Macewen's sign or Macewen sign () is a sign used to help to diagnose
hydrocephalus
Hydrocephalus is a condition in which an accumulation of cerebrospinal fluid (CSF) occurs within the brain. This typically causes increased intracranial pressure, pressure inside the skull. Older people may have headaches, double vision, poor ...
(accumulation of excess
cerebrospinal fluid
Cerebrospinal fluid (CSF) is a clear, colorless body fluid found within the tissue that surrounds the brain and spinal cord of all vertebrates.
CSF is produced by specialised ependymal cells in the choroid plexus of the ventricles of the bra ...
) and brain
abscess
An abscess is a collection of pus that has built up within the tissue of the body. Signs and symptoms of abscesses include redness, pain, warmth, and swelling. The swelling may feel fluid-filled when pressed. The area of redness often extends b ...
es. Tapping (
percussion
A percussion instrument is a musical instrument that is sounded by being struck or scraped by a beater including attached or enclosed beaters or rattles struck, scraped or rubbed by hand or struck against another similar instrument. Exc ...
) the skull near the junction of the frontal bone, frontal, temporal bone, temporal, and parietal bone, parietal bones will produce cracked pot sound. Positive test is indication of separated sutures. This is due to raised intracranial tension.
The sign was discovered and described by William Macewen, Sir William Macewen (1848–1924), a surgeon and professor of the University of Glasgow, Scotland, who also described Macewen's operation for inguinal hernia.
McEwan's sign in alcohol intoxication is different: Pupils are contracted, but on external painful stimulation of the person (e.g. by pinching or slapping) causes pupil to dilate followed by slow constriction. It is suggestive of alcoholic coma.
References
Symptoms and signs: Nervous system
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