Ecological Momentary Assessment of Activity Demand and Time-of-Day Effects on Post-Concussion Symptoms

= 26, 68.4%) characterized activities in this category most frequently. Open-ended responses elaborating on activities in this category included "doing nothing," "sleeping/relaxing," "watching TV," and "eating." Linear mixed-effects model (LMM) results (based on 38 participants with >33% response rates) showed that activity demands were significantly associated with symptoms. Mentally demanding activities were associated with increases in total and cognitive-migraine-fatigue symptoms, whereas physically demanding activities were associated with decreases in these symptoms. Mentally demanding and combined mentally and physically demanding activities were also associated with increased affective symptoms. Additionally, time of day was significantly associated with cognitive-migraine-fatigue symptoms, with increases in symptoms later in the day compared with early in the morning. The present findings extend existing literature by demonstrating the utility of EMA for capturing real-time associations between contextual factors and symptom expression in traumatic brain injury populations. We also provide evidence that time-of-day and activity demands are associated with symptom expression in individuals with PPCS. Collectively, these findings have implications for informing symptom management strategies in PPCS.