A stroke can occur at any point throughout the lifespan, including in utero. The timing of the injury relative to neural development can have implications on the type of lesion, plasticity, and motor deficits. However, associated reactions, which refer to involuntary movement in one limb in response to voluntary activity at another, have been observed in children and adults regardless of injury timing. The goal of this work was to quantify associated reactions in both pediatric and adult hemiplegia, as well as changes in neural structures, to understand how damage from lesions at different points in development can result in abnormal interlimb coupling. A novel method of measuring associated reactions was devised using a haptic robotic device. In adults with chronic stroke and children with prenatal and perinatal lesions, involuntary upper extremity movements and EMG activity were quantified while participants performed knee flexion and extension at varying effort levels with the instruction to relax their arm. Additionally, diffusion tensor imaging was used to assess the corticospinal tracts and corpus callosum. All groups displayed involuntary interlimb coupling, however, the patterns of coupling differed between groups. In adult stroke, upper extremity movements occurred in stereotyped patterns based on the lower extremity task. This was seen to some extent in individuals with perinatal lesions, but not with prenatal lesions. Additionally, participants with prenatal lesions displayed increased involuntary coupling in the non-paretic upper extremity. The coupling patterns seen in adult stroke are indicative of the extensively branching brainstem pathways that are upregulated after stroke. In earlier lesions, a direct ipsilateral corticospinal pathway may be used instead, which may account for the differences in interlimb coupling. Imaging findings show that the corticospinal tract is more impacted by perinatal lesions than prenatal lesions, which may affect differences in reorganization and motor deficits. Lastly, the corpus callosum was found to be affected more by earlier lesions, which may impact the bilateral nature of associated reactions and other deficits. This work demonstrates the need to address interlimb coupling in clinical practice rather than treat the upper and lower extremities in isolation.

Last modified

• 02/21/2018

Creator

• Rachel Lauren Hawe

DOI

• https://doi.org/10.21985/N2ZX0H

Subject

• Biomedical Engineering

Keyword

• hemiplegia
• interlimb coupling

Date created

• 2016-01-01

Resource type

• Dissertation

Rights statement

• In Copyright