Notaridis G, Ebbing K, Giannakopoulos P, Bouras C, Kövari E
Department of Psychiatry, HUG Belle-Idée, University of Geneva School of Medicine, Geneva, Switzerland.
Neuropathol Appl Neurobiol. 2006 Jun;32(3):344-50. doi: 10.1111/j.1365-2990.2006.00719.x.
The Dandy-Walker (DW) complex is a rare posterior fossa malformation, usually observed during the prenatal period or the early infancy. Clinically, it is characterized by mental retardation, seizures, cerebellar ataxia as well as symptoms of hydrocephalus. Structural imaging reveal a hypoplasia or agenesis of the cerebellar vermis, enlargement of the fourth ventricle with a posterior fossa cyst. Additional neurodevelopmental changes such as agenesis of the corpus callosum, lissencephaly and cortical dysplasia are also present. We report the first neuropathological analysis of an adult asymptomatic DW case. Brain computerized tomography showed a massive posterior fossa cyst and hypoplasia of the cerebellum. An Ehlers-Danlos syndrome type IV characterized by repetitive intestinal perforations and a saccular aneurysm on the left posterior communicating artery was also present. Macroscopic brain examination revealed hypoplasia of both cerebellar hemispheres and posterior part of the vermis, as well as dilatation of the fourth ventricle without hydrocephalus. The posterior fossa cyst wall was formed by an external arachnoid layer, middle layer with loose connective tissue and an internal layer of ependymal cells. There were two foci of cerebellar cortical dysplasia but no ectopic neurons, neuronal loss or gliosis in both cerebellum and cerebral cortex. No vascular or significant neurodegenerative lesions were observed. In comparison with previous reports in DW infants, this adult case displayed milder brain abnormalities compatible with a diagnosis of DW variant. The preservation of the cortical cytoarchitecture as well as the paucity of additional neurodevelopmental changes may explain the absence of clinical expression.
丹迪-沃克（DW）复合体是一种罕见的后颅窝畸形，通常在孕期或婴儿早期被发现。临床上，其特征为智力发育迟缓、癫痫、小脑共济失调以及脑积水症状。结构成像显示小脑蚓部发育不全或缺失，第四脑室扩大并伴有后颅窝囊肿。还存在其他神经发育异常，如胼胝体发育不全、无脑回畸形和皮质发育异常。我们报告了首例成年无症状DW病例的神经病理学分析。脑部计算机断层扫描显示巨大的后颅窝囊肿和小脑发育不全。还存在以反复肠穿孔和左后交通动脉囊状动脉瘤为特征的IV型埃勒斯-丹洛斯综合征。大体脑部检查显示双侧小脑半球和蚓部后部发育不全，以及第四脑室扩张但无脑积水。后颅窝囊肿壁由外层蛛网膜层、含疏松结缔组织的中层和内层室管膜细胞构成。有两个小脑皮质发育异常灶，但小脑和大脑皮质均未发现异位神经元、神经元丢失或胶质增生。未观察到血管或明显的神经退行性病变。与之前关于DW婴儿的报道相比，该成年病例的脑部异常较轻，符合DW变异型的诊断。皮质细胞结构的保留以及其他神经发育异常的稀少可能解释了其无临床表现的原因。
