Contingent Negative Variation Is Associated with Cognitive Dysfunction and Secondary Progressive Disease Course in Multiple Sclerosis

ABSTRACT

BACKGROUND AND PURPOSE: The relationship between contingent negative variation (CNV), which is an event-related potential, and cognition in multiple sclerosis (MS) has not been examined previously. The primary objective of the present study was thus to determine the association between CNV and cognition in a sample of MS patients. METHODS: The subjects of this study comprised 66 MS patients [50 with relapsing-remitting MS (RRMS) and 16 with secondary progressive MS (SPMS)] and 40 matched healthy volunteers. A neuropsychological battery was administered to all of the subjects; CNV recordings were made from the Cz, Fz, and Pz electrodes, and the amplitude and area under the curve (AUC) were measured at each electrode. RESULTS: RRMS patients exhibited CNVs with lower amplitudes and smaller AUCs than the controls at Pz. SPMS patients exhibited CNVs with lower amplitudes and smaller AUCs than the controls, and CNVs with a smaller amplitude than the RRMS patients at both Cz and Pz. After correcting for multiple comparisons, a lower CNV amplitude at Pz was significantly associated with worse performance on measures of speed of information processing, verbal fluency, verbal learning, and verbal recall. CONCLUSIONS: CNV may serve as a marker for disease progression and cognitive dysfunction in MS. Further studies with larger samples and wider electrode coverage are required to fully assess the value of CNV in these areas.