Microstructural Organization of Distributed White Matter Associated With Fine Motor Control in US Service Members With Mild Traumatic Brain Injury

• Published in: Journal of neurotrauma Vol. 41; no. 1-2; p. 32
• Main Authors: Wade, Benjamin S C, Tate, David F, Kennedy, Eamonn, Bigler, Erin D, York, Gerald E, Taylor, Brian A, Troyanskaya, Maya, Hovenden, Elizabeth S, Goodrich-Hunsaker, Naomi, Newsome, Mary R, Dennis, Emily L, Abildskov, Tracy, Pugh, Mary Jo, Walker, William C, Kenney, Kimbra, Betts, Aaron, Shih, Robert, Welsh, Robert C, Wilde, Elisabeth A
• Format: Journal Article
• Language: English
• Published: United States 01-01-2024
• Subjects: Brain; Brain Concussion - complications; Brain Concussion - diagnostic imaging; Brain Injuries - complications; Humans; Military Personnel; Veterans; White Matter - diagnostic imaging; service members; white matter organization; MRI; grooved pegboard; mild traumatic brain injury; fine motor control
• ISSN: 1557-9042
• DOI: 10.1089/neu.2022.0094

Mild traumatic brain injury (mTBI) is the most common form of brain injury. While most individuals recover from mTBI, roughly 20% experience persistent symptoms, potentially including reduced fine motor control. We investigate relationships between regional white matter organization and subcortical volumes associated with performance on the Grooved Pegboard (GPB) test in a large cohort of military Service Members and Veterans (SM&Vs) with and without a history of mTBI(s). Participants were enrolled in the Long-term Impact of Military-relevant Brain Injury Consortium-Chronic Effects of Neurotrauma Consortium. SM&Vs with a history of mTBI(s) (
 = 847) and without mTBI (
 = 190) underwent magnetic resonance imaging and the GPB test. We first examined between-group differences in GPB completion time. We then investigated associations between GPB performance and regional structural imaging measures (tractwise diffusivity, subcortical volumes, and cortical thickness) in SM&Vs with a history of mTBI(s). Lastly, we explored whether mTBI history moderated associations between imaging measures and GPB performance. SM&Vs with mTBI(s) performed worse than those without mTBI(s) on the non-dominant hand GPB test at a trend level (
 < 0.1). Higher fractional anisotropy (FA) of tracts including the posterior corona radiata, superior longitudinal fasciculus, and uncinate fasciculus were associated with better GPB performance in the dominant hand in SM&Vs with mTBI(s). These findings support that the organization of several white matter bundles are associated with fine motor performance in SM&Vs. We did not observe that mTBI history moderated associations between regional FA and GPB test completion time, suggesting that chronic mTBI may not significantly influence fine motor control.