Macewen sign: 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.
