Predictors of memory and processing speed dysfunctions after traumatic brain injury

The relationship between cognition and vocational training outcome in patients with acquired brain injury: Contribution of Machine Learning

The aim of this study was to identify specific cognitive patterns related to long-term vocational training outcome. Records of twenty-eight patients who had benefited from a professional rehabilitation program were retrospectively processed. Screening through machine learning algorithms of patients' neuropsychological scores identified cognitive patterns related to both vocational training outcomes: succeeded or failed. These patterns were based on cognitive performance intervals even if the cognitive ability was not impaired. The cognitive pattern related to a successful vocational training included performance intervals on measures underlying verbal memory consolidation, visual memory incidental recall, problem solving and planning abilities. The cognitive pattern explaining failure of vocational training included performance intervals on tasks involving planning and problem solving abilities. From a comprehensive neuropsychological battery, memory and executive measures appeared to be the best attributes related to the vocational training outcome in patients with brain injury. Even with a cognitive functioning above the pathological cutoff, patients suffering from a brain injury could fail a vocational training. The attributes related to the vocational training outcome would be more a specific level of cognitive functioning rather than an interpretation of neuropsychological scores only based on a normal versus pathological distinction.

Cognitive Reserve in Individuals Aging With Traumatic Brain Injury: Independent and Interactive Effects on Cognitive Functioning

OBJECTIVE

To examine the influence of 2 temporal factors-age and injury chronicity-on the relationship between cognitive reserve (CR) and cognitive functioning in older adults with chronic traumatic brain injury (TBI).

SETTING

Outpatient research laboratory.

PARTICIPANTS

Adults, 50 years or older, with a 1- to 45-year history of moderate or severe TBI (N = 108).

DESIGN

Cross-sectional observational study.

MAIN MEASURES

CR was estimated using demographically corrected performance on a word-reading test (an approximation of premorbid IQ). Injury chronicity was operationalized as number of years since the date of injury. Composite cognitive scores were computed from performances on neuropsychological tests of processing speed, executive functioning, and memory.

RESULTS

CR was positively and significantly related to all cognitive performances independent of age, injury chronicity, and injury severity. Greater injury chronicity significantly attenuated the effect of CR on processing speed such that individuals more distal from their injury date evidenced a weaker positive relationship between CR and performance.

CONCLUSION

Temporal factors may modify associations between CR and cognition. Findings suggest that the protective effects of CR are temporally delimited, potentially contending with declines in brain reserve. The prognostic value of traditional outcome determinants should be considered in the context of injury chronicity.