Long-term consequences of minimal brain injury: loss of consciousness does not predict memory impairment.

This study evaluated the memory and intellectual function of 32 adults following minimal brain injury. All patients had a Glasgow Coma Scale score of 15 upon evaluation in the Emergency Room, negative findings on radiographic examination, and negative history of prior neurologic disease or injury. Seventeen of these had experienced a loss of consciousness. Patients suffering a loss of consciousness postinjury obtained significantly lower mean verbal intelligence quotients than those obtained by patients who remained conscious following their accidents. Both groups exhibited memory impairments. This could indicate that loss of consciousness predicts intellectual impairment, but not degree of memory dysfunction. An alternative interpretation of these data is that patients referred for examination after a head injury that did not involve a loss of consciousness included a disproportionate number of patients from upper socioeconomic levels who have greater access to medical delivery systems or greater sophistication regarding cognitive function.