Computer-tomographic (CT) studies and anthropological measurements in patients with atlanto-occipital fusion

Computer tomographic (CT) studies and anthropological measurements were performed in individuals showing complete or partial atlanto-occipital fusion. In 13 patients and 13 matched controls all measurements excepting head length and head breadth gave smaller, and in some instances significantly smaller values in the patients. The two head measurements, on the other hand, turned out to be somewhat, though not significantly larger. This suggested a certain amount of hydrocephalus internus. Computer-tomographic (CT) studies in 11 patients and 9 controls gave some--not very clearcut--evidence in favor of this hypothesis. Moreover, some other mild anomalies such as prominent and dilated sulci and cisterns were observed in 9 of 11 patients and in 3 of 9 controls (P1 one tailed = 0.0399).