The treatment involves implanting electrodes in the brain, which are connected to a pacemaker-like device that delivers electrical pulses to modify the activity of a specific collection of neurons.
While the study was intended to assess the safety of deep-brain stimulation in patients with severe, treatment-resistant anorexia, three of the six women have experienced improvement in mood and moved towards a healthy weight, the researchers reported Wednesday in the journal the Lancet.
The six patients, who ranged in age from 24 to 57 and had suffered with anorexia between four and 37 years, had an average body mass index of 13.5. To put that in perspective, a five-foot-five woman with a BMI of 13.5 would weigh just 65 to 70 pounds.
"These patients are severely ill, they are malnourished and they're extremely low-weight," said neurosurgeon Dr. Andres Lozano of Toronto Western Hospital, who led the surgical team and described the women as being in a "state of starvation."
"And so we didn't know whether it would be safe to operate on them. And we didn't know whether it had any possibility of working or helping them."
The women have the most severe form of the illness, a highly complex psychiatric disorder marked by severe food restriction or binging and purging, often accompanied by excessive exercising, said psychiatrist Dr. Blake Woodside, medical director of the eating disorders program at Toronto General Hospital, who was part of the research team.
"The typical person who's in this study is someone who's been ill for many years, has had many, many attempts at (standard) treatment ... and generally never had a good response to treatment or not a long-lasting response," Woodside said.
Such patients "are likely to die very young," he said, noting that one person succumbed to complications of the disease while deciding whether to have the surgery.
"We're talking about a serious medical illness, we're not talking about a 'bad habit for silly young women,'" Woodside stressed. "Anorexia nervosa has a mortality rate between 10 and 20 per cent over the duration of the illness."
To perform the surgery — during which the patient is awake —doctors drill nickel-sized holes in each side of the skull, then implant electrodes in an area of the brain involved with regulating mood and anxiety. During the procedure, doctors stimulate each electrode to look for changes in mood, anxiety or any adverse effects.
Once implanted, the electrodes are connected by spaghetti-like wires down through the neck and into the upper chest, where they are hooked up to a battery-run pulse generator, a device similar to a pacemaker.
The area of the brain targeted, known as the subcallosal cingulate, is on overdrive in patients with anorexia, and likely gives rise to the anxiety, depression and other moods disorders that are hallmarks of the eating disorder.
Lozano said electrical stimulation was able to "turn down" this region of the brain.
"But surprisingly, we also found an area of the brain that we turned up that we weren't expecting" — one involved with self-perception, or body image, he said.
"It's like a butterfly flapping its wings. You operate on one area of the brain, you change the activity of one area of the brain and that has consequences at other areas that are remote but are connected."
For the first two months following surgery, the women showed little response. In fact, they all lost weight over that period, said Lozano. Adverse effects were relatively mild, although one patient had a seizure a week after the surgery, likely related to metabolic abnormalities linked to the illness.
But nine months after the electrodes were implanted and switched on, three of the six patients had added pounds to their once-skeletal bodies, while four of the six reported changes in mood, anxiety, emotional control, calorie-restriction and obsessive-compulsive behaviours.
Two of these patients were able to complete an in-patient eating disorders program for the first time in the course of their illness.
One of them is Kim Rollins, 36, of Kitchener, Ont., who developed anorexia at about age 15 — a response, she believes, to childhood trauma.
"My self-esteem was really low. I felt pretty much alone. And I remember kind of turning to it for something that would help me feel better or feel a bit more in control of things."
When she did eat, a meal was a couple of pieces of fruit. She also exercised incessantly.
"I would do running up and down the stairs, but not just up and down a few times, like up and down for hours," said Rollins, who managed to earn two university degrees despite her illness. "I would exercise so much that I was getting up in the middle of the night — I'm talking 2, 3 a.m. — and exercise then.
"And then, of course, not eating anything, my body was just breaking down at a very fast rate."
At age 28, Rollins had a heart attack. She also had two strokes and repeatedly broke the bones in her legs and feet while exercising due to osteoporosis caused by a lack of calcium and other nutrients.
"None of that really registered with me. It was like I was on a mission almost," she said of how she dealt with her distorted self-image, another symptom of anorexia. "I used to be ashamed of having a woman's body."
Socially isolated — with "zero friends" — a tearful Rollins said she missed out on having relationships and experiencing "fun things that 'normal' people would have gone through."
Although skeptical at first that the surgery might help her, Rollins knew she would die if she didn't take the chance — and the results have been "life-changing."
Weighing just 71 pounds at her lowest point, the 5-foot-2 Rollins now tips the scale at 112 pounds.
"I feel really good about myself. I'm a healthy weight. I'm getting together with friends now. I'm doing a lot more social things. My relationship with my family has improved so much.
"I'm feeling that there's a real purpose to my life now."
Deep-brain stimulation, or DBS, represents the first potential new treatment for anorexia in more than 20 years, said Lozano. The technique is used to treat Parkinson's disease and is also being tested in patients with intractable depression, epilepsy and Alzheimer's.
Lozano said DBS appears to reduce depression, anxiety and obsessive-compulsive behaviour in those patients who responded to the treatment, which makes them better able to tackle food-related aspects of their illness.
However, the researchers stressed that its use in anorexia is experimental, and DBS would not be used as a first-line treatment in milder cases. For the foreseeable future, studies will target chronically ill patients who have given up hope that their anorexia can be overcome.
"It's a nasty, nasty illness that kills people, ruins their life if it doesn't kill them, rips families apart and causes unbelievable suffering," said Woodside.
"And this research is all about offering people hope — hope for a better life and hope for recovery."
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