An anatomical and physiological basis for CSF pathway disorders

More than 60% of the human body weight is made of water (1). Water surrounds, permeates, flows, and forms an integral component of the brain and the spinal cord. Cerebrospinal fluid (CSF) is one part of this integrated system. CSF has important mechanical and biochemical functions and is actively produced at a rate of 500 mL/day, circulates through the ventricles, subarachnoid space and parenchyma, and is reabsorbed into the venous circulation (Fig. 1). Failures of this system manifest as clinical CSF disorders. This chapter reviews current concepts of the relevant anatomy and physiology to provide a basis for understanding CSF pathway disorders, and existing and future treatment options.