Temporal relations between peripheral and central arousals in good and poor sleepers

Significance

Arousals represent a fundamental property of the nervous system that enables organisms to perceive and properly respond to internal and external challenges. Arousal mechanisms are evident during wakefulness hours to mitigate external stressors and also, during sleep periods. Among the questions that have remained elusive are when and how central and peripheral arousals are coordinated or integrated. This study evaluated the temporal correlation between central and peripheral arousals. Poor sleepers exhibit a heightened arousal phenotype, and the communication between central and peripheral arousal mechanisms is inherently different from that of good sleepers. The etiology of insomnia remains poorly understood, but screening for peripheral arousal events may be a valuable tool in the assessment and diagnosis of poor sleeping.

Abstract

Good sleepers and patients with insomnia symptoms (poor sleepers) were tracked with two measures of arousal; conventional polysomnography (PSG) for electroencephalogram (EEG) assessed cortical arousals, and a peripheral arterial tonometry device was used for the detection of peripheral nervous system (PNS) arousals associated with vasoconstrictions. The relationship between central (cortical) and peripheral (autonomic) arousals was examined by evaluating their close temporal dynamics. Cortical arousals almost invariably were preceded and followed by peripheral activations, while large peripheral autonomic arousals were followed by cortical arousals only half of the time. The temporal contiguity of these two types of arousals was altered in poor sleepers, and poor sleepers displayed a higher number of cortical and peripheral arousals compared with good sleepers. Given the difference in the number of peripheral autonomic arousals between good and poor sleepers, an evaluation of such arousals could become a means of physiologically distinguishing poor sleepers.