Cognitive functioning following traumatic brain injury: a five-year follow-up

OBJECTIVE: To describe the long-term prevalence and severity of cognitive deficits following significant (i.e., ventilation required for >24 hours) traumatic brain injury. To assess a comprehensive range of cognitive functions using psychometric measures with established normative, reliability, and validity data. METHODS: A group of 71 adults was assessed at approximately five years (mean = 66 months) following injury. Assessment of cognitive functioning covered the domains of intelligence, attention, verbal and visual memory, visual-spatial construction, and executive functions. RESULTS: Impairment was evident across all domains but prevalence varied both within and between domains. Across aspects of intelligence clinical impairment ranged from 8–25% , attention 39–62% , verbal memory 16–46% , visual memory 23–51% , visual-spatial construction 38% , and executive functions (verbal fluency) 13% . In addition, 3–23% of performances across the measures were in the borderline range, suggesting a high prevalence of subclinical deficit. CONCLUSIONS: Although the prevalence of impairment may vary across cognitive domains, long-term follow-up documented deficits in all six domains. These findings provide further evidence that while improvement of cognitive functioning following significant traumatic brain injury may be possible, recovery of function is unlikely