Microstructural integrity of corticospinal and medial lemniscus tracts: insights from diffusion tensor tractography of right-hand amputees.
Microstructural integrity of corticospinal and medial lemniscus tracts: insights from diffusion tensor tractography of right-hand amputees.
复制标题
皮质脊髓和内侧丘系束的微观结构完整性：来自右手截肢者扩散张量束成像的见解。
DOI：
10.1152/jn.00316.2018
复制
发表时间：
2019
影响因子：
2.5
通讯作者：
Frey,ScottH
中科院分区：
文献类型：
--
作者：
Peng,Huiling;Cirstea,CarmenM;Kaufman,ChristinaL;Frey,ScottH
成年期单侧上肢截肢后感觉和运动活动的减少与中枢神经系统灰质和白质广泛的、活动依赖性的重组有关。同样，在先天性肢体缺失的情况下，有证据表明有限的传入或传出活动会影响服务于受影响一侧的白质通路的结构完整性。然而，控制失去上肢的成熟感觉和运动束的结构完整性表现出类似的活动依赖性的证据很少且不一致。在这里，我们使用扩散张量纤维束成像来测试成年期（n = 16）右手截肢是否会改变控制手功能缺失的主要感觉（内侧丘系，ML）和运动（皮质脊髓束，CST）通路的微观结构完整性。与之前的研究结果一致，健康对照受试者 (n = 27) 在占主导地位的左侧 CST 和非占主导地位的右侧 ML 中表现出较高的分数各向异性 (FA)，这是白质微结构完整性的指数。至关重要的是，与预期的情况相反，如果这些纤维束的微观结构组织是活动依赖性的，这些不对称性在截肢者中持续存在。此外，我们未能检测到健康对照受试者和截肢者之间显性左侧 ML 或 CST 的任何差异。我们的结果与这些白质束在成熟后对活动变化的鲁棒性一致，或者持续使用残肢（以代偿方式或假肢）提供了足以维持白质束完整性的刺激。新的和值得注意的我们报告，成人单侧手截肢对截肢对侧的主要感觉或运动通路的结构没有显着影响。我们的结果与这些白质束的组织在成熟后对活动变化的鲁棒性一致，或者持续使用残肢（有或没有假肢）提供了足以维持白质束完整性的刺激。
Reductions in sensory and motor activity following unilateral upper limb amputation during adulthood are associated with widespread, activity-dependent reorganization of the gray matter and white matter through the central nervous system. Likewise, in cases of congenital limb absence there is evidence that limited afferent or efferent activity affects the structural integrity of white matter pathways serving the affected side. Evidence that the structural integrity of mature sensory and motor tracts controlling the lost upper limb exhibits similar activity dependence is, however, sparse and inconsistent. Here we used diffusion tensor tractography to test whether amputation of the dominant right hand during adulthood (n= 16) alters the microstructural integrity of the major sensory (medial lemniscus, ML) and motor (corticospinal tract, CST) pathways controlling missing hand function. Consistent with prior findings, healthy control subjects (n= 27) exhibited higher fractional anisotropy (FA), an index of white matter microstructural integrity, within dominant left CST and nondominant right ML. Critically, in contrast to what might be expected if the microstructural organization of these tracts is activity dependent, these asymmetries persisted in amputees. Moreover, we failed to detect any differences in dominant left ML or CST between healthy control subjects and amputees. Our results are consistent with these white matter tracts being robust to changes in activity once mature or that continued use of the residual limb (in a compensatory fashion or with prosthesis) provides stimulation sufficient to maintain tract integrity.NEW & NOTEWORTHYWe report that unilateral hand amputation in adults has no significant effects on the structure of major sensory or motor pathways contralateral to the amputation. Our results are consistent with the organization of these white matter tracts being robust to changes in activity once mature or that continued use of the residual limb (with or without a prosthesis) provides stimulation sufficient to maintain tract integrity.