Quantitative EEG differentiates multiple sclerosis with and without cognitive impairment from healthy controls at the beginning of the disease: preliminary data

Abstract

Background and aims: The present study aims to assess possible qEEG differences between newly diagnosed multiple sclerosis (MS) patients with or without cognitive impairment (CI). Methods: We enrolled 22 patients (18-55-years-old) treated with first-line drugs for <6 months, and 11 healthy controls. All subjects underwent neuropsychological assessment including BICAMS and BDI. EEG recordings were performed during a cognitive task (computerised “SDMT” subtest of BICAMS) and at rest. Based on neuropsychological assessment, patients were considered as affected (MSCI group) or not (MS group) by cognitive impairment. We analysed data comparing MSCI patients matched by sex, age (±5years) and education to an MS patient and a control. Power spectrum analysis (theta, alpha and beta bands and sub-bands) was performed (EEGLAB extension for Matlab). Data were log-transformed and analysed through repente measures ANOVA. Results: A significant interaction group (MSCI, MS, Controls) x condition (rest, task) x band (alpha, beta, theta) was observed. Post-hoc analyses showed significant differences between MSCI and both MS and Controls in all the bands at rest (p<.05). In task condition MSCI significantly differed from controls in alpha and theta bands (p<.05) but not beta (p=.9). Moreover, while a significant power spectrum difference was found in all bands in both MS and Controls between rest and tak condition, MSCI didn’t show any difference in alpha power (p=.6). Conclusion: If confirmed in larger series, our results seem to support the hypothesis that qEEG differences exist among MSCI, MS and healthy controls, opening to a possible neurophysiological hallmark of cognitive impairment in MS patients.