Effect of slow release-Fampridine on muscle strength, rate of force development, functional capacity and cognitive function in an enriched population of MS patients. A randomized, double blind, placebo controlled study.

DESIGN: This study was conducted as a randomized, double blind, placebo-controlled parallel group trial preceded by open label enrichment phase.

OBJECTIVES: The objectives of this study were 1) to examine the effect of SR-Fampridine treatment on muscle strength in terms of maximal voluntary contraction (MVC) and rate of force development (RFD) of the lower extremities and 2) to replicate previously published data on the effect of slow release-Fampridine (SR-Fampridine) on the functional capacity of the lower limbs, the upper limb and cognitive function, in persons with multiple sclerosis (pwMS).

METHODS: Previously identified responders to SR-Fampridine were randomized to SR- Fampridine or placebo treatment for four weeks. On days 0 and 26-28 participants underwent testing by isokinetic dynamometry, Nine Hole Peg Test (9-HPT), Symbol Digit Modalities Test (SDMT), Six Spot Step Test (SSST), Timed 25 Foot Walk Test (T25FW) and 5-Times Sit-to-Stand (5-STS).

RESULTS: A statistical significant effect of SR-Fampridine on MVC was demonstrated during knee extension, knee flexion and hip flexion of the weakest leg, as well as on RFD during knee extension and knee flexion of the weakest leg. Furthermore, a significant effect of SR-Fampridine on T25FW, SSST and 5-STS was demonstrated.

CONCLUSION: Gold standard dynamometry assessment of muscle strength showed improved MVC and RFD in persons with MS treated with SR-Fampridine compared to placebo. Furthermore, previous findings on the effects of SR-Fampridine on functional capacity of the lower limbs were replicated. ClinicalTrials.gov identifier: NCT01656148.