401. One Hertz rTMS of left temporoparietal cortex in schizophrenic patients reporting auditory hallucinations

Abstract

Studies suggest that auditory hallucinations (AHs) of spoken speech arise partly from brain regions responsible for speech processing. One Hz repetitive transcranial magnetic stimulation (rTMS) of ∼15 minutes duration has been shown to reduce cortical activation. We will present two studies testing the hypothesis that 1 Hz rTMS delivered to left temporoparietal cortex, a brain region critical for speech processing, reduces AHs. The first study used once daily rTMS at 80% motor threshold for 4–16 minutes duration built up over four days. Twelve schizophrenic patients with medication-resistant AHs were randomized to active versus sham stimulation and studied using a double-blind, cross-over design. Significant improvements in AHs were detected following 12 minutes (p < .02) and 16 minutes (p < .0001) of active rTMS but not following sham stimulation. Endpoint hallucination severity following the active stimulation trial was significantly less than hallucination severity following sham stimulation trial (p < .006). Duration of symptomatic improvement ranged from 1 day to 2 months. Results of a second, double-blind trial of rTMS utilizing seven instances of rTMS at 16 minutes duration will also be presented. Data from our first nine patients suggest that this more extended trial produces robust and sustained reductions in AHs in ∼70% of patients. Our findings emphasize the role of posterior, speech processing areas of the brain in the generation of AHs. One Hz rTMS deserves further study as a possible treatment for hallucinations and other psychotic symptoms.