# Long‐Term Outcome of Complex Regional Pain Syndrome versus Limb Pain of Other Origin: Results From a Telephone Survey With up to 5‐year Follow‐Up

## TL;DR

This study compares long-term outcomes of complex regional pain syndrome with other limb pain conditions, finding that CRPS patients often report severe disability despite similar pain levels.

## Contribution

The study provides new insights into the long-term disability and functional outcomes of CRPS compared to other chronic limb pain conditions.

## Key findings

- CRPS patients showed the highest rate of severe impairment (71%) compared to other groups.
- PN patients reported higher pain intensity and severe disability (70%) compared to CRPS and NLP.
- CRPS patients treated with corticosteroids had more positive baseline signs but poorer outcomes.

## Abstract

Complex regional pain syndrome (CRPS) is a disabling condition requiring long‐term treatment. This study evaluated long‐term outcomes in CRPS patients compared to posttraumatic neuralgia (PN) and nociceptive limb pain (NLP) 1–5 years after diagnosis and treatment initiation in a tertiary clinic.

Patients with CRPS lasting more than 1 year (n = 116), PN (n = 68), or NLP (n = 75) participated in a standardized telephone interview assessing pain intensity, functional impairment, neglect‐like symptoms, and disability in daily life and work.

PN patients had higher pain intensity compared to CRPS (NRS 5.7 ± 2.1 vs. 4.5 ± 2.6; main effect: p = 0.005; post hoc test: p = 0.003). Functional outcomes varied significantly between groups (p < 0.001). CRPS patients showed the highest rate of severe impairment (71%), especially in those with ≥ 3 clinical signs, while outcome was better in NLP (p ≤ 0.027), especially in part‐time workers. The global impression of disability varied between groups (p = 0.044): PN patients reported a high level of severe disability (70%), while CRPS had the most subjects with “none/slight” disability (23%). Pain and function were tightly linked to perceived disability in all groups. Neither the neglect‐like total score (CRPS: 2.4 (2.2–2.6); neuralgia: 2.5 (2.3–2.7); NLP: 2.2 (1.9–2.5); p = 0.055) nor the working ability differed between groups (p = 0.397); however, only in CRPS, neglect‐like symptoms were associated with higher pain intensity and global disability, as well as lower functional outcome. CRPS patients treated with corticosteroids (n = 55) had more positive clinical signs at baseline and poorer outcomes than patients without corticosteroids (n = 61).

Long‐term impairment, work‐related, and global disability in CRPS were similar to those of neuralgia and NLP patients treated in a tertiary pain clinic. Despite shorter disease duration, CRPS patients more often report severe disability, while pain is comparable to other chronic limb pain courses. More pronounced positive signs in CRPS at baseline are associated with poor outcomes. These findings emphasize the heterogeneous course of CRPS and the importance of individualized multidimensional approaches.