Posts tagged eating disorders
Posts tagged eating disorders
In a world first, a team of researchers at the Krembil Neuroscience Centre and the University Health Network have shown that Deep Brain Stimulation (DBS) in patients with chronic, severe and treatment-resistant Anorexia Nervosa (anorexia) helps some patients achieve and maintain improvements in body weight, mood, and anxiety.
The results of this trial, entitled Deep Brain Stimulation of the Subcallosal Cingulate Area for Treatment-Refractory Anorexia Nervosa: A Phase I Pilot Trial, are published in the medical journal The Lancet. The study is a collaboration between lead author Dr. Nir Lipsman a neurosurgery resident at the University of Toronto and PhD student at the Krembil Neuroscience Centre; Dr. Andres Lozano, a neurosurgeon, at the Krembil Neuroscience Centre of Toronto Western Hospital and a professor and chairman of neurosurgery at the University of Toronto, whose research lab was instrumental in conducting the DBS research; and Dr. Blake Woodside, medical director of Canada’s largest eating disorders program at Toronto General Hospital and a professor of psychiatry at the University of Toronto.
The phase one safety trial investigated the procedure in six patients who would likely continue with a chronic illness and/or die a premature death because of the severity of their condition. The study’s participants had an average age of 38, and a mean duration of illness of 18 years. In addition to the anorexia, all patients, except one, also suffered from psychiatric conditions such as major depressive disorder and obsessive-compulsive disorder. At the time of the study, all patients currently, or had previously, suffered multiple medical complications related to their anorexia – altogether, the six patients had a history of close to 50 hospitalizations during their illnesses.
Study participants were treated with Deep Brain Stimulation (DBS), a neurosurgical procedure that moderates the activity of dysfunctional brain circuits. Neuroimaging has shown that there are both structural and functional differences between anorexia patients and healthy controls in brain circuits which regulate mood, anxiety, reward and body-perception.
Patients were awake when they underwent the procedure which implanted electrodes into a specific part of the brain involved with emotion, and found to be highly important in disorders such as depression. During the procedure, each electrode contact was stimulated to look for patient response of changes in mood, anxiety or adverse effects. Once implanted, the electrodes were connected to an implanted pulse generator below the right clavicle, much like a heart pacemaker.
Testing of patients was repeated at one, three, and six-month intervals after activation of the pulse generator device. After a nine-month period following surgery, the team observed that three of the six patients had achieved weight gain which was defined as a body-mass index (BMI) significantly greater than ever experienced by the patients. For these patients, this was the longest period of sustained weight gain since the onset of their illness. Furthermore, four of the six patients also experienced simultaneous changes in mood, anxiety, control over emotional responses, urges to binge and purge and other symptoms related to anorexia, such as obsessions and compulsions. As a result of these changes, two of these patients completed an inpatient eating disorders program for the first time in the course of their illness.
“We are truly ushering in a new of era of understanding of the brain and the role it can play in certain neurological disorders,” says Dr. Lozano. “By pinpointing and correcting the precise circuits in the brain associated with the symptoms of some of these conditions, we are finding additional options to treat these illnesses.”
While the treatment is still considered experimental, it is believed to work by stimulating a specific area of the brain to reverse abnormalities linked to mood, anxiety, emotional control, obsessions and compulsions all of which are common in anorexia. In some cases after surgery, patients are then able to complete previously unsuccessful treatments for the disease. The research may not only provide an additional therapy option for these patients in the future, but also furthers practitioners’ understanding of anorexia and the factors that cause it to be persistent.
“There is an urgent need for additional therapies to help those suffering from severe anorexia,” says Dr. Woodside. “Eating disorders have the highest death rate of any mental illness and more and more women are dying from anorexia. Any treatment that could potentially change the natural course of this illness is not just offering hope but saving the lives for those that suffer from the extreme form of this condition.”
A leading international expert in the field of DBS research, Dr. Lozano has been exploring the potential of DBS to treat a variety of conditions. Most recently, his team began the first ever DBS trial of patients with early Alzheimer’s disease, and showed that stimulation may help improve memory. This trial has now entered its second phase and expanded to medical centres in the United States.
A new study published in Social Cognitive and Affective Neuroscience by researchers at the Center for BrainHealth at UT Dallas and UT Southwestern found brain-based differences in how women with and without anorexia perceive themselves. The findings shed light on how brain pathways function in ill and fully recovered individuals who have had anorexia nervosa.
ScienceDaily (June 25, 2012) — Deep brain stimulation reduces binge eating in mice, suggesting that this surgery, which is approved for treatment of certain neurologic and psychiatric disorders, may also be an effective therapy for obesity. Presentation of the results took place June 25 at The Endocrine Society’s 94th Annual Meeting in Houston.
“Doing brain surgery for obesity treatment is a controversial idea,” said the study’s presenting author, Casey Halpern, MD, a fifth-year neurosurgery resident physician at the University of Pennsylvania, Philadelphia. “However, binge eating is a common feature of obese patients that frequently is associated with suboptimal treatment outcomes.”
Currently the U.S. Food and Drug Administration has approved deep brain stimulation for use in various conditions that affect the brain, including Parkinson’s disease and essential tremor. The procedure does not destroy any part of the brain and typically does not cause pain, Halpern said.
Available treatments of obesity may inadequately address the neural basis of this compulsive overeating behavior, he suggested. A region of the brain called the nucleus accumbens is known to be dysregulated in both rodents and people who binge eat. Therefore, Halpern and his co-workers targeted that brain region with deep brain stimulation in a strain of obesity-prone mice.
The surgery involved implanting an electrode in the nucleus accumbens. Wires connected the electrode to an external neurostimulator, a device similar to a pacemaker. When switched on, the stimulator triggers the electrode to deliver continuous electrical pulses to the brain.
After recovery from surgery, the mice received high-fat food at the same time every day for one hour, and the researchers measured their food consumption. Binge eating was defined as consuming 25 percent or more of the usual daily caloric intake during this period.
For one week, mice consistently binged, eating almost half of their daily calories during this one hour, the authors reported. Then on alternating days, the investigators turned on the stimulator. On the days that deep brain stimulation was administered, or “on,” the scientists observed a significant (approximately 60 percent) decrease in consumption of the high-fat diet. On the alternate days when they turned off the stimulator, binge eating returned, Halpern said.
The researchers then studied how deep brain stimulation might work to improve binge eating. With medications, they blocked various receptors of dopamine neurons, or nerve cells. Dopamine is a brain neurotransmitter, a chemical messenger, whose release in the brain is linked to the desire for rewarding behaviors such as eating high-fat food, according to Halpern.
Only one of the medications had an effect. Raclopride, which blocks the type 2 dopamine receptor, weakened the beneficial effect of deep brain stimulation by 50 percent.
Their results, Halpern said, showed that “at least one way that deep brain stimulation functions to suppress binge eating might be by modulating activity of neurons expressing the type 2 dopamine receptor.”
Source: Science Daily
ScienceDaily (June 21, 2012) — Eating disorders are commonly seen as an issue faced by teenagers and young women, but a new study reveals that age is no barrier to disordered eating. In women aged 50 and over, 3.5% report binge eating, nearly 8% report purging, and more than 70% are trying to lose weight. The study published in the International Journal of Eating Disorders revealed that 62% of women claimed that their weight or shape negatively impacted on their life.
The researchers, led by Dr Cynthia Bulik, Director of the University of North Carolina Eating Disorders Program, reached 1,849 women from across the USA participating in the Gender and Body Image Study (GABI) with a survey titled, ‘Body Image in Women 50 and Over — Tell Us What You Think and Feel.’
“We know very little about how women aged 50 and above feel about their bodies,” said Bulik. “An unfortunate assumption is that they ‘grow out of’ body dissatisfaction and eating disorders, but no one has really bothered to ask. Since most research focuses on younger women, our goal was to capture the concerns of women in this age range to inform future research and service planning.”
The average age of the participants was 59, while 92% were white. More than a quarter, 27%, were obese, 29% were overweight, 42% were normal weight and 2% were underweight.
Results revealed that eating disorder symptoms were common. About 8% of women reported purging in the last five years and 3.5% reported binge eating in the last month. These behaviors were most prevalent in women in their early 50s, but also occurred in women over 75.
When it came to weight issues, 36% of the women reported spending at least half their time in the last five years dieting, 41% checked their body daily and 40% weighed themselves a couple of times a week or more.
62% of women claimed that their weight or shape negatively impacted their life, 79% said that it affected their self-perception and 64% said that they thought about it daily.
The women reported resorting to a variety of unhealthy methods to change their body, including diet pills (7.5%), excessive exercise (7%), diuretics (2.5%), laxatives (2%) and vomiting (1%).
Two-thirds, 66%, were unhappy with their overall appearance and this was highest when it came to their stomach, 84%, and shape, 73%.
“The bottom line is that eating disorders and weight and shape concerns don’t discriminate on the basis of age,” concluded Bulik. “Healthcare providers should remain alert for eating disorder symptoms and weight and shape concerns that may adversely influence women’s physical and psychological wellbeing as they mature.”
Source: Science Daily
April 3, 2012
The brains of people with anorexia and obesity are wired differently, according to new research. Neuroscientists for the first time have found that how our brains respond to food differs across a spectrum of eating behaviors – from extreme overeating to food deprivation. This study is one of several new approaches to help better understand and ultimately treat eating disorders and obesity.
Eating disorders have the highest mortality rate of any mental illness. And more than two-thirds of the U.S. population are overweight or obese – a health factor associated with cardiovascular issues, diabetes, and cancer. “This body of work not only increases our understanding of the relationship between food and brain function but can also inform weight loss programs,” says Laura Martin of Hoglund Brain Imaging Center at the University of Kansas Medical Center, one of several researchers whose work being presented today at a meeting of cognitive neuroscientists in Chicago.
“One of the most intriguing aspects of these studies of the brain on food,” Martin says, is that they show “consistent activations of reward areas of the brain that are also implicated in studies of addiction.” However, how those reward areas respond to food differs between people depending on their eating behaviors, according to the new brain imaging study by Laura Holsen of Harvard Medical School and Brigham and Women’s Hospital and colleagues.
Holsen’s team conducted fMRI brain scans of individuals with one of three eating conditions – anorexia nervosa, simple obesity, and Prader-Willi syndrome (extreme obesity) – as well as healthy control subjects. When hungry, those with anorexia, who severely restrict their food intake, showed substantially decreased responses to various pictures of food in regions of their brains associated with reward and pleasure. For those who chronically overeat, there were significantly increased responses in those same brain regions.
“Our findings provide evidence of an overall continuum relating food intake behavior and weight outcomes to food reward circuitry activity,” Holsen says. Her work also has implications, she says, for everyday eating decisions in healthy individuals. “Even in individuals who do not have eating disorders, there are areas of the brain that assist in evaluating the reward value of different foods, which in turn plays a role in the decisions we make about which foods to eat.”
Kyle Simmons of the Laureate Institute studies the neural mechanisms that govern such everyday eating decisions. His work with fMRI scans has found that as soon as people see food, their brains automatically gather information about how they think it will taste and how that will make them feel. The brain scans showed an apparent overlap in the region on the insula that responds to seeing food pictures and the region of the insula that processes taste, the “primary gustatory cortex.”
Simmons is currently expanding this work to better understand the differences in taste preferences between lean, healthy individuals and obese ones. “We simply don’t know yet if differences exist between lean and obese participants,” he says. “And knowing which brain regions underlie inferences about food taste and reward is critical if we are going to develop efficacious interventions for obesity and certain eating disorders, both of which are associated with enormous personal and public health costs.”
Provided by Cognitive Neuroscience Society