Effect of Trans‐Auricular Vagal Nerve Stimulation on Cognitive Functions in Diabetic Polyneuropathy Patients

ABSTRACT Background and Purpose Diabetic polyneuropathy is associated with poor cognitive performance in executive function, memory and reaction time. Patients had a 50% greater risk of developing dementia. Trans ‐auricular vagal nerve stimulation (ta‐VNS) is a new, safe and promising instrument for enhancing cognitive performance. This study aimed to investigate the effect of trans ‐auricular vagal nerve stimulation (ta‐VNS) on cognitive functions and its impact on quality of life (QOL) in diabetic polyneuropathy patients. Methods Forty individuals with type II diabetic polyneuropathy participated in this study. They were randomly assigned to two equal parallel groups: study group (GI) and control group (GII). The study group received active trans ‐auricular vagal nerve stimulation (ta‐VNS) in addition to a computer‐based cognitive rehabilitation (CBCR) program, while the control group received the same program with sham (ta‐VNS). Both groups underwent intervention three times per week for 3 weeks. Cognitive functions (attention‐concentration, and figural memory) and quality of life were assessed at baseline and after 3 weeks using the RehaCom system and the World Health Organization's Quality of Life Brief Questionnaire, respectively. Results Post‐treatment, there was a significant increase in the level of attention‐concentration, as well as a significant increase in the quality‐of‐life score. Additionally, there was a significant decrease in the mean time for attention‐concentration, as well as in figural memory acquisition time for both groups, with more improvement in favor of the study group ( p < 0.05). Furthermore, there was a significant increase in the task performance and level of figural memory, along with a significant decrease in figural memory solution time only in the study group ( p < 0.05). Discussions Adding trans ‐auricular vagal nerve stimulation (ta‐VNS) to Computer‐based cognitive rehabilitation (CBCR) program significantly enhancing cognitive functions and quality of life in diabetic polyneuropathy patients. Trial Registration: The study was registered at the ClinicalTrials.gov (NCT06048653)