VNS Therapy is expected to dampen activity in the vagus nerve, the main "information highway" from the stomach to the brain. A pacemaker-like pulse generator is implanted directly below the skin of a patient's chest to deliver intermittent pulses of electrical stimulation to the brain via the vagus nerve in the neck. Using an external programming system, doctors can adjust the timing and amount of stimulation the patient receives. This stimulation is expected to control vagus nerve activity and reduce the urges to binge eat and vomit.
"Most people don't realize that women with bulimia only self-induce vomiting at the early stages of the disorder. Later on, this behavior becomes involuntary as a result of changes in the activity level of the vagus nerve" says Patricia Faris, Ph.D., associate professor in the University of Minnesota Medical School's Department of Psychiatry and principal investigator of the VNS Therapy trial. "Bulimia is both a psychological and physiological disorder. The social pressure to be thin is probably the reason for an individual to start binge eating and vomiting, but after a while these behaviors induce changes in the activity of the vagus nerve. The goals of our research are to reverse the physiological changes that have occurred thereby reducing, or eliminating, the urges to vomit and to address the psychological components which originally led to the initiation of the disorder and which, if not re-structured, may result in future relapses."
A previous study conducted by the University of Minnesota published in The Lancet in March 2000 indicated that voluntary binge eating and vomiting early on in bulimia progressively stimulates the vagus nerve at higher intensities. Eventually, the vagus nerve spontaneously fires at this higher intensity. In this study, Zofran, a drug clinically used to modulate vagal activity, was found to be successful in dramatically reducing bulimic symptoms. VNS will provide enhanced ability to regulate vagus nerve activity, thereby allowing the individual to regain control over her disordered eating.
For more information on participating in this study or other eating disorder studies, call 612-626-4034 or e-mail eating@umn.edu
The Academic Health Center is home to the University of Minnesota's seven health professional schools and colleges as well as several health-related centers and institutes. Founded in 1851, the University is one of the oldest and largest land grant institutions in the country. The AHC prepares the new health professionals who improve the health of communities, discover and deliver new treatments and cures, and strengthen the health economy.