A preliminary normative profile of mild traumatic brain injury diagnostic criteria.

This study investigated how mild traumatic brain injury (MTBI) diagnostic and related variables present in a large, nonreferred MTBI sample. Participants were 119 adults with MTBI, drawn from consecutive admissions to two hospital emergency wards. Within 3 weeks of injury, they were asked how the 1993 American Congress of Rehabilitation Medicine MTBI diagnostic criteria and related phenomena presented in their particular cases. Results showed that retrograde amnesia was not reported or was generally very brief; retrograde amnesia was not reported unless posttraumatic amnesia was also reported; and the median ratio of posttraumatic amnesia to retrograde amnesia duration, when both were reported, was 300:1. These and other data provide a preliminary normative profile of such MTBI phenomena, and can help with differential diagnosis of MTBI in individual cases.