Hydrocephalus, Macewen sign of

Hydrocephalus, Macewen sign of: A sign to detect hydrocephalus (and brain abscess). Percussion (tapping) on the skull at a particular spot (near the junction of the frontal, temporal and parietal bones) yields an unusually resonant sound in the presence of hydrocephalus or a brain abscess.

Named for Sir William Macewen (1848-1924), a surgeon in Glascow, Scotland who also described Macewen's operation for inguinal hernia.