Juenger Hendrik, Koerte Inga K, Muehlmann Marc, Mayinger Michael, Mall Volker, Krägeloh-Mann Ingeborg, Shenton Martha E, Berweck Steffen, Staudt Martin, Heinen Florian
Department of Pediatrics, Klinikum rechts der Isar, Technical University Munich, Koelner Platz 1, 80804 Munich, Germany; Department of Pediatric Neurology and Developmental Medicine, University Children's Hospital, Tübingen, Germany.
Psychiatry Neuroimaging Laboratory, Department of Radiology and Psychiatry, Brigham and Women's Hospital, Harvard Medical School, Boston, USA; Institute for Clinical Radiology, Ludwig-Maximilian-University, Munich, Germany; Department of Child and Adolescent Psychiatry, Psychosomatic and Psychotherapy, Ludwig-Maximilian-University, Munich, Germany.
Eur J Paediatr Neurol. 2014 Nov;18(6):691-7. doi: 10.1016/j.ejpn.2014.05.006. Epub 2014 May 28.
Early unilateral brain lesions can lead to different types of corticospinal (re-)organization of motor networks. In one group of patients, the contralesional hemisphere exerts motor control not only over the contralateral non-paretic hand but also over the (ipsilateral) paretic hand, as the primary motor cortex is (re-)organized in the contralesional hemisphere. Another group of patients with early unilateral lesions shows "normal" contralateral motor projections starting in the lesioned hemisphere.
We investigated how these different patterns of cortical (re-)organization affect interhemispheric transcallosal connectivity in patients with congenital hemiparesis.
Eight patients with ipsilateral motor projections (group IPSI) versus 7 patients with contralateral motor projections (group CONTRA) underwent magnetic resonance diffusion tensor imaging (DTI). The corpus callosum (CC) was subdivided in 5 areas (I-V) in the mid-sagittal slice and volumetric information. The following diffusion parameters were calculated: fractional anisotropy (FA), trace, radial diffusivity (RD), and axial diffusivity (AD).
DTI revealed significantly lower FA, increased trace and RD for group IPSI compared to group CONTRA in area III of the corpus callosum, where transcallosal motor fibers cross the CC. In the directly neighboring area IV, where transcallosal somatosensory fibers cross the CC, no differences were found for these DTI parameters between IPSI and CONTRA. Volume of callosal subsections showed significant differences for area II (connecting premotor cortices) and III, where group IPSI had lower volume.
The results of this study demonstrate that the callosal microstructure in patients with congenital hemiparesis reflects the type of cortical (re-)organization. Early lesions disrupting corticospinal motor projections to the paretic hand consecutively affect the development or maintenance of transcallosal motor fibers.
早期单侧脑损伤可导致运动网络不同类型的皮质脊髓（重新）组织。在一组患者中，对侧半球不仅对同侧非瘫痪手而且对（同侧）瘫痪手施加运动控制，因为初级运动皮层在对侧半球发生了（重新）组织。另一组早期单侧损伤患者显示从受损半球开始的“正常”对侧运动投射。
我们研究了这些不同的皮质（重新）组织模式如何影响先天性偏瘫患者的半球间胼胝体连接。
8例同侧运动投射患者（同侧组）与7例对侧运动投射患者（对侧组）接受了磁共振扩散张量成像（DTI）。在矢状中切面上，胼胝体（CC）被细分为5个区域（I-V）并获取体积信息。计算了以下扩散参数：各向异性分数（FA）、迹、径向扩散率（RD）和轴向扩散率（AD）。
DTI显示，与对侧组相比，同侧组在胼胝体中运动纤维穿过CC的区域III中，FA显著降低，迹和RD增加。在胼胝体中躯体感觉纤维穿过CC的紧邻区域IV中，同侧组和对侧组之间这些DTI参数没有差异。胼胝体各亚区的体积在区域II（连接运动前皮层）和III中有显著差异，同侧组的体积较小。
本研究结果表明，先天性偏瘫患者的胼胝体微观结构反映了皮质（重新）组织的类型。早期损伤破坏了向瘫痪手的皮质脊髓运动投射，继而影响了胼胝体运动纤维的发育或维持。
