Spinal cord stimulation improves brain connectivity and consciousness level in patients with disorders of...

Spinal cord stimulation (SCS) is an advanced neuromodulation technology in disorders of consciousness (DOC) field. However, research on the modulation effects and mechanisms of SCS is limited.

We proposed a study design (SCS and sham) to study the short-term effects of 20 minutes' SCS, in which resting state EEG and Coma Recovery Scale-Revised (CRS-R) were used to measure the changes in neural and behavioral activity caused by SCS. We used the Genuine Permutation Cross Mutual Information(G_PCMI) to analyze EEG data and study changes in cortical connectivity during SCS. Finally, all patients' CRS-R results were obtained after 6 months' SCS treatment.

Short-term SCS (20 min) did not alter the patient's CRS-R score, but long-term SCS (6 months) can improve the CRS-R scores of all patients. EEG results show G_PCMI of the frontal and central brain regions significantly change before and after short-term SCS (p < 0.01) and PCMI of the F-P, F-O regions have significant differences before and after short-term SCS (p < 0.05). Besides, the G_PCMI changes in frontal, parietal, F-P and F-O regions show a significant positive correlation with CRS-R changes (r = 0.80, 0.66, 0.68 and 0.72; p < 0.05). However, the sham group showed no significant G_PCMI changes.

SCS can improve the awareness level of DOC patients. SCS improves cortical short- and long-distance connectivity of DOC patients may contribute the improvement of consciousness level.