Non-24 hour sleep-wake cycle disorder

Non-24-hour sleep-wake cycle disorder is a chronic circadian rhythm sleep-wake disorder in which an individual's intrinsic biological master clock fails to synchronize, or entrain, to the standard 24-hour environmental light-dark cycle Clinically, affected patients experience cyclical patterns of severe nighttime insomnia alternating with excessive daytime somnolence and impaired social or occupational functioning as their internal rhythm drifts in and out of phase with the solar day

Non-24-hour sleep-wake cycle disorder is a chronic circadian rhythm sleep-wake disorder in which an individual's intrinsic biological master clock fails to synchronize, or entrain, to the standard 24-hour environmental light-dark cycle Driven by an endogenous pacemaker period longer than 24 hours, the central nervous system's internal rhythms—including melatonin release and core body temperature fluctuations—run free, causing a daily progressive delay in sleep onset and waking times While it can...

Driven by an endogenous pacemaker period longer than 24 hours, the central nervous system's internal rhythms—including melatonin release and core body temperature fluctuations—run free, causing a daily progressive delay in sleep onset and waking times While it can occasionally manifest in sighted individuals, it most commonly affects individuals who are totally blind and lack the ocular photic input to the suprachiasmatic nucleus required for circadian alignment

Driven by an endogenous pacemaker period longer than 24 hours, the central nervous system's internal rhythms—including melatonin release and core body temperature fluctuations—run free, causing a daily progressive delay in sleep onset and waking times