The effects of action observation therapy based on mirror neuron theory on upper-extremity motor function and somatosensory evoked potentials after stroke

Abstract

Objective To explore the effects of action observation therapy based on mirror neuron theory on upper-extremity motor function and somatosensory evoked potentials after stroke.Methods Thirty stroke patients were randomly assigned to an observational group (15 cases) or a control group (15 cases).Both groups received conventional rehabilitation including,for example,good limb positioning,balance training and training in the activities of daily living (ADL).The observational group also received action observation therapy for 8 weeks,10 times per week.Both groups were assessed before treatment with the Fugl-Meyer assessment (FMA),the Barthel index (BI)and somatosensory evoked potentials (SEPs) and then again after 4 and 8 weeks of treatment.Their SEP N9 and N20 latencies were also analyzed.Results The average FMA scores at the 4th week (18.87 ± 6.62) and the 8th week (26.27± 9.22) in the observational group had increased significantly compared with the pre-treatment assessment.The control group's FMA score at the 8th week (20.07 ± 6.77) had also increased significantly compared with pretreatment.But at the 8th week the increase in the average FMA score of the observational group was significantly better than that of the control group.The average BI scores of both groups had increased significantly at both the 4th and the 8th week compared with each group's pre-treatment assessment.There was no significant difference in the increases in BI score between the two groups after 8 weeks of treatment.At both the 4th and the 8th week the N9 and N20 latencies on the affected side in the observational group had shortened significantly compared with the pre-treatment assessment.And the N9 and N20 amplitudes on the affected side in the observational group had also increased significantly compared with before treatment.In the control group,the N20 latency on the affected side had shortened significantly at the 4th week,and both the N9 and N20 latencies were significantly shortened at the 8th week compared with before treatment.Only the N20 amplitudes at the 8th week were observed to increase significantly compared with before treatment in the control group.Conclusions Action observation therapy promoted the recovery of upper-extremity motor function and SEPs in hemiparetic patients after stroke. Key words: Action observation; Mirror neurons; Stroke; Upper extremity function; Rehabilitation; Somatosensory evoked potentials