Evoked compound action potentials during spinal cord stimulation: effects of posture and pulse width on signal features and neural activation within the spinal cord.

Autor: Brucker-Hahn MK; Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, United States of America.; Biointerfaces Institute, University of Michigan, Ann Arbor, MI, United States of America., Zander HJ; Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, United States of America.; Biointerfaces Institute, University of Michigan, Ann Arbor, MI, United States of America., Will AJ; Twin Cities Pain Clinic, Edina, MN, United States of America., Vallabh JC; Ohio State Wexner Medical Center, Columbus, OH, United States of America., Wolff JS; iSpine Clinics, Maple Grove, MN, United States of America., Dinsmoor DA; Medtronic plc, Minneapolis, MN, United States of America., Lempka SF; Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, United States of America.; Biointerfaces Institute, University of Michigan, Ann Arbor, MI, United States of America.; Department of Anesthesiology, University of Michigan, Ann Arbor, MI, United States of America.
Jazyk: angličtina
Zdroj: Journal of neural engineering [J Neural Eng] 2023 Aug 11; Vol. 20 (4). Date of Electronic Publication: 2023 Aug 11.
DOI: 10.1088/1741-2552/aceca4
Abstrakt: Objective. Evoked compound action potential (ECAP) recordings have emerged as a quantitative measure of the neural response during spinal cord stimulation (SCS) to treat pain. However, utilization of ECAP recordings to optimize stimulation efficacy requires an understanding of the factors influencing these recordings and their relationship to the underlying neural activation. Approach. We acquired a library of ECAP recordings from 56 patients over a wide assortment of postures and stimulation parameters, and then processed these signals to quantify several aspects of these recordings (e.g., ECAP threshold (ET), amplitude, latency, growth rate). We compared our experimental findings against a computational model that examined the effect of variable distances between the spinal cord and the SCS electrodes. Main results. Postural shifts strongly influenced the experimental ECAP recordings, with a 65.7% lower ET and 178.5% higher growth rate when supine versus seated. The computational model exhibited similar trends, with a 71.9% lower ET and 231.5% higher growth rate for a 2.0 mm cerebrospinal fluid (CSF) layer (representing a supine posture) versus a 4.4 mm CSF layer (representing a prone posture). Furthermore, the computational model demonstrated that constant ECAP amplitudes may not equate to a constant degree of neural activation. Significance. These results demonstrate large variability across all ECAP metrics and the inability of a constant ECAP amplitude to provide constant neural activation. These results are critical to improve the delivery, efficacy, and robustness of clinical SCS technologies utilizing these ECAP recordings to provide closed-loop stimulation.
(Creative Commons Attribution license.)
Databáze: MEDLINE