Bär Karl-Jürgen, de la Cruz Feliberto, Berger Sandy, Schultz Carl C, Wagner Gerd
Psychiatric Brain & Body Research Group Jena, Department of Psychiatry and Psychotherapy, Jena University Hospital, Jena, Germany.
J Psychiatry Neurosci. 2015 Jul;40(4):269-79. doi: 10.1503/jpn.140193.
The dysfunction of specific brain areas might account for the distortion of body image in patients with anorexia nervosa. The present study was designed to reveal brain regions that are abnormal in structure and function in patients with this disorder. We hypothesized, based on brain areas of altered activity in patients with anorexia nervosa and regions involved in pain processing, an interrelation of structural aberrations in the frontoparietal-cingulate network and aberrant functional activation during thermal pain processing in patients with the disorder.
We determined pain thresholds outside the MRI scanner in patients with anorexia nervosa and matched healthy controls. Thereafter, thermal pain stimuli were applied during fMRI imaging. Structural analyses with high-resolution structural T1-weighted volumes were performed using voxel-based morphometry and a surface-based approach.
Twenty-six patients and 26 controls participated in our study, and owing to technical difficulties, 15 participants in each group were included in our fMRI analysis. Structural analyses revealed significantly decreased grey matter volume and cortical thickness in the frontoparietal-cingulate network in patients with anorexia nervosa. We detected an increased blood oxygen level-dependent signal in patients during the painful 45 °C condition in the midcingulate and posterior cingulate cortex, which positively correlated with increased pain thresholds. Decreased grey matter and cortical thickness correlated negatively with pain thresholds, symptom severity and illness duration, but not with body mass index.
The lack of a specific quantification of body image distortion is a limitation of our study.
This study provides further evidence for confined structural and functional brain abnormalities in patients with anorexia nervosa in brain regions that are involved in perception and integration of bodily stimuli. The association of structural and functional deviations with thermal thresholds as well as with clinical characteristics might indicate a common neuronal origin.
特定脑区功能障碍可能是神经性厌食症患者身体意象扭曲的原因。本研究旨在揭示该疾病患者结构和功能异常的脑区。基于神经性厌食症患者活动改变的脑区以及参与疼痛处理的区域，我们推测该疾病患者额顶叶 - 扣带回网络的结构畸变与热痛处理过程中异常的功能激活之间存在相互关系。
我们在磁共振成像（MRI）扫描仪外测定了神经性厌食症患者和匹配的健康对照者的疼痛阈值。此后，在功能磁共振成像（fMRI）扫描期间施加热痛刺激。使用基于体素的形态测量法和基于表面的方法，对高分辨率结构T1加权容积进行结构分析。
26名患者和26名对照参与了我们的研究，由于技术困难，每组15名参与者纳入fMRI分析。结构分析显示，神经性厌食症患者额顶叶 - 扣带回网络中的灰质体积和皮质厚度显著降低。我们检测到，在45°C疼痛条件下，患者的扣带回中部和扣带回后部皮质中血氧水平依赖信号增加，且与疼痛阈值增加呈正相关。灰质和皮质厚度降低与疼痛阈值、症状严重程度和病程呈负相关，但与体重指数无关。
缺乏对身体意象扭曲的具体量化是我们研究的一个局限性。
本研究为神经性厌食症患者在参与身体刺激感知和整合的脑区存在局限性的结构和功能脑异常提供了进一步证据。结构和功能偏差与热阈值以及临床特征之间的关联可能表明存在共同的神经元起源。
