Roles of Lesioned and Nonlesioned Hemispheres in Reaching Performance Poststroke.
Roles of Lesioned and Nonlesioned Hemispheres in Reaching Performance Poststroke.
- 2020
Available online from MWHC library: 2006 - 2009, Available in print through MWHC library: 1999 - March 2006
Background. Severe poststroke arm impairment is associated with greater activation of the nonlesioned hemisphere during movement of the affected arm. The circumstances under which this activation may be adaptive or maladaptive remain unclear. Objective. To identify the functional relevance of key lesioned and nonlesioned hemisphere motor areas to reaching performance in patients with mild versus severe arm impairment. Methods. A total of 20 participants with chronic stroke performed a reaching response time task with their affected arm. During the reaction time period, a transient magnetic stimulus was applied over the primary (M1) or dorsal premotor cortex (PMd) of either hemisphere, and the effect of the perturbation on movement time (MT) was calculated. Results. For perturbation of the nonlesioned hemisphere, there was a significant interaction effect of Site of perturbation (PMd vs M1) by Group (mild vs severe; P < .001). Perturbation of PMd had a greater effect on MT in the severe versus the mild group. This effect was not observed with perturbation of M1. For perturbation of the lesioned hemisphere, there was a main effect of site of perturbation (P < .05), with perturbation of M1 having a greater effect on MT than PMd. Conclusions. These results demonstrate that, in the context of reaching movements, the role of the nonlesioned hemisphere depends on both impairment severity and the specific site that is targeted. A deeper understanding of these individual-, task-, and site-specific factors is essential for advancing the potential usefulness of neuromodulation to enhance poststroke motor recovery.
English
1545-9683
10.1177/1545968319876253 [doi]
*Motor Activity/ph [Physiology]
*Motor Cortex/pp [Physiopathology]
*Paresis
*Stroke
*Stroke Rehabilitation
*Transcranial Magnetic Stimulation
Adolescent
Adult
Aged
Aged, 80 and over
Female
Functional Laterality/ph [Physiology]
Humans
Male
Middle Aged
Paresis/et [Etiology]
Paresis/pp [Physiopathology]
Paresis/rh [Rehabilitation]
Stroke/co [Complications]
Stroke/pp [Physiopathology]
Stroke/th [Therapy]
Young Adult
MedStar National Rehabilitation Network
Journal Article
Available online from MWHC library: 2006 - 2009, Available in print through MWHC library: 1999 - March 2006
Background. Severe poststroke arm impairment is associated with greater activation of the nonlesioned hemisphere during movement of the affected arm. The circumstances under which this activation may be adaptive or maladaptive remain unclear. Objective. To identify the functional relevance of key lesioned and nonlesioned hemisphere motor areas to reaching performance in patients with mild versus severe arm impairment. Methods. A total of 20 participants with chronic stroke performed a reaching response time task with their affected arm. During the reaction time period, a transient magnetic stimulus was applied over the primary (M1) or dorsal premotor cortex (PMd) of either hemisphere, and the effect of the perturbation on movement time (MT) was calculated. Results. For perturbation of the nonlesioned hemisphere, there was a significant interaction effect of Site of perturbation (PMd vs M1) by Group (mild vs severe; P < .001). Perturbation of PMd had a greater effect on MT in the severe versus the mild group. This effect was not observed with perturbation of M1. For perturbation of the lesioned hemisphere, there was a main effect of site of perturbation (P < .05), with perturbation of M1 having a greater effect on MT than PMd. Conclusions. These results demonstrate that, in the context of reaching movements, the role of the nonlesioned hemisphere depends on both impairment severity and the specific site that is targeted. A deeper understanding of these individual-, task-, and site-specific factors is essential for advancing the potential usefulness of neuromodulation to enhance poststroke motor recovery.
English
1545-9683
10.1177/1545968319876253 [doi]
*Motor Activity/ph [Physiology]
*Motor Cortex/pp [Physiopathology]
*Paresis
*Stroke
*Stroke Rehabilitation
*Transcranial Magnetic Stimulation
Adolescent
Adult
Aged
Aged, 80 and over
Female
Functional Laterality/ph [Physiology]
Humans
Male
Middle Aged
Paresis/et [Etiology]
Paresis/pp [Physiopathology]
Paresis/rh [Rehabilitation]
Stroke/co [Complications]
Stroke/pp [Physiopathology]
Stroke/th [Therapy]
Young Adult
MedStar National Rehabilitation Network
Journal Article