Neuromodulation: Technology at the Neural Interface Received: February 16, 2021 Revised: April 15, 2021 Accepted: April 26, 2021 (onlinelibrary.wiley.com) DOI: 10.1111/ner.13461 Exploring Patient Perceptions of Noninvasive Brain Stimulation: A Systematic Review Georgia Stillianesis, BPhysio (Hons) 1,2 ; Rocco Cavaleri, BPhysio (Hons) 1,2 ; Clarice Y. Tang, PhD 1,3 ; Simon J. Summers, PhD 2,4,5 ABSTRACT Objective: To synthesize and critically appraise literature exploring patient perceptions regarding the therapeutic use of non- invasive brain stimulation. Material and Methods: A systematic search of CINHAL, PUBMED, Web of Science, and Medline was performed. Reference lists of relevant articles were also screened. Studies exploring participant perceptions regarding the therapeutic use of noninvasive brain stimulation were eligible for inclusion. Perceptions were divided into three domains: knowledge, experience, and atti- tudes. Noninvasive brain stimulation was defined as any neuromodulation technique that alters brain activity but does not require invasive methods such as surgery. No restrictions were placed upon study design or participant population. Two reviewers performed data extraction and risk of bias assessment. Data relating to methodological characteristics, participant demographics, type of noninvasive brain stimulation, and nature of perceptions (knowledge, experience, or attitudes) were extracted. Results: Four studies comprising data from 163 participants met the inclusion criteria. All studies investigated perceptions of repetitive transcranial magnetic stimulation (rTMS) in psychiatric populations. Most participants perceived rTMS to be safe and beneficial, demonstrated low-levels of fear, and were willing to recommend the intervention to others. No studies were found investigating patient perception of transcranial direct current stimulation (tDCS). Conclusion: The findings from this review suggest that rTMS is well accepted as a therapeutic treatment among psychiatric populations, providing support for its clinical utility. Future work is needed to determine if similar findings exist for other con- ditions (e.g., chronic pain) and for other therapeutic forms of brain stimulation (e.g., tDCS). Keywords: Attitude, knowledge, perceptions, transcranial direct current stimulation, transcranial magnetic stimulation Conflict of Interest: The authors reported no conflict of interest. INTRODUCTION Brain stimulation is an innovative intervention with rapidly evolving evidence supporting its effectiveness in treating chronic conditions (e.g., chronic pain, psychiatric disorders) (1–3). Brain stimulation has been employed as a treatment across a range of pathological presentations, first demonstrating efficacy in psycho- logical conditions including anxiety, obsessive compulsive disor- ders, and schizophrenia (4–6). Noninvasive forms of brain stimulation, such as repetitive transcranial magnetic stimulation (rTMS) and transcranial direct current stimulation (tDCS), represent particularly promising means by which to modulate cortical activ- ity and address underlying abnormalities (7). These treatments are pain-free, require no surgical procedure, and are relatively inex- pensive compared to invasive forms of brain stimulation, such as intracranial stimulation (8). Accordingly, noninvasive brain stimulation is currently consid- ered the gold standard therapy for pharmacologically resistant depression (9), and the success of this treatment has led to its uptake in other central nervous system disorders, including chronic pain (10), stroke (11), and Parkinson’s disease (12). For example, a recent systematic review of 30 randomized control tri- als demonstrated the effectiveness of high frequency rTMS in the treatment of chronic pain (10). The results of the review favored the use of rTMS over the primary motor cortex in reducing chronic pain when compared to sham rTMS (10). These results are consistent with systematic reviews of rTMS in specific pain disor- ders such as complex regional pain syndrome, neuropathic pain, and fibromyalgia (13–15). 1 Address correspondence to: Simon J. Summers, PhD, Brain StAR Lab, Western Sydney University, Penrith, Sydney, NSW 2560, Australia. Email: summers. simonj@gmail.com 1 School of Health Sciences, Western Sydney University, Sydney, NSW, Australia; 2 Brain Stimulation and Rehabilitation (BrainStAR) Lab, Western Sydney University, Sydney, NSW, Australia; 3 College of Science, Health and Engineering, La Trobe University, Melbourne, VIC, Australia; 4 Research School of Biology, Australian National University, Canberra, ACT, Australia; and 5 Discipline of Sport and Exercise Science, Faculty of Health, University of Canberra, Canberra, ACT, Australia Source(s) of financial support: This research did not receive any specific funding from agencies in the public, commercial, or not-for profit sectors. For more information on author guidelines, an explanation of our peer review process, and conflict of interest informed consent policies, please go to http:// www.wiley.com/WileyCDA/Section/id-301854.html Neuromodulation 2021; ••: ••–•• © 2021 International Neuromodulation Society. www.neuromodulationjournal.com