Effects of prolonged cerebrospinal fluid shunting on the skull and brain

✓ A review of postoperative radiographs in hydrocephalic patients treated with ventriculojugular shunts reveals a marked decrease in the CSF fluid spaces, both subarachnoid and intraventricular, reflected in compensatory skull changes and alterations in ventricular configuration. Most of the changes appear to be reversible when shunt malfunction develops, with the exception of acquired synostosis. Exceptions to the generalized changes that can be expected in all cases include absence of changes in the sella turcica in the presence of an intact diaphragma sellae, persistence of the “right angle” sella turcica and concave basi-occiput in patients with an Arnold-Chiari Type II malformation, and shifts of the lateral ventricle when the septum pellucidum is intact. Experimental evidence in shunted hydrocephalic dogs suggests that differential damping of ventricular pulse pressure by the shunt is a factor.