Short-term changes in CRS-R scores during transcutaneous auricular vagus nerve stimulation in prolonged disorders of consciousness: a single-arm exploratory study.

OBJECTIVES

To describe short-term behavioral changes observed during a 2-week transcutaneous auricular vagus nerve stimulation (taVNS) intervention in patients with prolonged disorders of consciousness (pDOC) and to exploratorily compare these changes across baseline diagnostic states.

METHODS

This single-center, single-arm, open-label exploratory study included 50 patients with pDOC (25 with VS/UWS, 16 with MCS-, and 9 with MCS+) who received taVNS in addition to standard care for 2 weeks. CRS-R assessments were conducted at baseline, week 1, and week 2. The primary outcome was the longitudinal change in the CRS-R total score across the three assessment time points.

RESULTS

At week 2, the mean change in CRS-R total score from baseline was 2.40 ± 2.08 points (95% CI, 1.81-2.99), with no significant difference among the diagnostic groups. Upward diagnostic transitions occurred in 9/25 (36.0%) patients with VS/UWS (VS → MCS-, n = 7; VS → MCS+, n = 2) and Six of 16 (37.5%) patients with MCS- transitioned to MCS+, but in none of the patients with MCS+.

CONCLUSION

Short-term CRS-R changes and diagnostic transitions were observed during the 2-week taVNS intervention. Because the study lacked a control group and used unblinded outcome assessment, these changes cannot be attributed specifically to taVNS. The subgroup and early-outcome analyses are exploratory and require confirmation in adequately powered, sham-controlled studies with blinded assessment and longer follow-up.