The use of the sequential gamma camera technique with evaluation of the stored information in the digital analyzing system to investigate CSF dynamics quantitatively has given interesting new information about the circulation in the epicortical SA space. The streaming of I131HSA-labelled CSF in a protracted bolus or bulk was submitted to quantitative and temporal analysis by defining the activity maxima and their amounts as well as their times of appearance. Different modalities of activity evolution in various regions make it possible to define three main types of circulatory disturbance, which are: 1. Global epicortical inhibition, 2. circumscribed epicortical inhibition by a) restriction of the SA space, b) dilatation of the SA space, and 3. gamma cisternographic asymmetry, apparently due to restriction, with a fully functioning but dilated SA space and no real inhibition. The pathological conditions in the SA space leading to these different flow disturbance modalities are presented, and the necessity to perform quantitative and temporal analysis for definition of the functional flow conditions is emphasized.