Intracranial hypertension

Intracranial hypertension is a condition of increased pressure in the brain.

Idiopathic intracranial hypertension
When the cause of increased pressure is unknown it is called Idiopathic Intracranial Hypertension (IIH). It was previously known as pseudotumor cerebri as the symptoms can mimic that of a brain tumor, even though no tumor is present. It is considered to be a rare disease, affecting just 1 in 100,000.

Related conditions
A new body of research indicates some ME/CFS and Ehlers-Danlos syndrome patients may have borderline or subclinical intracranial hypertension and benefit from IIH treatments such as Diamox, venous stents, or shunts.

ME/CFS
A case study of a woman presenting with symptoms of CFS and pressure headache, who was diagnosed with borderline intracranial hypertension, found that her CFS symptoms resolved with the placement of a transverse sinus stent. A cross-sectional study of twenty patients presenting at a headache clinic found that a large proportion of patients had borderline intracranial hypertension, with four meeting the diagnostic criteria for IIH (mean cerebrospinal fluid pressure was 19 cm H2O (range 12–41 cm H2O); however, none had clinical signs of IIH. Cerebrospinal fluid drainage via lumbar puncture improved symptoms in 17/20 patients. Researchers speculate that a subset of CFS patients may have borderline cases of idiopathic intracranial hypertension without papillodema.