Visual pathway tumors and hydrocephalus.

The authors evaluated the impact of hydrocephalus on the clinical picture of children with visual pathway tumor (VPT) with or without neurofibromatosis (NF). Charts of children with VPT treated in the authors' center since 1985 were retrospectively reviewed, and those with hydrocephalus were selected and summarized. Thirty-five children with VPT were found, of whom 20 had NF. Hydrocephalus was found in 4 children with NF (20%) and in 5 without NF (33.3%). In 6 of the children, ventricular dilatation with signs of acute increased intracranial pressure already existed at the time of diagnosis and the hydrocephalus was shunted at this time. In the other 3 children, all with NF, the hydrocephalus resulted from slowly developing aqueductal stenosis, leading in 2 to severe visual acuity deterioration. The results suggest that in children with VPT and NF, hydrocephalus, and especially hydrocephalus resulting from aqueductal stenosis, is more frequent than in the general population of NF patients, and less frequent than in VPT patients without NF. The possibility of the indolent development of hydrocephalus should be borne in mind while following children with NF. The optic nerve, when already involved with a glioma, is more vulnerable to increased pressure. Thus, in children with VPT and NF, any ventricular dilatation should lead to a consideration of early shunting.