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

The role of cognitive reserve in traumatic brain injury: a systematic review of observational studies

OBJECTIVE

Evaluate the role of cognitive reserve (CR) on cognitive and physical sequelae in traumatic brain injury (TBI).

METHODS

A comprehensive search strategy was conducted in four databases in English and Spanish in the last 12 years (2011-2023). Inclusion criteria: original cross-sectional and longitudinal studies whose main or secondary objective was to evaluate the effect of CR in adult patients with TBI. PRISMA guidelines were used to report the search and selection method and STROBE checklist was used to evaluate the quality of studies.

RESULTS

Eighteen observational studies were included in this review. Multiple sources of variability were observed: number of patients, time of evolution, severity of the TBI, type of CR proxy, cognitive assessment instrument, etc. However, the most commonly used indicators of CR were premorbid IQ and educational attainment. A positive and consistent association between CR and performance on cognitive tests after injury was found.

CONCLUSIONS

CR has a consistent positive effect on cognition and on some other aspects of recovery in traumatic brain injury. In future studies, it will be necessary to promote the use of CR indices based on various indicators and explore the effects of CR on other aspects related to the recovery of brain trauma.

The Power of Perception: Beliefs About Memory Ability Uniquely Contribute to Memory Performance and Quality of Life in Adults Aging with Traumatic Brain Injury

OBJECTIVE

Personal beliefs about memory ability, which comprise memory self-efficacy (MSE), can influence memory performance in healthy older adults. Self-efficacy theory also predicts that MSE biases self-perceptions of functioning more globally, potentially impacting daily activity beyond cognitive performance. People with traumatic brain injury (PwTBI) frequently report debilitating memory problems long after acute recovery, but little is known about how MSE affects health outcomes in this population. We examined demographic and clinical correlates of MSE, as well as its relationship to memory test performance and health-related quality of life (QOL), in older adults with chronic moderate-to-severe TBI (msTBI).

METHOD

One hundred fourteen adults, aged 50+ and at least 1 year post-msTBI, underwent neuropsychological testing to assess their memory functioning. Participants also self-reported levels of psychological distress, MSE (Cognitive Confidence subscale of the Metacognitions Questionnaire), and health-related QOL (Quality of Life after Brain Injury questionnaire).

RESULTS

Demographic and injury-related predictors showed weak correlations with MSE. Although the relationship between MSE and general psychological distress was robust, only the former significantly predicted memory performance. Bivariate analyses revealed significant relationships between MSE and five out of the six QOL domains assessed. Multivariate linear regression revealed a significant impact of MSE on overall QOL independent of demographic and clinical variables.

CONCLUSIONS

Our findings support a unique role for MSE in both the objective cognitive performance and subjective health of PwTBI. Increased focus on self-perceptions of ability and their impact on measured outcomes is an important step towards personalized rehabilitation for adults with chronic msTBI.

Self-Reported Complaints as Prognostic Markers for Outcome After Mild Traumatic Brain Injury in Elderly: A Machine Learning Approach

Self-reported complaints are common after mild traumatic brain injury (mTBI). Particularly in the elderly with mTBI, the pre-injury status might play a relevant role in the recovery process. In most mTBI studies, however, pre-injury complaints are neither analyzed nor are the elderly included. Here, we aimed to identify which individual pre- and post-injury complaints are potential prognostic markers for incomplete recovery (IR) in elderly patients who sustained an mTBI. Since patients report many complaints across several domains that are strongly related, we used an interpretable machine learning (ML) approach to robustly deal with correlated predictors and boost classification performance. Pre- and post-injury levels of 20 individual complaints, as self-reported in the acute phase, were analyzed. We used data from two independent studies separately: UPFRONT study was used for training and validation and ReCONNECT study for independent testing. Functional outcome was assessed with the Glasgow Outcome Scale Extended (GOSE). We dichotomized functional outcome into complete recovery (CR; GOSE = 8) and IR (GOSE ≤ 7). In total 148 elderly with mTBI (median age: 67 years, interquartile range [IQR]: 9 years; UPFRONT: N = 115; ReCONNECT: N = 33) were included in this study. IR was observed in 74 (50%) patients. The classification model (IR vs. CR) achieved a good performance (the area under the receiver operating characteristic curve [ROC-AUC] = 0.80; 95% CI: 0.74-0.86) based on a subset of only 8 out of 40 pre- and post-injury complaints. We identified increased neck pain (p = 0.001) from pre- to post-injury as the strongest predictor of IR, followed by increased irritability (p = 0.011) and increased forgetfulness (p = 0.035) from pre- to post-injury. Our findings indicate that a subset of pre- and post-injury physical, emotional, and cognitive complaints has predictive value for determining long-term functional outcomes in elderly patients with mTBI. Particularly, post-injury neck pain, irritability, and forgetfulness scores were associated with IR and should be assessed early. The application of an ML approach holds promise for application in self-reported questionnaires to predict outcomes after mTBI.