Pneumoencephalographic Evidence of Increased Transventricular Absorption of Cerebrospinal Fluid

The rate of accumulation of cerebrospinal fluid in both lateral ventricles was calculated during pneumoencephalography in 20 patients. In patients with conditions known to be associated with increased transventricular absorption, the rates of accumulation of fluid were slower than in patients in whom increased transventricular absorption was unlikely. These findings suggest that this procedure can be used to distinguish atrophy from communicating hydrocephalus. One patient with pseudotumor cerebri also showed a slow rate of accumulation of fluid, suggesting increased transventricular absorption.