# Effect duration of lumbar sympathetic ganglion neurolysis in patients with complex regional pain syndrome: a prospective observational study

## TL;DR

This study measured how long the pain relief from a procedure called lumbar sympathetic ganglion neurolysis lasts in patients with complex regional pain syndrome.

## Contribution

The study provides the first measured estimate of the median duration of effect for lumbar sympathetic ganglion neurolysis in CRPS patients.

## Key findings

- The median time to return to baseline temperature after LSGN was 12 weeks at both the maximum pain site and plantar area.
- Pain intensity decreased significantly at all time points after the procedure.
- Skin temperature increased significantly at all time points compared to baseline.

## Abstract

Lumbar sympathetic ganglion neurolysis (LSGN) has been used for long-term pain relief in patients with complex regional pain syndrome (CRPS). However, the actual effect duration of LSGN has not been accurately measured. This prospective observational study measured the effect duration of LSGN in CRPS patients and investigated the relationship between temperature change and pain relief. After performing LSGN, the skin temperatures of both the maximum pain site and the plantar area in the affected and unaffected limbs were measured by infrared thermography, and pain intensity was assessed before and at 2 weeks, 1 month, and 3 months. The median time to return to baseline temperature was calculated using survival analysis. The skin temperature increased significantly at all-time points relative to baseline in both regions (maximum pain site: 1.4 °C ± 1.0 °C, plantar region: 1.28 °C ± 0.8 °C, all P < 0.001). The median time to return to baseline temperature was 12 weeks (95% confidence interval [CI] 7.7–16.3) at the maximum pain site and 12 weeks (95% CI 9.4–14.6) at the plantar area. Pain intensity decreased significantly relative to baseline, at all-time points after LSGN. In conclusion, the median duration of the LSGN is estimated to be 12 weeks.