Neurophysiological markers of cognitive deficits and recovery in concussed adolescents

Fact or Fiction-Accelerometry Versus Self-Report in Adherence to Pediatric Concussion Protocols: Prospective Longitudinal Cohort Study

Background

Concussion, or mild traumatic brain injury, is a growing public health concern, affecting approximately 1.2% of the population annually. Among children aged 1-17 years, concussion had the highest weighted prevalence compared to other injury types, highlighting the importance of addressing this issue among the youth population.

Objective

This study aimed to assess adherence to Return to Activity (RTA) protocols among youth with concussion and to determine if better adherence affected time to recovery and the rate of reinjury.

Methods

Children and youth (N=139) aged 5-18 years with concussion were recruited. Self-reported symptoms and protocol stage of recovery were monitored every 48 hours until symptom resolution was achieved. Daily accelerometry was assessed with the ActiGraph. Data were collected to evaluate adherence to the RTA protocol based on physical activity cutoff points corresponding to RTA stages. Participants were evaluated using a battery of physical, cognitive, and behavioral measures at recruitment, upon symptom resolution, and 3 months post symptom resolution.

Results

For RTA stage 1, a total of 13% of participants were adherent based on accelerometry, whereas 11% and 34% of participants were adherent for stage 2 and 3, respectively. The median time to symptom resolution was 13 days for participants who were subjectively reported adherent to the RTA protocol and 20 days for those who were subjectively reported as nonadherent (P=.03). No significant agreement was found between self-report of adherence and objective actigraphy adherence to the RTA protocol as well as to other clinical outcomes, such as depression, quality of life, and balance. The rate of reinjury among the entire cohort was 2% (n=3).

Conclusions

Overall, adherence to staged protocols post concussion was minimal when assessed with accelerometers, but adherence was higher by self-report. More physical activity restrictions, as specified in the RTA protocol, resulted in lower adherence. Although objective adherence was low, reinjury rate was lower than expected, suggesting a protective effect of being monitored and increased youth awareness of protocols. The results of this study support the move to less restrictive protocols and earlier resumption of daily activities that have since been implemented in more recent protocols.

Sports-Related Concussion Affects Cognitive Function in Adolescents: A Systematic Review and Meta-analysis

BACKGROUND

Rates of sports-related concussion (SRC) are high in adolescents. Ambiguity exists regarding the effect of SRC on cognitive function in adolescents.

PURPOSE

To rigorously examine adolescents' cognitive function after SRC.

STUDY DESIGN

Systematic review and meta-analysis; Level of evidence, 4.

METHODS

Web of Science, Scopus, and PubMed were searched from database inception until September 2021. Studies were included if participants were adolescents aged 13 to 18 years, if the definition of SRC was fully consistent with the Berlin Consensus Statement on Concussion in Sport, if the study included a control group or in-group baseline test, and if the study reported cognitive outcomes (eg, visual memory, processing speed) that could be separately extracted.

RESULTS

A total of 47 studies were included in the systematic review, of which 31 were included in the meta-analysis, representing 8877 adolescents with SRC. Compared with individuals in the non-SRC group, individuals with SRC had worse performance in cognitive function and reported more symptoms not only in the acute phase but also in the prolonged phase (1-6 months after injury) (visual memory: d = -0.21, 95% CI, -0.37 to -0.05, P = .012; executive function: d = -0.56, 95% CI, -1.07 to -0.06, P = .028; and symptoms: d = 1.17, 95% CI, 0.13 to 2.22, P = .028). Lower scores in most of the outcomes of cognitive function were observed at <3 days and at 3 to 7 days, but higher scores for verbal memory (d = 0.10; 95% CI, 0.03 to 0.17; P = .008) and processing speed (d = 0.17; 95% CI, 0.10 to 0.24; P < .001) were observed at 7 to 14 days after SRC relative to baseline. The effects of SRC on cognitive function decreased over time (100% of the variance in reaction time, P < .001; 99.94% of the variance in verbal memory, P < .001; 99.88% of the variance in visual memory, P < .001; 39.84% of the variance in symptoms, P = .042) in control group studies. Study design, participant sex, measurement tools, and concussion history were found to be modulators of the relationship between cognitive function and SRC.

CONCLUSION

This study revealed that adolescent cognitive function is impaired by SRC even 1 to 6 months after injury. Results of this study point to the need for tools to measure cognitive function with multiple parallel versions that have demographically diversiform norms in adolescents. Effective prevention of SRC, appropriate treatment, and adequate evaluation of cognitive function before return to play are needed in adolescent SRC management. Moreover, caution is warranted when using the baseline-to-postconcussion paradigm in return-to-play decisions.

School performance in youth after a concussion

Objective

This study aimed to identify school problems and levels of cognitive activity in youths aged 5-18 years with a concussion during the recovery stages of return to school (RTS).

Study Design

In a prospective cohort, participants completed in-person assessments at three time points: First Visit Post-injury, Symptom Resolution Visit, and Follow-Up Visit. These time points varied based on the participants' recovery progress. The post-concussion symptom scale (PCSS) and a cognitive activity scale were completed every 2 days until symptom resolution was achieved. Participants and their parents completed a school questionnaire detailing how their concussion had impacted their school learning/performance and their level of concern about their injury as well as the Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT).

Results

Sixty-three percent (N = 44/70) of participants returned to school by the First Visit Post-injury (average 7.7 days following injury), and of these, 50% (N = 22) were experiencing school problems. Sixty-five participants (out of 70) returned to school at the Follow-Up Visit, and of these, 18% reported school problems. There was a significant difference in the school problems reported by parents and youth. At the First Visit Post-injury, the youth reported more problems (p = 0.02), and the In-Person Symptom Resolution Visit with parents reported more problems (p = 0.01). The cognitive activity score increased, while the PCSS score decreased from RTS Stage 1 to Stage 5.

Conclusions

This study identified that 50% of youth experienced school problems at the First Visit Post-injury, whereas only 18% reported school problems at the Follow-Up Visit. There is a significant difference in the perception of school problems reported by youth and their parents at different stages of recovery. The amount and complexity of cognitive activity increased with decreasing symptoms and increasing RTS stage. Findings can guide youth with a concussion and their parents in supporting a cautious return to school with accommodations. Healthcare providers and researchers can use this knowledge to better support youth in their return to school and understand the importance of gathering information from youth and their parents to gain the best insight into recovery.

N2b Reflects the Cognitive Changes in Executive Functioning After Concussion: A Scoping Review

Objectives: The N2b is an event-related potential (ERP) component thought to index higher-order executive function. While the impact of concussion on executive functioning is frequently discussed in the literature, limited research has been done on the role of N2b in evaluating executive functioning in patients with concussion. The aims of this review are to consolidate an understanding of the cognitive functions reflected by the N2b and to account for discrepancies in literature findings regarding the N2b and concussion.

Methods: A scoping review was conducted on studies that used the N2b to measure cognitive functioning in healthy control populations, as well as in people with concussions.

Results: Sixty-six articles that met inclusion criteria demonstrated that the N2b effectively represents stimulus-response conflict management, response selection, and response inhibition. However, the 19 included articles investigating head injury (using terms such as concussion, mild head injury, and mild traumatic brain injury) found widely varied results: some studies found the amplitude of the N2b to be increased in the concussion group, while others found it to be decreased or unchanged.

Conclusion: Based on the available evidence, differences in the amplitude of the N2b have been linked to response selection, conflict, and inhibition deficits in concussion. However, due to large variations in methodology across studies, findings about the directionality of this effect remain inconclusive. The results of this review suggest that future research should be conducted with greater standardization and consistency.