Hydrocephalus 101

With Elizabeth at the Mbarara clinic. You can see a dent in the middle of her head where the CSF has drained. She's happy and recovering, though!

I've been wanting to explain hydrocephalus to everyone so they can better understand the conditions the hospital treats, so here's my unmedical attempt to do so!

Hydrocephalus basically means "water on the brain." There are four ventricles (cavities of sorts) in the brain, the two lateral ventricles, which are on top, and the third and fourth ventricles.

The choroid plexus produces cerebrospinal fluid (CSF), which flows around the brain and down the spinal cord (the arrows below show flow of CSF). CSF is a good thing, but sometimes one of the ventricles become blocked (usually between the third and fourth ventricles, I hear), preventing proper drainage of the CSF.

With nowhere to go, the CSF stays in the ventricles, causing them to swell with the fluid and putting great pressure on the brain. Since babies' skulls are still forming (remember the soft spot on their heads?), they grow with the increasing pressure, resulting in abnormally large heads.

Most of the hydrocephalus we see here occurs after the babies are born (PIHC - post-infectious hydrocephalus); it is mostly preventable. Hydrocephalus can be caused by blockage from tumors, cysts, swelling as a result of infections like meningitis, and other reasons.

Many babies born with spina bifida develop hydrocephalus as well. Here's where the hospital comes in. There are two surgical procedures currently available to treat hydrocephalus. The first is the ETV (endoscopic third ventriculostomy), in which the surgeon uses an endoscope to create a small hole on the bottom of the third ventricle to allow the CSF to drain. This has the highest success rate and requires less maintenance. However, an ETV does not work with all cases.

The second option is to insert a shunt. Basically, a system of tubes with a valve is inserted into the right lateral ventricle, travels out of the brain between the child's skull and skin down into the abdominal cavity, where the CSF can drain. Other types of shunts may empty into the heart or the lungs, but CURE mostly uses VP (ventriculo-peritoneal) shunts.

After the ETV or the shunt is placed, the CSF begins to drain, sometimes resulting in a large valley on the child's head. Eventually, this soft spot will close on its own, though it is at a very slow rate and the sides may overlap. However, the head size generally does not change, because the skull has formed as such, and bones do not change shape easily.

That is hydrocephalus in a nutshell. I am so thankful to be at a place that can repair these babies' heads and lives and give them hope.

further reading: www.hydroassoc.org, www.ifglobal.org/hydrocephalus

This baby looked a lot happier before this picture! You can see that his skull is slightly malformed. The surgeons were able to perform an ETV on him (you can just barely see the bandage on the top right section of his head).