The effects of low frequency electrical stimulation on connectivity changes in the brain and motor function after ischemic stroke

Objective To investigate any changes in motor functional connectivity in the brains of acute ischemic stroke patients after low frequency electrical stimulation.Methods Twenty-five ischemic stroke patients were given low frequency electrical stimulation in addition to their conventional rehabilitation treatment.Another 20 patients received only conventional treatment as a control group.Resting-state functional magnetic resonance imaging (rs-fMRl)was employed to assess motor function connectivity in the brains of all 45 subjects before and after treatment.Any differences in functional impairment,extremity motor function or ability in the activities of daily living were also recorded before and after treatment.Results In both groups,average scores on the Canadian neurological scale (CNS)and the National Institutes of Health stroke scale (NIHSS) had been reduced significantly after treatment and FuglMeyer assessment (FMA) and modified Barthel index (MBI) scores had significantly increased.The average improvements in terms of FMA and MBI scores were significantly greater in the observation group.Compared with before treatment,the coefficient of functional connectivity of the bilateral motor cortex had decreased significantly after treatment in both groups.In the observation group the changes were significantly correlated with the improvements in FMA scores.Conclusion Neural functional impairment after ischemic stroke can be reduced significantly and extremity motor function and ability in the activities of daily living can be significantly improved by low frequency electrical stimulation. Key words: Stroke; Functional magnetic resonance imaging; Motor cortex