Multimodal evoked potentials follow up in multiple sclerosis patients under fingolimod therapy

BACKGROUND: Clinical trials have shown the therapeutic effect of fingolimod in reducing disease activity in relapsing-remitting multiple sclerosis (RR-MS), but its influence on nervous conduction assessed by evoked potentials (EPs) has not been previously investigated.

METHODS: EP data of 20 patients examined 12months prior to initiation of fingolimod (t=-1), at treatment initiation (t=0) and 1year later (t=+1) were compared. Each EP (VEP, MEP, SEP) and EP sum score, a global evoked potential score as the sum score of the each EP score was evaluated and correlated with Expanded Disability Status Scale (EDSS).

RESULTS: During pre-treatment period (1year) EDSS worsened while one year after fingolimod treatment EDSS remained stable. From t-1 to t0 VEP, SEP, MEP and EP sum score worsened while from t0 to t+1 VEP, SEP and EP sum score improved, and MEP score remain stable. VEP and SEP were related to EDSS at baseline (t=-1), while MEP and total EP sum score were related to EDSS at all time points.

CONCLUSION: Fingolimod is able to improve visual and somatosensory evoked potential in RR-MS patients even if clinical disability scale remains stable. VEP and SEP could give eloquent information on pathway underweighted in EDSS. EPs are useful to evaluate fingolimod effects in clinical practice.