EA 1026, University of Lille Nord de la France, Lille, France; Neurological Rehabilitation Unit, CHRU, Lille, France.
Cortex. 2013 Nov-Dec;49(10):2607-15. doi: 10.1016/j.cortex.2013.07.007. Epub 2013 Jul 22.
In patients with spatial neglect, body perception and representation are impaired - especially the projection of the anterior body midline in anterior space (the subjective "straight ahead"). However, data on more lateral body parts and the posterior body surface are scarce. We explored deviations of the perception of different body points located to the left or right of the midline and on the anterior and posterior body surfaces, and their lesion correlates in right hemisphere stroke patients.
Nine patients with neglect (diagnosed with paper and pencil and behavioural tests) were compared with six non-neglect patients and 13 healthy controls. The subjects had to use a mannequin to designate the body location that had been stimulated by a blunt pencil tip. Four horizontally arranged series of locations were traced on the anterior and posterior body surfaces at shoulder and navel levels. Each horizontal series comprised five equidistant test points, from left to right and corresponded to eleven labelled points on the mannequin. Patient errors were confronted to their anatomic lesions (MRI).
We found a significant (p ≤ .05) rightward deviation of the left-side points and midpoint and a significant leftward deviation of the right-most point in neglect patients. Non-neglect patients and control subjects designated all the test points accurately. The body side (anterior or posterior) and the line (shoulder or navel) did not influence performance. Controls showed a definite reduction in variability for the midline points, which disappeared in neglect patients who showed a severe global increase of this variability. Errors depended on lesions centred on the intraparietal sulcus.
These observations were compatible with a complex bias in body perception-representation extending to various lateral body points, with a left to right gradient. The right parietal cortex likely participates in processing such information.
在空间忽视患者中，身体感知和表现受损 - 特别是在前空间中（主观的“正前方”）对身体中线前侧的投射。然而，关于更外侧身体部位和后身体表面的数据却很少。我们探讨了位于中线左侧或右侧以及前侧和后侧身体表面的不同身体点的感知偏差，以及右侧大脑半球中风患者的病变相关性。
将 9 名忽视患者（通过纸笔和行为测试诊断）与 6 名非忽视患者和 13 名健康对照者进行比较。要求受试者使用人体模型指定被钝铅笔尖刺激的身体位置。在肩部和肚脐水平的前侧和后侧身体表面上追踪四个水平排列的位置系列。每个水平系列包括五个等距测试点，从左到右，对应于人体模型上的十一个标记点。将患者的错误与他们的解剖病变（MRI）进行对比。
我们发现忽视患者的左侧点和中点存在明显的（p≤.05）向右偏差，右侧最右侧点存在明显的向左偏差。非忽视患者和对照组受试者准确指定了所有测试点。身体侧（前侧或后侧）和线（肩部或肚脐）不影响表现。对照组表现出中线点的变异性明显降低，而忽视患者则表现出这种变异性的严重全局增加，这种降低消失了。错误取决于以顶内沟为中心的病变。
这些观察结果与身体感知表现的复杂偏差一致，这种偏差延伸到各种外侧身体部位，并存在从左到右的梯度。右顶叶皮层可能参与了这种信息的处理。
