Transcranial magnetic stimulation of left temporoparietal cortex in three patients reporting hallucinated "voices"

Background: Prior studies suggest that auditory hallucinations of "voices" arise from activation of speech perception areas of the cerebral cortex. Lo w frequency transcranial magnetic stimulation (TMS) can reduce cortical act ivation. Methods: We have studied three schizophrenic patients reporting persistent auditory hallucinations to determine if low frequency TMS could curtail the se experiences. One hertz stimulation of left temporoparietal cortex was co mpared with sham stimulation using a double-blind crossover design. Results: All three patients demonstrated greater improvement in hallucinati on severity following active stimulation compared to sham stimulation. Two of the three patients reported near total cessation of hallucinations for g reater than or equal to 2 weeks. Conclusions: TMS may advance our understanding of the mechanism and treatme nt of auditory hallucinations. (C) 1999 Society of Biological Psychiatry.