Posts Tagged Bimanual coordination
[Abstract] Learning a Bimanual Cooperative Skill in Chronic Stroke Under Noninvasive Brain Stimulation: A Randomized Controlled Trial
Background. Transcranial direct current stimulation (tDCS) has been suggested to improve poststroke recovery. However, its effects on bimanual motor learning after stroke have not previously been explored.
Objective. We investigated whether dual-tDCS of the primary motor cortex (M1), with cathodal and anodal tDCS applied over undamaged and damaged hemispheres, respectively, improves learning and retention of a new bimanual cooperative motor skill in stroke patients.
Method. Twenty-one chronic hemiparetic patients were recruited for a randomized, double-blinded, cross-over, sham-controlled trial. While receiving real or sham dual-tDCS, they trained on a bimanual cooperative task called CIRCUIT. Changes in performance were quantified via bimanual speed/accuracy trade-off (Bi-SAT) and bimanual coordination factor (Bi-Co) before, during, and 0, 30, and 60 minutes after dual-tDCS, as well as one week later to measure retention. A generalization test then followed, where patients were asked to complete a new CIRCUIT layout.
Results. The patients were able to learn and retain the bimanual cooperative skill. However, a general linear mixed model did not detect a significant difference in retention between the real and sham dual-tDCS conditions for either Bi-SAT or Bi-Co. Similarly, no difference in generalization was detected for Bi-SAT or Bi-Co.
Conclusion. The chronic hemiparetic stroke patients learned and retained the complex bimanual cooperative task and generalized the newly acquired skills to other tasks, indicating that bimanual CIRCUIT training is promising as a neurorehabilitation approach. However, bimanual motor skill learning was not enhanced by dual-tDCS in these patients.
via Learning a Bimanual Cooperative Skill in Chronic Stroke Under Noninvasive Brain Stimulation: A Randomized Controlled Trial – Maral Yeganeh Doost, Jean-Jacques Orban de Xivry, Benoît Herman, Léna Vanthournhout, Audrey Riga, Benoît Bihin, Jacques Jamart, Patrice Laloux, Jean-Marc Raymackers, Yves Vandermeeren, 2019
- Post stroke motor impairments involving force control capabilities are devastating.
- Bimanual motor synergies provide robust data on coordinating forces between hands.
- Low-force frequency patterns reveal fine motor control strategies in paretic hands.
- Analyzing both novel approaches advance understanding of post stroke force control.
Force control deficits are common dysfunctions after a stroke. This review concentrates on various force control variables associated with motor impairments and suggests new approaches to quantifying force control production and modulation. Moreover, related neurophysiological mechanisms were addressed to determine variables that affect force control capabilities. Typically, post stroke force control impairments include:
(a) decreased force magnitude and asymmetrical forces between hands,
(b) higher task error,
(c) greater force variability,
(d) increased force regularity, and
(e) greater time-lag between muscular forces.
Recent advances in force control analyses post stroke indicated less bimanual motor synergies and impaired low-force frequency structure.Brain imaging studies demonstrate possible neurophysiological mechanisms underlying force control impairments:
(a) decreased activation in motor areas of the ipsilesional hemisphere,
(b) increased activation in secondary motor areas between hemispheres,
(c) cerebellum involvement absence, and
(d) relatively greater interhemispheric inhibition from the contralesional hemisphere.
Consistent with identifying neurophysiological mechanisms, analyzing bimanual motor synergies as well as low-force frequency structure will advance our understanding of post stroke force control.