Frontal foramina in pediatric skull in cases of congenital hydrocephalus.

Purpose: To describe a new observation, frontal calvarial foramina, in pediatric patients with congenital hydrocephalus secondary to central nervous system malformation.

Materials And Methods: Frontal foramina were initially identified in three female patients with Chiari II malformation. Subsequently, head computed tomographic (CT) scans in 99 patients with congenital hydrocephalus were retrospectively reviewed. CT scans in a control group of 116 patients without hydrocephalus were also retrospectively reviewed.

Results: Frontal foramina were found in eight of 61 (13%) patients with Chiari II malformation, in one child with Dandy-Walker malformation, and in one child with occipital horn dilatation (colpocephaly), but not in control patients. Sequential CT examinations in three patients with frontal foramina depicted gradual closure after ventriculoperitoneal shunt placement.

Conclusion: Frontal foramina may represent an abnormality variably expressed in certain central nervous system malformations that cause congenital hydrocephalus. The presence of frontal foramina palpated or visualized on plain radiographs may help in the diagnosis of congenital hydrocephalus and central nervous system malformation.