Core Terms & Classification
Ventriculomegaly
Ventriculomegaly is enlargement of the brain's ventricles, which can be a sign of hydrocephalus or other conditions.
In short: Ventriculomegaly
- It describes enlarged ventricles seen on imaging.
- It can be due to hydrocephalus, brain atrophy, or normal variation.
- It is measured with imaging and indices like the Evans index.
- It is a finding, not a diagnosis by itself.
What it is
Ventriculomegaly is the enlargement of the fluid-filled ventricles of the brain, identified on imaging. It is a descriptive finding that can have several underlying explanations.
Understanding Ventriculomegaly
Enlarged ventricles can result from hydrocephalus (fluid buildup under pressure), from loss of surrounding brain tissue (atrophy, called hydrocephalus ex vacuo), or sometimes as a mild, non-progressive variation. Because the same appearance can have different causes, doctors interpret ventriculomegaly alongside other findings — such as pressure signs, the person's symptoms, and how the ventricles change over time. Measurements like the Evans index help quantify the enlargement.
Why it matters
Understanding ventriculomegaly helps families see that enlarged ventricles are a starting point for evaluation, not an automatic diagnosis of hydrocephalus. The cause and whether it is progressing matter more than the finding alone.
Common questions
Does ventriculomegaly always mean hydrocephalus?
No — it can also reflect brain atrophy or normal variation.
How is it measured?
With imaging and indices such as the Evans index.
Is it the same as hydrocephalus?
Not necessarily — it is a finding that hydrocephalus can cause.
Bottom line
Ventriculomegaly is enlargement of the brain's ventricles, which can be caused by hydrocephalus but also by other conditions.
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