Spinal cord stimulation improves motor function in disorders of consciousness: A case report

A 38-year-old male patient with disorders of consciousness (DOC) successfully recovered consciousness and get obvious motor function improvements through three stages of cervical spinal cord stimulation (SCS) treatment (6 Hz, 40 Hz, and combined frequency stimulation). We used the Coma Recovery Scale-Revised (CRS-R), Fugl–Meyer Assessment Scale, activities of daily living, and Berg Balance Scale to detect changes in consciousness and motor function during the 7-month postoperative follow-up. Electroencephalography-based individual alpha frequency (IAF) and relative power spectral density (RP) were used to assess changes in cognitive function and brain network function before and after the combined stimulation. The results revealed a gradually increased patient's CRS-R score after stimulation at 6 Hz, and the patient recovered consciousness 12 weeks postoperatively. The patient's motor function score gradually increased after adjusting the stimulation frequency to 40 Hz. However, the patient regressed in motor function when the stimulation frequency was decreased to 2 Hz. The patient's fine motor control of both hands significantly improved, accompanied by an increased RP in the beta band but the IAF decreased, after combined stimulation (40 Hz and 6 Hz). Then, motor function continued to improve with an increased IAF and RP in the alpha band after switching the stimulation order to 6 Hz and 40 Hz. Our results demonstrated that different frequency stimulations of cervical SCS may improve consciousness and motor function in patients with DOC.