Core Terms & Classification
External hydrocephalus
External hydrocephalus is the accumulation of cerebrospinal fluid in the spaces surrounding the brain, often a benign condition in infants.
In short: External hydrocephalus
- It involves fluid in the subarachnoid spaces over the brain, not the ventricles.
- In infants, it is often a benign, self-resolving condition.
- It is associated with a larger-than-average head in some babies.
- It is also called benign external hydrocephalus when self-limited.
What it is
External hydrocephalus is the accumulation of CSF in the spaces around the outside of the brain (the subarachnoid spaces), particularly over the front of the brain. In infants, a benign form is relatively common.
Understanding External hydrocephalus
In babies, benign external hydrocephalus (also called benign enlargement of the subarachnoid spaces) often presents as a larger-than-average head with widened fluid spaces over the brain, typically without raised pressure or significant symptoms. It is frequently a self-resolving condition that improves as the child grows, and many affected children develop normally. Doctors monitor head circumference and development and use imaging to distinguish it from conditions needing treatment.
Why it matters
Understanding external hydrocephalus helps families see that fluid around the brain in infancy is often benign and self-limited, distinct from internal hydrocephalus that may need treatment. This distinction can be reassuring while monitoring continues.
Common questions
Where does fluid accumulate in external hydrocephalus?
In the spaces around the brain, not the ventricles.
Is it serious in infants?
Often it is benign and self-resolving.
What is the benign form called?
Benign external hydrocephalus, or benign enlargement of the subarachnoid spaces.
Bottom line
External hydrocephalus is fluid around the brain, often a benign, self-resolving condition in infants.
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