brain, spinal cord, and nerve disorders
Idiopathic Intracranial Hypertension
Diagnosis of Idiopathic Intracranial Hypertension
A doctor's evaluation Imaging tests A spinal tap Doctors suspect idiopathic intracranial hypertension based on symptoms and results of a physical examination. Sometimes doctors suspect it when they detect papilledema during a routine examination with an ophthalmoscope. If doctors suspect idiopathic intracranial hypertension, they check the Visual Field Testing (the entire area of vision that is seen out of each eye), including peripheral vision. They also examine the interior of the eye with an ophthalmoscope if they have not already done so. Magnetic resonance venography is done to evaluate the large veins (called venous sinuses) that carry blood from the brain. This test enables doctors to determine whether the venous sinuses are narrowed or blocked. Narrowed venous sinuses may be the only abnormality that imaging tests detect in people with idiopathic intracranial hypertension. Magnetic resonance imaging (MRI) of the brain is also done to check for other abnormalities that could increase pressure within the skull. A Spinal Tap (lumbar puncture) is done to measure the pressure of cerebrospinal fluid and to analyze the fluid. In idiopathic intracranial hypertension, the pressure of the fluid is increased, often to very high levels. The content of the fluid is usually normal. As soon as spinal fluid is removed during the spinal tap, the pressure inside the head decreases, the venous sinuses may widen, and more blood may flow from the brain. As a result, the headache lessens. These and other tests can help identify or rule out other possible causes of increased pressure within the skull (such as a brain tumor blocking the venous sinuses). 