Twice daily low frequency rTMS for treatment-resistant auditory hallucinations

Int J Clin Health Psychol. 2023 Jan-Apr;23(1):100344. doi: 10.1016/j.ijchp.2022.100344. Epub 2022 Oct 17.

Abstract

Background: Repetitive transcranial magnetic stimulation (rTMS) has emerged as a therapeutic solution in patients with treatment-resistant auditory verbal hallucinations. However, the optimal stimulation parameters remain unclear, especially for patients with clozapine-resistant symptoms.

Method: In an open label retrospective study, we investigated whether parameters of stimulation that were useful in patients with major depressive disorder would help schizophrenia patients with treatment-resistant auditory verbal hallucinations. Fourteen participants, including 9 under clozapine, received 30 sessions of 1 Hz rTMS over 3 weeks (360 pulses per sessions delivered with 60 s 'on' and 30 s 'off' at 110% of the resting motor threshold, 2 sessions per day). Stimulations were applied over the left temporoparietal junction (T3-P3 according to 10/20 system).

Results: After rTMS, a significant decrease of auditory verbal hallucinations was observed (-38.7% ± 31.8, p = 0.003) on the Auditory Hallucination Rating Scale. The beneficial effects were also significant in the 9 patients who were also receiving clozapine (-34.9% ± 28.4, p = 0.01).

Conclusions: Low frequency rTMS, 30 sessions over 3 weeks, appears to be a suitable approach to decrease treatment-resistant auditory verbal hallucinations, including in patients with clozapine-resistant symptoms. Results from the current retrospective study in the clinical settings need to be confirmed by large-scale randomized sham-controlled trials.

Keywords: Clozapine; Hallucination; Schizophrenia; rTMS.