The structure of post-concussion symptoms in adolescent student athletes: confirmatory factor analysis and measurement invariance

Cognitive, Sleep-Arousal, Physical, and Affective Domain Scores on the Post-Concussion Symptom Scale: Added Utility in Detecting Symptom Elevations among Student-Athletes with a Remote History of Concussion

OBJECTIVE

The evaluation of self-reported symptoms is a standard component of concussion assessment and management. Clinicians typically evaluate a total symptom severity score rather than scores corresponding to specific symptom domains (i.e., cognitive, sleep-arousal, physical, and affective symptoms). This study examined (i) whether elevations in specific symptom domains would be missed when interpreting only the total symptom severity score and (ii) if a single symptom domain elevation was more common than having elevated symptoms across multiple domains.

METHOD

Adolescent student-athletes (N = 1,008) with concussion history (i.e., ≥6 months since last concussion) completed the Post-Concussion Symptom Scale (PCSS). The PCSS total score and cognitive, sleep-arousal, physical, and affective domain scores were calculated. To determine if symptoms were elevated, scores were compared to normative data matched on gender and pre-existing conditions, with scores considered elevated if they were ≥84th percentile. The frequency of total and domain score elevations were calculated and stratified by gender and number of prior concussions (i.e., 1 or ≥2 prior concussions).

RESULTS

Overall, 26% of student-athletes had an elevated symptom domain score without being elevated on the total score. The most common symptom presentation was to have a single elevated symptom domain (21%), followed by two (11%), three (8%), or four elevated domains (6%).

CONCLUSIONS

Interpreting PCSS symptom domains may be beneficial in detecting student-athletes with elevated symptoms following a remote concussion. Roughly a quarter of student-athletes have domain-specific symptom elevations that would be missed by interpreting the total score alone.

The Sport Concussion Assessment Tool: A multidimensional symptom model for detecting elevated post-concussion symptoms

Objective: Investigate whether a four-factor model of post-concussion symptoms (i.e. cognitive, physical, affective, and sleep-arousal) aids in identifying student-athletes with persistent concerns not reflected by a total symptom score. Method: Collegiate student-athletes (N = 32,066) from the Concussion Assessment Research and Education consortium completed the Sport Concussion Assessment Tool, 3rd edition Symptom Evaluation at baseline and two post-injury follow-ups (i.e. beginning RTP and 6-month). Confirmatory factor analysis was used to compare a one- and four-factor model of post-concussion symptoms. Normative reference data were compared across stratifications (e.g. sex, prior concussions, and number of pre-existing conditions) using Mann-Whitney U tests, and elevation rates (i.e. ≥ 84th percentile) for subscales and the total score were recorded. Results: The four-factor model fit well before and after injury (CFIs > .95). Greater symptom severity on the subscale and total scores was associated with female sex (ps<.001, r range: .07 to .14) and more pre-existing conditions (ps<.001, η 2 range: .01 to .04), while having more prior concussions was only related to total symptom scores (ps<.001, η 2<.01). After a concussion, a sizeable portion of student-athletes (i.e., RTP = 11.8%; 6-month = 8.3%) had subscale elevations despite no total score elevation. Physical subscale elevations at RTP were the most common (i.e., 11.9%), driven by head and neck pain. Conclusion: After a sport-related concussion, a four-factor symptom model can be used to assess persistent symptoms in collegiate student-athletes. Identifying athletes with domain-specific elevations may help clinicians identify areas for further assessment and, in some cases, personalized rehabilitation plans.

Repetitive Head Injury and Cognitive, Physical, and Emotional Symptoms in Women Survivors of Intimate Partner Violence

Many women survivors of intimate partner violence (IPV) experience repetitive head injuries in their lifetime, but limited research has examined the cumulative effects of multiple head injuries on post-concussion symptom severity in this population. This study examined how number of lifetime head injuries and episodes of loss of consciousness (LOC) due to head injuries were related to current cognitive, physical, and emotional symptoms among women survivors of IPV. Cisgender women from Kentucky were recruited following a protective order against an intimate partner, including 268 women with no reported lifetime head injuries and 250 women with one or more IPV-related head injuries (mean [M] = 17.2 head injuries, standard deviation [SD] = 50.5, median [Mdn] = 4, range = 1-515; M = 1.8 LOC episodes, SD = 4.3, Mdn = 1, range = 0-35, respectively). Participants underwent in-person interviews about lifetime physical and sexual IPV history, head injury history, and current cognitive, physical, and emotional symptoms. Sociodemographic characteristics, physical and sexual IPV severity, and current symptom severity were examined in relation to number of head injuries and LOC episodes. A higher number of head injuries was associated with greater age, White race, less than high school education, unemployment, and rural residence. No sociodemographic variables differed based on number of LOC episodes. Greater number of lifetime head injuries and LOC episodes correlated significantly with physical IPV severity (rho = 0.35, p < 0.001; rho = 0.33, p < 0.001, respectively) and sexual IPV severity (rho = 0.22, p < 0.001; rho = 0.19, p = 0.003). Greater number of head injuries and LOC episodes correlated significantly with greater cognitive (rho = 0.33, p < 0.001; rho = 0.23, p < 0.001, respectively), physical (rho = 0.36, p < 0.001; rho = 0.31, p < 0.001), emotional (rho = 0.36, p < 0.001; rho = 0.18, p = 0.004), and total symptom severity (rho = 0.39, p < 0.001; rho = 0.26, p < 0.001). In group comparisons, participant groups stratified by number of head injuries (i.e., 0, 1-3, 4+) differed in total symptom severity (p < 0.001, η2 = 0.15), with greater symptom burden associated with more head injuries. Participants with and without LOC differed in symptom severity: cognitive (p < 0.001, d = 0.45), physical (p < 0.001, d = 0.60), emotional (p = 0.004, d = 0.37), and total symptom severity (p < 0.001, d = 0.53). Group differences between participants with and without LOC remained significant after controlling for sociodemographic variables and IPV severity. There was no cumulative effect of LOC, in that participants with 1 LOC episode did not differ from participants with 2 + LOC episodes (p > 0.05). Based on hierarchical regression analyses, only physical symptoms were independently related to number of head injuries (p = 0.008, ΔR2 = 0.011) and number of LOC episodes (p = 0.014, ΔR2 = 0.021) after controlling for sociodemographic characteristics and IPV severity. Among women survivors of IPV, cumulative head injuries appear related to greater symptom severity. Greater head injury history was independently related to worse physical symptoms (e.g., headaches, dizziness, sleep problems), whereas cognitive and emotional symptoms were, in part, attributable to cumulative physical and emotional trauma due to IPV. Women survivors of IPV with repetitive head injuries have unmet neurobehavioral health needs that may benefit from targeted interventions.

Head Injury Due to Intimate Partner Violence: Injury Characteristics, Subacute Symptoms, and Receipt of Care

Women survivors of intimate partner violence (IPV) have increased risk of repetitive neurotrauma in their lifetime but have received less research focus compared with populations of athletes, veterans, and emergency department patients. The current study examined the importance of IPV as a contextual mechanism of injury, by comparing women survivors of IPV based on whether they experienced a head injury due to IPV or a head injury not due to IPV. The analyses involved archival data from in-person interviews conducted with women who received a protective order against an intimate partner in Kentucky from 2001 to 2004 (n = 641). Women were excluded if they reported no head injury history (n = 268), resulting in two groups compared based on a retrospective cohort design: 255 women with at least one self-reported IPV-related head injury (M = 33.8 ± 9.0 years old, range: 19-65; 87.5% White) and 118 women with self-reported head injuries due to reasons other than IPV (M = 32.2 ± 9.1 years old, range: 18-62; 89.0% White). Participants were compared on injury characteristics, lifetime physical and sexual IPV severity, subacute symptoms of head injury, and receipt of care for head injury. Compared with women with head injuries unrelated to IPV, women with IPV-related head injuries reported a higher number of lifetime head injuries (Mdn[range]: IPV-related = 3[1-515] vs. non-IPV-related = 1[1-13], p < 0.001, r = 0.51) and a higher number of head injuries involving loss of consciousness (Mdn[range]: IPV-related = 1[1-35] vs. non-IPV-related = 1[1-4], p < 0.001, r = 0.27), but lower rates of hospitalization (IPV-related = 56.1% vs. non-IPV-related = 73.7%, p = 0.001, odds ratio [OR] = 2.20 [95% confidence interval (CI): 1.36, 3.55]) and formal rehabilitation (IPV-related = 3.2% vs. non-IPV-related = 9.4%, p = 0.011, OR = 3.18 [1.24, 8.13]) following head injury. Women with IPV-related head injuries had greater lifetime severity of physical IPV (p < 0.001, d = 0.64 [0.41, 0.86]) and sexual IPV (p < 0.001, d = 0.38 [0.16, 0.60]). Women with IPV-related head injuries endorsed all symptoms at greater rates than women with non-IPV-related head injuries (ps < 0.001), including physical (e.g., headaches: OR = 3.15 [1.81, 5.47]; dizziness: OR = 2.65 [1.68, 4.16]), cognitive (e.g., trouble problem solving: OR = 2.66 [1.53, 4.64]; inattention: OR = 2.39 [1.52, 3.78]), and emotional symptoms (e.g., depression: OR = 7.39 [4.48, 12.20]; anxiety: OR = 4.60 [2.82, 7.51]). The total count of symptoms endorsed was higher for women with IPV-related head injury than women with head injuries unrelated to IPV (p < 0.001, d = 0.71 [0.49, 0.94]). When controlling for lifetime physical and sexual IPV, IPV-related head injury was independently associated with symptom count (β = 0.261, p < 0.001) and accounted for additional variance in symptom count (ΔR2 = 0.06, p < 0.001). Among women survivors of IPV, those reporting IPV-related head injuries reported greater subacute symptoms, but a lower likelihood of being hospitalized or receiving rehabilitative care. Women with self-reported IPV-related head injuries represent an underserved population that is often unevaluated following injury and may have many unmet care needs. Future studies should examine persistent symptoms following IPV-related head injuries and interventions that would be most beneficial for this population.

Optimizing baseline and post-concussion assessments through identification, confirmation, and equivalence of latent factor structures: findings from the NCAA-DoD CARE Consortium

Objective: Concussion evaluations use a multidimensional assessment to evaluate unique patient function dimensions (e.g., subjective symptoms differ from balance assessments), but the overarching latent factor structure has not been empirically substantiated. Our objective was to determine the cumulative latent factor structure of pre-injury baseline and acute (<48-h) post-concussion assessment battery outcomes, and determine measurement equivalence among common factors in collegiate student-athletes. Methods: Collegiate student-athletes at baseline (n = 21,865) and post-concussion (n = 1,537) across 25-institutions completed standardized assessments. Individual items were used from the baseline and post-concussion assessments and consisted of: Sport Concussion Assessment Tool, Brief Symptom Inventory-18, Standardized Assessment of Concussion, Balance Error Scoring System, Immediate Post-Concussion Assessment and Cognitive Test, and vestibular-ocular motor screening. Exploratory factor analysis was used on half the baseline data, and confirmatory factor analysis on the remaining baseline data and post-concussion data separately. Measurement equivalence was assessed between sex, sport contact classification, concussion history, and time. Results: A 10-factor exploratory model was established and comprised of: depression, somatic, vestibulo-ocular, headache, postural stability, neurocognition, emotional, fatigue, cognitive, consciousness clouding. The 10-factor model was confirmed at baseline and post-concussion with strong measurement equivalence between timepoints. Strong to strict measurement equivalence was observed for sex, sport contact classification, and concussion history at both timepoints separately. Conclusion: Our findings established a robust 10-factor latent factor model equivalent across timepoints and common factors among healthy and concussed collegiate athletes. Clinicians can use these findings to target specific factors while reducing redundant elements to provide efficient, comprehensive post-concussion assessments.

Electrophysiological variability during tests of executive functioning: A comparison of athletes with and without concussion and sedentary control participants

OBJECTIVE

Sport participation may benefit executive functioning (EF), but EF can also be adversely affected by concussion, which can occur during sport participation. Neural variability is an emerging proxy of brain health that indexes the brain's range of possible responses to incoming stimuli (i.e., dynamic range) and interconnectedness, but has yet to be characterized following concussion among athletes. This study examined whether neural variability was enhanced by athletic participation and attenuated by concussion.

METHOD

Seventy-seven participants (18-25 years-old) were classified as sedentary controls (n = 33), athletes with positive concussion history (n = 21), or athletes without concussion (n = 23). Participants completed tests of attention switching, response inhibition, and updating working memory while undergoing electroencephalography recordings to index neural variability.

RESULTS

Compared to sedentary controls and athletes without concussion, athletes with concussion exhibited a restricted whole-brain dynamic range of neural variability when completing a test of inhibitory control. There were no group differences observed for either the switching or working memory tasks.

CONCLUSIONS

A history of concussion was related to reduced dynamic range of neural activity during a task of response inhibition in young adult athletes. Neural variability may have value for evaluating brain health following concussion.

What tests and measures accurately diagnose persisting post-concussive symptoms in children, adolescents and adults following sport-related concussion? A systematic review

OBJECTIVE

To determine what tests and measures accurately diagnose persisting post-concussive symptoms (PPCS) in children, adolescents and adults following sport-related concussion (SRC).

DESIGN

A systematic literature review.

DATA SOURCES

MEDLINE, Embase, PsycINFO, Cochrane Central Register of Controlled Trials, CINAHL and SPORTDiscus through March 2022.

ELIGIBILITY CRITERIA

Original, empirical, peer-reviewed findings (cohort studies, case-control studies, cross-sectional studies and case series) published in English and focused on SRC. Studies needed to compare individuals with PPCS to a comparison group or their own baseline prior to concussion, on tests or measures potentially affected by concussion or associated with PPCS.

RESULTS

Of 3298 records screened, 26 articles were included in the qualitative synthesis, including 1016 participants with concussion and 531 in comparison groups; 7 studies involved adults, 8 involved children and adolescents and 11 spanned both age groups. No studies focused on diagnostic accuracy. Studies were heterogeneous in participant characteristics, definitions of concussion and PPCS, timing of assessment and the tests and measures examined. Some studies found differences between individuals with PPCS and comparison groups or their own pre-injury assessments, but definitive conclusions were not possible because most studies had small convenience samples, cross-sectional designs and were rated high risk of bias.

CONCLUSION

The diagnosis of PPCS continues to rely on symptom report, preferably using standardised symptom rating scales. The existing research does not indicate that any other specific tool or measure has satisfactory accuracy for clinical diagnosis. Future research drawing on prospective, longitudinal cohort studies could help inform clinical practice.

Primary and Secondary Risk Factors Associated With Concussion Symptom Clusters in Collegiate Athletes: Results From the NCAA-DoD Grand Alliance CARE Consortium

Background

There is a broad and diverse range of symptoms after a concussion, from irritability to nausea. This heterogeneity of symptoms is a challenge for clinicians managing the different presentations among injuries. Prior research has investigated the structure of postconcussive symptoms to determine if they can be grouped into clusters of related symptoms.

Purpose/Hypothesis

The purpose of this study was to identify symptom clusters during the acute phase after a sports-related concussion using exploratory factor analysis and to understand the relationship between risk factors for postconcussion symptoms (ie, demographics, injury characteristics, mental health, and sleep qualities) and different symptom clusters. We hypothesized that certain factors would be predictive of specific symptom clusters.

Study Design

Cross-sectional study; Level of evidence, 3.

Methods

Collegiate athletes (N = 1104) from the Concussion, Assessment, Research, and Education (CARE) Consortium completed the Sport Concussion Assessment Tool-Third Edition symptom assessment tool 24 to 48 hours after concussion. Exploratory factor analysis was conducted on the symptom evaluation to determine symptom clusters 24 to 48 hours after concussion. Regression analysis was used to examine the effects of pre- and postinjury characteristics.

Results

Exploratory factor analysis revealed a 4-cluster structure for acute postconcussive symptoms that explained 62% of the variance in symptom reporting: vestibular-cognitive, migrainous, cognitive fatigue, and affective. Delayed reporting, less sleep before assessment, female sex, and being hurt outside of competition (during practice/training) was correlated with increased symptoms for 4 symptom clusters. Depression predicted higher vestibular-cognitive and affective symptoms. Amnesia was correlated with higher vestibular-cognitive and migrainous symptoms, whereas migraine history was associated with more migrainous and affective symptoms.

Conclusion

Symptoms can be grouped into 1 of 4 distinct clusters. Certain variables were associated with increased symptoms across multiple clusters and may be indicative of greater injury severity. Other factors (ie, migraine history, depression, amnesia) were associated with a more specific symptom presentation and may be mechanistically related to concussion outcomes and biological markers.

The Post-Concussion Symptom Scale: Normative Data for Adolescent Student-Athletes Stratified by Gender and Preexisting Conditions

BACKGROUND

The Post-Concussion Symptom Scale (PCSS) is a self-report questionnaire measuring symptoms that commonly occur after a concussion; however, these symptoms are nonspecific and can be related to co-occurring orthopaedic injuries (eg, cervical strain) or patient characteristics and preexisting conditions, even in the absence of a recent injury. As such, clinicians may have difficulty determining whether symptom elevations are attributable to a recent concussion as opposed to a confounding injury or a preexisting condition, which may be especially difficult when preinjury baseline symptom data are unavailable.

PURPOSE

This study aimed to further validate the 4-factor model of the PCSS (ie, cognitive, sleep-arousal, physical, and affective symptoms) with adolescent student-athletes and provide normative reference data for each factor and the total score, stratified by gender and preexisting health conditions.

STUDY DESIGN

Cross-sectional study; Level of evidence, 3.

METHODS

Participants were 9358 adolescent student-athletes who completed the PCSS during a preseason baseline evaluation (mean age, 14.9 years; SD, 1.3 years [range, 13-18 years]; 49.3% boys). The 4-factor model of the PCSS was tested for the full sample and separately for boys and girls using confirmatory factor analysis. Symptom severity percentiles were created for the PCSS total score and each factor, stratified by gender and preexisting conditions (ie, attention-deficit/hyperactivity disorder, mental health history, headache/migraine history, learning disability/dyslexia, academic problems, and concussion history).

RESULTS

The 4-factor model of the PCSS replicated in the full sample (comparative fit index [CFI] = 0.959) and in both gender groups (boys: CFI = 0.961; girls: CFI = 0.960). The total PCSS score at the 84th percentile varied by preexisting conditions as follows: healthy participants = 8, attention-deficit/hyperactivity disorder = 18, mental health history = 26, headache/migraine history = 18, learning disability = 19, and academic problems = 17. On all PCSS subscales, participants with a mental health history had the highest scores, and high scores were associated with having >1 preexisting condition. Girls had higher scores than boys for each stratification.

CONCLUSION

The 4-factor model of the PCSS replicates for adolescent student-athletes. Gender, number of preexisting conditions, and mental health history are important factors to account for when interpreting PCSS symptom severity. The normative data provided herein could assist clinicians in determining whether an adolescent student-athlete is presenting with persistent postconcussion symptoms or a typical symptom experience based on their gender and personal health history.

Preseason Symptom Reporting and Cognition in Middle School Athletes with Past Concussions

This study examined the association between past concussions and current preseason symptom reporting and cognitive performance in 9,257 youth ages 11-13. Participants completed neurocognitive testing prior to participating in a school sports between 2009 and 2019. We stratified the sample by gender and number of prior concussions and assessed group differences on the Post-Concussion Symptom Scale total score and the ImPACT cognitive composite scores. Those with≥2 prior concussions reported more symptoms than those with 0 concussions (d=0.43-0.46). Multiple regressions examining the contribution of concussion history and developmental/health history to symptom reporting showed the most significant predictors of symptoms scores were (in descending order): treatment for a psychiatric condition, treatment for headaches, history of learning disability (in boys only), history of attention-deficit/hyperactivity disorder, and age. Concussion history was the weakest statistically significant predictor in boys and not significant in girls. Cognitively, boys with 1 prior concussion had worse speed those with 0 concussions (d=0.11), and girls with≥2 prior concussions had worse verbal/visual memory than girls with 0 concussions (ds=0.38-0.39). In summary, youth with≥2 prior concussions reported more symptoms than those with no concussions. Boys with multiple concussions performed similarly on cognitive testing, while girls had worse memory scores.

Effect of parental education and household poverty on recovery after traumatic brain injury in school-aged children

OBJECTIVE

While prior studies have found parental socioeconomic status (SES) affects the outcomes of pediatric traumatic brain injury (TBI), the longitudinal trajectory of this effect is not well understood.

METHODS

This prospective cohort study included children 8-18 years of age admitted to six sites with a complicated mild (n = 123) or moderate-severe TBI (n = 47). We used caregiver education and household poverty level as predictors, and multiple quality of life and health behavior domains as outcomes. Differences at 6, 12, and 24 months from baseline ratings of pre-injury functioning were compared by SES. We examined the association between measures of SES and domains of functioning over the 24 months post-injury in children with a complicated mild or moderate- severe TBI, and determined how this association varied over time.

RESULTS

Parental education was associated with recovery among children with complicated mild TBI; outcomes at 6, 12, and 24 months were substantially poorer than at baseline for children with the least educated parents. After moderate-severe TBI, children in households with lower incomes had poorer outcomes compared to baseline across time.

IMPLICATIONS

Parental education and household income were associated with recovery trajectories for children with TBI of varying severity.