| 저자 |
Yun Kyung Seo1*, Jinmann Chon1†, Hee-Sang Kim1, Jong Ha Lee1, Dong Hwan Yun1, Seung Don Yoo1, Dong Hwan Kim1, Seung Ah Lee1, Yun Soo Soh1, Yong Kim1, Young Rok Han1, Myung Chul Yoo1 |
Objective
Pain threshold refers to the lowest intensity at which a given stimulus is perceived as painful. There are four commonly used ways to induce experimental pain in threshold assessment studies: Pressure, thermal, electrical and laser mediated stimulation of nociceptors. Pain assessment questionnaires such as visual analog scale (VAS), numeric rating scale (NRS) are based on the subjective reporting by patients themselves. so there is considerable individual variation in the evaluative criteria for pain and it is difficult to make comparison with other individuals. From these perspectives, Sensormeasure is a new objectively pain quantitative analyzer through neuroelectrophysiological pathways as the "degree of pain" calculated from the current production of electrical threshold perception and the current production of a comparable pain sensation. The aim of this study was to determine whether baseline pain threshold predicted response to treatment with C-arm guided lumbar injections (selective nerve root block/facet joint block) in patients with LBP.
Method
The study included 52 patients with LBP from August 2019 to January 2020. 30 patients were received C-arm guided selective nerve root block with 2 ml of 0.5% lidocaine+dexamethasone per site, 22 patients were received C-arm guided facet joint block with 2 ml of 1% lidocaine+triamcinolone per site. The pain threshold assessments by Sensormeasure (Sensor measure proⓇ, Unionmedical Corporation, 2015, Korea) were performed at injection site prior to interventions. VAS score was used to assess the pain at baseline and at the two weeks after C-arm guided lumbar injection. Self-reported questionnaire was conducted about symptoms that occurred during injection. The data related to pain and technical performance during the procedure was compared.
Results
In selective nerve root block group, difference in VAS (△VAS) score was significantly positive correlated with sensory threshold (r=0.495, p=0.005) and pain threshold (r=0.852, p<0.001), and in facet joint block group, △VAS score was significantly positive correlated with sensory threshold (r=0.629, p=0.002) and pain threshold (r=0.476, p=0.025). Multiple regression analysis showed that △VAS score was significantly associated with pain threshold (R2=0.651, β=0.133, p<0.001) in selective nerve root block group, and showed that △VAS score was significantly associated with pain threshold (R2=0.335, β=0.068, p=0.003) and sensory threshold (R2=0.497, β=0.109, p=0.013) in facet joint block group.
Conclusion
This study showed that pain thresholds values were positive correlated with △VAS score. In patients with low pain thresholds, the post-injection effect was not significant, and the pain relief related to procedure was also low. These findings suggested that by measuring the pain threshold, people with lower thresholds can objectively confirm that they are more sensitive to pain. |
