title: Acute concussion symptom severity and delayed symptom resolution.
abstract: OBJECTIVE
  Up to 30% of children who have concussion initially evaluated in the emergency department (ED) display delayed symptom resolution (DSR). Greater initial symptom severity may be an easily quantifiable predictor of DSR. We hypothesized that greater symptom severity immediately after injury increases the risk for DSR.
  
  
  METHODS
  We conducted a prospective longitudinal cohort study of children 8 to 18 years old presenting to the ED with concussion. Acute symptom severity was assessed using a graded symptom inventory. Presence of DSR was assessed 1 month later. Graded symptom inventory scores were tested for association with DSR by sensitivity analysis. We conducted a similar analysis for post-concussion syndrome (PCS) as defined by the International Statistical Classification of Diseases and Related Health Problems, 10th revision. Potential symptoms characteristic of DSR were explored by using hierarchical cluster analysis.
  
  
  RESULTS
  We enrolled 234 subjects; 179 (76%) completed follow-up. Thirty-eight subjects (21%) experienced DSR. Initial symptom severity was not significantly associated with DSR 1 month after concussion. A total of 22 subjects (12%) had PCS. Scores >10 (possible range, 0-28) were associated with an increased risk for PCS (RR, 3.1; 95% confidence interval 1.2-8.0). Three of 6 of the most characteristic symptoms of DSR were also most characteristic of early symptom resolution. However, cognitive symptoms were more characteristic of subjects reporting DSR.
  
  
  CONCLUSIONS
  Greater symptom severity measured at ED presentation does not predict DSR but is associated with PCS. Risk stratification therefore depends on how the persistent symptoms are defined. Cognitive symptoms may warrant particular attention in future study. Follow-up is recommended for all patients after ED evaluation of concussion to monitor for DSR.
authors: Departments of Pediatrics, andEmergency Department, and joe.grubenhoff@childrenscolorado.org.
authors: Joseph A
authors: JA
authors: Grubenhoff
authors: Department of Research Informatics, Children's Hospital Colorado, Aurora, Colorado; and.
authors: Sara J
authors: SJ
authors: Deakyne
authors: Departments of Pediatrics, andEmergency Department, and.
authors: Lina
authors: L
authors: Brou
authors: Departments of Pediatrics, andEmergency Department, and.
authors: Lalit
authors: L
authors: Bajaj
authors: Departments of Pediatrics, andDepartment of Epidemiology, Colorado School of Public Health, Aurora, Colorado.
authors: R Dawn
authors: RD
authors: Comstock
authors: Physical Medicine and Rehabilitation, University of Colorado, Aurora, Colorado;
authors: Michael W
authors: MW
authors: Kirkwood
mesh_terms: D000208:Acute Disease; D000293:Adolescent; D001924:Brain Concussion / Q000175:diagnosis; D002648:Child; D004630:Emergencies; D005260:Female; D006801:Humans; D015601:Injury Severity Score; D008297:Male; D038223:Post-Concussion Syndrome / Q000175:diagnosis*; D011446:Prospective Studies; D013997:Time Factors
keywords: acute; brain concussion; brain injury; emergency medicine; post-concussion symptoms; post-concussion syndrome; traumatic