Abstract
Hand weakness following stroke is often associated with a reduced representation of the hand in the primary motor cortex. Meaningful sensory input can induce sensorimotor reorganization in the brain, but the after-effect of continuous passive motion (CPM) on the cortical representation is unknown. The purpose of this study was to determine whether repeated sessions of continuous passive movement of the thumb induce a lasting increase in the motor cortical representation of a thumb muscle in healthy adults. Thirteen right-handed healthy adults (mean age 24.3 ± 4.3 years) participated in the study. Single-pulse Transcranial Magnetic Stimulation (TMS) was delivered over the motor area of the target muscle (abductor pollicis brevis) before and/or after a thirty minute session of thumb CPM administered on three consecutive days. TMS was also delivered 5 days after cessation of the CPM intervention. The response to TMS (motor evoked potential) was recorded in the target muscle with surface EMG. Resting motor threshold (RMT), motor evoked potential amplitude at a specified intensity, and the area and volume of the cortical representation of the target muscle were measured. Thumb CPM had no significant effect on TMS parameters (p > 0.05 all measures) and performance of an attention task remained unchanged within and across CPM sessions. The results suggest that three sessions of repetitive passive thumb movement is not sufficient to induce a change in the cortical representation of the thumb and is unlikely to reverse the decreased representation of the affected hand following stroke.
Highlights
IntroductionRecovery following stroke is variable but only a third of patients regain some dexterity in the first 6 months (Kwakkel et al, 2003) and the majority of stroke survivors are left with residual motor deficits (Duncan et al, 1992)
Stroke remains the leading cause of adult disability worldwide
There was no difference in Resting motor threshold (RMT) between baseline and the end of the first continuous passive motion (CPM) session or between days 1, 2, 3 and 8 (ANOVA, F4,12 = 0.43, P = 0.78)
Summary
Recovery following stroke is variable but only a third of patients regain some dexterity in the first 6 months (Kwakkel et al, 2003) and the majority of stroke survivors are left with residual motor deficits (Duncan et al, 1992). Upper limb deficits limit the ability to perform activities of daily living, primarily due to muscle weakness. This loss of independence contributes to increased healthcare costs and burden of stroke on the individual and the community (Deloitte Access Economics, 2013). Transcranial magnetic stimulation (TMS) has been used to investigate properties of the corticomotoneuronal projection and the potential for upper limb recovery post-stroke.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
