The Wonderful World of Hydrocephalus: Part 3, How Hydrocephalus Works

Posted by pforpeanuts on June 5, 2012 · Leave a Comment 

Let’s begin with your central nervous system.

Your brain and spinal cord form your central nervous system. Your central nervous system protects your skull and vertebrae. Between the skull and vertebrae are membranes (meninges) that surround your brain and spinal cord. This space, the subarachnoid space, is where cerebrospinal fluid (CSF) flows. CSF is basically salt water. To be more specific, it is a product of your own blood that’s been distilled.

Your brain floats in CSF in order to protect itself from hitting against the skull. CSF is produced and absorbed within the cavities of your brain called ventricles. You have four ventricles: two laterals and two centrals (the third and fourth). It’s within these cavities that hydrocephalus occurs.

Remember from Part 2 that hydrocephalus is a medical condition in which there is an abnormal accumulation of cerebrospinal fluid (CSF) in the ventricles, or cavities, of the brain. It’s not that hydro patients produce more CSF than the average person, it’s that they can’t absorb it naturally. So the accumulation of CSF builds-up within those ventricles. What next? The pressure has to be relieved and the CSF has to be removed or displaced.

How much CSF accumulates at what rate differs per person. Some people can go decades with the pressure slowly building (read this amazing story), and some can’t go a week without serious consequences. As pressure/ fluid builds in the ventricles these cavities expand like a balloon filling with air. As the balloon gets bigger it pushes out on brain matter causing brain damage. As an adult, there is only so much room for your ventricles to expand without permanent damage to brain tissue. Basically the ventricles are pushing outward while your skull is pushing brain matter inward. Not a good situation. Fortunately, infant’s heads can expand since their sutures aren’t yet fused (pushing out brain matter and skull vs. squeezing it) therefore accommodate for some pressure. However, this only lasts for the first 1-2 years and must be controlled ASAP.

That’s the basic idea behind hydrocephalus. Simple. Right? (I hope I’m explaining this okay. Again, I’m not a doctor!)

Not really. The problem with hydro is that everyone handles it differently. The human body does an amazing job at balancing the amount of CSF coming in and going out. It changes constantly–per year, season, month, hour, even minute. Unfortunately, the only way to control hydro is with a shunt, and manufactured shunts can’t do what the body naturally does. If only…

Let’s stop here and save shunt talk for next time when I’ll explain how shunts work (and don’t work). Until then.

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Resources:
hydroassoc.org
wiki/Hydrocephalus
My amazing neurosurgeon-Dr. George

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Filed under Hydrocephalus · Tagged with brain damage, cavities, central nervous system, centrals, cerebrospinal fluid, CSF, hydro, hydrocephalus, laterals, shunt, spinal cord, sutures, ventricles