Patel Sandeep, Barkovich A James
Neuroradiology Section, University of California, San Francisco, San Francisco, CA 94143, USA.
AJNR Am J Neuroradiol. 2002 Aug;23(7):1074-87.
Because of improved visualization of posterior fossa structures with MR imaging, cerebellar malformations are recognized with increasing frequency. Herein we attempt to describe and propose a rational classification of cerebellar malformations.
MR images obtained in 70 patients with cerebellar malformations were retrospectively reviewed. The cerebellar malformations were initially divided into those with hypoplasia and those with dysplasia. They were then divided into focal and diffuse malformations. Finally, they were separated according to other features, such as brain stem involvement and cerebral involvement.
All patients with diffuse cerebellar dysplasia (muscular dystrophy [n = 10], cytomegalovirus [n = 6], lissencephaly [n = 3],) had abnormalities of the cerebrum. Patients with focal cerebellar dysplasia of the Joubert (n = 12) and rhombencephalosynapsis (n = 8) types had variable cerebral dysplasia. Patients with nonsyndromic focal cerebellar dysplasia (isolated focal cerebellar cortical dysplasia [n = 2], cerebellar heterotopia with cerebellar cortical dysplasia [n = 1], idiopathic diffuse cerebellar dysplasia [n = 1], Lhermitte-Duclos syndrome [n = 1]) and those with cerebellar hypoplasia (isolated cerebellar hypoplasia [n = 6], pontocerebellar hypoplasia type 1 [n = 1]) had normal cerebra. Patients with features of Dandy-Walker malformation (n = 19) had both hypoplasia and dysplasia of the cerebellum. No notable difference was found between the cerebella of patients with large fourth ventricle cysts (Dandy-Walker malformations) and those without large fourth ventricle cysts (isolated cerebellar hypoplasia). Therefore, the Dandy-Walker malformation seems to be heterogeneous.
Use of this classification system helps in the segregation and understanding of the relationship among cerebellar malformations. Although it will undoubtedly require revisions, this classification is a first step in combining imaging with molecular biology to facilitate understanding of cerebellar development and maldevelopment.
由于磁共振成像对后颅窝结构的显示有所改善，小脑畸形的诊断频率日益增加。在此，我们试图描述并提出一种合理的小脑畸形分类方法。
回顾性分析70例小脑畸形患者的磁共振图像。小脑畸形最初分为发育不全型和发育异常型。然后再分为局灶性和弥漫性畸形。最后，根据其他特征进行区分，如脑干受累情况和大脑受累情况。
所有弥漫性小脑发育异常患者（肌营养不良[n = 10]、巨细胞病毒感染[n = 6]、无脑回畸形[n = 3]）均有大脑异常。Joubert型（n = 12）和菱形脑融合型（n = 8）局灶性小脑发育异常患者有不同程度的大脑发育异常。非综合征性局灶性小脑发育异常患者（孤立性局灶性小脑皮质发育异常[n = 2]、伴有小脑皮质发育异常的小脑异位[n = 1]、特发性弥漫性小脑发育异常[n = 1]、Lhermitte-Duclos综合征[n = 1]）以及小脑发育不全患者（孤立性小脑发育不全[n = 6]、1型脑桥小脑发育不全[n = 1]）的大脑均正常。具有Dandy-Walker畸形特征的患者（n = 19）小脑既有发育不全又有发育异常。第四脑室大囊肿患者（Dandy-Walker畸形）和无第四脑室大囊肿患者（孤立性小脑发育不全）的小脑之间未发现明显差异。因此，Dandy-Walker畸形似乎具有异质性。
使用这种分类系统有助于区分小脑畸形并理解它们之间的关系。尽管无疑需要修订，但这种分类是将影像学与分子生物学相结合以促进对小脑发育和发育异常理解的第一步。
