Anxiety Symptoms Reduction in Long COVID Patients after Auricular Vagal Neuromodulation Therapy

Abstract

The study evaluated the effectiveness of Nurosym Auricular Vagal Neuromodulation Therapy (AVNT) in reducing anxiety in Long COVID patients with pre-existing anxiety and depression. Given the significant overlap between symptoms of dysautonomia and anxiety, the trial focused on the role of the vagus nerve in autonomic regulation. Participants underwent 10 days of home-based Nurosym therapy, with sessions twice daily. Results showed a significant and sustained reduction in anxiety scores, with large effect sizes indicating a strong treatment effect. The findings suggest that Nurosym therapy, by modulating the vagus nerve, could be a valuable treatment for anxiety in Long COVID patients, warranting further research to understand its mechanisms and confirm long-term efficacy and safety.

Background and aims

Viral infections can cause dysautonomia, a condition often characterised by symptoms similar to those seen in anxiety disorders, such as increased nervousness and panic. Recent research suggests that this overlap of symptoms may be attributable to impairment of the vagus nerve, which plays a key role in autonomic regulation. Studies have also shown a significant correlation between decreased vagal tone and increased levels of anxiety, highlighting the importance of the vagus nerve in the pathophysiology of anxiety-related symptoms in dysautonomia. The study aimed to determine if Nurosym could be an effective treatment for reducing persistent symptoms in long-term COVID-19 patients, particularly when it comes to easing anxiety. 

Methods

The clinical trial involved female patients, who have been experiencing persistent symptoms of Long COVID, specifically cognitive impairments. Notably, 37.5% of the participants had pre-existing anxiety or depression. Participants underwent a 10-day course of Nurosym, administered at home. Each day consisted of two 30-minute sessions - one in the morning and one in the evening. The intensity of the current was personalised for each participant, adjusted to achieve a constant tingling sensation without discomfort. The study placed a special emphasis on measuring anxiety, using the BURNS Anxiety Inventory, a standardised tool designed to assess levels of anxiety. In addition to anxiety, secondary outcomes related to depression, fatigue, sleep quality, and olfactory function were explored. Anxiety scores were analysed using a repeated-measures ANOVA to assess the effect of the intervention over three timepoints: pre-intervention, post-intervention, and 1-month follow-up.

Results

The significant and sustained reduction in anxiety scores suggests that Nurosym could be considered a valuable treatment strategy for managing anxiety in Long COVID patients. The large effect sizes (Cohen's d) indicate a strong treatment effect of Nurosym on reducing anxiety symptoms among the participants.

The figure illustrates changes in anxiety across three timepoints: pre-intervention (D0: Day 0), post-intervention (D10: Day 10), and 1-month follow-up after accomplished treatment. Boxplots are used for nonparametric data, while column graphs depict parametric data. Error bars represent the standard error. Significant level is indicated as ***p < 0.001.

The analysis revealed significant changes across the study period (F(2, 46) = 14.46, p < 0.001). Bonferroni-adjusted post hoc tests showed marked improvements from baseline to post-intervention (p = 0.001, d = 0.619) and from baseline to 1-month follow-up continue to improve, reaching 35% (p < 0.001, d = 0.803).

Conclusion

The Nurosym therapy shows promise in delivering sustained benefits after treatment. The vagus nerve, key in the parasympathetic nervous system, helps regulate mood and stress responses. Nurosym works by directly influencing this nerve, which seems to help reduce anxiety by modifying stress-related pathways in the brain. This connection offers a plausible explanation for the improvements seen in patients. More research is needed to clearly understand how Nurosym works and to confirm its long-term safety and effectiveness.