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.