Spinal cord stimulation in chronic pain: evidence and theory for mechanisms of action

Abstract

Well-established in the field of bioelectronic medicine, Spinal Cord Stimulation (SCS) offers an implantable, nonpharmacologic treatment for patients with intractable chronic pain conditions. Chronic pain is a widely heterogenous syndrome with regard to both pathophysiology and the resultant phenotype. Despite advances in our understanding of SCS-mediated antinociception, there still exists limited evidence clarifying the pathways recruited when patterned electric pulses are applied to the epidural space. The rapid clinical implementation of novel SCS methods including burst, high frequency and dorsal root ganglion SCS has provided the clinician with multiple options to treat refractory chronic pain. While compelling evidence for safety and efficacy exists in support of these novel paradigms, our understanding of their mechanisms of action (MOA) dramatically lags behind clinical data. In this review, we reconstruct the available basic science and clinical literature that offers support for mechanisms of both paresthesia spinal cord stimulation (P-SCS) and paresthesia-free spinal cord stimulation (PF-SCS). While P-SCS has been heavily examined since its inception, PF-SCS paradigms have recently been clinically approved with the support of limited preclinical research. Thus, wide knowledge gaps exist between their clinical efficacy and MOA. To close this gap, many rich investigative avenues for both P-SCS and PF-SCS are underway, which will further open the door for paradigm optimization, adjunctive therapies and new indications for SCS. As our understanding of these mechanisms evolves, clinicians will be empowered with the possibility of improving patient care using SCS to selectively target specific pathophysiological processes in chronic pain.

Spinal cord stimulation in Parkinson’s disease: a review of the preclinical and clinical data and future prospects

“…Another emerging electrical system that may disrupt the pathological neuronal oscillations in the basal ganglia in patients with PD is spinal cord stimulation (SCS) (Fuentes et al 2009). Spinal cord stimulation of the dorsal columns within the epidural space is an emerging bioelectronic technology that has been extensively studied in multiple painful conditions (Caylor et al 2019). More recently, SCS has been shown to improve locomotor symptoms in both animal models and human subjects with PD (Hassan et al 2013;Santana et al 2014).…”

A Regions of Interest Voxel‐Based Morphometry Study of the Human Brain During High‐Frequency Spinal Cord Stimulation in Patients With Failed Back Surgery Syndrome

“…However, there is a relative absence of literature evaluating the supraspinal mechanisms of HF-10 SCS. 36 Evaluation of the supraspinal effects of SCS by neuroimaging might include measuring functional The last row presents the summary statistics with the median value and corresponding quartiles for all patients or the absolute number and percentages in cases of categorical data.…”

“…Summarizing, converging lines of evidence support the direct effect of HF‐10 SCS on local dorsal structures in the spinal cord. However, there is a relative absence of literature evaluating the supraspinal mechanisms of HF‐10 SCS 36 …”

Neuromodulatory hacking: a review of the technology and security risks of spinal cord stimulation

“…This form of SCS therapy is offered by Abbott Laboratories (Chicago, IL, USA), Boston Scientific (Marlborough, MA, USA), and Medtronic (Minneapolis, MN, USA). The recently developed high-frequency therapy is paresthesia-free, but its mechanism of action has not been elucidated [6]. It incorporates impulses with high frequency (10,000 Hz), low amplitude (1-5 mA), and short pulse width (30 μs).…”