Research Reports - Functional recovery after traumatic brain injury: A role for cognitive reserve?
Neurology. 2014 May 6;82(18):1636-42
Schneider EB(1), Sur S, Raymont V, Duckworth J, Kowalski RG, Efron DT, Hui X, Selvarajah S, Hambridge HL, Stevens RD
OBJECTIVE: To evaluate the hypothesis that educational attainment, a marker of
cognitive reserve, is a predictor of disability-free recovery (DFR) after
moderate to severe traumatic brain injury (TBI).
METHODS: Retrospective study of the TBI Model Systems Database, a prospective
multicenter cohort funded by the National Institute on Disability and
Rehabilitation Research. Patients were included if they were admitted for
rehabilitation after moderate to severe TBI, were aged 23 years or older, and had
at least 1 year of follow-up. The main outcome measure was DFR 1 year postinjury,
defined as a Disability Rating Scale score of zero.
RESULTS: Of 769 patients included, 214 (27.8%) achieved DFR at 1 year. In total,
185 patients (24.1%) had <12 years of education, while 390 (50.7%) and 194
patients (25.2%) had 12 to 15 years and ≥16 years of education, respectively. DFR
was achieved by 18 patients (9.7%) with <12 years, 120 (30.8%) with 12 to 15
years, and 76 (39.2%) with ≥16 years of education (p < 0.001). In a logistic
regression model controlling for age, sex, and injury- and
rehabilitation-specific factors, duration of education of ≥12 years was
independently associated with DFR (odds ratio 4.74, 95% confidence interval
2.70-8.32 for 12-15 years; odds ratio 7.24, 95% confidence interval 3.96-13.23
for ≥16 years).
CONCLUSION: Educational attainment was a robust independent predictor of 1-year
DFR even when adjusting for other prognostic factors. A dose-response
relationship was noted, with longer educational exposure associated with
increased odds of DFR. This suggests that cognitive reserve could be a factor
driving neural adaptation during recovery from TBI.