Introduction: 10kHz Spinal Cord Stimulation (SCS) is usually applied in a bipolar configuration over the T9/T10 disc space for neuropathic back and leg pain. There is however a lack of programming information beyond using this supposed ‘sweet spot’ of T9/10. Radiological evidence suggest neuroinflammation covers a broader area of the spinal cord beyond a single disc space for chronic neuropathic back pain. Cascade is a sequential bi-polar configuration across an entire eight contact electrode lead. Potential advantages include a broader range of SCS coverage, mitigation against minor lead migration and a reduction in the need for re-programming. It can also be utilised during the trial period to identify all potential responders to the therapy.

Methods: Patients with neuropathic back pain (with or without leg pain) were implanted with an SCS lead covering T9/10. Patients were put on 10kHz SCS using cascade during the trial period and continued unless reporting inadequate pain relief. Over a 2-year period patients were followed up by telephone or outpatients at 6 months and 1 year to obtain average weekly Numerical Rating pain (NRS) and Patient Global Impression of Change (PGIC) scores. Up-to-date pain scores were obtained for patients over a year following implantation. Morbidity and deviations from cascade were also reported.

Results: There was a significant reduction in back NRS [8.3 vs 3.9 (SEM 0.285,p< 0.0001), N=97} and leg pain [7.53 vs3.83(SEM 0.364,p< 0.001),N=77] at 6 months and latest follow up (mean 15.1 months): Back [8.3 vs 3.95 (SEM 0.3181,p<0.0001),N=72], Leg [7.53 vs 3.534 (0.368,p< 0.001),N=58]. 70/97 (72%) of patients had a PGIC score of 6 or 7 at 6 months and 49/72 (68%) at latest follow-up. At 6 months 87/97(90.6%) of patients were using cascade and 58/72(81%) at latest follow-up beyond a year. Out of the patients who came off cascade, only 8.7% (2/23) reported superior pain scores when converted to multiple programming options and a single bipole program. 
 
Conclusion: Cascade is an effective programming methodology that may have benefits over a single bipole configuration for 10kHz SCS. This is the first ever programmability research on 10kHz SCS using a sequential pattern. More research is required into finding the most appropriate anatomical site of the spinal cord for delivering novel waveforms including 10kHz SCS.

CASCADE 10KHZ SPINAL CORD STIMULATION IN PATIENTS WITH FBSS AND CNLBP, A SINGLE CENTRE EXPERIENCE OVER 2 YEARS