Longitudinal examination of the relationship between changes in white matter organization and cognitive outcome in chronic TBI

ABSTRACT

Background and Objective: Changes in cerebral white matter organization have been documented in acute phases of recovery from traumatic brain injury (TBI). However, little is known about reorganization processes in more chronic stages of recovery. The current study identified changes in white matter organization in chronic cases of TBI, and determined the relationship between structural changes and cognitive functioning.

Methods: 15 adults with moderate to severe TBI and eight healthy controls completed neuropsychological testing and diffusion tensor imaging (DTI) scanning. Participants returned 3 years from the initial session to complete identical neuropsychological tests and scans.

Results: Adults with TBI were found to have significantly reduced fractional anisotropy (FA), a metric of white matter organization, compared to healthy participants at baseline and also at 3-year follow-up. Within the sample of adults with TBI, increases in FA were observed over time. Importantly, increases in FA in the TBI sample were also correlated with improvements in cognitive performance.

Conclusions: This study provides evidence of a dynamic process of white matter change occurring beyond the initial phases of recovery after moderate to severe TBI. The observed relationship between structural reorganization and changes in cognitive performance has implications for rehabilitation potential in more chronic phases of recovery.

KEYWORDS:

• Longitudinal studies
• diffusion tensor imaging
• traumatic brain injury

Acknowledgments

This research was supported by the New Jersey Commission for Brain Injury Research under Grant #CBIR12IRG004 awarded to Dr. Helen Genova.

Declaration of Interests Statement

The authors report no conflict of interest.

Additional information

Funding

This work was supported by the New Jersey Commission on Brain Injury Research [CBIR12IRG004].