Insula H-coil deep transcranial magnetic stimulation in severe and enduring anorexia nervosa (SE-AN): a pilot study

INTRODUCTION: Anorexia nervosa (AN) is a complex disorder of unknown etiology, characterized by obsessions and compulsions around body shape, weight, and calorie intake. In the course of AN, 10%–30% will recover, while the rest will develop a treatment-resistant course with a high mortality rate due to AN-related complications. The insula is a region in the brain of considerable interest to its role in gustatory modulation, feeding behavior, and processing of interoceptive stimuli. OBJECTIVE: Recent advances in the neurophysiology of AN suggest insula dysfunction as a potential biomarker for people with severe and enduring AN (SE-AN). Deep transcranial magnetic stimulation (dTMS) is of particular interest in SE-AN because of its ability to target deep areas of the brain. DESIGN: We conducted a pilot study to investigate the feasibility and safety of insula dTMS in subjects with SE-AN. RESULTS: We found that dTMS is a safe and well-tolerated treatment. We also found a reduction in AN-related obsessions and compulsions, as well as depression and anxiety scores from baseline to the end of the trial. Due to small sample size, the results of this study should be interpreted with great caution. DISCUSSION: The results suggest that dTMS is safe and well tolerated and may be of some clinical interest in patients with SE-AN. However, to determine the true efficacy of dTMS for SE-AN, there is a need to conduct a randomized controlled trial comparing real versus sham dTMS in a larger number of AN subjects.