La fisiologia del sonno Luigi Ferini-Strambi Centro di Medicina del Sonno Università Vita-Salute San Raffaele, Milano IL SONNO NEGLI ANIMALI (DURATA IN % DI 24 ORE) IN BASE ALL’OSSERVAZIONE: MUCCA 3 IN BASE A REGISTRAZIONI EEG: ASINO 13 ELEFANTE 19 RATTO 50 CAVALLO 29 GATTO 60 GORILLA 70 CONIGLIO 60 CENNI STORICI “The electric currents of the brain” Caton, 1875 “waking and sleeping states” Berger, 1930 “Cerebral states during sleep as studied by humans brain potentials” Loomis, 1937 “electro-oculography” Aserinsky & Kleitman, 1953 “The REM sleep”; Dement & Kleitman, 1957 “electromyographic activity is suppressed in REM sleep” Jouvet, 1959 Video-EEG / PSG ‘70 Organizzazione gerarchica delle strutture responsabili del sonno ( L. Parmeggiani ) Veglia NREM REM corteccia ipotalamo tronco ipotalamo tronco corteccia tronco corteccia ipotalamo PARAMETRI FISIOLOGICI PER LA DEFINIZIONE DEL SONNO C MS D R IPNOGRAMMA Pre - sleep - W SWS REM - sleep Post - sleep - W ACTIVATION ACTIVATION High High DEACTIVATION DEACTIVATION Low Low DEACTIVATION DEACTIVATION BRAUN et al; Brain (1997) Sleep Academic Award 12 Dijk and Edgar, 1999, Lung Biology in Health and Disease, vol.133 VARIAZIONI DEL CICLO SONNO-VEGLIA Neonato / Bambino Adulto % REM / NREM 50 / 50 20 / 80 Periodicità stadi di sonno 50-60’ 90-100’ Esordio sonno REM NREM Organizzazione temporale stadi di sonno I cicli REM/NREM egualmente distribuiti durante il sonno I cicli NREM 3-4 nel primo terzo della notte; REM nell’ultimo terzo Maturazione pattern EEG 1 solo stadio NREM > stadi indeterminati K-complex Onde delta St. NREM differenti Arousal Sleep No sleep 20 20 15 15 Cortisol 10 10 (µg/dl) 5 5 0 10 05 14 18 22 02 06 10 0 10 05 04 04 Thyrotropin 03 03 (µU/ml) 02 02 01 10 01 10 Prolactin (ng/ml) (µg/L) 18 22 02 06 10 25 25 20 20 15 15 10 10 5 5 0 10 Growth Hormone 14 14 18 22 02 06 10 0 10 20 20 15 15 10 10 5 5 0 10 14 18 22 02 06 10 0 10 14 18 22 02 06 10 14 18 22 02 06 10 14 18 22 02 06 10 14 18 22 02 06 10 Clock Time acute sleep deprivation Cortisol rhythm Impact of sleep debt on metabolic and endocrine function Spiegel K, et al. The Lancet 1999, 354:1435–1439. • Intolleranza glucidica • ↓Clearance glucosio 40% • ↓Risposta insulinica al glucosio 30% • Recupero sonno normalizza i valori Grasso è bello ??? Self-reported Sleep and the Prevalence of Obesity in the US 25% 20% 8 15% 7 10% 6 Sleep (adult) Obesity 5% 0% 5 1950 1960 1970 1980 1990 2000 2010 Obesity prevalence Sleep (hours) 9 DAYTIME LEPTIN AND GHRELIN LEVELS Continuous glucose infusion (5g/kg/24h) 3.5 LEPTIN (ng/ml) 3.0 2.5 2.0 1.5 AFTER 2 DAYS OF 10-H BEDTIMES 3.4 GHRELIN (ng/ml) AFTER 2 DAYS OF 4-H BEDTIMES 2.8 2.2 9 11 13 15 17 CLOCK TIME 9-21 leptin levels (ng/ml) 2.6 ± 0.5 12-21 ghrelin levels (ng/ml) 2.6 ± 0.2 19 2.1 ± 0.4 3.3 ± 0.2 21 p level 0.041 0.038 % change -19% +24% PRIVAZIONE DI SONNO • Diminuisce l’attività delle cellule “natural killers” nell’uomo Moldofsky, 1989 • Impedisce nel topo messo a contatto con un virus influenzale di sviluppare “memoria immunitaria” Brown et al, 1989 sleep loss impairs the human antibody response to hepatisis A vaccination total loss of sleep in the night following vaccination impairs immune response 28 days later Lange et al (2003) Psychosomatic Medicine 65: 831-835 response to influenza vaccination is impaired in individuals with chronic partial sleep restriction Sleep restriction to 4 hours/night, for 4 days before and 2 days after vaccination, impairs immune response to vaccination Spiegel et al (2002) JAMA 288: 1471-1472 Brain Structures That Did Not Show Decreased Metabolic Rate From Waking to Sleep States in Patients With Insomnia (A) and Brain Structures Where Relative Metabolism While Awake Was Significantly Higher in Healthy Subjects Than in Patients With Insomnia (B) Nofzinger et al. Am J Psychiatry 2004;161:2126-2128 SLEEP DEBT Reduced cortical cholinergic activity Increased Adenosine Frontal Lobe dysfunctions Harrison & Horne, 2000; Boonstra et al., 2007 PET studies One single night of sleep loss significantly reduces prefrontal metabolic activity Thomas et al., J Sleep Res, 2007, 9: 335-352 J Clin Sleep Med, 2007