Pia Lorenzo, Fossataro Carlotta, Burin Dalila, Bruno Valentina, Spinazzola Lucia, Gindri Patrizia, Fotopoulou Katerina, Berti Anna, Garbarini Francesca
SAMBA (SpAtial, Motor & Bodily Awareness) Research Group, Psychology Department, University of Turin, Italy; Neuroscience Institute of Turin (NIT), University of Turin, Italy.
MANIBUS Lab, Psychology Department, University of Turin, Italy.
Cortex. 2020 Sep;130:203-219. doi: 10.1016/j.cortex.2020.05.002. Epub 2020 May 19.
Recently, a monothematic delusion of body ownership due to brain damage (i.e., the embodiment of someone else's body part within the patient's sensorimotor system) has been extensively investigated. Here we aimed at defining in-depth the clinical features and the neural correlates of the delusion. Ninety-six stroke patients in a sub-acute or chronic phase of the illness were assessed with a full ad-hoc protocol to evaluate the embodiment of an alien arm under different conditions. A sub-group of seventy-five hemiplegic patients was also evaluated for the embodiment of the movements of the alien arm. Fifty-five patients were studied to identify the neural bases of the delusion by means of voxel-based lesion-symptom mapping approach. Our results show that, in forty percent of the whole sample, simply viewing the alien arm triggered the delusion, but only if it was a real human arm and that was seen from a 1st person perspective in an anatomically-correct position. In the hemiplegic sub-group, the presence of the embodiment of the alien arm was always accompanied by the embodiment of its passive and active movements. Furthermore, the delusion was significantly associated to primary proprioceptive deficits and to damages of the corona radiata and the superior longitudinal fasciculus. To conclude, we show that the pathological embodiment of an alien arm is well-characterized by recurrent and specific features and might be explained as a disconnection deficit, mainly involving white matter tracts. The proposed exhaustive protocol can be successfully employed to assess stroke-induced disorders of body awareness, unveiling even their more undetectable or covert clinical forms.
最近，因脑损伤导致的单一主题身体所有权妄想（即患者感觉运动系统中他人身体部位的具象化）已得到广泛研究。在此，我们旨在深入界定这种妄想的临床特征及神经关联。我们采用一套完整的专门方案，对96名处于疾病亚急性期或慢性期的中风患者进行评估，以在不同条件下评估异体手臂的具象化情况。还对75名偏瘫患者的亚组进行了评估，以了解异体手臂运动的具象化情况。通过基于体素的病变 - 症状映射方法，对55名患者进行研究以确定这种妄想的神经基础。我们的结果表明，在整个样本的40%中，仅仅看到异体手臂就会引发这种妄想，但前提是它是一条真实的人类手臂，并且是从第一人称视角在解剖学正确的位置看到的。在偏瘫亚组中，异体手臂具象化的存在总是伴随着其被动和主动运动的具象化。此外，这种妄想与原发性本体感觉缺陷以及放射冠和上纵束的损伤显著相关。总之，我们表明异体手臂的病理性具象化具有反复出现的特定特征，并且可能被解释为一种主要涉及白质束的连接缺陷。所提出的详尽方案可成功用于评估中风引起的身体意识障碍，甚至揭示其更难以察觉或隐蔽的临床形式。
