Increases in frontstriatal connectivity are associated with response to dorosmedial prefrontal repetitive transcranial magnetic stimulation in refractory binge/purge behaviors

abstract Article history:Received 31 March 2015Received in revised form 25 June 2015Accepted 28 June 2015Available online 2 July 2015 Background: Conventional treatments for eating disorders are associated with poor response rates and frequentrelapse. Novel treatments are needed, in combination with markers to characterize and predict treatmentresponse. Here, resting-state functional magnetic resonance imaging (rs-fMRI) was used to identify predictorsand correlates of response to repetitive transcranial magnetic stimulation (rTMS) of the dorsomedial prefrontalcortex (dmPFC) at 10 Hz for eating disorders with refractory binge/purge symptomatology.Methods: 28 subjects with anorexia nervosa, binge−purge subtype or bulimia nervosa underwent 20–30sessions of 10 Hz dmPFC rTMS. rs-fMRI data were collected before and after rTMS. Subjects were stratified intoresponderandnonrespondergroupsusingacriterionof≥50%reductioninweeklybinge/purgefrequency.Neuralpredictors and correlates of response were identified using seed-based functional connectivity (FC), using thedmPFC and adjacent dorsal anterior cingulate cortex (dACC) as regions of interest.Results: 16 of 28 subjects met response criteria. Treatment responders had lower baseline FC from dmPFC tolateralorbitofrontal cortex and right posterior insula,and from dACCtoright posterior insula and hippocampus.Responders had low baseline FC from the dACC to the ventral striatum and anterior insula; this connectivity in-creased over treatment. However, in nonresponders, frontostriatal FC was high at baseline, and dmPFC-rTMSsuppressed FC in association with symptomatic worsening.Conclusions: Enhanced frontostriatal connectivity was associated with responders to dmPFC-rTMS for binge/purgebehavior.rTMScausedparadoxicalsuppressionoffrontostriatalconnectivityinnonresponders.rs-fMRIcouldprovecritical for optimizing stimulation parameters in a fut ure sham-controlled trial of rTMS in disordered eating.© 2015 The Authors. Published by Elsevier Inc. This is an open access article under the CC BY-NC-ND license(http://creativecommons.org/licenses/by-nc-nd/4.0/).