by Petti Fong

For more than a quarter of a century, researchers have known that deep brain stimulation (DBS)—the delivery of tiny amounts of electricity to targeted areas of the organ—is a proven way to improve some neurological symptoms or movement disorders. The procedure involves the implantation of electrodes deep inside the brain that are connected via a wire to an implantable pulse generator.

Now, researchers in Toronto have used the circuit-based treatment on patients with the eating disorder anorexia nervosa for the first time.

In a small sample study published in the journal Lancet this month, researchers at the Krembil Neuroscience Centre and Toronto’s University Health Network have shown that DBS can help patients with chronic, severe and treatment-resistant anorexia.

During the procedure, electrodes were implanted into a part of the brain called the subcallosal cingulate gyrus, an area associated with emotion known to be important in disorders like depression. Doctors stimulated each electrode contact and noted changes in a patient’s mood, anxiety, sense of reward and body perception. They kept patients awake during the procedure and connected electrodes to a pulse generator implanted below the right clavicle. Patients spoke during the surgery when circuits in their brain were stimulated, which allowed doctors to know when the right neurons were targeted.

Kim Rollins, one of the patients in the study, said no other treatment or therapy to help her fight anorexia has worked for 20 years. At one point, her weight dropped down to 71 pounds—a metric made even more meager by her 5-foot-2-inch frame.

“My mother was planning my funeral,” Rollins recalls. Depression and her mental disorder drove her to exercise as much as three hours a day and something deep inside urged her to starve herself.

During her surgery, Rollins was able to tell doctors when the intensity of her fear lessened and when she felt happier or “brighter” with lower anxiety.

Electric medicine

With DBS, doctors attempt to pinpoint and correct precise circuits in the brain using electrical nodes. The circuitry stimulates specific areas that are neurological centers related to mood, anxiety, emotional control, obsessions and compulsions. Those tendencies are all factors in patients with anorexia.

The procedure has been used to treat depression and movement disorders like tremors and dystonia. It has also been extensively studied for treatment of Parkinson’s disease. New research is being conducted in the area on patients with Alzheimer’s disease, with the first phase of trials showing DBS may help improve their memory.

Anorexia is notoriously difficult to treat and, as Rollins’ psychiatrist Dr. Blake Woodside notes, eating disorders have the highest death rates of any mental illness. Almost half of anorexia patients are unable to complete current medical treatment and 10 percent die in the first 10 years after diagnosis.

The six women who participated in the recent Toronto study had been battling the disease for a mean duration of 18 years. Study participants were all between the ages of 20 and 60, and had been diagnosed with treatment-resistant restricting or binge-purging anorexia nervosa.

“Those who have chosen to participate have been sick for many, many years and have tried everything to try to get better,” says Woodside, medical director of Canada’s largest eating disorders program at Toronto General Hospital and one of the authors in the Lancet study. “Many have been near to death and have just given up because they believed traditional treatments were not helping them.”

Significant improvement

The implanted electrodes and the pulse generator delivered a continuous stream of electrical stimulation, which is thought to decrease the activity of dysfunctional brain circuits, weaken the compulsive urges of anorexia patients and modulate activity in other circuits.

Nine months after the nodes were implanted, half of the patients had achieved and maintained weight gain. Four of the six reported diminished anxiety, obsessions and compulsions related to anorexia and improved mood. Half also noted improvements in their quality of life.

Investigators compared participants’ PET scans performed before and after surgery. They found changes in the sufferers’ cerebral glucose metabolism, which was consistent with a reversal of the abnormalities typically seen in the brain scans of patients with the disorder.

Krembil Neuroscience Centre neurosurgeon Dr. Andres Lozano says the results show that positive changes occurred after the electrodes were implanted in the patients.

“We were able to turn down areas that were abnormal in the brain of someone who had anorexia, and this in turn alleviated some of the associated anxiety and depression,” he says. “In some of these cases, with half the patients, we were able to restore their weight.”

Top Image: Salad on a plate via Shutterstock.

P-S Fong, a graduate from Columbia University’s School of Journalism, is a science and technology writer based in Vancouver, Canada, specializing in technological changes in the resource sector.