Department of Neurology, Medical University of South Carolina, Charleston, SC, USA.
Department of Clinical Neurophysiology, Medical University of South Carolina, Charleston, SC, USA.
Neuromodulation. 2024 Jan;27(1):160-171. doi: 10.1016/j.neurom.2023.04.468. Epub 2023 May 27.
Dorsal root ganglion stimulation (DRG-S) is a viable interventional option for intractable pain management. Although systematic data are lacking regarding the immediate neurologic complications of this procedure, intraoperative neurophysiological monitoring (IONM) can be a valuable tool to detect real-time neurologic changes and prompt intervention(s) during DRG-S performed under general anesthesia and deep sedation.
In our single-center case series, we performed multimodal IONM, including peripheral nerve somatosensory evoked potentials (pnSSEPs) and dermatomal somatosensory evoked potentials (dSSEPs), spontaneous electromyography (EMG), transcranial motor evoked potentials (MEPs), and electroencephalogram (EEG) for some trials and all permanent DRG-S lead placement per surgeon preference. Alert criteria for each IONM modality were established before data acquisition and collection. An IONM alert was used to implement an immediate repositioning of the lead to reduce any possible postoperative neurologic deficits. We reviewed the literature and summarized the current IONM modalities commonly applied during DRG-S, including somatosensory evoked potentials and EMG. Because DRG-S targets the dorsal roots, we hypothesized that including dSSEP would allow more sensitivity as a proxy for potential sensory changes under generalized anesthesia than would including standard pnSSEPs.
From our case series of 22 consecutive procedures with 45 lead placements, one case had an alert immediately after DRG-S lead positioning. In this case, dSSEP attenuation was seen, indicating changes in the S1 dermatome, which occurred despite ipsilateral pnSSEP from the posterior tibial nerve remaining at baselines. The dSSEP alert prompted the surgeon to reposition the S1 lead, resulting in immediate recovery of the dSSEP to baseline status. The rate of IONM alerts reported intraoperatively was 4.55% per procedure and 2.22% per lead (n = 1). No neurologic deficits were reported after the procedure, resulting in no postoperative neurologic complications or deficits. No other IONM changes or alerts were observed from pnSSEP, spontaneous EMG, MEPs, or EEG modalities. Reviewing the literature, we noted challenges and potential deficiencies when using current IONM modalities for DRG-S procedures.
Our case series suggests dSSEPs offer greater reliability than do pnSSEPs in quickly detecting neurologic changes, and subsequent neural injury, during DRG-S cases. We encourage future studies to focus on adding dSSEP to standard pnSSEP to provide a comprehensive, real-time neurophysiological assessment during lead placement for DRG-S. More investigation, collaboration, and evidence are required to evaluate, compare, and standardize comprehensive IONM protocols for DRG-S.
背根神经节刺激（DRG-S）是一种可行的介入性顽固性疼痛管理选择。尽管缺乏关于该手术即时神经并发症的系统数据，但术中神经生理监测（IONM）可以成为一种有价值的工具，用于在全身麻醉和深度镇静下进行 DRG-S 时实时检测神经变化并及时进行干预。
在我们的单中心病例系列中，我们进行了多模态 IONM，包括周围神经体感诱发电位（pnSSEPs）和皮节体感诱发电位（dSSEPs）、自发肌电图（EMG）、经颅运动诱发电位（MEPs）和脑电图（EEG），一些试验和所有外科医生偏好的永久性 DRG-S 导联放置都进行了 IONM。在数据采集和收集之前，为每个 IONM 模式建立了警报标准。IONM 警报用于立即重新定位导联，以减少任何可能的术后神经缺陷。我们回顾了文献，总结了目前在 DRG-S 中常用的 IONM 模式，包括体感诱发电位和肌电图。因为 DRG-S 针对背根，我们假设包括 dSSEP 将比包括标准 pnSSEPs 更能作为潜在感觉变化的替代指标，从而具有更高的敏感性。
从我们的 22 例连续手术的病例系列中，有 45 个导联放置，有 1 例在 DRG-S 导联定位后立即出现警报。在这种情况下，观察到 dSSEP 衰减，表明 S1 皮节发生变化，尽管对侧胫后神经的 pnSSEP 仍保持基线，但仍发生了这种变化。dSSEP 警报促使外科医生重新定位 S1 导联，导致 dSSEP 立即恢复到基线状态。术中报告的 IONM 警报率为每例 4.55%，每例 2.22%（n=1）。手术后没有报告任何神经功能缺陷，因此没有术后神经并发症或缺陷。在 pnSSEP、自发 EMG、MEPs 或 EEG 模式中没有观察到其他 IONM 变化或警报。回顾文献，我们注意到当前用于 DRG-S 手术的 IONM 模式存在挑战和潜在缺陷。
我们的病例系列表明，dSSEPs 比 pnSSEPs 更可靠，能够在 DRG-S 病例中快速检测神经变化和随后的神经损伤。我们鼓励未来的研究集中在将 dSSEP 添加到标准 pnSSEP 中，以在 DRG-S 导联放置期间提供全面的实时神经生理评估。需要更多的研究、合作和证据来评估、比较和标准化用于 DRG-S 的全面 IONM 方案。
