Normal Sleep - Sleep Medicine Series - PDF

Sleep Medicine Series Normal Sleep Axel Shum, MD Overview Learning Objectives Normal Human Sleep Additional Resources - Define “sleep” - Importance - Questions - Sleep Medicine - Stages - Canonical texts Terminology -...

Sleep Medicine Series Normal Sleep Axel Shum, MD Overview Learning Objectives Normal Human Sleep Additional Resources - Define “sleep” - Importance - Questions - Sleep Medicine - Stages - Canonical texts Terminology - Circadian rhythm - Fun reading - Sleep Architecture - Demographics - Why is sleep - Evaluation important? - Sleep disorder overview Guiding Questions What is sleep? What are the stages of sleep? How is sleep quantified/evaluated? How does sleep change with age? What are the differences between normal sleep and sleep disorders?  Why learn about sleep? Interest in sleep has influenced all cultures since antiquity1 Sleep is the third pillar of health, along with diet and exercise2 CDC: daily sufficient sleep is key for chronic disease prevention3 ”Sleep medicine is experiencing a moment” 4 ○ 2017 Nobel Prize ○ Wearable technology Lack of sleep results in death (e.g., fatal familial insomnia) 1 1 Kryger, M. H., Roth, T., & Goldstein, C. A. (2022). Kryger's Principles and Practice of Sleep Medicine (7th ed.). Elsevier - OHCE. https://bookshelf.health.elsevier.com/books/9780323675062 2 Castillo M. (2015). The 3 pillars of health. AJNR. American journal of neuroradiology, 36(1), 1–2. https://doi.org/10.3174/ajnr.A4025 3 Liu, Y., Croft, J. B., Wheaton, A. G., Kanny, D., Cunningham, T. J., Lu, H., Onufrak, S., Malarcher, A. M., Greenlund, K. J., & Giles, W. H. (2016). Clustering of Five Health-Related Behaviors for Chronic Disease Prevention Among Adults, United States, 2013. Preventing chronic disease, 13, E70. https://doi.org/10.5888/pcd13.160054 4 Chiang, A. A., & Khosla, S. (2023). Consumer Wearable Sleep Trackers: Are They Ready for Clinical Use?. Sleep medicine clinics, 18(3), 311–330. https://doi.org/10.1016/j.jsmc.2023.05.005  Role of Sleep Learning/memory: ○ Increases in slow brain wave activity (slow wave sleep) after learning a task results in improved task performance ○ Empirically and reproducibly, sleep has been shown to play an instrumental role in memory consolidation and learning in general Immune system: ○ Fatigue and sleepiness often occur during illness (IL-1, TNF, etc.) ○ Sleep deprivation impairs antibody response to vaccination Avidan, A. Y. (2017). Review of Sleep Medicine (4th ed.). Elsevier - OHCE. https://bookshelf.health.elsevier.com/books/9780323473507 Stickgold R. (2005). Sleep-dependent memory consolidation. Nature, 437(7063), 1272–1278. https://doi.org/10.1038/nature04286  Role of Sleep Cardiovascular: ○ Untreated obstructive sleep apnea is associated with hypertension ○ Poor sleep duration associated with CV disease risk and higher all- cause mortality 9 hours (long sleep) Avidan, A. Y. (2017). Review of Sleep Medicine (4th ed.). Elsevier - OHCE. https://bookshelf.health.elsevier.com/books/9780323473507  Role of Sleep Metabolism: ○ Acute and chronic sleep deprivation associated with insulin resistance, impaired glucose metabolism ○ Leptin levels rise during sleep (satiety) ○ Ghrelin levels rise in setting of sleep deprivation (hunger) ○ Growth hormone is released during slow wave sleep ○ Clearance of central nervous system waste via “glymphatic” system (lymphatic-like cleansing dependent on glial cells) Avidan, A. Y. (2017). Review of Sleep Medicine (4th ed.). Elsevier - OHCE. https://bookshelf.health.elsevier.com/books/9780323473507  What is sleep? Reversible state of perceptual disengagement from the environment It is a complex amalgam of physiologic and behavioral processes It is typically accompanied by: ○ Postural recumbence ○ Behavioral quiescence ○ Closed eyes Kryger, M. H., Roth, T., & Goldstein, C. A. (2022). Kryger's Principles and Practice of Sleep Medicine (7th ed.). Elsevier - OHCE. https://bookshelf.health.elsevier.com/books/9780323675062  What is sleep? Reversible state of perceptual disengagement from the environment It is a complex amalgam of physiologic and behavioral processes It is typically accompanied by: ○ Postural recumbence ○ Behavioral quiescence ○ Closed eyes Kryger, M. H., Roth, T., & Goldstein, C. A. (2022). Kryger's Principles and Practice of Sleep Medicine (7th ed.). Elsevier - OHCE. https://bookshelf.health.elsevier.com/books/9780323675062  What is sleep? A state distinguished from waking by the following criteria: 1. Reduced motor activity 2. Decreased response to stimulation 3. Stereotypic posture 4. Relatively easy reversibility 5. Homeostatic regulation 6. Loss of consciousness of the environment Kryger, M. H., Roth, T., & Goldstein, C. A. (2022). Kryger's Principles and Practice of Sleep Medicine (7th ed.). Elsevier - OHCE. https://bookshelf.health.elsevier.com/books/9780323675062  What is sleep? Research/clinical defining criteria are from: Electroencephalography (EEG)—brain waves Electromyography (EMG)—skeletal muscle activity Electrooculography (EOG)—eye movements Kryger, M. H., Roth, T., & Goldstein, C. A. (2022). Kryger's Principles and Practice of Sleep Medicine (7th ed.). Elsevier - OHCE. https://bookshelf.health.elsevier.com/books/9780323675062  What is normal sleep? Working baseline pattern of young adult sleep 2 sleep states exist based on collections of physiologic characteristics: ○ Rapid eye movement (REM) ○ Non-rapid eye movement (NREM) N1 N2 N3 Kryger, M. H., Roth, T., & Goldstein, C. A. (2022). Kryger's Principles and Practice of Sleep Medicine (7th ed.). Elsevier - OHCE. https://bookshelf.health.elsevier.com/books/9780323675062  Sleep Onset Sleep normally begins in NREM ○ EEG: alpha waves (wake) → low voltage mixed frequency (N1) ○ EOG: slow (possibly asynchronous) eye movements ○ EMG: gradual decrease in muscle tone ○ Exceptions: infancy, narcolepsy, sleep deprivation Sleep onset latency: ○ Time interval from lights out to sleep ○ Normally