Binge eating disorder may be eased by deep brain stimulation, small study says

Aug. 29 (UPI) -- A device implanted deep in the brain disrupted food cravings and led to far fewer binge eating episodes in the two patients involved in a small pilot study on its safety.

The research findings, published Monday in Nature Medicine, followed two adult female patients with loss-of-control binge eating disorder over six months.

Both women were severely obese, and with the implanted device, both lost weight not kept off with bariatric surgery. One improved so much that she no longer met the criteria for binge-eating disorder.

Neither patient appeared to have significant adverse side effects.

Over that time, the implanted device -- similar to one typically used to treat drug-resistant epilepsy -- monitored activity in a brain region called the nucleus accumbens.

Researchers said this part of the brain processes pleasure and reward, and has been implicated in addiction. Whenever the device sensed signals that had been found to predict food cravings in prior studies, it automatically stimulated that brain region, disrupting the craving-related signals.

The pilot study was led by investigators at the University of Pennsylvania's Perelman School of Medicine.

"This was an early feasibility study in which we were primarily assessing safety, but certainly the robust clinical benefits these patients reported to us are really impressive and exciting," Dr. Casey Halpern, the study's senior author, said in a news release.

Halpern is associate professor of neurosurgery and chief of stereotactic and functional neurosurgery at Penn Medicine and the Veterans Affairs Medical Center in Philadelphia.

According to the researchers, binge eating disorder is considered the most common eating disorder in the United States, affecting at least a few million people. Bingeing peoples have a sense of losing control over their eating and frequent episodes of continuing to eat beyond the usual point of feeling sated.

Binge eating disorder is typically associated with being overweight or obese, because unlike with anorexia or bulimia, people with the condition don't throw up their food, exercise a lot or starve themselves.

According to the Penn Medicine investigators, episode of binge eating are preceded by cravings for specific foods. Their previous research on mice found evidence of "distinctive low-frequency electrical activity" in the brain's nucleus accumbens occurring just before these cravings. This didn't occur before normal, non-binge eating.

The device used to record signals from and then stimulate the brains of the mice is commercially available and approved for treating drug-resistant epilepsy, the scientists said in the release.

It is surgically placed beneath the scalp, with wires running through the skull to the nucleus accumbens in each hemisphere of the brain.

The new study was a preliminary test of the same brain-stimulation device and strategy in human subjects, recording signals from the two severely obese patients with binge eating disorder for six months.

When the patients were in the laboratory, they were offered buffets of their favorite foods -- commonly fast-food and candy -- but mostly they were at home going about their daily routines and self-reporting the times of bingeing episodes, the scientists said.

As in their previous study, researchers observed the same type of signal in the brain's nucleus accumbens in the seconds before the patients' first bites of their binge meals.

In the study's next phase, the implanted devices automatically delivered high-frequency electrical stimulation whenever the craving-linked signals occurred.

Over six months, both patients reported sharp reductions in their feelings of loss-of-control eating, and in the frequencies of their bingeing episodes, and each lost more than 11 pounds, the release said.

Using this method, the scientists said they "helped patients with severe obesity lose weight without providing them instruction or guidance on a dietary plan."

The researchers said they encountered early challenges in capturing binge eating episodes in the real world. Before surgery, both study participants underwent training from a psychiatrist with expertise in obesity and eating disorders to learn how to identify and document their loss-of-control eating behaviors.

The scientists have continued to follow the subjects for another six months, and have started to enroll new patients for a larger study. They said the same treatment approach might be used for other loss-of-control-related disorders including bulimia.

The National Institute of Mental Health provides information on binge eating disorder, as does the Department of Health and Human Services' Office on Women's Health. NIH funded this study.