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Influence of interhemispheric interactions on motor function in chronic stroke
Author(s) -
Murase Nagako,
Duque Julie,
Mazzocchio Riccardo,
Cohen Leonardo G.
Publication year - 2004
Publication title -
annals of neurology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 4.764
H-Index - 296
eISSN - 1531-8249
pISSN - 0364-5134
DOI - 10.1002/ana.10848
Subject(s) - psychology , neuroscience , stroke (engine) , physical medicine and rehabilitation , primary motor cortex , motor cortex , facilitation , chronic stroke , lateralization of brain function , right hemisphere , medicine , rehabilitation , stimulation , cognitive psychology , mechanical engineering , engineering
In patients with chronic stroke, the primary motor cortex of the intact hemisphere (M1 intact hemisphere ) may influence functional recovery, possibly through transcallosal effects exerted over M1 in the lesioned hemisphere (M1 lesioned hemisphere ). Here, we studied interhemispheric inhibition (IHI) between M1 intact hemisphere and M1 lesioned 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 M1 intact hemisphere to M1 lesioned 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.