Tin ear syndrome: rotational acceleration in pediatric head injuries.

An array of signs pathognomonic of child abuse is described for three young children. The eponym "tin ear syndrome" describes distinct unilateral ear bruising, radiographic evidence of ipisilateral cerebral edema with obliteration of the basilar cisterns, and hemorrhagic retinopathy. Rotational acceleration produced by blunt trauma to the ear is shown to be a necessary and sufficient cause for the production of this syndrome. An approximate value of 4,670 radians/s2 produced by a force of 309 to 347 N (70 to 80 lb) results in shear stress and tearing of the subdural veins, loss of cortical vasomotor tone, cerebral hyperemia, herniation, and death. Past history and environmental circumstances implicated child abuse in every case.