Atypicals, rTMS Weighed for Resistant Anorexia Nervosa
Wendling, Patrice, Clinical Psychiatry News
FT. LAUDERDALE, FLA. - What do atypical antipsychotics, an analeptic, and targeted magnets have in common? They all might play a role in the treatment of anorexia nervosa.
"When you have a disorder that is so treatment resistant, it's like metastatic breast cancer; you have to think outside of the box for new interventions," Dr. Allan S. Kaplan said at a workshop on eating disorders at the meeting.
Current statistics indicate that 20% of patients who are diagnosed with anorexia are resistant to any intervention, and remain chronically ill and disabled. The needs of these patients have been largely neglected by the field, even though their numbers continue to grow because mortality has gradually decreased from 22% in older studies to about 8%-10% today, said Dr. Kaplan, the Loretta Anne Rogers Chair in Eating Disorders and professor of psychiatry at the University of Toronto.
In his experience, many of these patients are now in their 40s and 50s, and have been ill for 20-30 years. Most of them suffer from significant medical complications, including renal failure, cardiac arrhythmias, and osteoporosis with resulting hip fractures that have left them wheelchair bound.
"They are unbelievably disabled," he said. "They are more disabled on quality of life measurements than a comparative group of schizophrenics in the hospital. It's a sobering experience to spend time with these patients."
One novel approach that might be useful is use of repetitive transcranial magnetic stimulation (rTMS), which has been shown to be effective in some patients with depression, schizophrenia, and obsessive-compulsive disorder. Current magnets stimulate superficial cortical areas of the brain, but Dr. Kaplan suggests that a better target might be the insula - a cerebral cortex structure located deep within the lateral fissure that plays a role in interoceptive awareness and motor control.
His group has completed an unpublished meta-analysis of neuroimaging studies in anorexia that provides evidence for over activity in the insula.
The team members have subsequently contracted with an Israeli biotechnology firm to construct a patented magnet for rTMS that will specifically target the insula. They also plan to launch an open-label pilot trial of rTMS for anorexia.
The approach is not without controversy, Dr. Kaplan acknowledged. Although the seizure rate with rTMS is very low in patients with depression, patients with anorexia are at an increased risk for seizures at a rate of about 10% in general. "It's a bit of a shot in the dark, but when you have no other effective treatment, you have to do that," he said.
Atypical antipsychotics have come under increased scrutiny for anorexia, but with limited success in the few small studies and case reports to date. A recent metaanalysis of 43 publications concluded that there is not enough evidence to confirm that these medications increase weight in anorexia (Eur. …