MRI-targeted repetitive transcranial magnetic stimulation of Heschl’s gyrus for refractory auditory hallucinations

Background Repetitive transcranial magnetic stimulation (rTMS) has shown promise as a treatment for refractory auditory hallucinations (AH) in Schizophrenia. Most previous studies have examined the effect of low frequency, left-sided stimulation (LFL) (1 Hz) to the temporoparietal cortex (TPC). Priming stimulation (6 Hz) prior to LFL stimulation (hereby simply referred to as priming) has been shown to enhance the neurophysiological effects of LFL rTMS alone and, as such, may lead to greater attenuation of AH. Objective Therefore, this study evaluated the efficacy of priming rTMS and LFL rTMS compared to sham rTMS using MRI targeting of Heschl’s gyrus (HG) within the TPC of subjects with SCZ experiencing refractory auditory hallucinations (AH). Methods Subjects between the ages of 18 and 65 were recruited from a tertiary care university hospital. Fifty-four subjects with medication resistant AH were randomized to receive LFL, priming, or sham rTMS for 20 treatments. The primary outcome was reduction of hallucinatory symptoms as indexed by response rates on the Psychotic Symptoms Rating Scale (PSYRATS). Results The response rates did not differ among the three treatment groups using an intention to treat analysis. The response rates did not differ in any of the secondary outcome measures. The treatment was well tolerated with minimal adverse effects including no changes in cognition during the study. Conclusion These findings suggest that neither priming nor LFL rTMS of Heschl’s gyrus are effective at ameliorating refractory AH in schizophrenia. ClinicalTrials.gov Identifier: NCT01386918