The neuropsychological similarities of mild and more severe head injury.

Reports in the literature have suggested that the neuropsychological effects of mild head injury are selective, represented by impairment of attention, information processing, and memory, and that evaluations with comprehensive and standard test batteries are likely to miss such deficits. The present study compared groups of individuals with mild head injuries, more severe head injuries, and non-brain-damaged controls using 19 tests from the Halstead-Reitan Battery. The results indicated that the group with mild head injuries performed significantly poorer than the controls, and that the group with more severe head injuries scored significantly more poorly than either of the other groups. Comparisons of the pattern of test scores for the two head-injured groups were remarkably similar across the 19 tests, yielding a rank difference correlation of 0.87. The findings yielded no evidence of selective or delimited impairment in the group with mild head injuries, but instead, showed them to have test results that were very similar, though showing less neuropsychological impairment, to the group of subjects with more severe head injuries. These findings suggest that a comprehensive neuropsychological test battery is necessary to detect the broad range of deficits that may result from mild head injury.