scholarly journals Effects of arm weight support on neuromuscular activation during reaching in chronic stroke patients

2019 ◽  
Author(s):  
Keith D Runnalls ◽  
Pablo Ortega-Auriol ◽  
Angus J C McMorland ◽  
Greg Anson ◽  
Winston D Byblow
Keyword(s):  
Upper Limb ◽  
Muscle Activity ◽  
Chronic Stroke ◽  
Support Surface ◽  
Healthy Controls ◽  
Stroke Patients ◽  
Corticomotor Excitability ◽  
Weight Support ◽  
Mild Impairment ◽  
Arm Weight Support

AbstractTo better understand how arm weight support (WS) can be used to alleviate upper limb impairment after stroke, we investigated the effects of WS on muscle activity, muscle synergy expression, and corticomotor excitability (CME) in 13 chronic stroke patients and 6 age-similar healthy controls. For patients, lesion location and corticospinal tract integrity were assessed using magnetic resonance imaging. Upper limb impairment was assessed using the Fugl-Meyer upper extremity assessment with patients categorised as either mild or moderate-severe. Three levels of WS were examined: low=0, medium=50 and high=100 % of full support. Surface EMG was recorded from 8 upper limb muscles, and muscle synergies were decomposed using non-negative matrix factorisation from data obtained during reaching movements to an array of 14 targets using the paretic or dominant arm. Interactions between impairment level and WS were found for the number of targets hit, and EMG measures. Overall, greater WS resulted in lower EMG levels, although the degree of modulation between WS levels was less for patients with moderate-severe compared to mild impairment. Healthy controls expressed more synergies than patients with moderate-severe impairment. Healthy controls and patients with mild impairment showed more synergies with high compared to low weight support. Transcranial magnetic stimulation was used to elicit motor-evoked potentials (MEPs) to which stimulus-response curves were fitted as a measure of corticomotor excitability (CME). The effect of WS on CME varied between muscles and across impairment level. These preliminary findings demonstrate that WS has direct and indirect effects on muscle activity, synergies, and CME and warrants further study in order to reduce upper limb impairment after stroke.

scholarly journals Effects of arm weight support on neuromuscular activation during reaching in chronic stroke patients

2019 ◽  
Vol 237 (12) ◽  
pp. 3391-3408 ◽  
Author(s):  
Keith D. Runnalls ◽  
Pablo Ortega-Auriol ◽  
Angus J. C. McMorland ◽  
Greg Anson ◽  
Winston D. Byblow
Keyword(s):  
Chronic Stroke ◽  
Stroke Patients ◽  
Neuromuscular Activation ◽  
Weight Support ◽  
Arm Weight Support

Abstract T P123: Non-invasive Brain Stimulation for Motor Function of Chronic Stroke Patients

Stroke ◽  
2014 ◽  
Vol 45 (suppl_1) ◽  
Author(s):  
Eunhee Park ◽  
Tae Gun Kwon ◽  
Won Hyuk Chang ◽  
Yun-Hee Kim
Keyword(s):  
Motor Function ◽  
Brain Stimulation ◽  
Movement Time ◽  
Motor Task ◽  
Chronic Stroke ◽  
Stroke Patients ◽  
Dual Mode ◽  
Simultaneous Application ◽  
Corticomotor Excitability ◽  
Cathodal Tdcs

Objective: The purpose of this study was to investigate the effect of dual-mode noninvasive brain stimulation (NBS) by combining transcranial direct current stimulation (tDCS) over the unaffected primary motor cortex (uM1) and high-frequency repetitive transcranial magnetic stimulation (rTMS) over the affected M1 (aM1) on motor functions and corticomotor excitability in chronic stroke patients. Methods: Seventeen chronic stroke patients (12 men; mean age 58.7 years; 12 infarctions and 5 hemorrhages) participated in this double blinded random-order crossover study. All participants received three randomly arranged, dual-mode stimulations with 24 hours of washout period; Condition 1, simultaneous application of 10 Hz rTMS over the aM1 and cathodal tDCS over the uM1; Condition 2, simultaneous application of 10 Hz rTMS over the M1a and anodal tDCS over the uM1; Condition 3, 10 Hz rTMS over the aM1 and sham tDCS over the uM1. Corticomotor excitability using motor evoked potential (MEP) amplitude and hand motor functions using the sequential motor task were assessed before and after stimulation. Results: MEP amplitude was significantly increased after condition 1 and 3, respectively (p<0.05). The changes of MEP amplitude were significantly higher in condition 1 than condition 2 (p<0.05). In sequential motor task, the movement time was significantly decreased after condition 1 and 3, respectively (p<0.05). The change of movement time was significantly larger in condition 1 than the other conditions (p<0.05). Conclusions: Simultaneous stimulation of cathodal tDCS over the uM1 produced enhancement of 10 Hz rTMS effect over the aM1 in patients with stroke. These results suggest the dual-mode NBS as a method of enhancing motor function probably by inducing interhemispheric interaction of bilateral primary motor cortices in chronic stroke patients (Supported by the National Research Foundation of Korea grant (No.2011-0016960) and a KOSEF grant (M10644000022-06N4400-02210)).

Upper limb robot-assisted therapy in subacute and chronic stroke patients using an innovative end-effector haptic device: A pilot study

2018 ◽  
Vol 42 (1) ◽  
pp. 43-52 ◽  
Author(s):  
S. Mazzoleni ◽  
E. Battini ◽  
R. Crecchi ◽  
P. Dario ◽  
F. Posteraro
Keyword(s):  
Pilot Study ◽  
Upper Limb ◽  
Chronic Stroke ◽  
Haptic Device ◽  
Stroke Patients ◽  
Robot Assisted ◽  
End Effector

The Influence of Cortico-Cerebellar Structural Connectivity on Cortical Excitability in Chronic Stroke

2019 ◽  
Vol 30 (3) ◽  
pp. 1330-1344
Author(s):  
Stephanie Guder ◽  
Benedikt M Frey ◽  
Winifried Backhaus ◽  
Hanna Braass ◽  
Jan E Timmermann ◽  
...  
Keyword(s):  
Primary Motor Cortex ◽  
Structural Integrity ◽  
Cortical Excitability ◽  
Structural Information ◽  
Motor Evoked Potentials ◽  
Structural Connectivity ◽  
Chronic Stroke ◽  
Motor Output ◽  
Healthy Controls ◽  
Stroke Patients

Abstract Brain imaging has recently evidenced that the structural state of distinct reciprocal cortico-cerebellar fiber tracts, the dentato-thalamo-cortical tract (DTCT), and the cortico-ponto-cerebellar tract (CPCeT), significantly influences residual motor output in chronic stroke patients, independent from the level of damage to the corticospinal tract (CST). Whether such structural information might also directly relate to measures of cortical excitability is an open question. Eighteen chronic stroke patients with supratentorial ischemic lesions and 17 healthy controls underwent transcranial magnetic stimulation to assess recruitment curves of motor evoked potentials of both hemispheres. Diffusion-weighted imaging and probabilistic tractography were applied to reconstruct reciprocal cortico-cerebellar motor tracts between the primary motor cortex and the cerebellum. Tract-related microstructure was estimated by means of fractional anisotropy, and linear regression modeling was used to relate it to cortical excitability. The main finding was a significant association between cortical excitability and the structural integrity of the DTCT, the main cerebellar outflow tract, independent from the level of damage to the CST. A comparable relationship was neither detectable for the CPCeT nor for the healthy controls. This finding contributes to a mechanistic understanding of the putative supportive role of the cerebellum for residual motor output by facilitating cortical excitability after stroke.

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