Abnormal patterns of cerebrospinal fluid flow and absorption after head injuries; diagnosis by isotope cisternography.

Abstract

RIHSA cisternography was performed in 47 patients after head injuries. Five patterns of abnormal C.S.F. flow and absorption were distinguished: 1. complete obstruction of the subarachnoid space over both cerebral convexities, with ventricular filling; 2. partial obstruction of the subarachnoid space over both cerebral convexities, with transient or persistent ventricular filling; 3. obstruction of the subarachnoid space over one brain convexity, with transient or persistent ventricular filling; 4. obstruction of the subarachnoid space over one convexity without ventricular filling; 5. delayed absorption of C.S.F. with a normal pattern of C.S.F. pathways. Patterns 2–5 are considered to be intermediary stages in the development or regression of hydrocephalus, which if progressive causes the final result observed in pattern 1.-In the abnormal scintigrams the subarachnoid space over one or both cerebral convexities is obstructed, the normal flow of C.S.F. to the absorption areas around the superior sagittal sinus is disturbed, and alternative mechanisms of absorption through the walls of the cerebral ventricles come into play. These abnormal C.S.F. dynamics are reversible. The significance of these observations in the context of possible ventriculo-atrial shunting is discussed.