does muscle fatigue alter eeg bands of brain hemispheres?

Background: muscle fatigue has been known to influence brain activity, but very little is known about how cortical centers respond to muscle fatigue. objective: this study was conducted to investigate the effects of muscle contraction and fatigue induced by two different percents of maximal voluntary contraction (mvc) on electroencephalography (eeg) signals. material and methods: in this quasi-experimental study, eeg signals were recorded from twenty-one healthy human subjects during three phases (rest, pre fatigue and post fatigue) contraction of adductor pollicis muscle (apm) at 30% and 70% mvc. the mean powers of eeg bands (alpha, beta and gamma) were computed offline in the frequency domain. results: none of the three phases with each percent of mvc revealed significant differences for all bands (p>0.05). comparison of two hemispheres showed that right hemisphere gamma band activity was enhanced during pre-fatigue state at 30% mvc (p= 0.042) and post-fatigue state at 70% mvc (p= 0.028). right hemisphere beta band activity also increased prominently at 70% mvc in post-fatigue condition (p = 0.030). conclusion: these results suggest muscle contraction and fatigue at 30% and 70% mvc have no significant effect on eeg activity, but the trends of beta and gamma band activities are almost similar in each percent of 30% and 70% mvc. right brain hemisphere shows more activity than left hemisphere in beta and gamma rhythm after fatigue state at 70% mvc.