Natalizumab restores evoked potential abnormalities in patients with relapsing–remitting multiple sclerosis

Background and Objective: The objective of this study was to examine the effects of natalizumab on functional parameters assessed by evoked potentials (visual [VEP], somatosensory [SEP] and motor evoked potentials [MEP]) in a cohort study in relapsing–remitting multiple sclerosis patients. Methods: EP data of 44 patients examined 12 months prior to natalizumab treatment, at the timepoint of treatment initiation and 1 year later were compared. Sum scores (VEP, MEP, SEP) were evaluated and correlated with the Expanded Disability Status Scale. Results: Improvement of the VEP sum score was found in 33% of natalizumab-treated patients but only in 9% of the same patients prior to treatment ( p = 0.041). A comparable situation was found for SEP (improvement: 32% versus 5%; worsening: 11% versus 37%; p = 0.027). For MEP no significant differences were seen (improvement: 10% versus 18%; worsening: 5% versus 29%; p = 0.60). EP recordings (VEP = SEP > MEP) have the capacity to demonstrate treatment effects of natalizumab on a functional level. Conclusions: Natalizumab therapy increases the percentage of patients showing stable or even ameliorated electrophysiological parameters in the investigated functional systems.