Kenefati George, Rockholt Mika M, Ok Deborah, McCartin Michael, Zhang Qiaosheng, Sun Guanghao, Maslinski Julia, Wang Aaron, Chen Baldwin, Voigt Erich P, Chen Zhe Sage, Wang Jing, Doan Lisa V
Department of Anesthesiology, Perioperative Care and Pain Management, New York University Grossman School of Medicine, New York, NY, United States.
Interdisciplinary Pain Research Program, New York University Grossman School of Medicine, New York, NY, United States.
Front Neurosci. 2023 Oct 13;17:1278183. doi: 10.3389/fnins.2023.1278183. eCollection 2023.
Chronic pain negatively impacts a range of sensory and affective behaviors. Previous studies have shown that the presence of chronic pain not only causes hypersensitivity at the site of injury but may also be associated with pain-aversive experiences at anatomically unrelated sites. While animal studies have indicated that the cingulate and prefrontal cortices are involved in this generalized hyperalgesia, the mechanisms distinguishing increased sensitivity at the site of injury from a generalized site-nonspecific enhancement in the aversive response to nociceptive inputs are not well known.
We compared measured pain responses to peripheral mechanical stimuli applied to a site of chronic pain and at a pain-free site in participants suffering from chronic lower back pain ( = 15) versus pain-free control participants ( = 15) by analyzing behavioral and electroencephalographic (EEG) data.
As expected, participants with chronic pain endorsed enhanced pain with mechanical stimuli in both back and hand. We further analyzed electroencephalographic (EEG) recordings during these evoked pain episodes. Brain oscillations in theta and alpha bands in the medial orbitofrontal cortex (mOFC) were associated with localized hypersensitivity, while increased gamma oscillations in the anterior cingulate cortex (ACC) and increased theta oscillations in the dorsolateral prefrontal cortex (dlPFC) were associated with generalized hyperalgesia.
These findings indicate that chronic pain may disrupt multiple cortical circuits to impact nociceptive processing.
慢性疼痛会对一系列感觉和情感行为产生负面影响。先前的研究表明，慢性疼痛的存在不仅会导致损伤部位的超敏反应，还可能与解剖学上不相关部位的疼痛厌恶体验有关。虽然动物研究表明扣带回和前额叶皮质参与了这种全身性痛觉过敏，但区分损伤部位敏感性增加与对伤害性输入的厌恶反应中全身性非特异性增强的机制尚不清楚。
我们通过分析行为和脑电图（EEG）数据，比较了慢性下背痛患者（n = 15）与无疼痛对照参与者（n = 15）对施加于慢性疼痛部位和无疼痛部位的外周机械刺激的测量疼痛反应。
正如预期的那样，慢性疼痛患者在背部和手部对机械刺激的疼痛反应增强。我们进一步分析了这些诱发疼痛发作期间的脑电图（EEG）记录。内侧眶额叶皮质（mOFC）中θ和α波段的脑振荡与局部超敏反应有关，而前扣带回皮质（ACC）中γ振荡增加和背外侧前额叶皮质（dlPFC）中θ振荡增加与全身性痛觉过敏有关。
这些发现表明，慢性疼痛可能会破坏多个皮质回路，从而影响伤害性处理。
