INSERM, Unité 992, F-91191 Gif-sur-Yvette, France.
Neuroscientist. 2011 Dec;17(6):633-44. doi: 10.1177/1073858411402093. Epub 2011 Jun 13.
That disconnection causes clinical symptoms is a very influential concept in behavioral neurology. Criteria for subcortical disconnection usually are symptoms that are distinct from those following cortical lesions and damage to a single, long-range fiber tract. Yet, a recent study combining functional magnetic resonance imaging and fiber tracking concluded that a focal lesion in left parietal white matter provides the only tenable explanation for pure Gerstmann's syndrome, an enigmatic tetrad of acalculia, agraphia, finger agnosia, and left-right disorientation. Such a lesion would affect not only a single fiber tract but crossing or "kissing" of different fiber tracts and hence disconnect separate cortical networks. As fiber crossing is prominent in the cerebral white matter, the authors propose an extension to the subcortical disconnection framework that opens the door to ascribing a more diversified clinical phenomenology to white matter damage and ensuing disconnection than has been the case so far.
这种连接中断导致临床症状的概念在行为神经学中非常有影响力。皮质下连接中断的标准通常是与皮质损伤和单一长程纤维束损伤后出现的症状不同的症状。然而，最近一项结合功能磁共振成像和纤维追踪的研究得出结论，左顶叶白质的局灶性病变为纯粹的格斯特曼综合征（一种神秘的计算障碍、失写症、手指失认症和左右定向障碍四联征）提供了唯一可行的解释。这样的病变不仅会影响单一的纤维束，还会影响不同纤维束的交叉或“亲吻”，从而使不同的皮质网络失去连接。由于纤维交叉在大脑白质中很明显，作者提出了对皮质下连接框架的扩展，这为将更多样化的临床现象归因于白质损伤和随后的连接中断打开了大门，而这在以前是不可能的。
