Spinal cord stimulation for axial low back pain: a prospective controlled trial comparing 16-contact insulated electrodes with 4-contact percutaneous electrodes.

Use of multicontact electrodes and programmable implanted pulse generators has increased the efficacy of spinal cord stimulation for pain. Some investigators find dual column electrodes advantageous for difficult-to-treat axial low back pain, but we have reported significantly improved measures with a single percutaneous midline electrode vs. dual percutaneous electrodes and even better results with an insulated, 1 × 4, midline electrode. In this study, 10 patients provided computerized, quantitative parameter measures for a temporary percutaneous 1 × 4 electrode and for a permanent insulated 2 × 8 electrode. Compared with the 2 × 8, the 1 × 4 resulted in marginally better patient-rated (109%, p = 0.06) and computer-calculated pain/paresthesia overlap (107%, p = 0.17); higher scaled amplitude to cover the low back (106%, NS); and significantly lower voltage (78%, p = 0.0004), increased extraneous coverage (141%, p = 0.0000), and improved symmetry (25%, p = 0.001). Thus, we observed no significant technical advantage for the insulated 2 × 8 in treating axial low back pain.