LAUSR

Previous research utilizing factor analytic methods, such as principal components analysis (PCA) has focused on concussion factors derived from symptom scales (Piland, 2003; Kontos, 2012) and neurocognitive testing (Schatz, 2013). However, researchers have yet to conduct a PCA that incorporates symptoms, cognitive, ocular, and vestibular outcomes. The purpose was to utilize PCA to examine the factor structure of concussion among adolescents within 31 days of injury. Participants included 238 adolescents (41.2% female) diagnosed with concussion. Average age was 14.81 ± 1.57 years (10 to 17 years). A PCA was performed on 11 variables, including PCSS (via symptom factors: cognitive/fatigue/migraine, affective, somatic, and sleep), near point of convergence (NPC), ImPACT composites, and VOMS symptoms. Items retained in the factor models on the basis of having a primary factor loading of .6 or above. A three-component model was supported that accounted for 65.12% of the variance: 1) cognitive, 2) symptoms, and 3) vestibular/ocular. The cognitive component included visual motor speed, reaction time, verbal, and visual memory (37.95%). Symptoms component included affective, cognitive/fatigue/migraine, and sleep (17.42%). Vestibular/ocular component included vestibular and ocular symptoms (9.75%). All items loaded into the PCA, with exception of somatic and NPC average were retained. The current study supported three factors and extended findings of previous PCAs by including ocular and vestibular components. The current study better reflects contemporary models of concussion involving clinical profiles or subtypes (e.g., Harmon, 2019). Moving forward, researchers should examine factors across subacute and chronic time points to evaluate potential temporal changes in factors.