Effects of Transcutaneous Vagus Nerve Stimulation on Emotion Regulation and Executive Functioning in Prader-Willi Syndrome

The aVNT device used in our study (Parasym ®) consists of a small portable unit connected to stimulation electrodes placed on the left ear. These electrodes deliver painless electrical microcurrents through the skin to stimulate the auricular branch of the vagus nerve (ABVN). The device parameters will be defined in accordance with the recommendations for use of the Parasym ® device and the pilot studies: frequency of 25 Hz, pulse width of 250 µS, and an intensity of 1 mA to 36 mA. Stimulation sessions will last for four hours each day, each of which can be divided into two sessions and conducted over a period of nine months. Patients will adjust the intensity at each session according to their comfort level, starting with a gradual increase until they feel a slight tingling sensation, followed by a decrease until discomfort disappears completely. Stimulation should take place during a relaxing activity but not should not take place during sleep, meals or major physical activity.

The sham stimulation control condition will be performed using the same aVNT Parasym® device under similar conditions (four hours a day, seven days a week, for nine months) but with a different location (without afferent vagus nerve fibers) or a control condition integrated into the device.