Hours of Sleep Prior to ImPACT Testing, Symptom Report, and Cognitive Function

J Int Neuropsychol Soc. 2011 Mar;


Kakos, L. S., T. Stratton, A. J. Szabo and J. Gunstad.



Objective: Inadequate sleep has adverse effects on cognitive function, particularly attention, working memory, and recall. The Immediate Postconcussion Assessment and Cognitive Testing (ImPACT) is used to assess these abilities in athletes. The effects of reduced sleep on baseline test performance are unknown. Participants and Methods: Division I football players (n=229, mean age= 20.4±1.4, mean concussions=0.52±1.0) were administered baseline ImPACT testing. As part of standardized testing, the student athletes reported the number of hours of sleep obtained prior to testing and subjective symptoms. Cognitive testing generated composite indices of verbal and visual memory, visual motor speed, reaction time, impulse control, delayed memory, and working memory. Results: A mean of 7.3 (±1.3) hours of sleep prior to testing was reported. In general, symptom report varied and ranged from vomiting and balance problems (0.4% each) to fatigue (20.1%). Partial correlations controlling for number of concussions demonstrated that hours of sleep prior to testing was negatively correlated with reported headache (r=-0.21, r=0.00), fatigue (r=-0.15, r=0.02), trouble falling asleep (r=0.16, r=0.02), sleeping less than usual (r=-0.17, p=0.01), and irritability (r=-0.20, p=0.00). Hours of sleep was not significantly correlated with measures of cognitive function in the sample or those individuals with history of concussion. Conclusions: While hours of sleep was not associated with cognitive test performance in university football players, it was associated with reports of physical symptoms. Clinicians may benefit from assessing sleep in differential diagnosis of concussion, as common symptoms of reduced sleep and concussions may be over-reported due to inadequate sleep before testing.

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