Laboratoire de Neurosciences Fonctionnelles et Pathologies, EA-4559, Université Lille Nord de France, Lille,
PLoS One. 2013;8(1):e54928. doi: 10.1371/journal.pone.0054928. Epub 2013 Jan 18.
In anorexia nervosa (AN), body distortions have been associated with parietal cortex (PC) dysfunction. The PC is the anatomical substrate for a supramodal reference framework involved in spatial orientation constancy. Here, we sought to evaluate spatial orientation constancy and the perception of body orientation in AN patients. In the present study, we investigated the effect of passive lateral body inclination on the visual and tactile subjective vertical (SV) and body Z-axis in 25 AN patients and 25 healthy controls. Subjects performed visual- and tactile-spatial judgments of axis orientations in an upright position and tilted 90° clockwise or counterclockwise. We observed a significant deviation of the tactile and visual SV towards the body (an A-effect) under tilted conditions, suggesting a multisensory impairment in spatial orientation. Deviation of the Z-axis in the direction of the tilt was also observed in the AN group. The greater A-effect in AN patients may reflect reduced interoceptive awareness and thus inadequate consideration of gravitational inflow. Furthermore, marked body weight loss could decrease the somatosensory inputs required for spatial orientation. Our study results suggest that spatial references are impaired in AN. This may be due to particular integration of visual, tactile and gravitational information (e.g. vestibular and proprioceptive cues) in the PC.
在神经性厌食症（AN）中，身体扭曲与顶叶皮层（PC）功能障碍有关。PC 是参与空间方位恒常性的超模式参考框架的解剖基质。在这里，我们试图评估 AN 患者的空间方位恒常性和身体方位感知。在本研究中，我们调查了被动横向身体倾斜对 25 名 AN 患者和 25 名健康对照组的视觉和触觉主观垂直（SV）和身体 Z 轴的影响。在直立和顺时针或逆时针倾斜 90°的位置，受试者进行了轴方向的视觉和触觉空间判断。我们观察到在倾斜条件下触觉和视觉 SV 向身体的明显偏差（A 效应），这表明空间定向存在多感觉障碍。在 AN 组中也观察到 Z 轴向倾斜方向的偏差。AN 患者的 A 效应更大可能反映了内脏感觉意识的降低，从而对重力流入的考虑不足。此外，明显的体重减轻可能会减少空间定向所需的躯体感觉输入。我们的研究结果表明，空间参考在 AN 中受损。这可能是由于 PC 中视觉、触觉和重力信息（例如前庭和本体感觉提示）的特殊整合。
