Irregular sleep-wake type

Introduction
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By Baruch El-Ad MD

Dr. El-Ad of the Sleep Medicine Center, Technion - Israel Institute of Technology explains the pathophysiology and treatment of this circadian rhythm sleep disorder. Seen mainly in individuals with neurodegenerative disorders causing dementia, irregular sleep-wake pattern may further complicate the care of these patients. Institutionalization may follow the emergence of the irregular sleep-wake pattern because it can make a caregiver’s already difficult job unbearable. A rich environment and sufficient timely exposure to bright light may minimize the disturbance. Medical therapy with melatonin was generally ineffective in randomized control trials, despite encouraging open studies in small series of patients. The review enables basic understanding of the circadian clock biology and its interactions with the sleep-wake cycle.

Key Points

  • Irregular sleep-wake pattern consists of a breakdown of a single consolidated sleep period into multiple naps irregularly dispersed around the 24-hour period.
  • It is common in elderly patients with neurodegenerative disorders or in patients of any age with neurodevelopmental disorders.
  • Disease-related malfunction of the endogenous circadian timing systems is presumed to be the principal underlying change causing the disorganized sleep timing.
  • Other medical, neurologic, or psychiatric disorders and medication side-effects may contribute to the sleep-wake cycle disruption.
  • Multimodal therapy that includes combination of timed light-melatonin treatment and nonpharmacological interventions like scheduled contacts, physical activity, and enriched environment may improve the sleep-wake pattern.H