Dynamic Changes of Visual Evoked Potentials and Brainstem Auditory Evoked Potentials in Patients with Multiple Sclerosis

Abstract

Evoked potentials are widely used in diagnosis of multiple sclerosis (MS), but not sufficient data are available for their prospective role in the course of disease. The presentation is a longitudinal study in the Clinic of Neurology at MHAT – NHH – Sofia from Aug 2009 to Mar 2012. It includes 52 patients with clinically definite multiple sclerosis according to revised MacDonald criteria (2005/2010). Paternal visual evoked potentials (PVEP) and brainstem auditory evoked potentials (BAEP) were examined consecutively during the study and these results were compared with the grade of disability according to Expanded Disability Statement Scale (EDSS). The follow-up was done at registered relapses and also at patients without new complaints – one or two years since the initial examination. For quantitative assessment of pathological EP changes, a total evoked potential (EP) score was formulated. This score is a sum of the individual PVEP and BAEP scores. The time interval to the first change of total EP score and the time interval to the first change in EDSS were assessed. The results were compared to Kaplan–Meier survival curves. We found more prominent sensitivity of the total EP score compared to EDSS in the course of disease. Our study concludes that the neurophysiologic method is more sensitive test than EDSS for earlier detection of deterioration and disease progression.