Slowing neuronal activity in the parietotemporal cortical areas and the thalamus is common in patients with multiple sclerosis (MS). Measuring this activity may hold promise for identifying cognitive impairment in these patients, according to study results published in Multiple Sclerosis Journal.

Magnetoencephalography data from 83 patients with MS and 34 healthy control participants were included in the analysis. Data were obtained in the eyes-closed resting-state and researchers calculated peak frequencies and relative power of 6 canonical frequency bands for cortical (n=78) and deep grey matter areas (n=10). In addition, study investigators evaluated the association between cognitive performance and magnetoencephalography biomarkers in linear regression models adjusted for age, sex, and education.

Increased whole-brain alpha 1 was significantly associated with impaired cognition (standardized β −0.30; t(116)=−3.50; P =.005). Further, specific performance measures associated with impaired cognition included attention (β=−0.41; t(116)=−3.61; P <.001), working memory (β=–0.39; t(116)=–4.25; P <.001), and verbal memory (β =–0.26; t(116)=–3.80; P =.020). In addition, increased whole-brain theta power was associated with worse cognitive performance (β =–0.24; t(116)=–2.04; P =.009) and verbal memory (β =–0.33; t(116) =–3.45; P =.003). The investigators observed widespread oscillatory slowing in the deep grey matter, yet the most noticeable slowing was observed in the thalamus.

Lack of potential confounder data (eg, fatigue or depression) and the small number of patients in the MS and healthy control groups were potential limitations of the analysis.

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The study investigators noted that future research should seek to “elucidate the relationship between cortical and thalamic oscillatory slowing and further unravel the complex interplay between different pathological processes that ultimately determine the disease course and burden in MS.”

Reference

Schoonhoven DN, Fraschini M, Tewarie P, et al. Resting-state MEG measurement of functional activation as a biomarker for cognitive decline in MS [published online November 22, 2018]. Mult Scler. doi:10.1177/1352458518810260