FIG 4.

Schematic of the components of craniospinal compliance and hypothesized physiology of CVF (CSF = green, arterial blood = red, venous blood = blue). A normal CSC encompasses both intraventricular and subarachnoid CSF and is defined by cranial and spinal compartments (larger and smaller boxes, respectively) as well as the arteriovenous vascular bed (A). In dural tear CSF leak or CVF at low pressure, an equilibrium state (B) may exist in which the leak is occult by CTM. With special maneuvers (dynamic CTM, respiratory-phase variation, jugular pressure, and bolus-pressure augmentation), pressure gradients may open the leak, allowing detection on CTM (C).