Impact of age on long-term cognitive function after traumatic brain injury.

OBJECTIVE: To examine the association of age and time postinjury with cognitive outcome 5-22 years following traumatic brain injury (TBI), in relation to matched uninjured controls.

METHODS: One hundred twelve participants with mild to very severe TBI, aged 16-81 years at the time of injury, were cognitively assessed on measures of processing speed and attention, verbal and visual memory, executive function, and working memory. Results were compared with those of 112 healthy controls individually matched for current age, gender, education, and estimated IQ.

RESULTS: Older injured individuals performed worse than did younger injured individuals across all cognitive domains, after controlling for the performance of controls. In relation to matched controls, long-time survivors performed disproportionately worse than did more recently injured individuals, irrespective of age.

CONCLUSIONS: After maximum spontaneous recovery from TBI, poorer cognitive functioning appears to be associated with both older age at the time of injury and increased time postinjury. These findings have implications for prognosis, early treatment recommendations, and long-term issues of differential diagnosis and management planning.