This study investigates the effect of Spinal Cord Stimulation (SCS) on sensory processing of chronic pain patients and demonstrates that enhanced central sensitization and reduced conditioned pain modulation (CPM) correlate with more effective pain relief by SCS.
Spinal Cord Stimulation (SCS) is a promising and gaining popularity treatment for various pain conditions. Its mechanism is currently not well understood.
In the current study a battery of tests was performed on 24 patients with a range of chronic-pain conditions suitable for SCS treatment. The testing procedure included assessment of pain thresholds, allodynia, cold pressor test, CPM, mechanical and thermal temporal summation before SCS, during trial stimulation, 1 and 3 months following permanent implantation.
The results of this study demonstrated that both central sensitization, represented by the results of the temporal summation test, and CPM were associated with the level of pain after 3 months of SCS stimulation. The results suggest that patients with greater central sensitization and less efficient CPM at baseline will gain more benefit from SCS treatment.
The above results throw a light on the potential mechanism of SCS treatment and suggest that dynamic sensory testing (temporal summation, CPM) may be used in the future to categorize the candidates for the treatment and to detect those for whom this treatment will be most useful and effective.