Key Project Outcomes
Drowsy driving accounts for one in eight crashes leading to hospitalization or death and obstructive sleep apnea (OSA) patients with excessive daytime sleepiness have a two to three-fold increased risk of drowsy driving (i.e., lapses in vigilance). However, there is a large inter-individual variability in the relationship between OSA severity and lapses in vigilance.
In order to further our understanding of the causes of inter-individual variability in lapses in vigilance and developing markers of this neurobehavioral impairment, we assessed night-time EEG markers (K-complex/slow-wave coupling) and daytime thalamic and prefrontal activity during a 10-min psychomotor vigilance test (PVT) in subjects with severe OSA who show a high degree of lapses in vigilance.
Pilot data at baseline, in newly diagnosed severe OSA subjects, suggests that thalamic activity is significantly lower during PVT as compared to a rest condition where there is no requirement of sustaining attention. Further, this reduction in thalamic activity was positively correlated, but not statistically significant, to low overnight EEG K-complex/slow-wave coupling (N = 6 subjects, r = 0.69, p = 0.08).
We are currently analyzing follow up data in these subjects obtained after 3 months of treatment with continuous positive airway pressure (CPAP).
Relationship Between Sleep EEG K-Complex Slow Wave Coupling and Next-Day Thalamic Activity During Psychomotor Vigilance Test in Obstructive Sleep Apnea