Contact: Heather Woolwine
843.792.7669
Feb. 1, 2007
Charleston -- Scientists at the Medical University of South Carolina (MUSC) have determined that vagus nerve stimulation (VNS) may play a role in developing clinical treatments for obesity and emotional eating. The first of its kind, the study examined the effects of VNS on food cravings in adults with major depression.
"While it is still too early to think of cervical VNS as a treatment for emotional eating or obesity, the study results do demonstrate the need for more investigation and suggest that it is plausible that cervical VNS could one day be used to treat obesity," Borckardt said. "We also learned that VNS device settings may be key in understanding how to target specific areas in the brain responsible for satiety, and emotional eating."
Food cravings are related to eating behaviors and therefore they may influence weight change over time. This study provides initial evidence that food cravings, at least for sweet foods, may be one mechanism underlying the relationship between acute left cervical VNS and eating behaviors and weight. This type of VNS involves implanting the electrical device under the patient's skin in the upper left quadrant of the chest. "For some of the patients, we saw a decrease in the craving of sweets, whereas for others, we saw an increase," said Jeffrey Borckardt, Ph.D., MUSC Brain Stimulation Laboratory, Institute of Psychiatry, and one of the study's authors. "Based on certain VNS device parameters, {i.e. electrical current intensity, length of time the device was on or off, depression severity, body mass index, and emotional eating tendencies} we could predict if cravings would increase or decrease when the VNS device was turned on and off."
The vagus nerve, one of 12 cranial nerves, is an information highway between the brain and major organs, including the heart, stomach, lungs and esophagus. It plays a central role in satiety and short-term regulation of food intake and research suggests a relationship between VNS and weight loss. The underlying mechanisms of this relationship are unknown. VNS is an FDA-approved treatment for epilepsy and treatment-resistant depression.
Additional study authors include: Jamie S. Bodenlos, Ph.D., MUSC Department of Psychiatry and Behavioral Sciences; Samet Kose, M.D., MUSC Brain Stimulation Laboratory, Institute of Psychiatry; Ziad Nahas, M.D., MUSC Brain Stimulation Laboratory, Institute of Psychiatry; Darlene Shaw, Ph.D., Counseling and Psychological Services Center; Patrick M. O'Neil, Ph.D., MUSC Weight Management Center; and Mark S. George, M.D., MUSC Brain Stimulation Laboratory, Institute of Psychiatry.
The study will be published in the March 2007 issue of the journal Appetite. The full text of the study can be found at www.sciencedirect.com, key word search "vagus nerve stimulation."
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