Table 2.

Modifications to Improve Traditional SCS Low Back Coverage

Modification	Study	Pertinent Inclusion and Exclusion Criteria	Findings	Warranted Future Research
Stimulation target zone
Target region: T9–T10	Sharan et al 200226	Inclusion: previous lumbar spine surgery.	Cathode positioned at T9–T10; 6–12 months postop, most effective cathode position was at T10 and lower.	Further examination of optimal lead position.
Target region: T10–T11; modified anchoring methods	Mironer et al 200827	Inclusion: axial and/or radicular symptoms maintained after >2 years of SCS treatment.	The use of a single, percutaneous, octad lead with midline anchoring allowed for better coverage of axial and lower extremity pain.	Further examination of optimal lead selection, lead position, and parameters of stimulation.
Target region: T9–T10; non-neuronal cells in the nervous system	Ruiz-Sauri 201972	Dissection of posterior spinal cord segments from 11 human cadavers.	Glial to neuronal ratio in posterior gray matter within the T8– T11 vertebral region ranges from 11:1 to 13:1. At T9–T10, population of oligodendrocytes is significantly larger than any other segment.	Further clinical investigation of the role of glial cells in the development and maintenance of chronic pain. The ability of SCS to modulate glial cells and their relationship to pain control.
Lead design/stimulation parameters
Anode-Cathode Configuration	Holsheimer and Wesselink 199728	Computer modeling	Widest area of coverage found with bipolar or tripolar configuration on single electrode.	Further examination of optimal electrode configuration for low back coverage
Multiple electrode paddle lead	Barolat et al 200129	Inclusion: Axial symptoms ≥ radicular symptoms. Exclusion: PLPS patients excluded if leg pain >back pain.	Multiple electrode paddle lead was found to decrease leg and back pain, while improving quality of life at 6 and 12 months compared to baseline.	Randomized controlled trial with large cohort comparing the efficacy of paddle leads vs percutaneous leads.
Multiple electrodes/leads	North et al 200530	Inclusion: PLPS with back pain >leg pain.	There was no advantage in pain coverage using two 4-electrode leads vs a single 4-electrode lead.	Further examination of optimal number of leads and lead spacing.
Laminectomy vs percutaneous electrodes	North et al 200631	Inclusion: PLPS with back pain >leg pain.	2x8 paddle lead provided no benefit over a single 1x4 percutaneous lead for the treatment of axial pain and resulted in increased power requirements.	Longer-term study comparing the effectiveness of laminectomy vs percutaneous electrode with new programming and SCS system designs.
Sensor-driven position-adaptive system	Schultz et al 201236	Inclusion: axial and/or radicular symptoms; PLPS patients included.	Stimulation parameters are altered as body position changes.	Further examination of sensor-driven position-adaptive systems
Anatomically guided 3D neural targeting	Veizi et al 201732	Inclusion: PLPS with axial and/or radicular symptoms.	SCS therapy with 3D neural targeting algorithm was more effective at targeting axial symptoms than traditional SCS stimulation therapy.	Further examination of 3D neural targeting for axial low back pain with and without previous lumbar spine surgery.
ECAP controlled closed-loop system	Mekhail et al 202022	Inclusion: axial and/or radicular symptoms.	At 12 months, 83.1% of patients in the closed-loop group achieved ≥50% decrease in axial/radicular symptoms vs 61.0% in the open-loop group.	Development of methods to reduce the needed energy input to maintain the ECAP controlled system.

Note: Adapted from Provenzano DA, Rebman J, Kuhel C, Trenz H, Kilgore J. The efficacy of high-density spinal cord stimulation among trial, implant,and conversion patients: A retrospective case series.Neuromodulation. 2017;20(7):654–660. Copyright 2017, Wolters Kluwer Health, Inc.²⁵

Abbreviations: PLPS, postlaminectomy pain syndrome; SCS, spinal cord stimulation; ECAP, evoked compound action potential.