Relationship between event-related potentials and cognitive dysfunction in multiple sclerosis: A systematic review.

• Multiple Sclerosis (MS) can originate cognitive impairment (CI), but the cognitive assessment is not routinely performed. • Most of MS patients in this review showed abnormalities in the event-related potentials (ERPs), suggesting effective CI in MS. • ERPs seem to help detect possible cognitive impairment earlier and may facilitate the use of preventive measures. This systematic review aimed to evaluate if event-related potentials (ERPs) can be a relevant tool for cognitive dysfunction diagnosis in Multiple Sclerosis (MS). Four databases were consulted (PubMed, Embase, Scielo, and Web of Science). The included studies should include adults with clear MS diagnoses, independently of having cognitive complaints, and all should have been submitted to ERPs (P300, N400 or mismatch negativity (MMN)). The main outcomes evaluated were ERPs' amplitude and/or latency. 425 studies were obtained initially from all databases, with 26 studies fulfilling the eligibility criteria. P300 was the most used ERP (25 studies), showing a reduced amplitude or an increased latency in 84% of those. N400 was evaluated in one study, showing also abnormal results. MMN was addressed in two studies with inconsistent findings. Some studies further suggest that ERPs may show earlier abnormal results compared with neuropsychological tests. Most MS patient groups revealed ERP abnormalities, suggesting that these neurophysiological tests may be a relevant and appropriate diagnostic aid method for cognitive impairment in MS. The use of ERPs in MS patients seems able to demonstrate cognitive impairment and its use should be considered as part of the regular patient evaluation. [ABSTRACT FROM AUTHOR]