Verma Nishant, Romanauski Ben, Lam Danny, Lujan Luis, Blanz Stephan, Ludwig Kip, Lempka Scott, Shoffstall Andrew, Knudson Bruce, Nishiyama Yuichiro, Hao Jian, Park Hyun-Joo, Ross Erika, Lavrov Igor, Zhang Mingming
Abbott Neuromodulation, 6901 Preston Rd, Plano, TX, 75024, USA.
Department of Biomedical Engineering, University of Wisconsin Madison, Madison, USA.
Bioelectron Med. 2023 Feb 28;9(1):5. doi: 10.1186/s42234-023-00106-5.
Epidural electrical stimulation (EES) of the spinal cord has been FDA approved and used therapeutically for decades. However, there is still not a clear understanding of the local neural substrates and consequently the mechanism of action responsible for the therapeutic effects.
Epidural spinal recordings (ESR) are collected from the electrodes placed in the epidural space. ESR contains multi-modality signal components such as the evoked neural response (due to tonic or BurstDR™ waveforms), evoked muscle response, stimulation artifact, and cardiac response. The tonic stimulation evoked compound action potential (ECAP) is one of the components in ESR and has been proposed recently to measure the accumulative local potentials from large populations of neuronal fibers during EES.
Here, we first review and investigate the referencing strategies, as they apply to ECAP component in ESR in the domestic swine animal model. We then examine how ECAP component can be used to sense lead migration, an adverse outcome following lead placement that can reduce therapeutic efficacy. Lastly, we show and isolate concurrent activation of local back and leg muscles during EES, demonstrating that the ESR obtained from the recording contacts contain both ECAP and EMG components.
These findings may further guide the implementation of recording and reference contacts in an implantable EES system and provide preliminary evidence for the utility of ECAP component in ESR to detect lead migration. We expect these results to facilitate future development of EES methodology and implementation of use of different components in ESR to improve EES therapy.
脊髓硬膜外电刺激（EES）已获得美国食品药品监督管理局（FDA）批准，并已用于治疗数十年。然而，对于局部神经基质以及由此产生治疗效果的作用机制仍未完全了解。
硬膜外脊髓记录（ESR）是从放置在硬膜外间隙的电极收集的。ESR包含多种信号成分，如诱发神经反应（由于强直或BurstDR™波形）、诱发肌肉反应、刺激伪迹和心脏反应。强直刺激诱发的复合动作电位（ECAP）是ESR中的成分之一，最近有人提出用它来测量EES期间大量神经纤维的累积局部电位。
在此，我们首先回顾并研究了参考策略，因为它们适用于家猪动物模型中ESR中的ECAP成分。然后，我们研究了ECAP成分如何用于检测电极移位，电极移位是电极植入后的一种不良后果，会降低治疗效果。最后，我们展示并分离了EES期间局部背部和腿部肌肉的同时激活，证明从记录触点获得的ESR包含ECAP和肌电图（EMG）成分。
这些发现可能会进一步指导可植入EES系统中记录和参考触点的实施，并为ESR中ECAP成分检测电极移位的实用性提供初步证据。我们期望这些结果能促进EES方法的未来发展，以及在ESR中使用不同成分来改善EES治疗。
