## 3 Results  
Twenty-five volunteer college students participated (48% females; mean age of 25.0 years, \(SD=5.96\) years) in this study between July 2017 and March 2018. Descriptive statistics were used to find any differences in the demographic characteristics between mTBI cases and controls (Table 1). mTBI cases consisted of 11 individuals (27.3% females; mean age of 28.7 years, \(SD=5.92\)) with a self-reported history of single or multiple injuries (63.6% multiple; \(2.5\pm 1.29\) injuries). Traumatic occurrences include sports-related activities (4 in 11 cases; 36.4%) and military operations (3 in 11 cases; 27.3%). The average time elapsed since the last injury was 7.1 (SD = 6.77) years. Controls consisted of 14 individuals (64.3% females; mean age of 22.0 years, \(SD=4.13\) years). Only age has a statistical difference between mTBI and controls (\(p=0.007\)) among all demographic variables. Table 2 depicts functional differences between mTBI and healthy control groups. mTBI cases reported significantly poorer age-corrected episodic memory (mTBI, 99.00 \(\pm\) 17.19; controls, 115.57 \(\pm\) 15.64; \(p=0.022\)), more severe anxiety (mTBI, 56.55 \(\pm\) 9.77; controls, 49.00 \(\pm\) 5.09; \(p=0.022\)) and sleep disturbance problems (mTBI, 56.34 \(\pm\) 11.82; controls, 45.89 \(\pm\) 9.17; \(p=0.023\)), along with higher total scores in both RPQ and NSI. When comparing each post-mTBI symptom item in both RPQ and NSI, 18 out of 22 NSI items (e.g., dizziness with body balance, visual, cognitive, and psychological dysfunctions, etc. ), and 14 out of 16 RPQ items (e.g., headache, dizziness, cognitive, psychological, \begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Characteristic** & **Overall (\(n=25\))** & **mTBI (\(n=11\))** & **Control (\(n=14\))** & \(x^{2}\) **or \(t\)** & \(p\) \\ \hline Age & 24.96 \(\pm\) 5.96 & 28.73 \(\pm\) 5.92 & 22.00 \(\pm\) 4.13 & 3.348 & 0.003 \\ Gender & & & & & \\ Males & 13 (52) & 8 (72.7) & 5 (35.7) & 3.381 & 0.066 \\ Females & 12 (48) & 3 (27.3) & 9 (64.3) & & \\ Weight (kg) & 70.85 \(\pm\) 16.77 & 75.67 \(\pm\) 14.97 & 67.07 \(\pm\) 17.66 & 1.129 & 0.210 \\ Height (cm) & 169.06 \(\pm\) 11.81 & 173.87 \(\pm\) 10.62 & 165.28 \(\pm\) 11.64 & 1.903 & 0.070 \\ Ethnicity/Race & & & & & \\ Hispanic & 4 (16.0) & 2 (18.2) & 2 (14.3) & 0.263 & 0.992 \\ White & 14 (56.0) & 6 (54.5) & 8 (57.1) & & \\ Black & 2 (8.0) & 1 (9.1) & 1 (7.1) & & \\ Asian & 3 (12.0) & 1 (9.1) & 2 (14.3) & & \\ Other & 2 (8.0) & 1 (9.1) & 1 (7.1) & & \\ Handedness & & & & & \\ Right & 22 (88.0) & 9 (81.8) & 13 (92.9) & 0.711 & 0.399 \\ Left & 3 (12.0) & 2 (18.2) & 1 (7.1) & & \\ Education & & & & & \\ In college & 22 (88.0) & 10 (90.9) & 12 (85.7) & 0.834 & 0.659 \\ In graduate school & 3 (12.0) & 1 (9.1) & 2 (14.3) & & \\ Marital Status \({}^{*}\) & & & & & \\ Single & 21 (84.0) & 9 (81.8) & 12 (92.6) & 1.376 & 0.503 \\ Married & 3 (12.0) & 2 (18.2) & 1 (7.7) & & \\ Employment Status & & & & & \\ Yes & 16 (64.0) & 5 (45.5) & 10 (71.4) & 0.762 & 0.383 \\ No & 9 (36.0) & 6 (54.5) & 4 (28.6) & & \\ Income \({}^{*}\) & & & & & \\ Low (\(\leq\) 550K) & 13 (52.0) & 6 (54.2) & 7 (58.3) & 1.703 & 0.427 \\ Middle (550K \(<\)\(\leq\) 5100K) & 6 (24.0) & 2 (18.2) & 4 (33.3) & & \\ High (5100K \(<\)) & 4 (16.0) & 3 (27.3) & 1 (8.3) & & \\ \hline \hline \end{tabular} Note: Characteristic variables with asterisk mark (\({}^{*}\)) have missing data.  
\end{table} 
Table 1: Demographic differences (\(n\) (%) or \(M\pm SD\)) between mTBI and healthy control college student participants. and visual dysfunctions, etc.) showed significantly higher item scores in mTBI, compared to control group (all \(p^{\prime}\)s \(<\) 0.05). There were no statistically significant differences found in visual and postural balance performances between the two groups. Because of a statistical difference in age between mTBI and controls, age was further adjusted as a confounding variable or covariate. When controlling for age by one-way ANCOVA, there was no significant effect of having mTBI history on sleep disturbance problems.