Idiopathic intracranial hypertension (IIH), also known as pseudotumor cerebri, is a disorder of elevated intracranial pressure of unknown cause. Patients present with daily headache, pulse-synchronous tinnitus, transient visual obscurations, papilledema with its associated visual loss, and diplopia from sixth nerve paresis. Many disease associations have been alleged, but few besides obesity, h...

In contrast to virtually all organ systems of the body, the central nervous system was until recently believed to be devoid of a lymphatic system. The demonstration of a complex system of paravascular channels formed by the endfeet of astroglial cells ultimately draining into the venous sinuses has radically changed this idea. The system is subsidized by the recirculation of cerebrospinal fluid...