Background: Recently, repetitive Transcranial Magnetic Stimulation (rTMS) has been introduced as an alternative treatment for auditory hallucinations in schizophrenic patients that fail to respond to antipsychotics. Until now, application of rTMS has been at low frequency, and most commonly applied to the left temporoparietal cortex. This 6-month follow-up pilot study was performed to demonstrate the efficacy of high frequency rTMS guided by anatomical and functional Magnetic Resonance Imaging (MRI).
Methods: Eleven patients with schizophrenia (DSM-IV) were treated with high frequency (20 Hz) rTMS delivered over 2 days; they were then followed for 6 months. The target area was identified by fMRI as the highest activation cluster along the posterior part of the left superior temporal sulcus from the BOLD signal of each subject during a language task.
Results: A significant reduction in global severity and frequency of auditory hallucinations between baseline and post-treatment day 12 was observed. Auditory hallucinations were entirely relieved at 6-month follow-up in 2 patients. The treatment was well tolerated in all patients.
Conclusions: This is the first study reporting successful treatment of auditory hallucinations with 20 Hz rTMS. The efficacy at short term, the strength of the clinical response, the persistence of therapeutic effect over a 6-month follow-up, the safety profile, and the short duration of treatment present a considerable therapeutic gain compared to low frequency rTMS.