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Updated: Nov 24, 2025
Dynamic Quantitative Sensory Testing to Characterize Central Pain Processing
Published on: February 16, 2017
Dorsal Root Ganglion Stimulation Normalizes Measures of Pain Processing in Patients with Chronic Low-Back Pain: A
Kenneth B Chapman1,2,3, Bert-Kristian van Roosendaal1,4, Tariq A Yousef1
1The Spine & Pain Institute of New York, New York City, New York, U.S.A.
Background:
Dorsal root ganglion stimulation (DRG-S) is used as a treatment for chronic low-back pain (CLBP), although its underlying mechanisms remain elusive. CLBP patients have been found to have reduced mechanoreceptive perception, reduced endogenous analgesia, as well as deep-tissue hyperalgesia when compared with healthy controls. Using quantitative sensory testing (QST), we studied if DRG-S in CLBP patients results in changes in pain processing.
Methods:
Quantitative sensory testing was performed in patients before trial implantation of a DRG-S system for CLBP and just before the trial lead removal or at 1-month follow-up after the permanent implant. We determined the pressure pain threshold (PPT) and mechanical detection threshold (MDT) at the most painful lower-back location. PPT was also measured on the contralateral shoulder as a control. We obtained a measure of endogenous inhibitory pain modulation using conditioned pain modulation (CPM).
Results:
We enrolled 11 patients (60 ± 16 years). Pain decreased from 8.5 ± 1.0 at baseline to 2.0 ± 1.5 on a 0-10 numerical rating scale with DRG-S (P < 0.01). From baseline to with DRG-S, PPT on the most painful location on the low back increased from 28.7 ± 13.6 to 43.4 ± 17.2 N/cm2 (P < 0.01). MDT on the same location decreased from 8.1 ± 10.4 to 3.4 ± 4.7 mN (P = 0.07). PPT on the control location and CPM did not change significantly.
Conclusions:
Our results suggest that DRG-S in CLBP patients reduces deep-tissue hyperalgesia in the low back, while improving mechanoreceptive perception. These changes in both neuropathic and nociceptive components of CLBP were accompanied by clinical improvements in pain and function.
