Brain Advance Access published online on March 20, 2008
Brain, doi:10.1093/brain/awn051
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Priming the motor system enhances the effects of upper limb therapy in chronic stroke
1Movement Neuroscience Laboratory, Department of Sport & Exercise Science, University of Auckland and 2Department of Medicine, University of Auckland, Auckland, New Zealand
Correspondence to:
Winston D. Byblow, Movement Neuroscience Laboratory, Department of Sport & Exercise Science, University of Auckland, Private Bag 92019, Auckland, New Zealand E-mail: w.byblow{at}auckland.ac.nz
After stroke, the function of primary motor cortex (M1) between the hemispheres may become unbalanced. Techniques that promote a re-balancing of M1 excitability may prime the brain to be more responsive to rehabilitation therapies and lead to improved functional outcomes. The present 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. Transcranial magnetic stimulation was used to assess M1 excitability. Immediately after the intervention, motor function of the affected upper limb improved in both groups (P < 0.005). One month after the intervention, the APBT group had better upper limb motor function than control patients (P < 0.05). The APBT group had increased ipsilesional M1 excitability (P < 0.025), increased transcallosal inhibition from ipsilesional to contralesional M1 (P < 0.01) and increased intracortical inhibition within contralesional M1 (P < 0.005). None of these changes were found in the control group. APBT produced sustained improvements in upper limb motor function in chronic stroke patients and induced specific and sustained changes in motor cortex inhibitory function. We speculate that APBT may have facilitated plastic reorganization in the brain in response to motor therapy. The utility of APBT as an adjuvant to physical therapy warrants further consideration.
Key Words: stroke; rehabilitation; upper limb; primary motor cortex; transcranial magnetic stimulation; inhibition; bilateral therapy
Abbreviations: APBT, Active–Passive Bilateral Therapy; BIT, bilateral isokinematic training; ECR, extensor carpi radialis; EMG, electromyography; FCR, flexor carpi radialis; FM, Fugl–Meyer; MEP, motor evoked potential; MSO, maximum stimulator output; NIHSS, National Institutes of Health Stroke Scale; RMT, rest motor threshold; SICI, short-latency intracortical inhibition; TCI, transcallosal inhibition; TMS, transcranial magnetic stimulation
Received September 17, 2007. Revised January 15, 2008. Accepted February 22, 2008.
CiteULike 
Connotea 
Del.icio.us What's this?
This article has been cited by other articles:
|
|
 |
|
  M. E. Stoykov, G. N. Lewis, and D. M. Corcos Comparison of Bilateral and Unilateral Training for Upper Extremity Hemiparesis in Stroke Neurorehabil Neural Repair, November 1, 2009; 23(9): 945 - 953. [Abstract] [PDF]
|
|
|
|
|
|
Transformational Technologies in Single-Event Neurological Conditions: Applying Lessons Learned in Stroke to Cerebral Palsy (August 14-15, 2008) Neurorehabil Neural Repair, September 1, 2009; 23(7): 747 - 765. [PDF]
|
|
|
|
 |
|
 J. H. Cauraugh and J. J. Summers Invited Commentary Physical Therapy, June 1, 2009; 89(6): 539 - 541. [Full Text] [PDF]
|
|
|
|
 |
|
 E. B. Plow, J. R. Carey, R. J. Nudo, and A. Pascual-Leone Invasive Cortical Stimulation to Promote Recovery of Function After Stroke: A Critical Appraisal Stroke, May 1, 2009; 40(5): 1926 - 1931. [Abstract] [Full Text] [PDF]
|
|