Age-related changes of cerebral ventricular size. Part II: Normalization of ventricular size following shunting.

Thirty-one hydrocephalic patients were investigated prospectively by means of computed tomographic scan performed prior to and one week after cerebrospinal fluid (CSF) shunting. Planimetric measurements of the size of the cerebral ventricles were compared before and after shunting. Children under two years of age and elderly patients showed significantly less reduction of ventricular size (8.5 +/- 6.3% and 9.7 +/- 3.5% respectively) than older children and young adults (61.2 +/- 5.2%). The degree of reduction of ventricular size did not correlate with pre-operative size of ventricles, duration of disease, or clinical improvement. These findings suggest that reduction of ventricular size following CSF shunting is related to age. We postulate that the size of cerebral ventricles in hydrocephalic patients is not exclusively related to CSF dynamics, but also depends upon the intrinsic elastic properties of the cerebral parenchyma which vary with age.