A variety of health conditions can be managed by sending electrical impulses to the vagus nerve located in the ear. However, this approach does not consistently yield results. Recent research has indicated that these electrical impulses need to align with the body’s inherent rhythms, specifically the heartbeat and breathing.
Medication isn’t always necessary. Certain health issues—ranging from persistent pain and inflammation to neurological disorders—can be addressed through nerve stimulation, such as using electrodes placed on the ear to activate the vagus nerve. This technique is sometimes called an “electric pill.”
Nonetheless, vagus nerve stimulation doesn’t always perform as expected. A study by TU Wien (Vienna), in collaboration with the Vienna Private Clinic, has highlighted ways to enhance this treatment: Research shows that the effectiveness dramatically improves when the electrical stimulation is matched with the body’s natural rhythms—heartbeats and breaths.
The ‘electric pill’ for enhancing the parasympathetic nervous system
The vagus nerve plays a crucial role in our bodily functions: it is the longest nerve in the parasympathetic nervous system, which is essential for accurately regulating internal organs and blood circulation. It also facilitates recovery and conservation of the body’s energy reserves. A part of the vagus nerve extends from the brain directly into the ear, enabling the use of small electrodes in the ear to stimulate the vagus nerve and, consequently, the brain, which can influence various bodily functions.
“However, it has been discovered that this stimulation doesn’t always yield the anticipated outcomes,” states Prof. Eugenijus Kaniusas from the Institute of Biomedical Electronics at TU Wien. “The electrical impulses don’t continuously affect the nervous system. In a sense, you could say that the brain doesn’t always pay attention. It resembles a gate to the nervous system’s control center, which can be either open or closed, and this can switch in less than a second.”
A pilot study monitored five individuals, whose vagus nerve was electrically stimulated to decrease their heart rates. Previous studies indicate that heart rate can be a reliable indicator of the effectiveness of stimulation therapy.
The results revealed that the timing of the stimulation in relation to the heartbeat was crucial. If the vagus nerve was stimulated at a rhythm not synchronized with the heartbeat, there was minimal effect. Conversely, when the stimulation occurred during the heart’s contraction phase (systole), the results were significantly more pronounced—much more so than when the stimulation happened during the heart’s relaxation phase (diastole).
Breathing patterns also play a role: stimulation was found to be notably more effective during inhalation compared to exhalation.
“Our findings indicate that aligning vagus nerve stimulation with the rhythms of the heartbeat and breathing substantially boosts its effectiveness. This advancement could enhance treatment outcomes for chronic illnesses, particularly for patients who have not responded to this therapy for reasons that remain unclear,” explains Eugenijus Kaniusas.
Next steps: Larger clinical trials
By customizing nerve stimulation electronically to match the individual’s specific rhythms at any moment, greater successes could be achieved than what has previously been possible. Future research will focus on larger clinical participant groups and developing more accurate algorithms to tailor the stimulation to individual requirements.
“This technology holds the potential to provide a targeted and gentle way of modulating the autonomic nervous system, which could represent a significant milestone in the neuromodulatory treatment of diverse chronic diseases,” asserts Dr. Joszef Constantin Szeles from the Vienna Private Clinic.
