Abstract:
1) To resolve contradictory reports in the literature regarding adverse effects of acute blood alcohol level (BAL) on neuropsychological outcome from traumatic brain injury (TBI). 2) 459 adults with nonpenetrating TBI who were inpatients at one of 6 rehabilitation centers in the TBI Model Systems project, whose BAL had been measured at hospital arrival, and who emerged from post-traumatic amnesia (PTA) and underwent neuropsychological testing before rehabilitation discharge. 3)15 neuropsychological tests were administered after resolution of post-traumatic amnesia and at one year post-injury. 4) BAL was classified as 1) negative vs. positive and 2) intoxicated (BAL > 100 mg/dl) vs. non-intoxicated. The effect of BAL on neuropsychological performance was analyzed by linear models adjusting for age, education, and PTA duration. Results: 51% had positive BAL and 32% were intoxicated. Alcohol involvement adversely affected the Glasgow Coma Scale score but not PTA duration. Those with alcohol involvement were less likely to complete testing during rehabilitation. There was no adverse effect of BAL on neuropsychological performance during rehabilitation. The sample size provided 80% power to detect a standardized mean difference of at least .33. Results of testing at one year post-injury also showed no adverse effect of BAL although the sample size was decreased by attrition. 5) In TBI rehabilitation inpatients, any adverse effects of BAL on early neuropsychological outcome are smaller than detectable from the present sample size. Therefore, adverse effects of alcohol involvement on functional outcome from TBI may be mediated by factors other than neuropsychological deficits.