Cognitive Symptoms Are Not Associated with Cognitive Performance in Post-Acute mTBI

Subjective cognitive symptoms are commonly reported after mild traumatic brain injury (mTBI) but are often not associated with objective cognitive performance. This may be due to limitations in traditional cognitive performance measures, which may not be sensitive to subtle variations in cognition in post-acute mTBI. This study explored associations between objective and subjective cognition using computer-based tasks of increasing cognitive load, proposed to be more sensitive to subtle differences in performance.

Individuals with mTBI (n = 68) and trauma controls (n = 40) were prospectively recruited and assessed approximately 8 weeks post-injury. Participants completed measures of subjective symptom reporting, objective cognitive performance (including two computer-based tasks of increasing cognitive load), and psychological distress.

There were no significant associations between subjective and objective cognition reporting in the mTBI group, both in bivariate correlations (|r| = 0.01-0.20, p > .05) and when controlling for psychological distress (|r| = 0.00-0.17, p > .05). A similar pattern of results was observed in trauma controls, suggesting that the limited relationships between objective and subjective cognition in mTBI may not be specific to this population.

Despite employing measures of cognitive performance proposed to be more sensitive than traditional tasks, no significant relationships were observed between objective and subjective cognition in post-acute mTBI, and estimated effect sizes were small to negligible. This provides further evidence that at a group level 8 weeks after mTBI subjective cognitive symptoms primarily reflect factors aside from objective cognition.