Imagine There Is No Plegia. Mental Motor Imagery Difficulties in Patients with Traumatic Spinal Cord Injury

Abstract

In rehabilitation of patients with spinal cord injury (SCI), imagination of movement is a candidate tool to promote long-term recovery or to control futuristic neuroprostheses. However, little is known about the ability of patients with spinal cord injury to perform this task. It is likely that without the ability to effectively perform the movement, the imagination of movement is also problematic. We therefore examined, whether patients with SCI experience increased difficulties in motor imagery (MI) compared to healthy controls. We examined 7 male patients with traumatic spinal cord injury (aged 23–70 years, median 53) and 20 healthy controls (aged 21–54 years, median 30). All patients had incomplete SCI, with AIS (ASIA Impairment Scale) grades of C or D. All had cervical lesions, except one who had a thoracic injury level. Duration after injury ranged from 3 to 314 months. We performed the Movement Imagery Questionnaire Revised as well as the Beck Depression Inventory in all participants. The self-assessed ability of patients to visually imagine movements ranged from 7 to 36 (Md = 30) and tended to be decreased in comparison to healthy controls (ranged 16–49, Md = 42.5; W = 326.5, p = 0.055). Also, the self-assessed ability of patients to kinesthetically imagine movements (range = 7–35, Md = 31) differed significantly from the control group (range = 23–49, Md = 41; W = 337.5, p = 0.0047). Two patients yielded tendencies for depressive mood and they also reported most problems with movement imagination. Statistical analysis however did not confirm a general relationship between depressive mood and increased difficulty in MI across both groups. Patients with spinal cord injury seem to experience difficulties in imagining movements compared to healthy controls. This result might not only have implications for training and rehabilitation programs, but also for applications like brain-computer interfaces used to control neuroprostheses, which are often based on the brain signals exhibited during the imagination of movements.

Characterization of kinesthetic motor imagery compared with visual motor imageries

“…However, without specific instructions, subjects may be confused in the imagery tactics. Furthermore, people with motor disabilities had more difficulties with kinesthetic imagination compared to healthy participants 15 . It would be helpful if we could classify the imagery types and give feedback to the subject.…”

Cognitive Training Improves Disconnected Limbs’ Mental Representation and Peripersonal Space after Spinal Cord Injury

“…Deficits in motor imagery have also been found in cases of SCI [ 28 , 29 ] involving modifications in MI strategies [ 30 ], neuro-functional anomalies in the dynamics of event-related potentials [ 31 ], altered cortical activation [ 32 , 33 , 34 ] and altered functional connectivity [ 35 ]. Again, a link with the sensorimotor system is suggested by the topography of these modifications [ 29 ] which mainly affect motor imagery relating to actions involving the paralysed limbs.…”

A BCI System Based on Motor Imagery for Assisting People with Motor Deficiencies in the Limbs

“…These exoskeletons use the EEG signal acquired during the MI task, which activates brain regions to enable individuals to move [ 23 , 24 ]. Several studies indicated the positive impact of BCI systems on the rehabilitation process [ 25 , 26 ]. EEG signals acquired during MI tasks are commonly used to constructed assistive BCI systems.…”