The results of a multicenter, double-blind, crossover, randomized controlled trial (RCT) that investigated the effects of rate of stimulation on analgesia in kilohertz frequency (1–10 kHz) spinal cord stimulation (SCS) suggests that patients experienced EQUIVALENT PAIN RELIEF as measured by (e-diary numeric rating scale) ED-NRS (p ≤ 0.002). For details, please see the source.
Patients were implanted with SCS systems and underwent an eight-week search to identify the best location (“sweet spot”) of stimulation at 10 kHz within the searched region (T8–T11). Patients who responded to 10 kHz per ED-NRS pain scores proceeded to double-blind rate randomization. Patients received 1, 4, 7, and 10 kHz SCS at the same sweet spot found for 10 kHz in randomized order (four weeks at each frequency). For each frequency, pulse width and amplitude were titrated to optimize therapy.
All frequencies provided equivalent pain relief, while 1 kHz requiring 60–70% less charge than higher frequencies (p ≤ 0.0002).
One important question is about the sensitivity of analgesia to frequencies outside the range of 1–10 kHz., both below and above.
Benefit of lower frequency would be even lesser charge for higher battery longevity and equivalent pain relief without paresthesia. Lower frequencies for SCS may be effective in the sub-perception modality (although, whether the mechanisms of action underlying burst SCS and kilohertz frequency SCS are the same is an open question). Other questions include whether the mechanisms of action for these two broad modalities of SCS (paresthesia and sub-perception) overlap in frequency range, and whether they can be engaged simultaneously to potentially yield an additive effect that further improves therapy.
The bottom line is: As fundamental understanding of mechanisms of action increases, continued optimization is likely and awaiting researchers.
A full-featured, fully programmable, pulse-generator platform such as Lone Star Neuro's 'indication agnostic platform' may be an ideal tool to empower institutions immediately to further medical research, since the platform can be set to deliver constant current or constant voltage pulses with programmable amplitude and pulse-width, at any frequency from 1 Hz to well above 40 (forty) kHz with simple C-code programming.