Brain motor system function in a patient with complete spinal cord injury following extensive brain–computer interface training

摘要

Although several features of brain motor function appear to be preserved even in chronic complete SCI, previous functional MRI (fMRI) studies have also identified significant derangements such as a strongly reduced volume of activation, a poor modulation of function and abnormal activation patterns. It might be speculated that extensive motor imagery training may serve to prevent such abnormalities. We here report on a unique patient with a complete traumatic SCI below C5 who learned to elicit electroencephalographic signals β-bursts in the midline region upon imagination of foot movements. This enabled him to use a neuroprosthesis and to “walk from thought” in a virtual environment via a brain–computer interface (BCI). We here used fMRI at 3T during imagined hand and foot movements to investigate the effects of motor imagery via persistent BCI training over 8 years on brain motor function and compared these findings to a group of five untrained healthy age-matched volunteers during executed and imagined movements. We observed robust primary sensorimotor cortex (SMC) activity in expected somatotopy in the tetraplegic patient upon movement imagination while such activation was absent in healthy untrained controls. Sensorimotor network activation with motor imagery in the patient (including SMC contralateral to and the cerebellum ipsilateral to the imagined side of movement as well as supplementary motor areas) was very similar to the pattern observed with actual movement in the controls. We interpret our findings as evidence that BCI training as a conduit of motor imagery training may assist in maintaining access to SMC in largely preserved somatopy despite complete deafferentation.