5 Types of Hydrocephalus and Their Causes
Hydrocephalus is a condition where too much cerebrospinal fluid (CSF) builds up inside the brain. Even though it was once called “water on the brain,” the fluid isn’t actually water, it’s CSF, a clear liquid that surrounds the brain and spinal cord. CSF plays an important role in protecting the brain, delivering nutrients, and getting rid of waste.
Normally, CSF moves through spaces in the brain called ventricles and is eventually absorbed into the bloodstream. But if something blocks the flow or prevents the body from reabsorbing it properly, the fluid starts to collect, making the ventricles bigger. This increases pressure inside the skull, which can damage brain tissue and cause various symptoms.
Hydrocephalus can affect people of all ages, from newborns to older adults. About 1 to 2 out of every 1,000 babies in the U.S. are born with this condition. If medical negligence is the cause of your child’s hydrocephalus, you need to speak with a lawyer. They can help you with your claim.
Now, let’s break down the different types of hydrocephalus and what causes them.
- Communicating Hydrocephalus
This type happens when the CSF flow gets blocked after leaving the ventricles. Even though the fluid can still move between the ventricles, it can’t drain properly into the bloodstream.
One common cause is a thickening of membranes at the base of the brain called the arachnoid, which can stop CSF from flowing freely. Other causes include infections, bleeding in the brain, or inflammation from an injury.
- Non-Communicating Hydrocephalus (Obstructive Hydrocephalus)
This type is also called obstructive hydrocephalus because something physically blocks the CSF from flowing between the ventricles. The blockage usually happens in one of the small, narrow passages that connect different parts of the brain.
A common cause is aqueductal stenosis, where a small canal called the aqueduct of Sylvius becomes too narrow or completely closed off. This stops CSF from flowing between the third and fourth ventricles, leading to fluid buildup. Other causes include tumors, cysts, or congenital defects (conditions present at birth).
- Normal Pressure Hydrocephalus (NPH)
Unlike other types, normal pressure hydrocephalus doesn’t cause a major increase in pressure inside the skull, even though the ventricles still become enlarged. It develops slowly, and symptoms can take time to appear.
NPH mostly affects older adults and can be caused by head injuries, bleeding in the brain, infections, tumors, or complications from surgery. In some cases, doctors can’t find a specific cause. this is called idiopathic NPH (idiopathic means unknown cause).
Symptoms of NPH often include difficulty walking, memory problems, and loss of bladder control.
- Hydrocephalus Ex-Vacuo
This type isn’t caused by a blockage or absorption problem. Instead, it happens when brain tissue shrinks because of damage from a stroke, injury, or diseases like Alzheimer’s.
When brain tissue shrinks, the ventricles expand to fill the extra space, creating a buildup of CSF. However, unlike other types of hydrocephalus, the pressure inside the skull usually stays normal.
- Congenital/Acquired Hydrocephalus
Hydrocephalus can also be classified based on when it develops. Congenital hydrocephalus means the condition is present at birth. It can be caused by genetic factors, infections during pregnancy, or developmental abnormalities like aqueductal stenosis.
Acquired hydrocephalus on the other hand, happens later in life due to injury, infections, tumors, or bleeding in the brain. This type can affect people of any age.
