Abstract
Objective
First, to explore demographic/injury characteristics associated with increased sleep disruption post-concussion. Second, to examine the association between sleep disruption post-concussion and symptom reporting and cognitive variability.
Method
124 athletes (M = 103, F = 21) completed neuropsychological testing within 14 days of concussion. Athletes were categorized as sleep-disrupted (n = 52) or not sleep-disrupted (n = 72). Athletes in the sleep-disrupted group endorsed one or more of the following from the Immediate Post-concussion Assessment and Cognitive Testing (ImPACT) Post-Concussion Symptom Scale (PCSS): trouble falling asleep, sleeping more than usual, and sleeping less than usual. Loss of consciousness (LOC) and concussion history were explored. Two neurocognitive variability measures were derived from the neuropsychological battery: intraindividual standard deviation (ISD) and maximum discrepancy score (MDS). Variability in memory and attention/processing speed (APS) composites were explored. Total PCSS symptom score, without sleep items, was calculated.
Results
A significantly greater proportion of sleep-disrupted athletes experienced LOC (30%) compared to not sleep-disrupted athletes (13%), χ2(1,N = 118) = 4.99, p < 0.03, φ = 0.21. Sleep-disrupted athletes reported more symptoms, t(122) = −5.42, p < 0.001, d = 0.98, and demonstrated more memory variability (memory ISD, t(122) = −2.22, p = 0.03, d = 0.40, and memory MDS, t(122) = −2.29, p = 0.02, d = 0.41) than not sleep-disrupted athletes. Groups did not differ in APS variability or concussion history.
Conclusions
Given the higher rate of LOC in sleep-disrupted athletes, it is possible that LOC is a mechanism leading to post-concussion sleep difficulties. Furthermore, sleep disruption following concussion results in more variable memory performance and higher symptom reporting. Symptom reporting and/or return to baseline cognitive functioning are often decision-making tools in concussion management. The difficulties experienced by sleep-disrupted athletes may complicate recovery.