High-frequency stimulation may be an effective treatment option for some patients who had a failure of conventional spinal cord stimulation (SCS) therapy for chronic pain. These findings, from a prospective study, were published in the European Journal of Pain.
For this study, between 2016 and 2018, researchers recruited 18 patients treated at the Virgen de las Nieves University Hospital in Spain who had standard tonic SCS but treatment failure. They offered patients 10-kHz high-frequency (HF10)-SCS that used their previously implanted device for tonic SCS therapy (2 MedtronicÒ or SJMÒ epidural electrodes). HF10-SFS was achieved via a SENZA (NevroÒ) high-frequency generator in which the researchers tested ³3 programs over a 2-week period. They defined treatment success as ³50% improvement as assessed by Functional Rating Index (FRI) and numerical pain rating scale (NPRS).
Patients were a mean age of 49.38±9.1 years; 72.2% were men; 27.8% were obese, 83.3% were diagnosed with failed back surgery syndrome; and 72.2% had used preoperative opioids.
Overall, 11 patients reported HF10-SFS success and 7 had treatment failure.
Among patients who reported treatment success, the average perceived improvement from baseline was 52.7% and NPRS decreased from 7.16 to 4.06 points for the lower back. The perceived improvement of pain in the limbs was 56.8%, and NPRS decreased from 8.77 to 3.45 points. Only 3 patients reported an improvement (³50%) to both their lower back and limb pain.
For the treatment failure cohort, the average perceived improvement was 13.5% and 19.2% for the lower back and limbs, respectively. Three patients reported no improvement to their lower back, and two had no improvement to their limb pain.
At 12 months, FRI scores improved by 28.4% (95% CI, 21.19-35.62); P =.0001; 36% discontinued opioid use, and 45% reduced opioid use.
Patient groups differed significantly for success on the basis of sex, in which all treatment failures occurred among men (P =.037). Treatment failure occurred among a population who had a mean body mass index (BMI) of 30.05±3.19 kg/m2 compared with 25.17±3.33 kg/m2 among the successes (P =.007). In a linear model, male sex (coefficient, -42.7% [95% CI, -85 to -0.4]) and BMI (coefficient, 6.7% [95% CI, 1.8-11.5]) had significant coefficients.
This study was limited by its low sample size and significant cohort heterogeneity.
These data indicated HF10-SCS was effective at reducing lower back and/or limb pain among patients, particularly among women and patients who were not obese, who experienced treatment failure with tonic SFS.
Cordero Tous N, Sánchez Corral C, Ortiz García IM, Jover Vidal A, Gálvez Mateos R, Olivares Granados G. High-frequency spinal cord stimulation as rescue therapy for chronic pain patients with failure of conventional spinal cord stimulation. Eur J Pain. Published online April 7, 2021. doi:10.1002/ejp.1776