In patients with disorders of consciousness, acute pressure pain stimulation did not produce significant changes in oxygenated or deoxygenated hemoglobin concentrations across multiple brain regions, indicating minimal activation of pain-related areas. However, functional connectivity between the primary somatosensory cortex, primary motor cortex, and dorsolateral prefrontal cortex significantly increased during stimulation, with correlation coefficients exceeding 0.9. This enhanced coordination among sensory, motor, and cognitive regions suggests that the brain continues to process pain information through altered network connectivity even when regional activation is absent. The findings underscore the potential of functional connectivity measures for evaluating pain processing in patients with disorders of consciousness.
Transcutaneous auricular vagus nerve stimulation (taVNS) may help restore consciousness in patients with prolonged disorders of consciousness (pDOC), but clinical results have been inconsistent. This study will enroll 50 patients with pDOC who will receive a 4-week taVNS treatment. Before and after treatment, each patient will undergo a 30-minute resting electroencephalogram (EEG) and a Coma Recovery Scale-Revised (CRS-R) assessment. After treatment, patients will be followed up at 1, 3, 6, and 12 months. Patients will be classified as responders or non-responders based on whether their CRS-R scores increase. The study aims to identify EEG characteristics—such as differences in brain power spectrum and functional connectivity—that predict which patients are suitable for taVNS, to improve treatment selection.