Repetitive Transcranial Magnetic Stimulation

Reviewed by Elizabeth Wassenaar, MD

Dalton, B., Bartholdy, S., McClelland, J., Kekic, M., Rennalls, S. J., Werthmann, J., . . . Schmidt, U. (2018). Randomised controlled feasibility trial of real versus sham repetitive transcranial magnetic stimulation treatment in adults with severe and enduring anorexia nervosa: the TIARA study. BMJ Open, 8(7), e021531.

https://doi.org/10.1136/bmjopen-2018-021531

Transcranial magnetic stimulation (TMS) is a relatively new non-invasive neuromodulatory treatment for severe mental illness.  Initially approved for treatment-resistant depression, TMS is now being evaluated for efficacy in other mental illness, including OCD and Autism Spectrum Disorder. Repetitive TMS (rTMS) acts by delivering magnetic pulses to specific areas of the brain and has been shown to potentially change cortical activity and increase neuroplasticity.  In severe, enduring anorexia nervosa (SE-AN) effective treatment interventions have been limited.  rTMS is being evaluated as a viable treatment option for these most severely ill patients. As a treatment, it is promising because it does not require compliance with daily medication, it is a time-limited intervention, and it is not contingent on weight restoration for efficacy.

In this study, patients with AN-SE, defined here as having AN for greater than three years, having fully completed one previous treatment course, were recruited for a one-month treatment course. Patients had to be relatively medically stable, without a history of seizures, and with a BMI >14.  This study compared daily treatments of active treatment targeted to the dorsolateral prefrontal cortex (DLPFC) to sham treatment. The DLPFC was targeted because it has been noted that hypoactivity in the region is associated with rigidity and poor reward response.

The initial results from this study were promising.  No patients withdrew from the study due to side effects of TMS and the primary difficult with intervention was necessity of daily visits to receive the treatment.  Although AN-SE was defined as have the disease for greater than three years, the patient population that participated were patients in their late 20’s-early 30’s with an approximately 14-year duration of disease and with BMI around 16.

At four-month follow up, positive changes in mood, obsessive compulsive symptoms and quality of life scores were noted. Although there were only small changes in eating disorder targets or BMI, both measures also favored rTMS intervention.

Why is This Important?

At this time, TMS is usually considered an intervention after other interventions, pharmacologic and therapeutic, have failed.  However, perhaps the future holds a time when non-invasive neuromodulatory interventions can prepare the mind for the psychological and medical treatments that effect lasting change in severe eating disorders.