Wallerian degeneration is defined as axonal fiber and myelin sheath degeneration that affects myelinated axons within the peripheral or central nervous system. Wallerian degeneration or anterograde axonal degeneration before myelination is rarely reported. Involvement of both corticospinal tracts (CSTs) is rarely documented in the literature. We present the postmortem neuropathologic findings of a 1-week-old male neonate born at 23 weeks of gestation with bilateral CST degeneration extending from the posterior limb of the internal capsule through the brainstem into the lumbar spinal cord. Abundant CD68- and CD163-positive macrophages were the prominent histopathology in both CSTs. The cerebrum, brainstem, and spinal cord were unmyelinated, as expected. In contrast, the spinal nerve roots demonstrated early myelination. This case illustrates that Wallerian degeneration occurs in unmyelinated axis cylinders.

中文翻译：

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髓鞘形成前的皮质脊髓沃勒变性：病例报告。

Wallerian 变性被定义为轴索纤维和髓鞘变性，影响外周或中枢神经系统内的有髓轴突。很少报道髓鞘形成前的沃勒变性或顺行性轴索变性。文献中很少记录两个皮质脊髓束 (CST) 的受累。我们展示了一名 1 周大的男性新生儿在 23 周出生时的死后神经病理学发现，双侧 CST 变性从内囊后肢通过脑干延伸到腰椎脊髓。丰富的 CD68 和 CD163 阳性巨噬细胞是两种 CST 中突出的组织病理学。正如预期的那样，大脑、脑干和脊髓都没有髓鞘。相反，脊神经根表现出早期髓鞘形成。