A - 28 Within-Day Changes in Neurocognitive Performance Among Concussion Patients With a Cognitive-Fatigue Clinical Profile

Abstract Purpose Determine whether patient-reports of late-afternoon cognitive impairment, associated with the cognitive-fatigue clinical profile, can be objectively observed with ecological momentary assessment (EMA). Method Patients (13–25 yrs) seeking concussion care within one week of injury completed a clinical interview, multi-domain assessment battery, and were assigned a primary clinical profile (Migraine, Anxiety/Mood, Vestibular, Ocular, Cognitive-Fatigue). Patients enrolled in a smart phone EMA study and completed four ultra-brief (<60 sec) neurocognitive assessments daily for the next seven days (i.e., 7:30 a.m., 10:30 a.m., 3:00 p.m., and 8:00 p.m.). Performance on all administrations of a visuospatial working memory assessment embedded within the EMA protocol (Grid Memory task) were examined. Results 107 patients (M = 16.07, SD = 2.84) enrolled in the study and nine had a primary cognitive-fatigue profile. Performance on the Grid Memory task was modeled in a multi-level modeling framework to examine the influence of assessment timing (time-of-day) on visuospatial working memory errors. Results revealed a small, significant effect of assessment timing on working memory across all patients (0.5 units change from AM to PM, p < 0.05). We then examined the cognitive fatigue profile as a moderator of the assessment timing effect. Results indicated a significant interaction effect (p < 0.05), indicating that patients with the cognitive fatigue profile exhibited a significant increase in working memory errors (~2 units change from AM to PM, p < 0.01) while those with other profiles did not. Conclusions A hallmark patient report of the cognitive-fatigue profile is late afternoon cognitive impairment, and these data are the first to corroborate this report.