Cognitive performance in older adults at three months following mild traumatic brain injury

ABSTRACT

Introduction: In the context of limited research assessing outcomes following mild traumatic brain injury (mTBI) in older adults, this study evaluated cognitive outcomes through prospective memory, and expected that performance of an older mTBI group (≥65 years) would be lower compared to orthopedic and community controls. The study also explored whether cognitive resources (retrospective memory, executive function) moderated any association between presenting Glasgow Coma Scale (GCS) and prospective memory.

Method: At three-months post-injury, a mTBI group (n = 39), an orthopedic control group (n = 63), and a community control group (n = 46) completed a neuropsychological assessment, including (i) prospective memory, using a standardized paper-and-pencil task (Cambridge Prospective Memory Test), an augmented reality task and a naturalistic task, and (ii) standardized measures of retrospective memory (Hopkins Verbal Learning Test) and executive function (Trail Making Test). Group performances were compared, and bootstrapped moderation analyses evaluated the role of cognitive resources in the relationship between GCS and prospective memory outcome.

Results: The mTBI group, as compared to community controls, performed significantly lower on the augmented reality task (d = −0.64 to d = −0.79), and there was a small-moderate but non-significant effect (d = −0.45) on the naturalistic task. There were no differences between the mTBI group and orthopedic controls. Retrospective memory was a unique predictor of the augmented reality task (B = 1.83) and moderated the relationship between presenting GCS and the naturalistic task (B = −5.60). Executive function moderated the association between presenting GCS and augmented reality (B = −1.13) and naturalistic task (B = −1.57).

Conclusions: At three-months post-mTBI, older adults are at risk of poor cognitive performance; and the relationship between GCS and prospective memory can be moderated by cognitive resources. Further follow-up is indicated to determine whether impairments resolve or persist over time.

KEYWORDS:

• Cognition
• prospective memory
• older adults
• mild traumatic brain injury
• augmented reality

Acknowledgments

We thank the participants for their contribution to the study and Camilla Hume for assistance with recruitment and data collection. We would also like to acknowledge the contribution of Dr Stephen Lee and Professor Ben Ong in the development of the LaTrobe Itemised Shopping Task and involvement in the early stages of this study.

Data availability statement

The data that support the findings of this study are available from B.J.W. upon reasonable request.

Disclosure Statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by a Commonwealth Research Training Scheme award to L.G.