Feasibility and acceptance of transdermal auricular vagus nerve stimulation using a TENS device in females suffering from long COVID fatigue

Wien Klin Wochenschr. 2025 Feb 19. doi: 10.1007/s00508-025-02501-1. Online ahead of print.

Abstract

Background: The COVID-19 pandemic has led to significant health challenges, with some individuals developing long COVID characterized by persistent symptoms such as fatigue, dyspnea and cognitive difficulties lasting weeks or months after infection. This condition predominantly affects women and may involve prolonged inflammation and autonomic nervous system dysfunction. Current treatments focus on symptom relief and vagus nerve stimulation (VNS) is being investigated for its potential therapeutic benefits.

Methods: This pilot study was a prospective, blinded, randomized controlled trial involving 36 female long COVID patients aged 18-70 years. Participants were assigned to three groups receiving VNS at frequencies of 10 Hz, 25 Hz, or a control of 2 Hz for 3 months. Outcomes were assessed at baseline, after 4 and 12 weeks.

Results: The study revealed that all VNS treatment groups experienced reduction in symptoms associated with long COVID, particularly in fatigue and dyspnea, after 12 weeks. Participants across all frequencies reported an improvement in health-related quality of life. Heart rate variability remained stable throughout the trial, and no significant changes in morning salivary cortisol levels were seen across groups.

Discussion: Vagus nerve stimulation may offer therapeutic benefits for women with long COVID, particularly in reducing fatigue and dyspnea. The treatment was found to be safe, with no significant side effects reported; however, further research with larger study groups is needed to confirm these findings and examine the long-term effects of VNS on autonomic nervous system function.

Keywords: Long COVID; Parasympathetic; TENS; Transcutaneous auricular vagus stimulation.