Fatal cerebral injury from blows to the site of a nonadherent bone fragment from a previous craniotomy.

A young man with a prior left temporal craniotomy was brought to the emergency room after being beaten, including a blunt trauma to the head. After receiving a cranial X-ray, the patient was discharged home. He was found in a deep coma eight hours later. Autopsy revealed an approximately 4 x 5 cm bone fragment fixed to the left temporal bone, except at the inferior margin, where it had no osseous connection. There were a 44 g subdural hematoma in the left frontotemporal region, small hematomata within the left temporal lobe, and bilateral subarachnoid hemorrhage. Microscopically, we detected ruptured choroid plexus at the surface of the left temporal lobe. We speculated that the combination of the unfixed bone fragment and hyperplastic choroid plexus after craniotomy increased the decedent's vulnerability to external trauma at that site.