Re: benign intercranial hypertension

Posted By CCF MD mdf on May 22, 1998 at 12:23:40:

In Reply to: benign intercranial hypertension posted by Kari Gallagher on May 22, 1998 at 10:33:37:






I have been experiencing a rhythmic muffling in my right ear for over a year now.  I have had many tests done, including audiograms, MRI's, and MRA's.  My hearing is gradually getting worse but everything else is normal.  Now my ENT wants me to see an eye doctor for "benign intercranial hypertension".  What is this?  Can you give me as much information as possible on this subject.
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Benign intracranial hypertension, also called pseudotumor cerebri. This has nothing to do with a tumor, in fact part of the definition of the disease is that there is no tumor.
The cerebrospinal fluid (CSF) is a clear fluid (mostly water) which bathes the brain and spinal cord. It is produced in the ventricles (hollow cavities in the center of the brain), flows through certain openings in and around the brain, and over the surface of the brain and spinal cord, and is eventually reabsorbed in the lining of the brain (the meninges). There are just a few tablespoons of CSF, but that's all you need to act as a shock absorber and nutrient medium for the central nervous system. There is quite a bit of turnover. For example, if you remove a tablespoon (as in a spinal tap), that is replaced within an hour or so.
The CSF is under pressure. There is a "normal" range of pressure. Too much pressure can be due to a variety of causes. For example, if there is a blockage in the flow at one point, fluid can get backed up behind the obstruction and you get "noncommunicating" hydrocephalus. On the other hand, if fluid is not reabsorbed as fast as it is made, the pressure also can go up ("communicating" hydrocephalus).
Sometimes the fluid pressure is elevated for no reason that anyone can figure out. It isn't a matter of too much fluid, so hydrocephalus is not the right term. Benign intracranial hypertension is such a case. By definition, the ONLY abnormality is the increased CSF pressure - there is no abnormality of the amount of fluid, or of the circulation or of reabsorption. There is NO mass, and no loss of brain tissue as a result.
Symptoms include headaches (sometimes changing with position), and subtle vision problems which may not be apparent at first. Although the disorder is "benign" (not life-threatening), over the long term it can cause visual problems, and for that reason opthalmologists are involved in management.
There are several risk factors (obesity, use of certain medications) but sometimes no clear cause is identified.
Treatment is aimed at reducing the pressure or volume of fluid.
I hope this helps. I can't say specifically what your diagnosis is, but at least you can be prepared when you see the doctor to ask the right questions and understand what he/she tells you. CCF MD mdf.

[wenners]

A related discussion, Intercranial Pressure Guages was started.