Isolated hypoplasia of the tentorium.

Developmental defects of the tentorium represent a spectrum of disease with small defects and apertures that have little clinical significance on one end and hypoplasia or aplasia on the other. The latter is associated with serious central nervous system malformations, it is seldom isolated, and aside from the 3 cases described below, there have only been 2 case reports published on isolated hypoplasia. This condition is important to recognize so as to avoid unnecessary investigations and interventions.