U of MN doctors receive NIH grant to test promising new bulimia treatment that aims to stop involuntary binge-eating and vomiting
MINNEAPOLIS / ST. PAUL (February 24, 2004) -- The University of Minnesota's Neuroscience Research Group received nearly $300,000 from the National Institutes of Health to study the effectiveness of a common epilepsy therapy in treating bulimia nervosa. This is the first study of Vagus Nerve Stimulation Therapy (VNS) for this disorder. VNS Therapy aims to reverse the physiological changes that have occurred in the function of the vagus nerve from repeated binge eating and vomiting. By controlling vagus nerve activity through electrical stimulation, doctors hope to reduce the frequency of vomiting in bulimics.
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.
Source: Eurekalert & othersLast reviewed: By John M. Grohol, Psy.D. on 21 Feb 2009
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