Central motor conduction time may predict response to fampridine in patients with multiple sclerosis

INTRODUCTION Most patients with multiple sclerosis (MS) experience walking impairment during the course of their disease. From an MS patient’s perspective, walking ability is the most important bodily function. Currently, sustained-release oral fampridine (fampridine-SR) is the only drug approved for the symptomatic treatment of walking disability due to MS. Fampridine is a potassium channel blocker that improves the impaired axonal conduction associated with CNS demyelination. However, only a subpopulation of MS patients with walking disability respond to fampridine. Herein, we prospectively evaluated whether pretherapy motor-evoked potentials (MEP), reflecting pyramidal demyelination by an increased central motor conduction time (CMCT), are suited as a predictive therapeutic response marker.