Supplementary Material for: Where Are We with Deep Brain Stimulation? A Review of Scientific Publications and Ongoing Research

Background: Deep brain stimulation (DBS) is a neuromodulatory technique that delivers adjustable electrical stimuli to brain targets to relieve symptoms associated with dysregulated neural circuitry. Over the last several decades, DBS has been applied to a number of conditions, including motor, pain, mood, and cognitive disorders. An assessment of the body of work in this field is warranted to determine where we have been, define the current state of the field, and chart a path toward the future. Objective: The aim of the study was to assess the state of DBS-related research by analyzing the DBS literature as well as active studies sponsored by the National Institutes of Health (NIH) or German Research Foundation (Deutsche Forschungsgemeinschaft [DFG]). Methods: Peer-reviewed DBS publications were extracted from PubMed. Active NIH-funded DBS projects were extracted from the RePORT database and active DFG projects from the German Research Foundation database. Records were analyzed using custom-developed algorithms to generate a detailed overview of past and present DBS-related research. Specifically, records were categorized by publication year, journal, language, country of origin, contributing authors, disorder, brain target, study design, and topic. Expected project duration and costs were also provided for active studies. Results: In total, 8,974 publications, 172 active NIH-funded projects, and 34 active DFG projects were identified. Records spanned 52 different disorders across 31 distinct brain targets and showed a recent shift toward studies examining conditions other than movement disorders. Most published works involved human research (80.6% of published studies), of which 10.2% were identified as clinical trials. Increasingly, studies focused on imaging or electrophysiological changes associated with DBS (69.8% NIH-active and 70.6% DFG-active vs. 25.8% published) or developing new stimulation techniques and adaptive technologies (37.8% NIH-active and 17.6% DFG-active vs. 6.5% published). Conclusions: This overview of past and present DBS-related studies provides insight into the status of DBS research and what we can anticipate in the future concerning new indications, improved/novel target selection and stimulation paradigms, closed-loop technology, and a better understanding of the mechanisms of action of DBS.

背景：脑深部电刺激（Deep brain stimulation, DBS）是一种神经调控技术，通过向特定脑靶点递送可调式电刺激，以缓解神经环路失调相关症状。近数十年来，DBS已被应用于多种疾病的治疗，包括运动障碍、疼痛、情绪障碍及认知障碍。有必要对该领域的现有研究成果进行系统性梳理，以明晰该领域的发展历程、明确当前研究现状，并为未来发展绘制路径。
研究目的：本研究旨在通过分析DBS相关文献，以及由美国国立卫生研究院（National Institutes of Health, NIH）或德国研究基金会（Deutsche Forschungsgemeinschaft, DFG）资助的在研项目，对DBS相关研究的现状进行评估。
研究方法：从PubMed数据库中提取经同行评议的DBS相关文献；从RePORT数据库中提取由NIH资助的在研DBS项目，从德国研究基金会数据库中提取DFG资助的在研DBS项目。研究人员采用自研算法对检索到的记录进行分析，以全面梳理DBS相关研究的历史与现状。具体而言，将记录按发表年份、刊载期刊、语言、原产国、作者、所针对的疾病、脑靶点、研究设计及研究主题进行分类，并记录在研项目的预计执行周期与经费预算。
研究结果：最终共检索到8974篇相关文献、172项NIH资助的在研项目及34项DFG资助的在研项目。这些记录涵盖了31个不同脑靶点对应的52种疾病，且研究方向近期已从运动障碍类疾病向其他疾病领域拓展。大部分已发表研究涉及人体试验（占已发表研究的80.6%），其中10.2%被归类为临床试验。越来越多的研究聚焦于DBS相关的影像学或电生理变化（NIH在研项目占比69.8%、DFG在研项目占比70.6%，而已发表研究仅为25.8%），以及新型刺激技术与自适应技术的研发（NIH在研项目占比37.8%、DFG在研项目占比17.6%，而已发表研究仅为6.5%）。
结论：本研究对DBS相关研究的历史与现状进行的系统性梳理，有助于明晰当前DBS研究的整体态势，并可展望未来在新适应证拓展、优化/新型靶点选择与刺激范式、闭环技术以及深入解析DBS作用机制等领域的发展方向。