Estimation of premorbid functioning after traumatic brain injury

Estimation of premorbid functioning in patients with traumatic brain injury (TBI) is a difficult but necessary step both in the assessment of neurological impairment and in planning treatment. Because the estimation process is almost always retrospective, its reliability is questionable. The use of multiple sources of information improves the likelihood of an accurate estimate. The effects of TBI cross a number of domains in the victim's life. Thus, premorbid functioning must be estimated in the physical, cognitive, emotional, social, financial and vocational spheres. Knowledge of baseline or premorbid functioning levels allows the clinician to appreciate the severity of injury, provide a prognosis, and shape treatment goals that are specific to the individual. In this article, we present the key questions to be addressed, suggest sources of information to obtain the answers, describe the processes through which answers should be obtained, and outline the uses for this important information in working with victims of TBI.