To evaluate whether cognitive reserve (CR) moderates the relationship between neuropathology and cognitive outcomes after traumatic brain injury (TBI).
Outpatient research organization.
Patients with complicated mild (n = 8), moderate (n = 9), and severe (n = 44) TBI.
Prospective, cross-sectional study.
Cognitive reserve was estimated using a test of word reading (Wechsler Test of Adult Reading). Diffusion tensor imaging (functional anisotropy) was used to quantify neuropathology. Neuropsychological test scores were submitted to principal components analyses to create cognitive composites for memory, attention, executive function, and processing speed domains.
At lower levels of neuropathology, people with higher CR exhibited better memory than those with lower CR. This benefit diminished as neuropathology increased and disappeared at the highest levels of neuropathology. Cognitive reserve ceased exerting a protective effect at premorbid intelligence levels below average.
Cognitive reserve may differentially protect some cognitive domains against neuropathology relative to others. A clinical cutoff below which CR is no longer protective, together with a possible neuropathology ceiling effect, may be instructive for prognostication and clinical decision-making in cognitive rehabilitation.
Traumatic Brain Injury Research, Kessler Foundation, East Hanover, New Jersey (Drs Krch, Chiaravalloti, and DeLuca, and Ms Frank); Department of Physical Medicine and Rehabilitation, Rutgers-New Jersey Medical School, Newark (Drs Krch, Chiaravalloti, and DeLuca); Department of Psychology, University of Oregon, Eugene (Ms Frank); and Psychology Department and Gonda Multidisciplinary Brain Research Center, Bar Ilan University, Ramat-Gan, Israel (Dr Vakil).
Corresponding Author: Denise Krch, PhD, Traumatic Brain Injury Department, Kessler Foundation, 120 Eagle Rock Ave, Ste 100, East Hanover, NJ 07936 (firstname.lastname@example.org).
This work was funded by a grant from the New Jersey Commission on Brain Injury Research (CBIR11PJT020) to conduct the work in this article.
The authors declare no conflicts of interest.