Motor Imagery Training of Reaching-to-Grasp Movement Supplemented by a Virtual Environment in an Individual With Congenital Bilateral Transverse Upper-Limb Deficiency

Abstract

This study explored the effect of kinesthetic motor imagery training on reaching-to-grasp movement supplemented by a virtual environment in a patient with congenital bilateral transverse upper-limb deficiency. Based on a theoretical assumption, it is possible to conduct such training in this patient. The aim of this study was to evaluate whether cortical activity related to motor imagery of reaching and motor imagery of grasping of the right upper limb was changed by computer-aided imagery training (CAIT) in a patient who was born without upper limbs compared to a healthy control subject, as characterized by multi-channel electroencephalography (EEG) signals recorded before and 4, 8, and 12 weeks after CAIT. The main task during CAIT was to kinesthetically imagine the execution of reaching-to-grasp movements without any muscle activation, supplemented by computer visualization of movements provided by a special headset. Our experiment showed that CAIT can be conducted in the patient with higher vividness of imagery for reaching than grasping tasks. Our results confirm that CAIT can change brain activation patterns in areas related to motor planning and the execution of reaching and grasping movements, and that the effect was more pronounced in the patient than in the healthy control subject. The results show that CAIT has a different effect on the cortical activity related to the motor imagery of a reaching task than on the cortical activity related to the motor imagery of a grasping task. The change observed in the activation patterns could indicate CAIT-induced neuroplasticity, which could potentially be useful in rehabilitation or brain-computer interface purposes for such patients, especially before and after transplantation. This study was part of a registered experiment (ID: NCT04048083).

Keywords: EEG; amelia; grasping; mental training; neuroplasticity; reaching; transplantation.

Figure 1

Scheme of the experimental protocol consisting of four measurement sessions (PRE, POST4, POST8, and POST12) and 12 weeks of computer-aided imagery training (CAIT).

Figure 2

The mean value of ERP amplitude [*−1 (μV)] related to the motor imagery of reaching for the right upper limb from four channels in: the contralateral prefrontal cortex (above the left hemisphere) – area of standard “F3” channel, ipsilateral prefrontal cortex (above the right hemisphere) – area of standard “F4” channel, and contralateral sensorimotor cortex – area of standard “C3” channel and ipsilateral sensorimotor cortex – area of standard “C4” channel for the patient (black color) and control subject (white color) for sessions before 12 weeks of computer-aided imagery training (PRE) and after intervals of 4 weeks each (POST4, POST8, and POST12).

Figure 3

Topographic maps of electroencephalography (EEG) during motor imagery of reaching (MIR) of the right upper limb for the patient (left) and the control subject (right) for four measurement sessions (PRE, POST4, POST8, and POST12).

Figure 4

The mean value of ERP amplitude [*−1 (μV)] related to motor imagery of grasping of the right hand from four channels in: the contralateral prefrontal cortex (above left hemisphere) – area of standard “F3” channel and ipsilateral prefrontal cortex (above right hemisphere) – area of standard “F4” channel, contralateral sensorimotor cortex – area of standard “C3” channel and ipsilateral sensorimotor cortex – area of standard “C4” channel for the patient (black color) and the control subject (white color) for the session before 12 weeks of computer-aided imagery training (PRE) and after intervals of 4 weeks (POST4, POST8, and POST12).

Figure 5

Topographic maps of EEG during motor imagery of grasping (MIG) of the right hand for the patient (left) and the control subject (right) for four measurement sessions (PRE, POST4, POST8, and POST12).