Dandy-Walker症候群の同胞例

SIB CASES OF DANDY-WALKER SYNDROME

I．はじめに

　Dandy-Walker症候群は先天性水頭症の重要な位置を占め，胎生4〜5カ月の第IV脳室形成期における何らかの異常にもとずき，第IV脳室蓋の膨隆した嚢胞，小脳虫部，扁桃形成不全，Magendie孔，Luschka孔の閉塞，水頭症などを呈する稀な奇型である。病因については多くの論があるが，Benda^1）らは一家系に3例の本症候群を認めたことから，遺伝的要因を重視している。我々はこのたび，本症候群と思われる同胞例を経験し得たので報告する。

Two children of normal parents had "Dandy-Walker syndrome" (cystic dilatation of the 4th ventricle with incomplete development of the cere-beller vermis).

Both cases were admitted to our hospital in neo-natal period, because of apneic spell. Air study showed the enlargement of the 4th ventricle in both cases.

One case (22 days after birth, male infant) was operated by occipital craniotomy, and cystic mem-brane of the roof of the 4th ventricle was removed. But his head was growing rapidly in size, which suggested hydrocephalus. He died of pneumonia at 70 days after V-P shunt operation. At autopsy, defect of the cerebellar vermis and tonsil, involv-ing the enlargement of the 4th ventricle was found.

Another case, younger sister of the previous one, was complicated by occipital meningocele, which did not communicated with ventricular system. Her occipital tumor was removed, and now, she is growing normally in body size, but does not react to the visual stimuli with considerable psychomotor retardation.

In our cases, occulsion of the foramina Luschka and Magendie was not present.

So, we have come to the conclusion that primary underdevelopment of the cerebellum is of major importance for understanding of the etiopathoge-nesis of this syndrome.