Early disturbances in multimodal evoked potentials as a prognostic factor for long-term disability in relapsing-remitting multiple sclerosis patients

Abstract

Objective: The aim of this study was to investigate whether early alterations in evoked potentials (EPs) have a prognostic value in relapsing-remitting multiple sclerosis (RRMS).

Methods: We retrospectively selected 108 early MS patients with a neurological follow-up ranging from 5 to 15years, in whom multimodal EPs (visual, brainstem auditory, somatosensory and motor) were performed at diagnosis. A conventional ordinal score was used to quantify the observed abnormalities.

Results: The extent of change in the composite EP score was well correlated to the Expanded Disability Status Scale (EDSS) at ten years (Y₁₀) and up to 15years (Y_11-15) after disease onset. Analysis of the predictive value of the EP score showed an increased risk of disability progression at Y₁₀ and Y_11-15 of 60% (p<0.0001) and 73% (p<0.0001) respectively in patients with an EP score >4. Conversely, the risk of disability progression at Y₁₀ and Y_11-15 associated with a lower EP score (⩽4) was reduced to 16% and 20% respectively.

Conclusions: Our data support the good predictive value for long-term disability progression of multimodal EPs performed early after disease onset in RRMS patients.

Significance: This study, performed in a homogeneous RRMS cohort with long term follow-up, demonstrates the value of an early comprehensive neurophysiological assessment as a marker for future disability.

Keywords: Disability; EDSS; Multimodal evoked potentials; Multiple sclerosis; Predictive value.