Cortical changes after mental imagery training combined with electromyography-triggered electrical stimulation in patients with chronic stroke.
OBJECTIVE
Paresis of the upper extremity after stroke is not effectively solved by existing therapies. We investigated whether mental imagery training combined with electromyogram-triggered electric stimulation improved motor function of the paretic upper extremity in patients with chronic stroke and induced cortical changes.


METHODS
Fourteen subjects with chronic stroke (≥12 months) were randomly allocated to receive mental imagery training combined with electromyogram-triggered electric stimulation (n=7) or generalized functional electric stimulation (n=7) on the forearm extensor muscles of the paretic extremity in 2 20-minute daily sessions 5 days a week for 4 weeks. The upper extremity component of the Fugl-Meyer Motor Assessment, the Motor Activity Log, the modified Barthel Index, and (18)F-fluorodeoxyglucose brain positron emission tomography were measured before and after the intervention.


RESULTS
The group receiving mental imagery training combined with electromyogram-triggered electric stimulation exhibited significant improvements in the upper extremity component of the Fugl-Meyer Motor Assessment after intervention (median, 7; interquartile range, 5-8; P<0.05), but the group receiving functional electric stimulation did not (median, 0; interquartile range, 0-3). Differences in score changes between the 2 groups were significant. The mental imagery training combined with electromyogram-triggered electric stimulation group showed significantly increased metabolism in the contralesional supplementary motor, precentral, and postcentral gyri (P(uncorrected)<0.001) after the intervention, but the functional electric stimulation group showed no significant differences.


CONCLUSIONS
Mental imagery training combined with electromyogram-triggered electric stimulation improved motor function of the paretic extremity in patients with chronic stroke. The intervention increased metabolism in the contralesional motor-sensory cortex.  Clinical Trial Registration- URL: https://e-irb.khmccri.or.kr/eirb/receipt/index.html?code=02&status=5. Unique identifier: KHUHMDIRB 1008-02.
Hoegi-dong, Dongdaemun-gu, Seoul 130-701, Republic of Korea.
Il Ki
IK
Hong
Jong Bae
JB
Choi
Jong Ha
JH
Lee
D000368:Aged; D002908:Chronic Disease; D004558:Electric Stimulation / Q000379:methods*; D004576:Electromyography / Q000379:methods*; D004594:Electrophysiology; D005260:Female; D019788:Fluorodeoxyglucose F18; D005947:Glucose / Q000378:metabolism; D006801:Humans; D019018:Imagery, Psychotherapy / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009044:Motor Cortex / Q000503:physiopathology; D009068:Movement / Q000502:physiology; D049268:Positron-Emission Tomography; D019275:Radiopharmaceuticals; D020521:Stroke / Q000000981:diagnostic imaging* / Q000523:psychology; D000071939:Stroke Rehabilitation; D016896:Treatment Outcome
D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18; D005947:Glucose