title: Neuropsychological performance, postural stability, and symptoms after dehydration.
abstract: BACKGROUND
  Dehydration and concussion are common in athletic performance. Some experts have speculated that dehydration may negatively influence performance on tests commonly used for concussion assessment.
  
  
  OBJECTIVE
  To determine how the signs and symptoms, neuropsychological performance, and postural stability are affected by dehydration.
  
  
  METHODS
  Repeated-measures design assessing subjects in the euhydrated and dehydrated conditions.
  
  
  METHODS
  Sports Medicine Research Laboratory.
  
  
  METHODS
  Twenty-four healthy, male recreational athletes participated in the study.
  
  
  METHODS
  Subjects participated in 2 counterbalanced sessions (euhydrated and dehydrated) separated by at least 7 days. Subjects were dehydrated using fluid restriction and an exercise task. No direct intervention was provided for the euhydrated condition.
  
  
  METHODS
  We used the Standardized Assessment of Concussion to test mental status, the Automated Neuropsychological Assessment Metrics (ANAM) to evaluate neuropsychological performance, the NeuroCom Sensory Organization Test and Balance Error Scoring System to test postural stability, the Graded Symptom Checklist to assess symptom presence and severity in our participants, and urine specific gravity and body mass to determine hydration status.
  
  
  RESULTS
  No differences were noted for the Standardized Assessment of Concussion, total Balance Error Scoring System errors, composite Sensory Organization Test, and composite ANAM scores between conditions. Subjects in the dehydrated condition had significant deterioration in visual memory (t(23) = 2.130, P < .001) and fatigue measures (t(23) = -7.880, P < .001) as assessed by ANAM. The dehydrated condition resulted in subjects reporting a significantly higher number (t(23) = -8.585, P < .001) and severity (t(23) = -7.673, P < .001) of symptoms than the euhydrated subjects on the Graded Symptom Checklist.
  
  
  CONCLUSIONS
  Our results suggest that moderate dehydration (-2.5 +/- 0.63%) significantly influenced the self-report of symptoms commonly associated with concussion. Dehydration resulted in a deterioration of visual memory and increases in the self-report of fatigue. Despite these findings, dehydration did not affect other neuropsychological and postural stability objective testing measures for concussion.
authors.affiliation: University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.
authors.forename: Akshay V
authors.initials: AV
authors.lastname: Patel
authors.forename: Jason P
authors.initials: JP
authors.lastname: Mihalik
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Notebaert
authors.forename: Kevin M
authors.initials: KM
authors.lastname: Guskiewicz
authors.forename: William E
authors.initials: WE
authors.lastname: Prentice
mesh_terms: D000328:Adult; D001924:Brain Concussion / Q000503:physiopathology*; D016022:Case-Control Studies; D003681:Dehydration / Q000209:etiology / Q000503:physiopathology; D006801:Humans; D008297:Male; D009483:Neuropsychological Tests; D004856:Postural Balance / Q000502:physiology*; D020127:Recovery of Function; D012016:Reference Values; D018570:Risk Assessment; D013177:Sports / Q000502:physiology; D013178:Sports Medicine; D013647:Task Performance and Analysis; D013997:Time Factors