Regnath Franziska, Biersack Katharina, Jäger Nina, Glasauer Stefan, Lehnen Nadine
Department of Psychosomatic Medicine and Psychotherapy, University Hospital Rechts der Isar, Technical University of Munich, Munich, Germany.
TUM Graduate School, Graduate Center of Medicine and Health (GC MH), Technical University of Munich, Munich, Germany.
Front Neurol. 2023 Dec 19;14:1294702. doi: 10.3389/fneur.2023.1294702. eCollection 2023.
Functional disorders are prevalent in all medical fields and pose a tremendous public health problem, with pain being one of the most common functional symptoms. Understanding the underlying, potentially unifying mechanism in functional (pain) disorders is instrumental in facilitating timely diagnosis, stigma reduction, and adequate treatment options. Neuroscientific models of perception suggest that functional symptoms arise due to dysregulated sensorimotor processing in the central nervous system, with brain-based predictions dominating the eventual percept. Experimental evidence for this transdiagnostic mechanism has been established in various functional symptoms. The goal of the current study was to investigate whether erroneous sensorimotor processing is an underlying transdiagnostic mechanism in chronic (functional) pain.
A total of 13 patients with chronic (functional) pain [three patients with chronic (functional) pain disorder, F45.40, ICD-10; 10 patients with chronic pain disorder with somatic and psychological factors, F45.41, ICD-10]; and 15 healthy controls performed large combined eye-head gaze shifts toward visual targets, naturally and with increased head moment of inertia. We simultaneously measured participants' eye and head movements to assess head oscillations at the end of the gaze shift, which are an established indicator of (transdiagnostic) sensorimotor processing deficits of head control.
Using a Bayesian analysis protocol, we found that patients with chronic (functional) pain and control participants stabilized their heads equally well (Bayes Factor = 3.7, Bayes Factor = 5.23; corresponding to substantial evidence) during all sessions of the experiment.
Our results suggest that patients with chronic (functional) pain do not show measurable symptom-unspecific sensorimotor processing deficits. We discuss outcome parameter choice, organ system specificity, and selection of patient diagnoses as possible reasons for this result and recommend future avenues for research.
功能障碍在所有医学领域都很普遍，构成了一个巨大的公共卫生问题，疼痛是最常见的功能症状之一。了解功能（疼痛）障碍潜在的、可能统一的机制有助于及时诊断、减少污名化并提供适当的治疗选择。感知的神经科学模型表明，功能症状是由于中枢神经系统中感觉运动处理失调而产生的，基于大脑的预测主导了最终的感知。这种跨诊断机制的实验证据已在各种功能症状中得到证实。本研究的目的是调查错误的感觉运动处理是否是慢性（功能性）疼痛的潜在跨诊断机制。
共有13例慢性（功能性）疼痛患者[3例慢性（功能性）疼痛障碍患者，F45.40，ICD - 10；10例伴有躯体和心理因素的慢性疼痛障碍患者，F45.41，ICD - 10]；以及15名健康对照者自然地并在增加头部转动惯量的情况下，对视觉目标进行大幅度的联合眼 - 头注视转移。我们同时测量参与者的眼睛和头部运动，以评估注视转移结束时的头部振荡，这是头部控制（跨诊断）感觉运动处理缺陷的既定指标。
使用贝叶斯分析方案，我们发现慢性（功能性）疼痛患者和对照参与者在实验的所有阶段中，头部稳定情况同样良好（贝叶斯因子 = 3.7，贝叶斯因子 = 5.23；对应充分证据）。
我们的结果表明，慢性（功能性）疼痛患者未表现出可测量的非特异性症状感觉运动处理缺陷。我们讨论了结果参数选择、器官系统特异性和患者诊断选择作为该结果的可能原因，并推荐了未来的研究方向。
