Abstract
Computed tomographic images of brains from 26 individuals (10 males and 16 females) with Down syndrome were analysed for roentogenographic measurement. Their ages ranged from 14 to 47 years, the average being 28 years. The results showed that their Sylvian fissure ratio was larger in the aged group. A high incidence of calcification in basal ganglia, choroid plexus and pineal body was noted (85%). An increased Sylvian fissure ratio and a high incidence of intracranial calcification may be practically used as representatives of premature aging. Furthermore, a high incidence of mega cisterna magna implicates that it is worthy of study whether individuals with Down syndrome have a predisposition to underdevelopment of cerebellum.