title: Activity-Related Symptom Exacerbations After Pediatric Concussion.
abstract: OBJECTIVE
  Recovery from concussion generally follows a trajectory of gradual improvement, but symptoms can abruptly worsen with exertion. This phenomenon is poorly understood.
  
  
  OBJECTIVE
  To characterize the incidence, course, and clinical significance of symptom exacerbations (spikes) in children after concussion.
  
  
  METHODS
  This secondary analysis of clinical trial data analyzes 63 eligible participants prospectively recruited from an emergency department who were asked to complete a postconcussion symptom scale and record their activities in a structured diary for the next 10 days. They completed standardized assessments of symptoms (postconcussion symptom scale), cognition (Immediate Post-Concussion Assessment and Cognitive Testing), and balance (Balance Error Scoring System) 10 days following the injury. Eligible participants were aged 11 to 18 years and sustained a concussion (according to the Centers for Disease Control and Prevention criteria) that did not result in an abnormal computed tomography scan or require hospital admission. The trial was conducted from May 2010 to December 2012, and the analysis was conducted from November 2015 to February 2016.
  
  
  METHODS
  The occurrence of symptom spikes, defined as an increase of 10 or more points on the postconcussion symptom scale over consecutive days.
  
  
  RESULTS
  Of the 63 participants, there were 41 boys (65.1%) and 22 girls (34.9%), and the mean (SD) age was 13.8 (1.8) years. Symptom spikes occurred in one-third of the sample (20 participants [31.7%]). Symptom spikes tended to partially resolve within 24 hours. An abrupt increase in mental activity (ie, returning to school and extracurricular activities) from one day to the next increased the risk of a symptom spike (relative risk, 0.81; 95% CI, 0.21-3.21), but most symptom spikes were not preceded by a documented increase in physical or mental activity. Patients with symptom spikes were initially more symptomatic in the emergency department and throughout the observation period but did not differ from the group without symptom spikes on cognition or balance 10 days following injury.
  
  
  CONCLUSIONS
  Certain patients appeared susceptible to high and variable symptom reporting. Symptom spikes may not themselves be detrimental to recovery. The present findings support clinical guidelines for adolescents to return to school and activities gradually after concussion.
  
  
  BACKGROUND
  clinicaltrials.gov Identifier: NCT01101724.
authors.affiliation: Division of Physical Medicine and Rehabilitation, Department of Medicine, University of British Columbia, Vancouver, British Columbia, Canada2Department of Physical Medicine and Rehabilitation, Harvard Medical School, Boston, Massachusetts3Red Sox Foundation and Massachusetts General Hospital Home Base Program, Boston, Massachusetts.
authors.forename: Noah D
authors.initials: ND
authors.lastname: Silverberg
authors.affiliation: Department of Physical Medicine and Rehabilitation, Harvard Medical School, Boston, Massachusetts3Red Sox Foundation and Massachusetts General Hospital Home Base Program, Boston, Massachusetts4Spaulding Rehabilitation Hospital, Boston, Massachusetts5MassGeneral Hospital for Children Sports Concussion Program, Boston, Massachusetts.
authors.forename: Grant L
authors.initials: GL
authors.lastname: Iverson
authors.affiliation: Department of Neurosurgery, Medical College of Wisconsin, Clement J. Zablocki VA Medical Center, Milwaukee.
authors.forename: Michael
authors.initials: M
authors.lastname: McCrea
authors.affiliation: Department of Psychiatry and Behavioral Medicine, Medical College of Wisconsin, Milwaukee.
authors.forename: Jennifer N
authors.initials: JN
authors.lastname: Apps
authors.affiliation: Department of Psychiatry and Behavioral Medicine, Medical College of Wisconsin, Milwaukee.
authors.forename: Thomas A
authors.initials: TA
authors.lastname: Hammeke
authors.affiliation: Department of Pediatrics, Medical College of Wisconsin, Milwaukee.
authors.forename: Danny G
authors.initials: DG
authors.lastname: Thomas
mesh_terms: D000293:Adolescent; D001265:Athletic Injuries / Q000150:complications*; D001924:Brain Concussion / Q000150:complications*; D002648:Child; D003071:Cognition; D018450:Disease Progression; D004638:Emergency Treatment; D005260:Female; D006801:Humans; D008297:Male; D038223:Post-Concussion Syndrome / Q000209:etiology*; D011446:Prospective Studies; D012720:Severity of Illness Index