Stinear CM, Alan Barber P, Coxon JP, Fleming MK, Byblow WD
This study examined the effects of Active-Passive Bilateral Therapy (APBT), a putative movement-based priming strategy designed to reduce intracortical inhibition and increase excitability within the ipsilesional M1. Thirty-two patients with upper limb weakness at least 6 months after stroke were randomized to a 1-month intervention of self-directed motor practice with their affected upper limb (control group) or to APBT for 10-15 min prior to the same motor practice (APBT group). A blinded clinical rater assessed upper limb function at baseline, and immediately and 1 month after the intervention. Immediately after the intervention, motor function of the affected upper limb improved in both groups. One month after the intervention, the APBT group had better upper limb motor function than control patients. The APBT group had increased ipsilesional M1 excitability, increased transcallosal inhibition from ipsilesional to contralesional M1 and increased intracortical inhibition within contralesional M1. None of these changes were found in the control group.
APBT produces sustained improvements in upper limb motor function in chronic stroke patients and induces specific and sustained changes in motor cortex inhibitory function. APBT may facilitate plastic reorganization in the brain in response to motor therapy.
Brain, 20 March 2008, online article ahead of press