An index of decline or recovery following nonimpact and impact mTBI.

This study investigated the degree to which litigants/insurance claimants sustaining Nonimpact mild traumatic brain injury (mTBI) in motor vehicle accidents differed from compensation-seeking motor vehicle accident victims that suffered Impact mTBI in terms of neuropsychological decline/recovery, using as a control litigants/insurance claimants that did not experience mTBI in motor vehicle accidents. A clinical index (C-Voc) was employed as the dependent measure for decline/recovery, consisting of T-score algebraic differences between a highly sensitive neurocognitive measure (Category Test) and a relatively insensitive "hold" measure (Wechsler Adult Intelligence Scale Vocabulary subtest). Nonimpact mTBI subjects showed significantly greater neurocognitive decline than Impact mTBI participants and, interestingly, Impact mTBI individuals did not differ significantly from individuals with no diagnosis of mTBI. These findings suggest that Nonimpact subjects may experience significantly greater persistent neurocognitive residua of mTBI than Impact participants.