The Effect of Oral Verapamil on the Visual Evoked Potentials in Definite Multiple Sclerosis Patients

Introduction: Ionic channel rearrangements through the demyelinated axons or supporting media play significant role in remission of the neurological deficit in MS patients. In this study the effects of Verapamil as a calcium channel blocker on central conduction have been investigated through the evaluation of changes in P100 latency of the visual evoked potential. Method: This randomized double blinded, placebo-controlled, clinical trial was performed on two groups of 20 multiple sclerosis patients who had been diagnosed for definite MS and had no relapse during the last year. Case group received oral Verapamil, 40 mg, every 8 hours and was compared to Placebo group for changes in P100 latency. Results: In the Verapamil group, the P100 latencies showed an average decrease of 5ms comparing to the placebo group (6.1±4ms vs1 ± 0.5 ms). Verapamil had no significant effect on the VEP duration. Discussion: The present study suggests that pharmacological manipulation of calcium-dependent process, possibly at the level of demyelinated axon, can acutely facilitate central conduction of electrical impulses in some patients with clinically stable multiple sclerosis.