Combined evoked potentials as markers and predictors of disability in early multiple sclerosis

ObjectiveTo prospectively assess combined evoked potentials (EP) as markers and predictors of the disease course of early MS over 3 years.MethodsFifty patients in the early phase of relapsing remitting MS prospectively received visual, somatosensory and motor EP and EDSS assessments at baseline (T1) and at 6 months intervals during 3 years. Spearman rank correlation was used to determine the relationship between z-transformed EP-latencies (z-EPL) and EDSS. Multivariable linear regression was performed to predict EDSS at year 3 (T7) in function of z-EPLT1. Validity of the models was assessed using group cross-validation.ResultsAt each of the seven points in time, EDSS correlated with the sum of z-EPL (0.64 ⩽ rho ⩽ 0.79, p < 0.001). The change of the sum of z-EPLT7–T1 correlated with the change of EDSST7–T1 (rho = 0.51, p = 0.001). EDSST7 as predicted by the sum of z-scores of EP latencies or by the number of pathological EP results at baseline correlated with the observed clinical values after 3 years (rho > 0.70, p < 0.001, for both measures).ConclusionsMultimodal EPs correlate well with clinical disability in cross-sectional and longitudinal comparison in early MS and allow prediction of disease evolution over 3 years.SignificanceEPs seem well suited as markers of the disease course in early MS in clinical trials and bear potential for supporting decision-finding in individual patients.

► Multimodal evoked potentials can be summarized in a rational number which correlates well with clinical assessment in groups of patients with early MS.
► Prediction of the disease course over 3 years in patient groups is possible with a correlation coefficient of 0.7.
► Multimodal evoked potentials bear the potential to improve clinical trial design and counselling of individual patients.