Consideration of individual differences in recovery after concussion has become a focus of concussion research. Sex and racial/ethnic identity as they may affect reporting of concussion symptoms have been studied at single time points but not over time. Our objective was to investigate the factors of self-defined sex and race/ethnicity in reporting of lingering concussion symptoms in a large sample of adolescents.

Concussed, symptomatic adolescents (n=849; Female=464, Male=385) aged 13-18 years were evaluated within 30 days of injury at a North Texas Concussion Registry (ConTex) clinic. Participants were grouped by self-defined race/ethnicity into three groups: Non-Hispanic Caucasian (n=570), Hispanic Caucasian (n=157), and African American (n=122). Measures collected at the initial visit included medical history, injury related information, and the Sport Concussion Assessment Tool-5 Symptom Evaluation (SCAT-5SE). At a three-month follow-up, participants completed the SCAT-5SE. Pearson’s Chi-Square analyses examined differences in categorical measures of demographics, medical history, and injury characteristics. Prior to analysis, statistical assumptions were examined, and log base 10 transformations were performed to address issues of unequal group variances and nonnormal distributions. A three-way repeated measures ANOVA (Sex x Race/Ethnicity x Time) was conducted to examine total severity scores on the SCAT-5SE. Bonferroni post-hoc tests were performed to determine specific group differences. SPSS V28 was used for analysis with p<0.05 for significance. Data reported below has been back transformed.

A significant interaction of Time by Race/Ethnicity was found for SCAT-5SE scores reported at initial visit and three-month follow-up (F(2, 843)=7.362, p<0.001). To understand this interaction, at initial visit, Race/Ethnicity groups reported similar levels of severity for concussion symptoms. At three month follow-up, African Americans reported the highest level of severity of lingering symptoms (M= 3.925, 95% CIs [2.938-5.158]) followed by Hispanic Caucasians(M= 2.978, 95% CIs [2.2663.845]) and Non-Hispanic Caucasians who were the lowest(M= 1.915, 95% CIs [1.6262.237]). There were significant main effects for Time, Sex, and Race/Ethnicity. Average symptom levels were higher at initial visit compared to three-month follow-up (F(1, 843)=1531.526, p<0.001). Females had higher average symptom levels compared to males (F(1, 843)=35.58, p<0.001). For Race/Ethnicity (F(2, 843)=9.236, p<0.001), Non-Hispanic Caucasians were significantly different than African Americans (p<0.001) and Hispanic Caucasians (p=0.021) in reported levels of concussion symptom severity.

Data from a large sample of concussed adolescents supported a higher level of reported symptoms by females, but there were no significant differences in symptom reporting between sexes across racial/ethnic groups. Overall, at three-months, the African American and Hispanic Caucasians participants reported a higher level of lingering symptoms than Non-Hispanic Caucasians. In order to improve care, the difference between specific racial/ethnic groups during recovery merits exploration into the factors that may influence symptom reporting.

Episodic memory functioning is distributed across two brain circuits, one of which courses through the dorsal anterior cingulate cortex (dACC). Thus, delivering non-invasive neuromodulation technology to the dACC may improve episodic memory functioning in patients with memory problems such as in amnestic mild cognitive impairment (aMCI). This preliminary study is a randomized, double-blinded, sham-controlled clinical trial to examine if high definition transcranial direct current stimulation (HD-tDCS) can be a viable treatment in aMCI.

Eleven aMCI participants, of whom 9 had multidomain deficits, were randomized to receive 1 mA HD-tDCS (N=7) or sham (N=4) stimulation. HD-tDCS was applied over ten 20-minute sessions targeting the dACC. Neuropsychological measures of episodic memory, verbal fluency, and executive function were completed at baseline and after the last HD-tDCS session. Changes in composite scores for memory and language/executive function tests were compared between groups (one-tailed t-tests with a = 0.10 for significance). Clinically significant change, defined as > 1 SD improvement on at least one test in the memory and non-memory domains, was compared between active and sham stimulation based on the frequency of participants in each.

No statistical or clinically significant change (N-1 X2; p = 0.62) was seen in episodic memory for the active HD-tDCS (MDiff = 4.4; SD = 17.1) or sham groups (MDiff = -0.5; SD = 9.7). However, the language and executive function composite showed statistically significant improvement (p = 0.04; MDiff = -15.3; SD = 18.4) for the active HD-tDCS group only (Sham MDiff = -5.8; SD = 10.7). Multiple participants (N=4) in the active group had clinically significant enhancement in language and executive functioning tests, while nobody in the sham group did (p = 0.04).

HD-tDCS targeting the dACC had no direct benefit for episodic memory deficits in aMCI based on preliminary findings for this ongoing clinical trial. However, significant improvement in language and executive function skills occurred in response to HD-tDCS, suggesting HD-tDCS in this configuration has promising potential as an intervention for language and executive function deficits in MCI.