A double-blind sham-controlled trial of repetitive transcranial magnetic stimulation in the treatment of refractory auditory hallucinations.

BACKGROUND: Previous research suggests that repetitive transcranial magnetic stimulation (rTMS) applied to the temporoparietal cortex may have therapeutic benefits for patients with schizophrenia and treatment-resistant auditory hallucinations. We aimed to test this hypothesis in a randomized double-blind trial. METHODS: Thirty-three patients with treatment-resistant auditory hallucinations entered a randomized sham-controlled, double-blind trial. rTMS was applied for 10 consecutive weekdays, for 15 minutes at 1 Hz and 90% of the resting motor threshold. We assessed clinical symptoms and cognitive function. RESULTS: rTMS was safe with no adverse effects on memory and cognitive parameters assessed. Active treatment did not result in a greater therapeutic effect than sham on any measure except for the loudness of hallucinations where there was a significant reduction in the active versus the sham group over time. CONCLUSIONS: The study does not support the effectiveness of rTMS using the stimulation parameters provided. However, it does suggest that rTMS methods may have a therapeutic role and indicates the need for further exploration of alternative and more effective stimulation methods.

Motor cortical excitability and clinical response to rTMS in depression.

BACKGROUND: The relationship between frontal lobe activity in the left and right hemispheres and the pathophysiology of depression remains unclear. In addition, it is uncertain whether levels of frontal or motor cortical excitability relate to clinical response to treatment modalities. We aimed to explore whether motor cortical excitability as assessed with single and paired pulse transcranial magnetic stimulation (TMS) could be used to predict the response to treatment with repetitive TMS (rTMS) applied to the left or right prefrontal cortex. METHODS: Motor thresholds, cortical excitability and cortical inhibition (CI) were assessed prior to a trial of rTMS in patients with treatment resistant depression. RESULTS: There was no consistent pattern of differences in hemispheric activity, although there was a relationship between the degree of psychopathology and cortical excitability (right hemisphere) and an inverse relationship between inhibitory activity and clinical response (left hemisphere). CONCLUSIONS: The study does not support a simple model of laterality in motor cortical excitability in depression. The TMS measures used in this study appear to be of limited use in the prediction of clinical response to rTMS.