What is Idiopathic Intracranial Hypertension?

Idiopathic intracranial hypertension refers to an increase in the amount of pressure and cerebrospinal fluid (CSF) in the brain. Elevated pressure can cause significant migraine headaches and vision problems, sometimes leading to partial or total blindness. The disorder is not well understood, and doctors have not discovered an underlying cause. Medications to slow the production of CSF and flush excess fluid from the skull are effective in treating mild cases of idiopathic intracranial hypertension, though a very large increase in pressure often requires surgical intervention.

While the exact causes of idiopathic intracranial hypertension are unknown, researchers have identified several risk factors. Women are about 90 percent more likely to develop the condition than men, and the majority of patients are between the ages of 20 of 40. Obesity greatly increases the risk, and many people have family histories of intracranial hypertension complications. Long-term use of steroids, birth control pills, lithium, and several other medications appear to increase the likelihood of developing the condition as well.

In most cases, idiopathic intracranial hypertension symptoms develop slowly over several weeks or months. A person may have frequent or constant dull headaches that are centralized behind the eyes. Ringing in the ears and a throbbing, pulsating sensation in the temples is common as the disorder worsens. Pressure on the optic nerve can cause blurry or dim peripheral vision and induce nausea, dizziness, and vomiting. Without treatment, headaches and vision loss tend to become more debilitating and possibly lead to blindness.

A diagnosis of idiopathic intracranial hypertension is made only after doctors rule out all other possible causes of symptoms. Imaging tests such as computerized tomography scans are performed to check for physical problems, including brain tumors, contusions, and aneurysms. Blood is drawn to look for signs of leukemia or infections, and an eye test is used to confirm the presence of swelling in the back of the eye along the optic nerve. A doctor may also decide to perform a lumbar puncture along the spine to collect a CSF sample and gauge the severity of intracranial pressure.

Once other conditions have been ruled out, treatment decisions can be discussed with the patient. Diet and exercise are usually important elements of treatment for patients who are obese, and many people see improvements in their symptoms within a few weeks of making better lifestyle choices. Corticosteroids or glaucoma medications may be prescribed to relieve swelling in the optic nerve. Surgery is considered if vision problems and other symptoms worsen despite medical care.

A procedure called an optic nerve sheath fenestration can usually relieve pressure in the skull by creating a slit in the optic nerve for CSF to drain. A surgeon may also consider inserting a shunt that runs from the skull to the abdominal cavity. The shunt promotes constant CSF drainage, ensuring that pressure does not build up again. Most patients who receive surgical care are able to completely recover from their symptoms.