This article is a US Government work and, as such, is in the public domain in the United States of America.
Influence of interhemispheric interactions on motor function in chronic stroke†
Version of Record online: 3 FEB 2004
Copyright © 2004 American Neurological Association
Annals of Neurology
Volume 55, Issue 3, pages 400–409, March 2004
How to Cite
Murase, N., Duque, J., Mazzocchio, R. and Cohen, L. G. (2004), Influence of interhemispheric interactions on motor function in chronic stroke. Ann Neurol., 55: 400–409. doi: 10.1002/ana.10848
- Issue online: 20 FEB 2004
- Version of Record online: 3 FEB 2004
- Manuscript Accepted: 24 OCT 2003
- Manuscript Revised: 1 OCT 2003
- Manuscript Received: 11 AUG 2003
In patients with chronic stroke, the primary motor cortex of the intact hemisphere (M1intact hemisphere) may influence functional recovery, possibly through transcallosal effects exerted over M1 in the lesioned hemisphere (M1lesioned hemisphere). Here, we studied interhemispheric inhibition (IHI) between M1intact hemisphere and M1lesioned hemisphere in the process of generation of a voluntary movement by the paretic hand in patients with chronic subcortical stroke and in healthy volunteers. IHI was evaluated in both hands preceding the onset of unilateral voluntary index finger movements (paretic hand in patients, right hand in controls) in a simple reaction time paradigm. IHI at rest and shortly after the Go signal were comparable in patients and controls. Closer to movement onset, IHI targeting the moving index finger turned into facilitation in controls but remained deep in patients, a finding that correlated with poor motor performance. These results document an abnormally high interhemispheric inhibitory drive from M1intact hemisphere to M1lesioned hemisphere in the process of generation of a voluntary movement by the paretic hand. It is conceivable that this abnormality could adversely influence motor recovery in some patients with subcortical stroke, an interpretation consistent with models of interhemispheric competition in motor and sensory systems.