A comparative study on the effects of transcranial direct current stimulation and right median nerve stimulation in patients with altered levels of consciousness: a randomized clinical trial

Abstract Background: Transcranial direct current stimulation (tDCS) is a non-invasive neurostimulation technique that modulates cortical excitability with a weak polarizing current. Additionally, the right median nerve, serving as a peripheral gateway to the central nervous system, can be electrically stimulated to facilitate coma arousal. Aims and Objectives: This study aims to compare the effects of tDCS and right median nerve stimulation (RMNS) as arousal therapies in patients with altered consciousness resulting from traumatic or non-traumatic brain injury. Materials and Methods: A randomized clinical trial was conducted involving patients aged 20–70 with Glasgow Coma Scale (GCS) scores between eight and 12. Twenty participants with altered states of consciousness due to traumatic or non-traumatic brain injuries were randomly divided into two groups using the envelope method: Group 1 (tDCS) and Group 2 (RMNS). The Oromotor Functional Assessment Scale (OFAS) and the Coma Recovery Scale-Revised (CRS-R) were used to assess changes before and after the interventions. Results: Both groups demonstrated significant improvements in CRS-R and OFAS scores after two weeks of intervention. However, intergroup comparisons revealed no statistically significant difference, suggesting that both interventions are equally effective in enhancing arousal in patients with altered consciousness. Conclusion: tDCS and RMNS effectively improve arousal in patients with altered states of consciousness. However, the tDCS group showed greater improvement in effect size compared to the RMNS group.