Pediatric brain death: updated guidelines.

Logan, a 5-year-old boy, was riding his bike with his 7-year-old brother when he was struck from behind by a car traveling at approximately 40 mph. The driver indicated that she did not see the riders until she hit Logan, who was not wearing a helmet at the time of the accident. Logan was thrown from his bike and was found at the side of the road, unresponsive and posturing.