title: The effect of days since last concussion and number of concussions on cognitive functioning in Division I athletes.
abstract: OBJECTIVE
  Cognitive recovery from sports concussion may be incomplete after resolution of other symptoms. It was hypothesized that independent effects of the number of days since last concussion (Days) and total number of concussions (Number) would predict poorer cognitive functioning.
  
  
  METHODS
  Cognition was assessed in an NCAA Division I student-athlete population (n = 87) using the Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT) battery. In a MANOVA, the five ImPACT Composite scores were dependent variables, with Group (Concussion, Unaffected) as the independent variable and prior number of concussions (Number) and days since last concussion (Days; 68-2495 days) entered as covariates.
  
  
  RESULTS
  The hypothesis that Days and Number would each independently affect cognitive functioning (as assessed by ImPACT Composite scores) was only partly supported. A significant, multivariate, main effect of Days (p = 0.01) indicated that more Days predicted better cognitive functioning overall (p = 0.01). Univariate effects emerged such that more Days specifically predicted better visual memory (p = 0.004) and faster reaction times (p = 0.02). A trend toward a Group*Days*Number three-way interaction for reaction time emerged (p = 0.06), such that smaller Number and more Days each predicted slower reaction time.
  
  
  CONCLUSIONS
  Cognitive recovery following sports concussion may take far longer than was previously thought, the aetiology of cognitive reductions may be very complex and the ImPACT appears to be sensitive to subtle changes in cognition across time.
authors: Department of Psychiatry and.
authors: Robert J
authors: RJ
authors: Thoma
authors: Julia A
authors: JA
authors: Cook
authors: Christopher
authors: C
authors: McGrew
authors: John H
authors: JH
authors: King
authors: Andrew R
authors: AR
authors: Mayer
authors: Jeffrey D
authors: JD
authors: Lewine
authors: Ronald A
authors: RA
authors: Yeo
authors: Richard
authors: R
authors: Campbell
mesh_terms: D000293:Adolescent; D056352:Athletes / Q000523:psychology; D001265:Athletic Injuries / Q000523:psychology*; D001924:Brain Concussion / Q000209:etiology / Q000523:psychology*; D016022:Case-Control Studies; D003072:Cognition Disorders / Q000175:diagnosis / Q000209:etiology / Q000523:psychology*; D005260:Female; D006801:Humans; D008297:Male; D038223:Post-Concussion Syndrome / Q000209:etiology / Q000523:psychology; D020127:Recovery of Function; D013177:Sports / Q000523:psychology; D013997:Time Factors; D055815:Young Adult
keywords: Athletes; concussion; memory; neuropsychology; sport