Department of Neurology, University Medical Center of the Johannes Gutenberg University, Mainz, Germany.
Celenus Klinik Kinzigtal, Gengenbach, Germany.
Eur J Pain. 2018 Aug;22(7):1343-1350. doi: 10.1002/ejp.1223. Epub 2018 Apr 25.
Complex regional pain syndrome (CRPS) is associated with deficits in limb recognition. The purpose of our study was to determine whether mental load during this task affected performance, sympathetic nervous system activity or pain in CRPS patients.
We investigated twenty CRPS-I patients with pain in the upper extremity and twenty age- and sex-matched healthy controls. Each participant completed a limb recognition task. To experimentally manipulate mental load, the presentation time for each picture varied from 2 s (greatest mental load), 4, 6 to 10 s (least mental load). Before and after each run, pain intensity was assessed. Skin conductance was recorded continuously.
Patients with CRPS did not differ from controls in terms of limb recognition and skin conductance reactivity. However, patients with CRPS reported an increase in pain during the task, particularly during high mental load and during the latter stages of the task. Interestingly, state anxiety and depressive symptoms were also associated with increases in pain intensity during high mental load.
These findings indicate that high mental load intensifies pain in CRPS. The increase of pain in association with anxiety and depression indicates a detrimental effect of negative affective states in situations of high stress and mental load in CRPS.
The effects of mental load need to be considered when patients with CRPS-I are investigated for diagnostic or therapeutic reasons.
复杂性区域疼痛综合征（CRPS）与肢体识别缺陷有关。我们研究的目的是确定在进行该任务时，精神负荷是否会影响 CRPS 患者的表现、交感神经系统活动或疼痛。
我们调查了 20 名上肢疼痛的 CRPS-I 患者和 20 名年龄和性别匹配的健康对照者。每位参与者都完成了一项肢体识别任务。为了实验性地操纵精神负荷，每张图片的呈现时间从 2 秒（最大精神负荷）、4、6 秒到 10 秒（最小精神负荷）不等。在每次运行前后，都评估了疼痛强度。皮肤电导连续记录。
CRPS 患者在肢体识别和皮肤电导反应性方面与对照组没有差异。然而，CRPS 患者在任务过程中报告疼痛增加，特别是在高精神负荷和任务后期。有趣的是，状态焦虑和抑郁症状也与高精神负荷时疼痛强度的增加有关。
这些发现表明，高精神负荷会加剧 CRPS 的疼痛。疼痛的增加与焦虑和抑郁有关，表明在 CRPS 中，负面情绪状态在高压力和精神负荷情况下会产生不利影响。
当出于诊断或治疗原因对 CRPS-I 患者进行研究时，需要考虑精神负荷的影响。
