External hydrocephalus (benign extra-axial collections of infancy) - review of 15 cases

The authors studied 15 cases of external hydrocephalus over a 7-year period (September 1987 to May 1995). External hydrocephalus is a condition in which infants with rapidly enlarging heads are found to have a MRI showing widening of subarachnoid space with mild or no ventricular dilatation. Some of the MRI were compared with those of patients with cerebral atrophy and some etiopathogenic hypothesis are presented. These findings indicate that external hydrocephalus is an age-related self-limited condition occurring in infants with open cranial sutures and that it usually resolves without intervention after the second or third year of age. (author)