Effect of Cognitive Activity Level on Duration of Post-Concussion Symptoms

OBJECTIVE: To determine the effect of cognitive activity level on duration of post-concussion symptoms. METHODS: We conducted a prospective cohort study of patients who presented to a Sports Concussion Clinic within 3 weeks of injury between October 2009 and July 2011. At each visit, patients completed a scale that recorded their average level of cognitive activity since the previous visit. The product of cognitive activity level and days between visits ( cognitive activity-days) was calculated and divided into quartiles. Kaplan-Meier Product Limit method was used to generate curves of symptom duration based on cognitive activity level. To adjust for other possible predictors of concussion recovery, we constructed a Cox proportional hazard model with cognitive activity-days as the main predictor. RESULTS: Of the 335 patients included in the study, 62% were male, 19% reported a loss of consciousness, and 37% reported experiencing amnesia at the time of injury. The mean age of participants was 15 years ( range, 8-23) and the mean number of previous concussions was 0.76; 39% of athletes had sustained a previous concussion. The mean Post-Concussion Symptom Scale score at the initial visit was 30 ( SD, 26). The overall mean duration of symptoms was 43 days ( SD, 53). Of all variables assessed, only total symptom burden at initial visit and cognitive activity level were independently associated with duration of symptoms. CONCLUSIONS: Increased cognitive activity is associated with longer recovery from concussion. This study supports the use of cognitive rest and adds to the current consensus opinion. Pediatrics 2014; 133: e299e304