Hydrocephalus

One of the first difficulties that you may face is a recommendation that your child have a shunt placed. As children with Hydranencephaly are born with an accumulation of fluid in their skulls there is sometimes trouble with the drainage of the fluid. This problem is called Hydrocephalus. Some children with Hydra...are found to need a shunt almost immediately whereas others may never need one. The Dr will recommend a shunt if it is found that your baby's head is growing too rapidly or there are indications of increased intracranial pressure.

My child does not have a shunt, does he/she still have Hydranencephaly?
Over the years, several people have asked if their child never needs a shunt, do they still have Hydranencephaly. The following are answers to those questions by Dr. Bjorn Merker, Neuroscientist:

I am no expert on the ventricular system, and know almost nothing about how it is affected specifically in hydranencephaly, but there is one general principle which makes the hydranencephaly situation rather easy to understand. The principle is that cerebrospinal fluid, the fluid that bathes the brain, is produced in the ventricles by a flimsy tissue called choroid plexus, and that all the fluid that is produced has to drain "downwards" to get to the fourth ventricle, and from there out into the outer fluid-filled space surrounding the brain. So any obstruction at any place along this successive drainage path will cause pressure to build up ABOVE that place. There are the lateral ventricles (inside the hemispheres, one in each), the third ventricle (inside the tweenbrain), and the fourth ventricle (in the hindbrain), and there are narrow passages between each of these, which can be obstructed. The lateral ventricles produce more CSF than the others, and so a slow flow from them downwards along the chain is taking place all the time. Applying this to hydranencephaly, the choroid plexus continues to produce fluid after the hemispheres are resorbed in hydranencephaly, and if the passage to the third ventricle (tweenbrain) and fourth ventricle (hindbrain) is open, there is no problem. That child will not need a shunt. But you can imagine that it easily happens, during the massive damage to the hemispheres in hydranencephaly, that the passage to, say, the third ventricle, or between the third and the fourth, gets blocked, and so pressure will build up, and sooner or later such a child will need a shunt.

For your reference please see the various brain diagrams created by Bjorn
Brain in Hydranencephaly
Comparison between intact brain and Hydranencephaly brain

Hydrocephalus vs. Hydranencephaly
Another common discussion among families of children with Hydranencephaly is the difference between Hydrocephalus and Hydranencephaly. Following is an explanation of this from Dr. Bjorn Merker.

What may help you understand the difference between hydrocephalus and hydranencephaly-which is a big difference-is to imagine that in those first MRIs you saw, just inside the light-colored thin round "rim" that marks the skull bone, might have been a thin coating of brain tissue, so thin that it simply made the skull bone look a bit thicker. Now such a thin coating can actually be the whole thickness of the hemispheres pressed back against the skull (that is, all around the entire inside of the skull in a continuous balloon-like millimeter-thin continuous coating,-see enclosed figure) by expanding ventricles. Looking at such a picture the radiologist may think that the thin coating is not even there, and IF SO-if not there-that would mean the whole hemispheres are missing, and so it is a radical case of hydranencephaly. But if that millimeter-thin coating is there, the whole hemispheres are still there, just unbelievably compressed and distorted, and then it is hydrocephalus.

Now it may sound hard to believe that these big lumps of hemisphere can actually be compressed to that extent (so I quickly made a drawing to help your imagination), but it just happens to be a fact that they can, and I hope the drawing helps to understand how.

Other pages in this section:
Hydrocephalus Links
Hydrocephalus Experiences
Hydrocephalus Glossary

Back to Health Conditions Table of Contents Page

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August 16, 2001- January 12, 2005

This website is funded in loving memory of Jason S. by his mother Kammy

The information on this site is provided by families, caregivers, and professionals who are or have been caring for a child with Hydranencephaly.

Please report any broken links or missing photos to angelbearmom@shaw.ca