Electrical brain impulses eliminate binge eating in two women

Can the uncontrollable urge to eat large amounts of food originate from a compromised brain circuit? If this were the case, people living with binge eating disorder — a psychiatric diagnosis — would not be blamed for overeating, any more than a Parkinson’s disease patient is blamed for their tremors.

That question prompted doctors to try a new treatment unlike anything else tried to help people with this common but underreported eating disorder. At least 3% of the population has it, according to neurosurgeon Casey Halpern of the University of Pennsylvania.

Halpern and his colleagues decided to try deep brain stimulation, a method routinely used to curb tremors in Parkinson’s patients. It involves placing electrodes in the brain to regulate aberrant signals. The wires connected to the electrodes are positioned under the scalp, where they are invisible. For the treatment of binge eating, the device only stimulates neurons when it detects a signal to initiate an episode of binge eating.

Funded by the US National Institutes of Health (NIH) and published this year in the journal Nature Medicine, the pilot study involves two women and will expand in a few months to include four other people with binge eating who have regained weight lost after bariatric surgery. In order for the treatment to be approved by the Food and Drug Administration (FDA), researchers will need to rigorously test the method with at least 100 people at various medical centers. Such a study would take a few years to complete.

The two women who had the device implanted a year ago will be followed up for up to three years. They were given the option of having the device removed after 12 months, but both chose to keep it because they no longer feel the overwhelming urge to binge eat.

One, Robyn Baldwin, 58, of Citrus Heights, Calif., described herself as a “chubby kid” who “has always been obese.” She experimented with diets of various types — she once spent a month eating only protein shakes.

In 2003, she had bariatric surgery, which typically involves modifying the digestive system to reduce the size of the stomach and make it harder to digest food. Surgery allowed many people to lose weight when other methods had failed. But Baldwin regained the weight she had lost from the surgery.

Lena Tolly, 48, the other patient in the study, lives in Sacramento, California. She has also tried a number of diets and treatments for obesity. When she graduated from college, her parents gave her a month-long stay at a vegan center as a graduation gift, and while she was there, she walked 10 miles a day.

In August 2005, Tolly had bariatric surgery. He lost 45 kilos but regained the weight little by little. “It can’t just be a matter of willpower,” she commented.

In his case and Baldwin’s, it really wasn’t. Their binge eating isn’t what most people call binge eating — like when they start with a bag of potato chips or a pint of ice cream and then continue to eat.

Instead, their condition is described in the Diagnostic and Statistical Manual of Mental Disorders and involves binge eating episodes several times a week. These episodes are accompanied by a feeling of almost finding themselves in another state, in which they lose all control and consume large amounts of food in a short time. Embarrassed by their own behavior, many people eat in secret. It is common for them to feel disgust and shame when the episode ends.

Halpern led the pilot experiment with Baldwin and Tolly. But first, he and his colleagues experimented with obesity-prone mice. The animals had been fed, but when the scientists put butter in their cage, they devoured it, consuming more than 25% of their daily calories in an hour.

The area of ​​the animals’ brains that had been activated was the nucleus accumbens, an important focus of the brain’s reward center, located deep in the center of the brain. In mice, neurons in the nucleus accumbens became active just before an episode of binge eating. When the researchers used deep brain stimulation to calm these neurons, they were able to stop the mice from binge eating.

But would the method work with humans?

The group of scientists began posting advertisements asking for the participation of people who had regained the weight lost after bariatric surgery. They thought the weight regain could be caused by binge eating disorder.

Baldwin and Tolly responded to the ads. Neither of them was aware of having the disorder. But binge eating “is actually very common in individuals who are candidates for weight loss surgery,” said psychologist Lauren Breithaupt of Massachusetts General Hospital, who studies eating disorders.

When Baldwin and Tolly found Halpern, they both weighed more than they had before their bariatric surgeries.

The researchers recorded electrical impulses in the nuclei accumbens of the two women as they ate, determining that neurons were activated just before the binge-eating episode and that these electrical impulses correlated with the women’s feelings of loss of control. A direct brain stimulator could perhaps intercept the signals and prevent women from binge eating.

After plugging the devices into the women’s brains, the researchers told Baldwin and Tolly that they would activate the devices sometime within the next two months, but would not tell them when. The two women said they immediately noticed when the devices were triggered. Suddenly they no longer felt an uncontrollable desire to eat.

Now the weight of both is slowly dropping. The two patients said that, without actively thinking about it, they are changing their eating patterns.

“It’s not self-control,” Tolly said. “I’m just making better choices.” But she didn’t start consuming foods she never liked. “I didn’t start eating kale,” she said.

Baldwin also said he had noticed a change in his food preferences. She used to love peanut butter, which she ate by spoonfuls straight from the jar. Now, she no longer feels that desire.

“I had habits like going to the drugstore to buy medicine, but stopping in advance for ice cream,” she said. Once the device was activated, she said, “I went to the pharmacy and didn’t even think about ice cream.”

Baldwin also found that his tastes had changed. Today his favorite foods are savory, not sweet. “It’s not that I don’t think about food at all,” she said. “But I’m not a person with uncontrollable desires anymore.”

But does this mean that direct brain stimulation could be the answer for people with extreme binge eating disorder?

Breithaupt recommends caution. “It’s just two people,” he said.

Translation by Clara Allain