English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

The loss of independent joint control, clinically referred to as limb synergies, is prevalent in the paretic upper limb of individuals with chronic hemiparetic stroke. To understand the underlying neural mechanisms, we previously reported that an increased overlap of cortical representations of shoulder/elbow could contribute to the abnormal poststroke synergies. However, these previous results were limited to a fixed time window just before the onset of motor tasks. Questions such as (1) how this overlap develops during motor preparation and (2) whether such development is also linked to upper limb synergies, remain unclear. To answer these questions, we investigated cortical overlap during motor preparation of isometric shoulder and elbow torque generation tasks in healthy individuals (n = 8), and individuals with moderate to severe chronic hemiparesis following a subcortical stroke (n = 12). We found a significant group difference in how the cortical overlap developed. In the healthy control and moderately impaired stroke groups, cortical overlap between shoulder and elbow motor tasks decreased during the motor preparation; however, this overlap increased in individuals with severe stroke. Furthermore, the rate of cortical overlap decrease/increase was linked to the upper limb Fugl-Meyer scores and limb synergies. These results demonstrate, for the first time, that the increase in overlap of the cortical activity during motor preparation is associated with the expression of synergies in the paretic upper limb of severely impaired poststroke individuals.

The Increase in Overlap of Cortical Activity Preceding Static Elbow/Shoulder Motor Tasks Is Associated With Limb Synergies in Severe Stroke