Vandermeeren Yves, Davare Marco, Duque Julie, Olivier Etienne
Laboratory of Neurophysiology, Institute of Neuroscience (INES), Université catholique de Louvain, Brussels, Belgium.
Eur J Neurosci. 2009 Feb;29(4):845-54. doi: 10.1111/j.1460-9568.2009.06619.x. Epub 2009 Feb 6.
When damaged perinatally, as in congenital hemiplegia (CH), the corticospinal tract usually undergoes an extensive reorganization, such as the stabilization of normally transient projections to the ipsilateral spinal cord. Whether the reorganization of the corticospinal projections occurring in CH patients is also accompanied by a topographical rearrangement of the hand representations in the primary motor cortex (M1) remains unclear. To address this issue, we mapped, for both hands, the representation of the first dorsal interosseous muscle (1DI) in 12 CH patients by using transcranial magnetic stimulation co-registered onto individual three-dimensional magnetic resonance imaging; these maps were compared with those gathered in age-matched controls (n = 11). In the damaged hemisphere of CH patients, the representation of the paretic 1DI was either found in the hand knob of M1 (n = 5), shifted caudally (n = 5), or missing (n = 2). In the intact hemisphere of six CH patients, an additional, ipsilateral, representation of the paretic 1DI was found in the hand knob, where it overlapped exactly the representation of the non-paretic 1DI. In the other six CH patients, the ipsilateral representation of the paretic 1DI was either shifted caudally (n = 2) or was lacking (n = 4). Surprisingly, in these two subgroups of patients, the representation of the contralateral non-paretic 1DI was found in a more medio-dorsal position than in controls. The present study demonstrates that, besides the well-known reorganization of the corticospinal projections, early brain injuries may also lead to a topographical rearrangement of the representations of both the paretic and non-paretic hands in M1.
在围产期受损时，如先天性偏瘫（CH），皮质脊髓束通常会经历广泛的重组，例如向同侧脊髓的正常短暂投射的稳定。CH患者中发生的皮质脊髓投射重组是否也伴随着初级运动皮层（M1）中手部表征的拓扑重排仍不清楚。为了解决这个问题，我们通过使用与个体三维磁共振成像共同配准的经颅磁刺激，绘制了12例CH患者双手第一背侧骨间肌（1DI）的表征；这些图谱与年龄匹配的对照组（n = 11）收集的图谱进行了比较。在CH患者受损的半球中，患侧1DI的表征要么在M1的手部旋钮处发现（n = 5），要么向尾侧移位（n = 5），要么缺失（n = 2）。在6例CH患者的未受损半球中，在手部旋钮处发现了患侧1DI的额外同侧表征，它与非患侧1DI的表征完全重叠。在其他6例CH患者中，患侧1DI的同侧表征要么向尾侧移位（n = 2），要么缺失（n = 4）。令人惊讶的是，在这两个患者亚组中，对侧非患侧1DI的表征比对照组更偏中背侧。本研究表明，除了众所周知的皮质脊髓投射重组外，早期脑损伤还可能导致M1中患侧和非患侧手部表征的拓扑重排。
