Traumatic Brain Injury in Patient with Biparietal Thinning.

A 77-year-old man presented with progressive consciousness disturbance, presumably caused by a backward fall. Head computed tomography findings showed a large intracerebral hemorrhage in the left parietal lobe. Radiated fractures with an oval depression of the bilateral parietal bone crossing the midline were noted. Surgical evacuation of the hemorrhage was performed via a left-sided parietal craniotomy, during which fragments from the fracture with eggshell-like thinning were noted. Biparietal thinning is an uncommon condition noted in radiological findings of a symmetrical oval depression of bilateral parietal bones with reduced diploe thickness. Cases of traumatic brain injury in patients with biparietal thinning have rarely been reported. This condition should be recognized as a possible predisposing factor for traumatic brain injury.