Sympathetic Blockade with Botulinum Toxin Tied to Pain Relief in Complex Regional Pain Syndrome: Study
South Korea: Lumbar sympathetic ganglion block using botulinum toxin type A raised the temperature of the affected foot for 3 months in patients with complex regional pain syndrome and also reduced the pain, reveals a recent study. The study was published in the February 2022 issue of the journal Anesthesiology.
The study was designed to test the hypothesis that botulinum toxin prolongs the duration of a lumbar sympathetic block measured through a sustained increase in skin temperature. Jee Youn Moon, Seoul National University Hospital, Seoul, Republic of Korea, and colleagues performed a randomized, double-blind, controlled trial to examine the clinical outcome of botulinum toxin type A for lumbar sympathetic ganglion block in patients with complex regional pain syndrome.
For this purpose, the researchers conducted lumbar sympathetic ganglion block in patients with lower-extremity complex regional pain syndrome using 75 IU of botulinum toxin type A (botulinum toxin group) and local anesthetic (control group).
The change in the relative temperature difference on the blocked sole compared with the contralateral sole at 1 postoperative month was the primary outcome. The 3-month changes in relative temperature differences, and the pain intensity changes were the secondary outcomes.
A total of 48 participants (N = 24/group) were randomly assigned.
Based on the study, the researchers found the following:
- The change in relative temperature increase was higher in the botulinum toxin group than in the control group (1.0°C ± 1.3 vs. 0.1°C ± 0.8, respectively), which was maintained at 3 months (1.1°C ± 0.8 vs. –0.2°C ± 1.2, respectively).
- Moreover, pain intensity was greatly reduced in the botulinum toxin group compared with the control group at 1 month (–2.2 ± 1.0 vs. –1.0 ± 1.6, respectively) and 3 months (–2.0 ± 1.0 vs. –0.6 ± 1.6, respectively).
- There were no severe adverse events pertinent to botulinum toxin injection.
"We found that compared with local anesthetic, injections of botulinum toxin type A onto the lumbar sympathetic ganglia increased temperature on the affected foot for 3 months," the authors wrote. This was accompanied by pain reduction and cold tolerance improvement. Moreover, it also improved aching and numbness."
Reference:
Yongjae Yoo, Chang-Soon Lee, Jungsoo Kim, Dongwon Jo, Jee Youn Moon; Botulinum Toxin Type A for Lumbar Sympathetic Ganglion Block in Complex Regional Pain Syndrome: A Randomized Trial. Anesthesiology 2022; 136:314–325 doi: https://doi.org/10.1097/ALN.0000000000004084
