Department of Pediatrics, Klinikum Rechts der Isar, Technical University München, München, Germany; Department of Neuropediatrics and Muscle Disorders, University Children's Hospital, Freiburg, Germany.
Dev Med Child Neurol. 2013 Oct;55(10):941-51. doi: 10.1111/dmcn.12209. Epub 2013 Aug 13.
Early unilateral brain lesions can lead to a persistence of ipsilateral corticospinal projections from the contralesional hemisphere, which can enable the contralesional hemisphere to exert motor control over the paretic hand. In contrast to the primary motor representation (M1), the primary somatosensory representation (S1) of the paretic hand always remains in the lesioned hemisphere. Here, we report on differences in exercise-induced neuroplasticity between individuals with such ipsilateral motor projections (ipsi) and individuals with early unilateral lesions but 'healthy' contralateral motor projections (contra).
Sixteen children and young adults with congenital hemiparesis participated in the study (contralateral [Contra] group: n=7, four females, three males; age range 10-30y, median age 16y; ipsilateral [Ipsi] group: n=9, four females, five males; age range 11-31y, median age 12y; Manual Ability Classification System levels I to II in all individuals in both groups). The participants underwent a 12-day intervention of constraint-induced movement therapy (CIMT), consisting of individual training (2h/d) and group training (8h/d). Before and after CIMT, hand function was tested using the Wolf Motor Function Test (WMFT) and diverging neuroplastic effects were observed by transcranial magnetic stimulation (TMS), functional magnetic resonance imaging (fMRI), and magnetoencephalography (MEG). Statistical analysis of TMS data was performed using the non-parametric Wilcoxon signed-rank test for pair-wise comparison; for fMRI standard statistical parametric and non-parametric mapping (SPM5, SnPM3) procedures (first level/second level) were carried out. Statistical analyses of MEG data involved analyses of variance (ANOVA) and t-tests.
While MEG demonstrated a significant increase in S1 activation in both groups (p=0.012), TMS showed a decrease in M1 excitability in the Ipsi group (p=0.036), but an increase in M1 excitability in the Contra group (p=0.043). Similarly, fMRI showed a decrease in M1 activation in the Ipsi group, but an increase in activation in the M1-S1 region in the Contra group (for both groups p<0.001 [SnPM3] within the search volume).
Different patterns of sensorimotor (re)organization in individuals with early unilateral lesions show, on a cortical level, different patterns of exercise-induced neuroplasticity. The findings help to improve the understanding of the general principles of sensorimotor learning and will help to develop more specific therapies for different pathologies in congenital hemiparesis.
早期单侧脑损伤可导致对侧半球的皮质脊髓投射持续存在同侧，这可以使对侧半球对手部瘫痪施加运动控制。与原发性运动代表区（M1）不同，患侧手的初级体感代表区（S1）始终保留在损伤半球中。在这里，我们报告了具有这种同侧运动投射（ipsi）的个体与具有早期单侧损伤但“健康”对侧运动投射（contra）的个体之间的运动诱导神经可塑性差异。
16 名患有先天性偏瘫的儿童和年轻人参与了这项研究（对侧[Contra]组：n=7，女性 4 名，男性 3 名；年龄范围 10-30y，中位数年龄 16y；同侧[Ipsi]组：n=9，女性 4 名，男性 5 名；年龄范围 11-31y，中位数年龄 12y；两组所有个体的手动能力分类系统水平 I 至 II）。参与者接受了为期 12 天的强制性运动疗法（CIMT）干预，包括个体训练（2h/d）和小组训练（8h/d）。在 CIMT 之前和之后，使用 Wolf 运动功能测试（WMFT）测试手功能，并通过经颅磁刺激（TMS）、功能磁共振成像（fMRI）和脑磁图（MEG）观察发散的神经可塑性效应。使用非参数 Wilcoxon 符号秩检验对 TMS 数据进行统计分析，以进行成对比较；对于 fMRI，进行标准统计参数和非参数映射（SPM5、SnPM3）程序（第一级/第二级）。MEG 数据分析涉及方差分析（ANOVA）和 t 检验。
虽然 MEG 显示两组 S1 激活均显著增加（p=0.012），但 TMS 显示 Ipsi 组 M1 兴奋性降低（p=0.036），而 Contra 组 M1 兴奋性增加（p=0.043）。同样，fMRI 显示 Ipsi 组 M1 激活减少，但 Contra 组 M1-S1 区域激活增加（两组均为 p<0.001[SnPM3]在搜索体积内）。
早期单侧病变个体的感觉运动（再）组织的不同模式在皮质水平上显示出不同的运动诱导神经可塑性模式。这些发现有助于提高对感觉运动学习一般原理的理解，并有助于为先天性偏瘫中的不同病理开发更具体的治疗方法。
