Change in Reciprocal Inhibition of the Forearm with Motor Imagery among Patients with Chronic Stroke

Abstract

We investigated cortically mediated changes in reciprocal inhibition (RI) following motor imagery (MI) in short- and long(er)-term periods. The goals of this study were (1) to describe RI during MI in patients with chronic stroke and (2) to examine the change in RI after MI-based brain-machine interface (BMI) training. Twenty-four chronic stroke patients participated in study 1. All patients imagined wrist extension on the affected side. RI from the extensor carpi radialis to the flexor carpi radialis (FCR) was assessed using a FCR H reflex conditioning-test paradigm. We calculated the “MI effect score on RI” (RI value during MI divided by that at rest) and compared that score according to lesion location. RI during MI showed a significant enhancement compared with RI at rest. The MI effect score on RI in the subcortical lesion group was significantly greater than that in the cortical lesion group. Eleven stroke patients participated in study 2. All patients performed BMI training for 10 days. The MI effect score on RI at a 20 ms interstimulus interval was significantly increased after BMI compared with baseline. In conclusion, mental practice with MI may induce plastic change in spinal reciprocal inhibitory circuits in patients with stroke.

Effects of Leg Motor Imagery Combined With Electrical Stimulation on Plasticity of Corticospinal Excitability and Spinal Reciprocal Inhibition

“…MI and ES alone did not affect reciprocal inhibition. Long-term interventions that target the upper extremities using MI have been known to induce plasticity of the reciprocal inhibition circuits in patients after stroke (Kawakami et al, 2018). However, the effect of short-time MI on reciprocal inhibition remains unknown.…”

“…Brain activation during MI is similar to that observed during motor execution (Jackson et al, 2001; Chen et al, 2016; Sacheli et al, 2017). MI has been shown to increase corticospinal excitability, the H-reflex, spinal stretch reflex, and reciprocal inhibition (Kiers et al, 1997; Hale et al, 2003; Bakker et al, 2008; Aoyama and Kaneko, 2011; Lebon et al, 2012; Kato and Kanosue, 2017; Ruffino et al, 2017; Kawakami et al, 2018). Mental practice using MI is widely used in sports and rehabilitation (Jackson et al, 2001; de Lange et al, 2008; Malouin and Richards, 2010; Mrachacz-Kersting et al, 2012, 2016; Grospretre et al, 2016; Guerra et al, 2017; Ruffino et al, 2017).…”

The Effects of Combined Low Frequency Repetitive Transcranial Magnetic Stimulation and Motor Imagery on Upper Extremity Motor Recovery Following Stroke

“…For example, Kang et al and Xu et al demonstrated an increase in neural activity in the motor area during MI training (25, 26). And Kawakami et al also investigated changes of cortex in reciprocal inhibition following MI in patients with chronic stroke, and reported positive plastic changes during mental practice with MI (27). In another pilot study, Mihara et al demonstrated that NIRS-mediated neurofeedback MI could enhance the ipsilesional premotor area activation in correlation with MI training and could have significant effects on the motor deficit recovery in stroke patients.…”

Effect of the combination of motor imagery and electrical stimulation on upper extremity motor function in patients with chronic stroke: preliminary results

“… 44 – 46 MI affects the spinal neural circuits through the descending motor pathway. 45 – 48 Kawakami et al reported that RI of the antagonist muscle was increased during MI in patients with stroke. 45 The effect of ES on RI has also be reported, although the stimulus parameters were different from those used in the present study.…”

“… 45 – 48 Kawakami et al reported that RI of the antagonist muscle was increased during MI in patients with stroke. 45 The effect of ES on RI has also be reported, although the stimulus parameters were different from those used in the present study. 44 , 49 In this study, we consider that RI circuits may be reinforced by repetitive input from the cortex induced by MI, and peripheral nerves induced by ES.…”