multiple Sclerosis (MS) and imbalance. This small pilot study will help to show if dalfampridine improves imbalance in MS and will guide the design and implementation of a larger full scale study to definitively determine if dalfampridine improves balance and prevents falls in people with MS.

Primary Outcome

Automatic Postural Response (APR) latencies will be measured by Computerized Dynamic Posturography (CDP). The restoration of balance after an unexpected movement by Computerized Dynamic Posturography relies on automated postural responses in the upper and lower legs, trunk, shoulders, and neck muscles. APR latency is the reaction- time response to movements of the support surface on which the subject stands. These responses typically occur at onset latencies of \~100 milliseconds. In response to

Interventions

• DRUG Placebo
• DRUG Dalfampridine