Adjunctive treatment of bimodal repetitive transcranial magnetic stimulation (rTMS) in pharmacologically non-responsive patients with schizophrenia: A preliminary study

Objectives: We evaluated the efficacy of bimodal repetitive transcranial magnetic stimulation (rTMS) in treating pharmacologically non-responsive patients with schizophrenia. Methods: Ten patients with DSM-IV schizophrenia, unresponsive to pharmacological treatment, underwent treatment with 15 rTMS sessions, as an adjunctive therapy, for three weeks. Each session comprised 40 trains, beginning every 30. s: 20 trains of 10. Hz rTMS to the left dorsolateral prefrontal cortex (DLPFC) with a 3-s duration and 20 trains of 1. Hz rTMS to the left temporoparietal cortex (TPC) with a 30-s duration. We assessed patients via the Positive and Negative Syndrome Scale (PANSS) and Korean Version of the Calgary Depression Scale for Schizophrenia (K-CDSS), at five time points: baseline, Days 8, 15, and 22, and 1. week after final treatment (Day 29). Patients who agreed to take neurocognitive tests underwent neurocognitive function evaluations at baseline and 1. week after final treatment. Results: At Day 29, all PANSS subscale scores in had decreased significantly compared to baseline (Z=-2.214, p=0.027, positive; Z=-2.132, p=0.033, negative; Z=-2.023, p=0.043, general pathology; Z=-2.371, p=0.018, total). Effect over time was significant for the PANSS positive and negative subscale scores and total score (χ²=13.35, p=0.010; χ²=10.27, p=0.036; and χ²=16.50, p=0.002, respectively) but not for the general pathology subscale. Among the neurocognitive tests, the fourth and fifth trials and total K-AVLT scores showed significant increases (Z=-2.041, p=0.041; Z=-2.251, p=0.024; and Z=-2.201, p=0.028, respectively), suggesting improvement in short-term auditory verbal memory. Conclusions: Bimodal rTMS stimulation of left DLPFC and left TPC induced clinical improvement in pharmacologically non-responsive schizophrenia patients and may have improved their short-term verbal memories.