Some children with large or rapidly growing heads are diagnosed with a condition called 'benign' external hydrocephalus (BEH). This condition has often been considered harmless, but some children show signs of developmental delay or other symptoms. This study aimed to understand whether pressure inside the brain (intracranial pressure, or ICP) is truly normal in these cases, and whether monitoring it could help guide treatment.

What We Did: We followed 36 young children diagnosed with BEH. Each child had their brain pressure monitored continuously for at least 48 hours using a small sensor placed on the surface of the brain. We looked at average pressure levels, pressure wave patterns, and how these changed over time—especially during sleep.

What We Found: Over half of the children showed signs like delayed motor or language development. Many had pressure readings that were higher than expected, especially at night. Most children had unusual wave patterns (called B waves) during sleep, which can be a sign of unstable pressure. In some children, the pressure rose sharply and repeatedly—suggesting their brain might not be handling pressure changes well. Because of these findings, 30 of the 36 children eventually received a shunt (a device to drain excess fluid from the brain).

What This Means: Even though BEH is often considered a mild or “benign” condition, our study shows that some children may actually have harmful pressure changes in the brain. Continuous ICP monitoring can help identify which children might benefit from surgery and prevent long-term problems.

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