Posttraumatic ethmoidal pseudomeningoencephalocele.

Three cases are presented that illustrate the potential of craniofacial trauma to generate pseudomeningocele formation in the region of the ethmoidal air cells. In each case there was the further association of herniation of cerebral substance through the chronic diastatic fracture resulting in an acquired encephalocele. Contrast cisternography showed this important combination of anatomic findings and aided in planning the subsequent reparative surgery.