Sano Misako, Iwatsuki Katsuyuki, Hirata Hitoshi, Hoshiyama Minoru
Division of Prevention & Rehabilitation Sciences, Graduate School of Health Sciences, Nagoya University, 1-1-20 Daiko-Minami, Higashi-ku, Nagoya, 461-8673, Japan.
Department of Hnad Surgery, Graduate School of Medicine, Nagoya University, 65 Tsurumai-cho, Showa-ku, 466-8550, Japan.
Heliyon. 2024 Aug 22;10(17):e36463. doi: 10.1016/j.heliyon.2024.e36463. eCollection 2024 Sep 15.
To elucidate the functional characteristics of the brain in the presence of chronic pain using electroencephalography (EEG), with a focus on the dynamics of neural excitation and inhibition.
Resting-state EEG was performed in: 17 patients with complex regional pain syndrome (CRPS) who exhibited chronic pain higher than 20 on the visual analogue scale (VAS), 6 patients with reduced CRPS symptoms and chronic pain less than 20 on VAS, and healthy age-matched controls. For the analysis, 50 s of electroencephalogram (EEG) signals were extracted from EEG recordings during wakefulness and rest with eyes closed. The envelope of the alpha frequency band was calculated by examining the positive and negative accelerations of the envelope oscillation, ratio of positive (Ap) to negative (An) accelerations (Ap-An ratio), and mean amplitude of the envelope. Comparisons were made between patients and controls, and correlations between these EEG measures and the subjective pain VAS were evaluated.Significant differences in the value of Ap, An and Ap-An ratio were observed at temporal and central electrodes between patients with pain symptoms and controls. Those with reduced CRPS symptoms exhibited a distinct Ap-An ratio at the majority of electrodes when compared with those exhibiting chronic pain.
Distinct patterns in alpha wave envelope dynamics, reflecting excitatory and inhibitory activities, were associated with chronic pain in patients with CRPS. The pain-relieved state of CRPS suggested that a new balance of activities was established. This relationship indicated a potential association between altered alpha oscillation characteristics and the subjective experience of pain.
This study introduces a novel method for analyzing alpha oscillation envelopes, providing new insights into the neural pathophysiology of chronic pain in CRPS patients. This approach has the potential to enhance our understanding of the alterations in brain function that occur under chronic pain conditions.
使用脑电图（EEG）阐明慢性疼痛状态下大脑的功能特征，重点关注神经兴奋和抑制的动态变化。
对以下人群进行静息态脑电图检查：17例复杂性区域疼痛综合征（CRPS）患者，其视觉模拟量表（VAS）评分显示慢性疼痛高于20分；6例CRPS症状减轻且VAS评分显示慢性疼痛低于20分的患者；以及年龄匹配的健康对照者。分析时，从清醒且闭眼休息时的脑电图记录中提取50秒的脑电图（EEG）信号。通过检查包络振荡的正负加速度、正加速度（Ap）与负加速度（An）之比（Ap-An比）以及包络的平均幅度来计算α频段的包络。比较患者与对照者之间的差异，并评估这些脑电图指标与主观疼痛VAS之间的相关性。在疼痛症状患者和对照者的颞叶和中央电极处观察到Ap、An和Ap-An比值存在显著差异。与慢性疼痛患者相比，CRPS症状减轻的患者在大多数电极处表现出明显不同的Ap-An比。
反映兴奋和抑制活动的α波包络动态变化的独特模式与CRPS患者的慢性疼痛相关。CRPS的疼痛缓解状态表明建立了一种新的活动平衡。这种关系表明α振荡特征改变与疼痛的主观体验之间可能存在关联。
本研究引入了一种分析α振荡包络的新方法，为CRPS患者慢性疼痛的神经病理生理学提供了新见解。这种方法有可能增进我们对慢性疼痛条件下大脑功能改变的理解。
