A Neuroanatomical Framework for Upper Limb Synergies after Stroke

Use of the word 'may' 4 times tells me nothing useful comes out of this to get survivors recovered.  We need; do this and you get this result. WHEN THE HELL WILL YOU PROVIDE THAT?

A Neuroanatomical Framework for Upper Limb Synergies after Stroke

Angus J. C. McMorland , Keith D. Runnalls  and Winston D. Byblow *
Movement Neuroscience Laboratory, Department of Sport and Exercise Science, Centre for Brain Research,The University of Auckland, Auckland, New Zealand
Edited by:
Ana Bengoetxea, Universidad del País Vasco-Euskal Herriko Unibertsitatea,Spain
Reviewed by:
Jean-LouisThonnard, Université Catholique de Louvain, BelgiumAaron Batista, University of Pittsburgh, USA
*Correspondence:
Winston D. Byblow, Movement Neuroscience Laboratory,Department of Sport and Exercise Science, Centre for Brain Research,The University of Auckland, Private Bag 92019, Auckland 1142, New Zealand e-mail:  w.byblow@auckland.ac.nz
Muscle synergies describe common patterns of co- or reciprocal activation that occur during movement. After stroke, these synergies change, often in stereotypical ways.The mechanism underlying this change reflects damage to key motor pathways as a result ofthe stroke lesion, and the subsequent reorganization along the neuroaxis, which may be further detrimental or restorative to motor function.The time course of abnormal synergy formation seems to lag spontaneous recovery that occurs in the initial weeks after stroke.In healthy individuals, motor cortical activity, descending via the corticospinal tract (CST)is the predominant driver of voluntary behavior. When the CST is damaged after stroke,other descending pathways may be up-regulated to compensate.The contribution of these pathways may emerge as new synergies take shape at the chronic stage after stroke, as a result of plasticity along the neuroaxis.The location of the stroke lesion and properties ofthe secondary descending pathways and their regulation are then critical for shaping thesynergies in the remaining motor behavior. A consideration of the integrity of remaining descending motor pathways may aid in the design of new rehabilitation therapies.