Non-communicating hydrocephalus

What it is

Non-communicating hydrocephalus is a type in which CSF is obstructed somewhere within the ventricular system, so it cannot flow normally from one part to the next. It is also known as obstructive hydrocephalus.

Understanding Non-communicating hydrocephalus

Here, a physical blockage interrupts the normal pathway of CSF through the ventricles — for example, at the narrow cerebral aqueduct (aqueductal stenosis), at the foramina connecting the ventricles, or from a tumor or cyst pressing on the pathway. Fluid backs up behind the blockage, enlarging the ventricles upstream. This form is called "non-communicating" because the obstruction prevents free communication between parts of the ventricular system. It is often well suited to treatment with endoscopic third ventriculostomy (ETV), which creates a new pathway around the blockage.

Why it matters

Understanding the non-communicating type helps families see that the problem is a blockage inside the ventricles. This is important because such blockages can sometimes be bypassed with an endoscopic procedure rather than a shunt.