AUTHOR=Lima Santos João Paulo , Kontos Anthony P. , Mailliard Sarrah , Eagle Shawn R. , Holland Cynthia L. , Suss Stephen J. , Abdul-waalee Halimah , Stiffler Richelle S. , Bitzer Hannah B. , Blaney Nicholas A. , Colorito Adam T. , Santucci Christopher G. , Brown Allison , Kim Tae , Iyengar Satish , Skeba Alexander , Diler Rasim S. , Ladouceur Cecile D. , Phillips Mary L. , Brent David , Collins Michael W. , Versace Amelia 

TITLE=White Matter Abnormalities Associated With Prolonged Recovery in Adolescents Following Concussion

JOURNAL=Frontiers in Neurology

VOLUME=12

YEAR=2021

URL=https://www.frontiersin.org/journals/neurology/articles/10.3389/fneur.2021.681467

DOI=10.3389/fneur.2021.681467

ISSN=1664-2295

ABSTRACT=<p><bold>Background:</bold> Concussion symptoms in adolescents typically resolve within 4 weeks. However, 20 – 30% of adolescents experience a prolonged recovery. Abnormalities in tracts implicated in visuospatial attention and emotional regulation (i.e., inferior longitudinal fasciculus, ILF; inferior fronto-occipital fasciculus, IFOF; uncinate fasciculus; UF) have been consistently reported in concussion; yet, to date, there are no objective markers of prolonged recovery in adolescents. Here, we evaluated the utility of diffusion MRI in outcome prediction. Forty-two adolescents (12.1 – 17.9 years; female: 44.0%) underwent a diffusion Magnetic Resonance Imaging (dMRI) protocol within the first 10 days of concussion. Based on days of injury until medical clearance, adolescents were then categorized into SHORT (&lt;28 days; <italic>N</italic> = 21) or LONG (&gt;28 days; <italic>N</italic> = 21) recovery time. Fractional anisotropy (FA) in the ILF, IFOF, UF, and/or concussion symptoms were used as predictors of recovery time (SHORT, LONG). Forty-two age- and sex-matched healthy controls served as reference. Higher FA in the ILF (<italic>left</italic>: adjusted odds ratio; AOR = 0.36, 95% CI = 0.15 – 0.91, <italic>P</italic> = 0.030; <italic>right</italic>: AOR = 0.28, 95% CI = 0.10 – 0.83, <italic>P</italic> = 0.021), IFOF (<italic>left:</italic> AOR = 0.21, 95% CI = 0.07 – 0.66, <italic>P</italic> = 0.008; <italic>right</italic>: AOR = 0.30, 95% CI = 0.11 – 0.83, <italic>P</italic> = 0.020), and UF (<italic>left</italic>: AOR = 0.26, 95% CI = 0.09 – 0.74, <italic>P</italic> = 0.011; <italic>right:</italic> AOR = 0.28, 95% CI = 0.10 – 0.73, <italic>P</italic> = 0.010) was associated with SHORT recovery. In additional analyses, while adolescents with SHORT recovery did not differ from HC, those with LONG recovery showed lower FA in the ILF and IFOF (<italic>P</italic> &lt; 0.014). Notably, inclusion of dMRI findings increased the sensitivity and specificity (AUC = 0.93) of a prediction model including clinical variables only (AUC = 0.75). Our findings indicate that higher FA in long associative tracts (especially ILF) might inform a more objective and accurate prognosis for recovery time in adolescents following concussion.</p>