Diffuse brain damage of immediate impact type. Its relationship to 'primary brain-stem damage' in head injury.

In a neuropathological analysis of 151 fatal non-missile head injuries, there were 19 cases with focal lesions in the dorsolateral quadrant of the brain-stem in the corpus callosum, and histological evidence of diffuse damage to white matter. Eight of these cases had not experienced a high intracranial pressure during life. All 19 cases had been rendered unconscious at the moment of impact and had remained so or in the persistent vegetative state until death. It is therefore concluded that diffuse damage to white matter may occur as a primary event at the moment of impact, that is, it is one type of immediate impact damage to the brain. It is also concluded that this type of damage is the pathological basis of 'primary brain-stem injury' since in no patient thought clinically to have sustained 'primary brain-stem injury' were abnormalities confined to the brain-stem. Since no patient with this type of brain damage recovered consciousness after injury, it is probable that diffuse damage to white matter is the most important single factor governing the outcome in a patient who sustains a non-missile head injury.