Neuronavigated Transcranial Magnetic Stimulation in Patients with Auditory Hallucinations

Abstract:
Abstract: Objective: Auditory verbal hallucinations are a common symptom of schizophrenia and possibly the result of dysfunctional language related cortical areas. Recent functional neuroimaging studies found an increase of activity in left inferior frontal (Broca) and temporal (medial and superior) areas during hallucinatory experiences (1). Transcranial magnetic stimulation (TMS) can affect neuronal cell assemblies, depending on the stimulation frequency. The fact that low frequency (< 1 Hz) stimulation decreases the level of excitability of cortical neurons suggests its therapeutic efficacy in hyperactive cortical areas. A recent study reported improvement of hallucinations intensity after 1 Hz TMS in three patients (2). Methods: We used functional magnetic resonance imaging (fMRI) activation data to detect sensory, motor and working memory language areas on a single patient basis (patients suffering from auditory verbal hallucinations) in order to chose the site of a 16 minute 1 Hz magnetic stimulation. A neuronavigational system (Surgical Tool Navigator, Zeiss) allowed to stimulate the chosen cortical area with high precision. Results: Preliminary data show a reduction of the hallucination's severity after 1 week of daily stimulation of either Broca or left auditory regions. Conclusion: Neuronavigated TMS may offer a novel tool in the treatment of hallucinations.(1) Dierks et al. Neuron 1999;22:615-21 Hoffman et al. Biolog. Psychiatry 1999;46:130-32