Alexander R. Kent

Longer Delay From Chronic Pain to Spinal Cord Stimulation Results in Higher Healthcare Resource Utilization.

A shorter delay time from chronic pain diagnosis to spinal cord stimulation (SCS) implantation may make it more likely to achieve lasting therapeutic efficacy with SCS. The objective of this analysis was to determine the impact of pain‐to‐SCS time on patients’ post‐implant healthcare resource utilization (HCRU).

Proceedings of the second annual deep brain stimulation think tank: What's in the pipeline

The proceedings of the 2nd Annual Deep Brain Stimulation Think Tank summarize the most contemporary clinical, electrophysiological, and computational work on DBS for the treatment of neurological and neuropsychiatric disease and represent the insights of a unique multidisciplinary ensemble of expert neurologists, neurosurgeons, neuropsychologists, psychiatrists, scientists, engineers and members of industry. Presentations and discussions covered a broad range of topics, including advocacy for DBS, improving clinical outcomes, innovations in computational models of DBS, understanding of the neurophysiology of Parkinsons disease (PD) and Tourette syndrome (TS) and evolving sensor and device technologies.

Mechanisms of Dorsal Root Ganglion Stimulation in Pain Suppression: A Computational Modeling Analysis: MECHANISMS OF DRG STIMULATION

The mechanisms of dorsal root ganglion (DRG) stimulation for chronic pain remain unclear. The objective of this work was to explore the neurophysiological effects of DRG stimulation using computational modeling.

Burst Spinal Cord Stimulation: Review of Preclinical Studies and Comments on Clinical Outcomes: REVIEW OF BURST SPINAL CORD STIMULATION

Burst spinal cord stimulation (SCS) technology uses a novel waveform that consists of closely packed high‐frequency electrical impulses followed by a quiescent period. Within the growing field of neuromodulation, burst stimulation is unique in that it mimics the natural burst firing of the nervous system, in particular the thalamo‐cingulate rhythmicity, resulting in modulation of the affective and attentional components of pain processing (e.g., medial thalamic pathways).

Computational modeling analysis of a spinal cord stimulation paddle lead reveals broad, gapless dermatomal coverage.

Spinal cord stimulation (SCS) is an effective therapy for treating chronic pain. The St. Jude Medical PENTATM paddle lead features a 4×5 contact array for achieving broad, selective coverage of dorsal column (DC) fibers. The objective of this work was to evaluate DC activation regions that correspond to dermatomal coverage with use of the PENTA lead in conjunction with a lateral sweep programming algorithm. We used a two-stage computational model, including a finite element method model of field potentials in the spinal cord during stimulation, coupled to a biophysical cable model of mammalian, myelinated nerve fibers to determine fiber activation within the DC. We found that across contact configurations used clinically in the sweep algorithm, the activation region shifted smoothly between left and right DC, and could achieve gapless medio-lateral coverage in dermatomal fiber tract zones. Increasing stimulation amplitude between the DC threshold and discomfort threshold led to a greater area of activation and number of dermatomal zones covered on the left and/or right DC, including L1-2 zones corresponding to dermatomes of the lower back. This work demonstrates that the flexibility in contact selection offered by the PENTA lead may enable patient-specific tailoring of SCS.

Impact of ventricular tachycardia ablation on health care utilization

BACKGROUND Catheter ablation of ventricular tachycardia (VT) has been shown to reduce the number of recurrent shocks in patients with an implantable cardioverter-defibrillator (ICD). However, how VT ablation affects postprocedural medical and pharmaceutical usage remains unclear. OBJECTIVE The purpose of this study was to investigate changes in health care resource utilization (HCRU) after VT ablation. METHODS This large-scale, real-world, retrospective study used the MarketScan databases to identify patients in the United States with an ICD or cardiac resynchronization therapy-defibrillator (CRT-D) undergoing VT ablation. We calculated cumulative medical and pharmaceutical expenditures, office visits, hospitalizations, and emergency room (ER) visits in the 1-year periods before and after ablation. RESULTS A total of 523 patients met the study inclusion criteria. After VT ablation, median annual cardiac rhythm-related medical expenditures decreased by

Fundamentals and Mechanisms of Dorsal Root Ganglion Stimulation

5,408. Moreover, the percentage of patients with at least 1 cardiac rhythm-related hospitalization and ER visit decreased from 53% and 41% before ablation to 28% and 26% after ablation, respectively. Similar changes were observed in the number of all-cause hospitalizations and ER visits, but there were no significant changes in all-cause medical expenditures. During the year before VT ablation, there was an increasing rate of health care resource utilization, followed by drastic slowing after ablation. CONCLUSION This retrospective study demonstrated that catheter ablation seems to reduce hospitalization and overall health care utilization in VT patients with an ICD or CRT-D in place.

A Review of Spinal and Peripheral Neuromodulation and Neuroinflammation: Lessons Learned Thus Far and Future Prospects of Biotype Development: Neuromodulation and Neuroimmune Communication

Abstract The dorsal root ganglion (DRG) is a unique neural structure in the nervous system as it not only houses the somata of the primary sensory neurons (PSNs) but also is critically important in the development and maintenance of chronic pain. Recent technological advances have made it possible to effectively deliver neuromodulation therapy to this structure for the treatment of chronic pain. Specific neuroanatomic and physiologic aspects to the somatic nervous system and the DRG provide insight as to why this therapy can be so particularly advantageous for certain chronic pain conditions. Multiple mechanisms of action have been studied and include direct effects of the electrical field on PSNs in the ganglia, as well as indirect effects on upstream and downstream neural elements within the neuraxis. Both a systems and cellular approach are taken to understand this therapy and what potential advantages it may provide chronic pain patients.

Modeling dermatome selectivity of single-and multiple-current source spinal cord stimulation systems.

There is increasing literature evidence both clinically and experimentally on the existence of potent, adaptive interactions between the central and peripheral aspects of the neuroimmune system in the genesis and maintenance of chronic neuropathic extremity pain and nociceptive back pain. The neuroinflammatory pathways are modulated by the interaction of pro‐ and anti‐inflammatory cytokines and chemokines, which are released by peripheral immune system‐derived cell species (macrophages and leukocytes). This review examines the possible impact of spinal and peripheral neurostimulation on the inflammatory response in the context of acute and chronic pain pathologies of different origin.

SYSTEMS AND METHODS FOR RECORDING EVOKED RESPONSES FROM NEUROSTIMULATION

A recently published computational modeling study of spinal cord stimulation (SCS) predicted that a multiple current source (MCS) system could generate a greater number of central points of stimulation in the dorsal column (DC) than a single current source (1CS) system. However, the clinical relevance of this finding has not been established. The objective of this work was to compare the dermatomal zone selectivity of MCS and 1CS systems. A finite element method (FEM) model was built with a representation of the spinal cord anatomy and a 2×8 paddle electrode array. Using a contact configuration with two aligned tripoles, the FEM model was used to solve for DC field potentials across incremental changes in current between the two cathodes, modeling the MCS and 1CS systems. The activation regions within the DC were determined by coupling the FEM output to a biophysical nerve fiber model, and coverage was mapped to dermatomal zones. Results showed marginal differences in activated dermatomal zones between 1CS and MCS systems. This indicates that a MCS system may not provide incremental therapeutic benefit as suggested in prior analysis.