[A study of cisterna magna on brain computerized tomography in children].

Although many publications on cranial computerized tomography have been reported in recent years, very little attention has been directed to the cisterna magna (CM) and its variations. The size of the cisterna magna is still debatable and the criterion of the mega cisterna magna is obscure. We studied age distribution, clinical manifestations, and other CT findings in the children with enlarged cisterna magna. A consecutive series of 367 computerized tomographic scans were reviewed. We classified four classes according to the degree of enlargement of the cisterna magna: CM is undetectable; CM (-), CM is detectable at the level of sella turcica and the fourth ventricle; CM(+), CM extends upward at the level of suprasellar cistern and colliculus inferior; CM (+ +), and CM extends extensively at the level of the third ventricle and colliculus superior; CM (+ + +). We judged 55 CT scans (15%) to belong to CM (+ + +) class and 100 scans (27%) to CM (+ +) class. The greater part of children with CM (+ + +) were younger in contrast with CM (+ +), which distributed uniformly in every ages. Also we differentiated the patients into three groups from clinical manifestations as follows: patients with developmental delayed; group D, patients with organic neurological diseases; group N, patients with other diseases; group O. The ratio of group D is significantly higher in CM (+ + +) than that of other groups. No children had posterior fossa symptoms of mass effect and required treatment.(ABSTRACT TRUNCATED AT 250 WORDS)