Active Recharge Burst and Tonic Spinal Cord Stimulation Engage Different Supraspinal Mechanisms: A Functional Magnetic Resonance Imaging Study in Peripherally Injured Chronic Neuropathic Rats.
OBJECTIVES
To assess the supraspinal working mechanisms of the burst spinal cord stimulation (SCS) mode, we used functional magnetic resonance imaging (fMRI) in chronic neuropathic rats. We hypothesized that active recharge burst SCS would induce a more profound blood oxygenation level-dependent (BOLD) signal increase in areas associated with cognitive-emotional aspects of pain, as compared to tonic SCS.


METHODS
Sprague Dawley rats (n = 17) underwent a unilateral partial sciatic nerve ligation, which resulted in chronic neuropathic pain. Quadripolar SCS electrodes were epidurally positioned on top of the dorsal columns at Th13. Isoflurane-anesthetized (1.5%) rats received either tonic SCS (n = 8) or burst SCS (n = 9) at 66% of motor threshold. BOLD fMRI was conducted before, during, and after SCS using a 9.4-T horizontal bore scanner.


RESULTS
Overall, both tonic and burst SCS induced a significant increase of BOLD signal levels in areas associated with the location and intensity of pain, and areas associated with cognitive-emotional aspects of pain. Additionally, burst SCS significantly increased BOLD signal levels in the raphe nuclei, nucleus accumbens, and caudate putamen. Tonic SCS did not induce a significant increase in BOLD signal levels in these areas.


CONCLUSIONS
In conclusion, active recharge burst and tonic SCS have different effects on the intensity and localization of SCS-induced activation responses in the brain. This work demonstrates that active recharge burst is another waveform that can engage brain areas associated with cognitive-emotional aspects of pain as well as areas associated with location and intensity of pain. Previous studies showing similar engagement used only passive recharge burst.
['Meuwissen|Koen P V|KPV|0000-0001-9255-6513', 'van der Toorn|Annette|A|', 'Gu|Jianwen Wendy|JW|', 'Zhang|Tianhe C|TC|', 'Dijkhuizen|Rick M|RM|', 'Joosten|Elbert A J|EAJ|']
D000818:Animals D001921:Brain D008279:Magnetic Resonance Imaging D008297:Male D009437:Neuralgia D051381:Rats D017207:Rats, Sprague-Dawley D012584:Sciatic Nerve D013116:Spinal Cord D062187:Spinal Cord Stimulation
burst spinal cord stimulation rat fMRI chronic neuropathic pain