Abstract：
OBJECTIVE: After vertical parasagittal hemispherotomy a restricted diffusion is often seen ipsilaterally and even distant from the adjacent resection margin. This retrospective cohort study analyses the anatomic site and the time course of the diffusion restriction after vertical parasagittal hemispherotomy.
METHODS: Fifty-nine patients were included into this study, all of them having had one pre-operative and at least one post-operative MRI, including diffusion imaging at b‑values of 0 and 1000 s/mm2 with a calculated ADC.
RESULTS: Diffusion restriction occurred exclusively on the operated site in all patients. In the basal ganglia, diffusion restriction was present in 37 of 38 patients at the first postoperative day with a duration of 38 days. In the midbrain, the posterior limb of the internal capsule and the thalamus, a restricted diffusion became postoperatively prominent at day 9 in all three localizations, with a duration of 36, 34 and 36 days, respectively. The incidence of thalamic lesions was lower if a preoperative damage had occurred.
CONCLUSIONS: The restricted diffusion in the basal ganglia resembles direct effects of the operation at its edges, whereas the later appearing diffusion restriction in the midbrain and the posterior limb of the internal capsule rather belong to a degeneration of the descending fibers being transected by the hemispherotomy in the sense of a Wallerian degeneration. The presence of preoperative hemispheric lesions influences the development of diffusion restriction at subacute fiber degeneration.
METHODS: Fifty-nine patients were included into this study, all of them having had one pre-operative and at least one post-operative MRI, including diffusion imaging at b‑values of 0 and 1000 s/mm2 with a calculated ADC.
RESULTS: Diffusion restriction occurred exclusively on the operated site in all patients. In the basal ganglia, diffusion restriction was present in 37 of 38 patients at the first postoperative day with a duration of 38 days. In the midbrain, the posterior limb of the internal capsule and the thalamus, a restricted diffusion became postoperatively prominent at day 9 in all three localizations, with a duration of 36, 34 and 36 days, respectively. The incidence of thalamic lesions was lower if a preoperative damage had occurred.
CONCLUSIONS: The restricted diffusion in the basal ganglia resembles direct effects of the operation at its edges, whereas the later appearing diffusion restriction in the midbrain and the posterior limb of the internal capsule rather belong to a degeneration of the descending fibers being transected by the hemispherotomy in the sense of a Wallerian degeneration. The presence of preoperative hemispheric lesions influences the development of diffusion restriction at subacute fiber degeneration.
摘要：
目的：垂直矢状旁半半球切开术后，通常在同侧甚至远离邻近的切除边缘看到受限的弥散。这项回顾性队列研究分析了垂直矢状旁半球切开术后弥散限制的解剖部位和时间过程。
方法：59名患者被纳入本研究，他们都做了一次术前和至少一次术后核磁共振成像，包括b值为0和1000s/mm2的扩散成像，并使用计算的ADC。
结果：所有患者的手术部位均发生弥散受限。在基底神经节,38例患者中有37例患者在术后第一天出现弥散限制,持续时间为38天.在中脑，内囊的后肢和丘脑，在所有三个定位中，术后第9天限制扩散变得突出，持续时间为36、34和36天，分别。如果发生术前损害，丘脑病变的发生率较低。
结论：基底神经节的弥散受限类似于手术边缘的直接影响，而后来在中脑和内囊后肢出现的扩散限制则属于Wallerian变性意义上的半球切开术横切的下降纤维的变性。术前半球病变的存在会影响亚急性纤维变性时弥散限制的发展。
方法：59名患者被纳入本研究，他们都做了一次术前和至少一次术后核磁共振成像，包括b值为0和1000s/mm2的扩散成像，并使用计算的ADC。
结果：所有患者的手术部位均发生弥散受限。在基底神经节,38例患者中有37例患者在术后第一天出现弥散限制,持续时间为38天.在中脑，内囊的后肢和丘脑，在所有三个定位中，术后第9天限制扩散变得突出，持续时间为36、34和36天，分别。如果发生术前损害，丘脑病变的发生率较低。
结论：基底神经节的弥散受限类似于手术边缘的直接影响，而后来在中脑和内囊后肢出现的扩散限制则属于Wallerian变性意义上的半球切开术横切的下降纤维的变性。术前半球病变的存在会影响亚急性纤维变性时弥散限制的发展。
