Deep Brain Stimulation treatment shows promise for anorexia patients

Science and Weather

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Anorexia nervosa is often associated with supermodels and celebrities struggling to stay thin, but star-centred headlines downplay the seriousness of the illness. In severe cases, the body’s organs start to fail, and the condition can be fatal. A radical form of surgery is being studied by Canadian researchers as a potential treatment for chronic and acute cases of the eating disorder, and so far, results seem promising.

Affecting both men and women, anorexia has an estimated mortality rate between 10 per cent and 15 per cent, according to Psychiatric Times.

Deep Brain Stimulation (DBS) is a neurological procedure during which electrodes are implanted in the brain and an electrical signal is used to alter the region of the brain that causes unwanted symptoms. The electrodes are attached to a battery-powered stimulator, similar to a pacemaker, that’s inserted under the skin in the chest. To get those electrodes in the brain, the operation involves drilling holes on each side of the skull of the patient, who remains awake throughout the hours-long operation.

Taking place through Toronto’s University Health Network, the study into DBS is now in Phase 2, looking at safety, acceptability and efficacy of DBS in 22 patients; 20 procedures have been done so far. Dr. Blake Woodside, psychiatrist and director of inpatient eating-disorders service at Toronto General Hospital, says that although much more research into the treatment is required, the surgery is safe with few adverse effects, and most patients are experiencing positive results.

“This is still highly experimental, but…the majority of patients have a very stereotyped response to stimulation, which is within about three months they start to tell us they feel a great deal better,” says Woodside, who’s heading the study with neurosurgeons Nir Lipsman and Andres Lozano. “Most have been chronically depressed and anxious, very obsessional; some have had PTSD…and people tell us at three months that they feel better, they’re less depressed, they’re less anxious and more hopeful. They tend to tell us their ability to cope with their feelings is improved. They feel less out of control emotionally and can respond to things in their environment more reasonably.”

Symptoms of obsessive-compulsive disorder, post-traumatic stress disorder, bingeing, purging, and overexercise also tend to improve, Woodside says.

“At a year, in broad terms, we see substantial improvements with significant weight restored…and ongoing improvements in people’s depression,” he says. “They’re generally looking a lot better.”

Adverse effects to date have been minimal, Woodside says. As in any surgery there’s a risk of developing tiny air bubbles in the bloodstream; some patients have experienced panic attacks during the operation. They’re given a local anesthetic and a frame is put on their head to keep the skull immobile throughout; Woodside says although pain is minor, having your skull drilled into and the lining of your brain cut through are akin to having a tooth extracted; it’s not exactly comfortable, and you can hear and smell what’s happening. People are awake during the surgery because the neurosurgeons and psychiatrists need to be able to talk to them about their feelings, perceptions, and mood to determine exactly where the electrodes are to be placed and to adjust the level of electricity.

The stimulators run on batteries that need to be changed every two to four years.

DBS was initially developed to treat Parkinson’s disease and other movement disorders. However, it has also been used as a treatment for psychiatric conditions such as depression, OCD, and schizophrenia, and the number of trials for new uses continues to grow worldwide.

Despite early encouraging results in anorexic patients, if approved for use, DBS will never become frontline treatment.

“This is neurosurgery; it’s for people who are the sickest of the sick,” Woodside says. “It’s for cases where treatment has failed multiple times.”

Woodside emphasizes that it’s early days still of DBS to treat anorexia, and that future investigation requires significant funding. About one quarter of people who have the procedure don’t experience any benefits. However, he’s hopeful about the direction the research is taking.

“If you take somebody with a BMI [body mass index] of 14—which is really, really low—who’s chronically ill and who feels really depressed, and nothing can touch them—drugs don’t help, psychotherapy doesn’t help—this stimulation helps,” he says. “We think what’s happening is that by altering the function of some brain circuits with this really low level of electrical stimulus, it is helping people have a more normal experience in terms of their emotional life….The circuits that regulate emotional processing seem to be functioning better.

“We urgently need to invent new treatments for these people,” he adds. “The underlying theory is that by better regulating people’s experience with the world, they have a better chance of recovering from chronic illness.”