Pain & Autonomics - Integrative Research (PAIR), Department of Psychiatry and Psychotherapy, University Hospital Jena, Jena, Germany.
Acta Psychiatr Scand. 2013 Apr;127(4):269-78. doi: 10.1111/j.1600-0447.2012.01896.x. Epub 2012 Jul 2.
Reduced perception of pain is a well-established phenomenon in patients with anorexia nervosa (AN). We tested the hypothesis that altered processing of pain within the insula might account for reduced perception of pain.
Heat pain thresholds were obtained in nineteen patients with AN and matched controls. Thereafter, a thermode was used to deliver thermal painful stimuli to the right arm during functional magnetic resonance imaging (fMRI) measurements. Stimuli were initiated for 10 s from a baseline resting temperature (32°C) to three different levels (37, 42, 45°C).
Significantly increased heat pain thresholds were observed in patients. A stronger activation during heat pain perception was found in the left posterior insula in controls. In contrast, higher levels of activity were shown in the ipsilateral pons in patients when compared to controls. In patients, we found a significant interrelation between the depression score (Beck depression inventory) and heat pain activations.
We suggest that reduced activity in the left posterior insula might contribute to increased pain thresholds in patients, while increased activations in the right anterior insula and pons mirror augmented sympathetic modulation putatively related to amplification of adrenergic descending pain inhibition. In addition, pain thresholds and brain activations were influenced by disease-inherent depressed mood.
厌食症（AN）患者的疼痛感知减少是一种已被证实的现象。我们验证了这样一个假设，即在岛叶内疼痛处理的改变可能导致疼痛感知的减少。
在 19 名 AN 患者和匹配的对照组中获得热痛阈值。然后，在功能磁共振成像（fMRI）测量期间，使用热探头将热痛刺激施加到右臂。刺激从基线静息温度（32°C）开始持续 10 秒，分别达到三个不同的水平（37°C、42°C、45°C）。
患者的热痛阈值明显增加。对照组在热痛感知过程中发现左侧后岛叶的激活更强。相比之下，与对照组相比，患者同侧桥脑显示出更高水平的活动。在患者中，我们发现抑郁评分（贝克抑郁量表）与热痛激活之间存在显著的相互关系。
我们认为左侧后岛叶活动减少可能导致患者的疼痛阈值增加，而右侧前岛叶和桥脑的活动增加则反映了与肾上腺素能下行疼痛抑制的放大相关的增强交感神经调制。此外，疼痛阈值和大脑激活受疾病固有抑郁情绪的影响。
