Transcutaneous auricular vagus nerve stimulation shows modest cognitive improvements in mild cognitive impairment and post-stroke cognitive impairment.

This systematic review assessed the therapeutic potential of transcutaneous auricular vagus nerve stimulation (taVNS) in patients with various forms of cognitive impairment, specifically mild cognitive impairment and post-stroke cognitive impairment. The review synthesized data from small-scale studies to evaluate the intervention's impact on cognitive metrics. No specific comparator was consistently reported across the included studies, and sample sizes were generally small.

The main results indicate that some studies report modest improvements in cognitive metrics. However, exact effect sizes, absolute numbers, and statistical significance were not reported for the primary outcomes. Safety and tolerability data were not reported in the included studies, meaning adverse events, discontinuations, and serious adverse events remain unknown. Follow-up durations were also not reported.

Key limitations include heterogeneous parameters, short intervention durations, and inadequate sham controls. There is also an underdeveloped mechanistic understanding of the intervention. These methodological issues, combined with small sample sizes, prevent definitive conclusions regarding the role of taVNS in clinical management. Funding sources and potential conflicts of interest were not reported.

The practice relevance is currently limited by the preliminary nature of the evidence. Until standardized protocols and larger, well-controlled trials are conducted, the clinical utility of taVNS for cognitive impairment remains uncertain. Clinicians should not yet consider this as a definitive treatment option.