Driving evaluation after traumatic brain injury

Traumatic closed head injury results in a variety of cognitive and behavioral deficits that may be difficult to assess fully. Adequately evaluating driving safety is a common and important problem for health care professionals. The purpose of this study was to examine the relationship between standardized measures of cognitive function and measures of driving performance in patients with closed head injuries and in their age-matched relative or friend cohorts. Thirteen patients were evaluated. They had each sustained a closed head injury (followed by more than 1 h of coma) 3 to 6 months before testing. Their scores were analyzed along with those of seven cohorts. Assessments of cognitive function and behind-the-wheel driving performance were conducted by examiners blinded to subjects' group membership and medical condition. There was a significant relationship (r = 0.44) between the sum of rated scores of the Tactual Performance Test and Trail Making Test and the global pass/fail ratings of the behind-the-wheel driving test, but it was not related to the driving performance score. The difference between the verbal and performance IQs, and the difference between the block design and other performance tests of the Wechsler Adult Intelligence Scale-Revised were also not significantly related to driving performance. These results suggest that tests of cognitive function alone are not adequate to predict driving performance, and should be used along with standardized driving performance evaluations before recommendations are made.