Journal: JMIR Research Protocols (May 2023)
Authors: Anne-Marie Di Passa, Melissa Dabir, Allan Fein, Saba Khoshroo, Carly McIntyre-Wood, Emma Marsden, Emily MacKillop, Jane De Jesus, James MacKillop, Dante Duarte
Transcranial magnetic stimulation (TMS) stands as a widely utilized noninvasive technique for brain stimulation in the context of psychiatric and cognitive disorders. In recent times, deep TMS (dTMS) has emerged as an advanced form of TMS capable of reaching deeper brain structures and targeting broader networks. Distinct magnetic Hesed-coil (H-coil) designs, a characteristic feature of dTMS, have been employed to stimulate brain regions associated with the pathophysiology of specific psychiatric and cognitive disorders, thereby yielding therapeutic effects. Due to the relative novelty of dTMS in psychiatry, there is limited understanding of its clinical efficacy across various psychiatric and cognitive disorders—specifically, whether dTMS exhibits superior performance compared to sham or control interventions.
This paper delineates a protocol for a systematic review investigating the clinical efficacy of dTMS. The primary objective is to systematically review the literature on dTMS for psychiatric and cognitive disorders and, if feasible, conduct a meta-analysis to compare the efficacy of active dTMS versus sham/control for psychiatric disorders. Additionally, the review will encompass dementia and related cognitive disorders. A secondary objective involves examining subgroup differences (by age, sex, H-coil design, and dTMS parameters [e.g., pulses per session, percentage of motor threshold]) to assess whether dTMS differentially influences clinical outcomes based on these factors.
A thorough search of the APA PsycINFO, Embase, MEDLINE, and PubMed databases will be executed using keywords such as “H-coil” and “dTMS.” Two authors (AD and MD) will be responsible for screening relevant articles, assessing article eligibility based on predetermined inclusion and exclusion criteria, and extracting data. All included articles will undergo a quality and risk of bias assessment. A qualitative summary of data from included articles will be presented in the systematic review. If a sufficient number of comparable studies are available, a meta-analysis will be conducted to (1) determine the effect of active versus sham dTMS (or another control arm) across psychiatric and cognitive disorders, and (2) explore subgroup effects on clinical outcomes.
The preliminary search yielded a total of 1134 articles from APA PsycINFO, Embase, and MEDLINE databases. After full-text screening, 21 eligible articles remained, with an additional article identified from the references section of an existing systematic review. In total, 22 eligible articles were included, and ongoing procedures involve data extraction and quality assessment.
This systematic review will delineate the evidence regarding the clinical efficacy of dTMS across various psychiatric and cognitive disorders. The results will offer clinicians valuable insights into both clinical (e.g., participant age, sex, psychiatric or cognitive disorder) and methodological factors (e.g., H-coil design, dTMS parameters) that may contribute to dTMS efficacy. This information may assist clinicians in making informed decisions about prescribing dTMS for specific psychiatric and cognitive disorders.
