Efficacy of Intensive Bilateral Temporo-Parietal Continuous Theta-Burst Stimulation for Auditory Verbal Hallucinations (TPC-SAVE) in Schizophrenia: A Randomized Sham-Controlled Trial

SOURCE: Asian Journal of Psychiatry. 74:103176, 2022 Aug.

AUTHORS: Tyagi P; Dhyani M; Khattri S; Tejan V; Tikka SK; Garg S

ABSTRACT: Transcranial magnetic stimulation (TMS) is a non-invasive tool that moderates specific brain regions to ameliorate auditory verbal hallucinations (AVH) in schizophrenia. Citing the critical involvement of temporoparietal cortex (TPC) in AVH, our study aimed to evaluate the effect of continuous theta burst stimulation (cTBS) targeting bilateral TPC in schizophrenia subjects with AVH, on a randomized rater blinded placebo control trial. 59 patients were randomly allocated to active and
sham groups. They received 20 cTBS sessions (2 per day: first right TPC, then left TPC) 5 days a week for 2 weeks. PANSS (Positive and Negative Syndrome Scale), AVHRS (Auditory vocal hallucination rating scale), PSYRAT-AH (Psychiatric symptoms rating scale- Auditory hallucinations scale), CDSS (Calgary depression scale for schizophrenia), SCoRS (Schizophrenia cognition rating scale) and CGI-S (Clinical global impression-severity) were rated at baseline, immediately post 20th session and 2 weeks post-TBS. 50 patients (25-active, 25-sham) completed the study. Conducting an intention to treat analysis, we found a significant group*time effect for PANSS, AVHRS, PSYRAT-AH, CDSS, SCoRS, CGI-S but when controlled for confounding variables and multiple comparisons, only PANSS-PS (F=26.617, p < 0.001), PANSS-TOTAL (F=23.671, p < 0.001), AVHRS (F=17.779, p < 0.001), PSYRAT-AH (F=11.385, p < 0.001) and CGI-S (F=28.462, p < 0.001) retained significance. We conclude that cTBS over
TPC is safe and has efficacy in treating AVH in schizophrenia. Limited sample size and lack of integrity assessment for blinding in the study participants are major limitations of the study.