The impact of symptomatic mild traumatic brain injury on complex everyday activities and the link with alterations in cerebral functioning: Exploratory case studies

ABSTRACT

The objective of the study was to explore the neurophysiological correlates of altered functional independence using functional magnetic resonance imaging (fMRI) and event-related potentials (ERP) after a mild traumatic brain injury (mTBI). The participants consisted of three individuals with symptomatic mTBI (3.9 ± 3.6 months post-mTBI) and 12 healthy controls. The main measures used were the Instrumental Activities of Daily Living (IADL) Profile observation-based assessment; a visual externally ordered working memory task combined to event-related potentials (ERP) and fMRI recordings; neuropsychological tests; post-concussion symptoms questionnaires; and the Activities of Daily Living (ADL) Profile interview. Compared to normal controls, all three patients had difficulty with a real-world complex budgeting activity due to deficits in planning, ineffective strategy use and/or a prolonged time to detect and correct errors. Reduced activations in the right mid-dorsolateral prefrontal cortex on fMRI as well as abnormal frontal or parietal components of the ERP occurred alongside these deficits. Results of this exploratory study suggest that reduced independence in complex everyday activities in symptomatic mTBI may be at least partly explained by a decrease in brain activation in the prefrontal cortex, abnormal ERP, or slower reaction times on working memory tasks. The study presents an initial attempt at combining research in neuroscience with ecological real-world evaluation research to further our understanding of the difficulties in complex everyday activities experienced by individuals with mTBI.

KEYWORDS:

• Cognitive deficits
• Neuropsychology
• Brain injuries
• Rehabilitation
• Concussion

Acknowledgements

We thank the staff of the Magnetic Resonance Imaging Unit of the McConnell Brain Imaging Centre for their assistance. We presented an earlier version of this work to the International Neuropsychological Society in Montreal, 2012.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the Canadian Institutes of Health Research [Grant MOP-86509] to A.P. and fellowships to C.B. and N.G. and by the Fonds de recherche du Québec–Santé (fellowship to J.K.C.).