Also called “pseudotumor cerebri,” Idiopathic Intracranial Hypertension (I.I.H.) literally means “too much pressure in the brain, & nobody knows why.” It causes daily (or every-other-day) headaches that can be disabling, & poses a danger for permanent damage to vision. Though rare in general, I.I.H. is more common among obese women 15-45 years-old, especially if they gained weight recently.
Diagnosis is difficult, because there are no definite symptoms. If patients describe funny visual shadows, or sounds like rushing water, that occur on-and-off, we may suspect the condition. Sometimes on eye examination we can see signs of increased brain pressure, but this happens late in the disease.
Most I.I.H. probably gets diagnosed by specialists, when clinicians refer after being unsuccessful trying to make and treat a variety of other headache diagnoses. The key is for us to suspect it based on patient characteristics, & perhaps the eye & ear symptoms mentioned above.
There may be subtle abnormalities on MRI, but it’s often normal. The main purpose of the test is to rule out other diseases. Diagnosis is made by spinal tap, measuring the “opening pressure” and finding it’s high. Since the procedure is often done for a variety of reasons without making that measurement, & the technique may be tricky, it should be performed by someone experienced in it. Be sure they measure “opening pressure.” Treatments exist, but don’t always work. Weight loss seems to help.