University of Iowa Health Care

Ophthalmology and Visual Sciences

Idiopathic Intracranial Hypertension
(Pseudotumor Cerebri)

Michael Wall, M.D.

The University of Iowa
Department of Neurology and
Department of Ophthalmology and Visual Sciences


Idiopathic Intracranial Hypertension is a condition of high pressure in the fluid around the brain. It is also known as pseudotumor cerebri because there are some of the signs and symptoms of a brain tumor without a brain tumor being present (pseudo meaning false).

The results of a long-term prospective study are found in this Brain manuscript , and a recent review can be found at this link.

The space around the brain is filled with a water-like fluid. (Fig 1.) If there is too much of this fluid present, (for example, if not enough being absorbed, Fig 2), the pressure around the brain rises. This is because the space containing the fluid cannot expand. It is this high pressure that produces the symptoms of idiopathic intracranial hypertension (idiopathic means unknown cause; intracranial means inside the head; hypertension means the fluid is under high pressure).

figure 1, click image to enlarge
Figure 1. The cerebrospinal fluid circulation. (click image to enlarge)

figure 2. click image to enlarge
Figure 2. Meninges and Superficial Cerebral Veins. (click image to enlarge)

A bell-shaped curve that 
peaks at age 30-39
Age at diagnosis of IIH

Continue with What causes IIH?
Return to IIH Index

last updated: 03/11/2014
  Share this page: