Idiopathic intracranial hypertension

Last reviewed: March 2019

Last updated: October 2018

Summary

The most popular hypothesis is that idiopathic intracranial hypertension (IIH) is a syndrome of reduced cerebrospinal fluid absorption.

Clinical features include headaches, pulse-synchronous tinnitus, transient visual obscurations, visual loss, neck and back pain, and diplopia.

Signs include papilledema, sixth nerve paresis, and disturbances in sensory visual function. Visual field loss is ubiquitous, and the prototype pattern for early loss is enlargement of the blind spot and inferonasal loss. Diagnostic criteria are the modified Dandy criteria.

In all patients with IIH, treatment consists of first eliminating causal factors, such as drugs and other conditions known to cause increased intracranial pressure, and instituting a low-sodium weight-reduction diet plus acetazolamide when indicated. Therapy can be given to reverse and prevent loss of vision.

Definition

Idiopathic intracranial hypertension (IIH), also known as pseudotumor cerebri, is a disorder of increased intracranial pressure that occurs mainly in overweight women of childbearing years, often in the setting of weight gain. [1] Its cause is not known (hence the preferred name IIH). It is a syndrome characterized by increased intracranial pressure and its associated signs and symptoms in an alert and oriented patient, but without localizing neurologic ﬁndings. There is no evidence of deformity or obstruction of the ventricular system, and neurodiagnostic studies are normal except for increased CSF pressure and the related neuroimaging signs. Furthermore, no secondary cause of intracranial hypertension is apparent. IIH can either be self-limited or have a life-long chronic course. [1] [2]