Oliviero Bruni, Luigi Gallimberti Buona Notte: Il sonno tra fisiologia e

Oliviero Bruni, Luigi Gallimberti
Buona Notte: Il sonno tra fisiologia e disturbo
Conduttore: Mattia Doria
Grazie per l’attenzione!
The Harvard sleep researcher Robert
Stickgold has recalled his former
collaborator J. Allan Hobson joking that
the only known function of sleep was
to cure sleepiness
“if sleep doesn’t serve an
absolutely vital function, it is the
biggest mistake evolution ever
made.”
ALLAN RECHTSCHAFFEN
Why do we sleep?
• Sleep is a highly conserved behavior that occurs in
animals ranging from fruit flies to humans
• Despite decades of effort, one of the greatest mysteries in
biology is why sleep is restorative and, conversely, why
lack of sleep impairs brain function
Sleep is present in all animals
Reptiles do not have REM  omeothermy?
Birds have short REM/NREM cycles (9” to 2.5’)
ducks sleep while swimming
transoceanic migrators sleep while flying
All mammals have REM/NREM ciclicity
• Smaller animals 
more sleep (body
thermoregulation?)
• Generally, predators
and others that are
safe when they sleep
tend to sleep a great
deal;
• Animals in danger of
being attacked while
they sleep spend less
time asleep
Sleep is necessary for survival
• Whatever the reasons for sleeping, in mammals
sleep is evidently necessary for survival. For
instance, rats completely deprived of sleep die in a
few weeks
• In humans, lack of sleep leads to impaired
memory and reduced cognitive abilities, and, if
the deprivation persists, mood swings and even
hallucinations.
• The longest documented period of voluntary
sleeplessness is 264 hours (approximately 11
days), a record achieved without any
pharmacological stimulation.
Sleep for life
• In this apparatus, an
experimental rat is
kept awake because
the onset of sleep
(EEG detected)
triggers movement
of the cage floor.
The control rat can
thus sleep
intermittently,
whereas the
experimental animal
cannot.
After two to three weeks of sleep deprivation, the experimental
animals begin to lose weight, fail to control their body temperature,
and eventually die.
What’s strange in this picture?
Birds at extreme sides have one eye
opened
Does Unihemispheric Sleep Aid in Predator Detection?
Unihemispheric SWS increase as predation risk increases
Sleep–wake patterns in nonhuman
and human primates
• Sleep–wake patterns in nonhuman primates consist
mainly of polyphasic episodes of rest and activity
with frequent (up to 12) cycles of wakeful activity
through- out the 24-hour day.
• The biphasic sleep–wake pattern probably began in
human primates in the latter part of the Neolithic
period (since 10.000 BC).
• The monophasic sleep–wake pattern began with the
advent of electric light and of the 24-hr society
Theogony, Hesiod
Notte generò Destino (Moros), Vendetta
(Kere) e Morte, il Sonno e la specie dei Sogni
• Nyx (Notte) era la personificazione della notte terrestre, e
suo fratello Erebo (Buio) era la notte del mondo infernale
• Da Nix nacquero:
•
•
•
Etere (luce) and Emera (giorno)
Eris (discordia), Kere o Nemesis (vendetta), Moros (destino o
fato)
Hypnos (sonno) e il gemello Thanatos (morte)
Hypnos - Sonno
• Figlio delle Tenebre e della
Notte, fratello della Morte
(Thanatos) e del Destino
(Moros) e padre dei Sogni
Hypnos dormiva in una caverna in cui scorreva il Lete, fiume
dell'oblio (Stazio, Tebaide, X, 84-90), e davanti alla quale
crescevano piante di papavero (Ovidio, Metamorfosi, XI,
604-607).
Hypnos aveva 3 figli :
• Morfeo
• Phantasos
• Phobetor
THEORIES EXPLAINING THE FUNCTIONS OF SLEEP
1. Inactivity
2. Energy
conservation
3. Restorative
4. Tissue repair
5. Brain
plasticity
6. Cognition
Thermoregulation (McGinty
and Szymusiak, 1990)
 Adaptation to an ecological
niche (Webb, 1974)
 “Instinctual behavior”
(Meddis, 1977)
Neuronal plasticity (Krueger
et al., 1995)
 Processing of memory traces
(Tononi, 2006)
Theories of Why We Sleep
1- Inactivity Theory
• This theory, sometimes called adaptive or
evolutionary, suggests that inactivity at night is an
adaptation that served a survival function by
keeping organisms out of harm’s way at times when
they would be particularly vulnerable.
• Sleep is analogous to the hibernation of animals
• The theory suggests that animals that were able to
stay still and quiet during these periods of
vulnerability had an advantage over other animals
that remained active.
Frank MG. 2006. The mystery of sleep function: current perspectives and future
directions. Reviews in the Neurosciences. 17:375-392.
Theories of Why We Sleep
2 - Energy Conservation Theory
• The energy conservation theory suggests that the primary
function of sleep is to reduce an individual’s energy demand
and expenditure during part of the day or night, especially at
times when it is least efficient to search for food.
• The function of sleep is to conserve energy by:
– decreasing body temperature 1-2 Celsius degrees in mammals
– decreasing muscle activity
• Research has shown that energy metabolism is reduced
during sleep (by 10% in humans and more in other species)
• NREM sleep uses much less energy than wakefulness and may
provide time to restore our brains glycogen stores, which are
depleted by the demands of wakefulness
• Recent studies suggest that sleep may strengthen our immune
defenses and insufficient sleep impair them.
Frank MG. 2006. The mystery of sleep function: current perspectives and future
directions. Reviews in the Neurosciences. 17:375-392.
Theories of Why We Sleep
3 - Restorative Theories
• Sleep in some way serves to "restore" what is lost in the body while
we are awake and provides an opportunity for the body to repair
and rejuvenate itself.
• Many of the major restorative functions in the body like muscle
growth, tissue repair, protein synthesis, and growth hormone
release, immune functions occur mostly, or only, during sleep.
• While we are awake, neurons in the brain produce adenosine, a
by-product of the cells' activities. The build-up of adenosine in the
brain leads to our perception of being tired (is counteracted by
caffeine, which blocks the actions of adenosine and keeps us alert)
• During sleep, the body has a chance to clear adenosine from the
system.
Frank MG. 2006. The mystery of sleep function: current perspectives and future
directions. Reviews in the Neurosciences. 17:375-392.
Xie et al, Needergard. Sleep drives metabolite clearance from the adult brain.
Science 2013
• Using real-time assessments of
tetramethylammonium diffusion
and two-photon imaging in live
mice, we show that natural sleep
or anesthesia are associated with
a 60% increase in the interstitial
space, resulting in a striking
increase in convective exchange
of cerebrospinal fluid with
interstitial fluid.
• Thus, the restorative function of
sleep may be a consequence of
the enhanced removal of
potentially neurotoxic waste
products that accumulate in the
awake central nervous system.
Glymphatic system
Neurons enlarge when active and
shrink when dormant. At night,
during sleep, neurons dramatically
shrink to allow more extra cellular
space with an increased flow of
fluid through the space. (In picture,
flow is red.)
In the glymphatic system a convective
flow of fluid from arterial blood
vessels and the cerebrospinal fluid
goes through the extra cellular space
and then flows near other venous
vessels into the lymphatic system.
These neuronal and extra cellular
changes that increase the space and
the flow appear to be triggered by
brainwaves during sleep
Theory Why we sleep
4 – Restoration somatic tissue repair (NREM)
1. Slow-wave sleep (SWS) increases following sleep
deprivation
2. SWS percentage of is increased during development
3. Release of growth hormone occurs at sleep onset and
peak during SWS in prepubertal children. The release of
many endogenous anabolic steroids occurs in relation
to a sleep cycle (prolactin, testosterone, and LH).
4. The nadir of catabolic steroid release, occurs during the
first hours of sleep, coincident with the largest
percentage of SWS. Increased mitosis of lymphocytes
and increased rate of bone growth occur during sleep.
Theories of Why We Sleep
5 - Brain Plasticity Theory
• Sleep is correlated to changes in the structure and
organization of the brain  brain plasticity,
• REM sleep may have evolved in order to
‘reprogram’ innate behaviors and to incorporate
learned behaviors and knowledge acquired during
wakefulness
• Synaptic efficiency and efficacy of the brain depends
on keeping the synaptic connections refined
integrating new neuronal firing patterns. Sleep
periodically occurs to allow the brain to do this, thus
maintaining brain plasticity. This synaptic
reorganization occurs during NREM sleep
Frank MG. 2006. The mystery of sleep function: current perspectives and future
directions. Reviews in the Neurosciences. 17:375-392.
Synaptic homeostasis hypothesis
the homeostatic regulation of SWA is tied to the amount of synaptic
potentiation occurred during previous wakefulness: the higher the amount of
synaptic potentiation in cortical circuits during wakefulness, the higher the
increase in SWA during subsequent sleep
The role of sleep
(mainly SWS) is to
downscale synaptic
strength to a baseline
level that is
energetically
sustainable, makes
efficient use of gray
matter space, and is
beneficial for learning
and memory
Tononi G, Cirelli C. Sleep Med Rev 2006 10:49–62
Per capire a cosa seve il sonno basta vedere cosa
succede quando il sonno è disturbato /alterato
• Sleep apnea has been associated with diabetes
and cardiovascular disease and lead to
cognitive impairment.
• Chronic insomnia has been linked to low
quality of life, depression, increases in
cardiovascular disease and hypertension,
cognitive and motor impairment
• REM-sleep behavior disorder is a reliable
predictor of neurodegenerative disease like
Parkinson’s or Alzheimer’s.
Il sonno tra fisiologia e disturbo
• Quale è la prevalenza dei disturbi del
sonno nell’infanzia e nell’adolescenza?
• Quanto devono dormire i bambini e gli
adolescenti?
• Quali sono le conseguenze di un
sonno insufficiente o disturbato nel
bambino?
DISTURBO
PREVALENZA
INSONNIA
10-30%
DISTURBI RESPIRATORI IN SONNO
Russamento
Apnee ostruttive
8% (range 3-35%)
1-4%
DISTURBI DEL RITMO CIRCADIANO
7-10% in adolescenza (ritardo di fase)
PARASONNIE
Disturbi dell’arousal
Enuresi
15-18%
15-20% a 5 anni; 2.1% negli adulti)
NARCOLESSIA
.02% to 0.18%
S. DELLE GAMBE SENZA RIPOSO
 2-4 % (medio/grave 0.5-1%)
MOVIMENTI RITMICI ADDORMENT.
body rocking
head banging
head rolling
59% almeno una volta (a 5 anni< 5%)
43%
22%
24%
Sleep is essential for optimal health in children and adolescents. Members of the
recommendations
the amountLJ,
of sleep
needed to promote
health in ch
Paruthi S,forBrooks
D’Ambrosio
C, optimal
Hall WA,
The recommendations
summarized
A manuscript
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Kotagal S, are
Lloyd
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published
in the Journal
of Clinical
Medicine.
Nichols
C, Quan
SF,Sleep
Rosen
CL, Troester MM,
Keywords:
sleep duration, consensusamount of sleep
Wisepediatric,
MS. Recommended
Citation:for
Paruthi
S, Brooks LJ,populations:
D’Ambrosio C, Hall WA,
Kotagal S, Lloyd RM, Ma
pediatric
a consensus
MS. Recommended
amount
sleepAmerican
for pediatric populations:
a consensus
statement
ofofthe
Academy
of state
2016;12(6):785–786.
Sleep Medicine. J Clin Sleep Med
2016;12(6):785–786.
CONSENSUS RECOMMENDATIONS
Infants
12 months
to 16
•• Infants*
4 months4toto
12 months
should sleep 12
hours
24 hours
(including naps)
on anaps)
regular basis
12perto
16 hours
(with
to promote optimal health.
•• Children
Children
years
11
1 to 2 years1ofto
age 2
should
sleep 11
to 14
hours
14 (including
hoursnaps)
(with
naps)basis to
perto
24 hours
on a regular
promote optimal health.
•• Children
Children
3 to 5 years  10
3 to 5 years of age should sleep 10 to 13 hours
13 (including
hoursnaps)
(with
naps)basis to
perto
24 hours
on a regular
optimal health.
• promote
Children
6 to 12 years  9
• Children 6 to 12 years of age should sleep 9 to 12 hours
12 onhours
perto
24 hours
a regular basis to promote optimal
• health.
Teenagers 13 to 18 years 
• Teenagers 13 to 18 years of age should sleep 8 to 10
8 per
to2410
hours
hours
hours
on a regular basis to promote
optimal health.
◦ Sleeping the number of recommended hours on a
*
Sadeh et al., 2009
Iglowstein et al. 2003
Blair et al. 2012
B.C. Galland et al. Normal sleep
patterns in infants and children: A
systematic review of observational
studies. Sleep Medicine Reviews.
2012; 16: 213-222
 690,747 children from 20 countries, from
1905 to 2008.
 This study identified a secular decline of 0.75
min per year in children’s sleep duration over
the last 100 years (more than 1 h per night) .
 The greatest rate of decline in sleep occurred
for older children, boys and on schooldays.
 Regional analyses indicated secular declines
in Asia, Canada, USA and Europe
 Europe (excluding UK and Scandinavia) have
experienced the greatest rate of decline.
Screening sui disturbi del sonno in età scolare (8
anni) nel distretto Roma F4

7-8 ore 5-7 ore
0%
5%
8-9 ore
42%

> 9 ore
53%


I bambini dormono meno di
quanto sia necessario (il 47%
dorme meno di 9 ore per notte)
Alta prevalenza di stanchezza e
difficoltà a svegliarsi al mattino
(15-26%)
Questi disturbi possono essere
concausa o fattore favorente i
disturbi di attenzione e di
apprendimento
Alcuni disturbi come la cefalea, i
dolori addominali o il sovrappeso
sono associati alla presenza di
specifici disturbi del sonno.
Dist. comportamento
• Iperattività (ADHD) : ↑ probl. scol. = ↑ aggr.
• Dist. Apprendimento (Touchette, 2009)
• Disattenzione  incidenti (Valent, 2001; Owens, 2005)
• 4.2 aumento rischio nei cattivi dormitori
Obesità
(Touchette, 2009)
• 58% - 92% aumento rischio se deprivazione di
sonno (Xiaoli Chen, 2008)
Salute dei genitori
• Scarsa salute fisica e mentale (Hiscock , 2007)
• Depressione materna (Armitage, 2009; Mindell , 2009)
• Abuso al bambino, infanticidio?
Abuso
sostanze/tecnologia
• In adolescenza abuso di sostanze, depressione,
int. suicidarie (Roane & Taylor, 2008; Roberts et al, 2008)
• Uso di social network e internet correla con
cattiva qualità del sonno (Gradisar & Cain, 2010; Bruni
et al., 2015)
Il sonno insufficiente determina:
• Ridotte performance scolastiche (Beebe, 2010)
– 28% si addormenta a scuola 1/sett. e 22% facendo I compiti
– 32% troppo stanchi per fare sport
– A students sleep 15 min more than B; B students sleep 11 min more than C; C students
sleep 10 min more than D students
• sonnolenza (Dewald, 2010)
• disattenzione, memoria di lavoro, controllo degli impulsi e
regolazione del comportamento (Sadeh et al., 2002; Paavonen et al., 2009;
Beebe et al., 2010; Steenari et al., 2003)
•
•
•
•
•
rischio incidenti (Pizza et al., 2010), traumi accidentali in bambini (Owens
et al., 2005) e adolescenti (O’Brienet al., 2005)
basso QI (Gruber et al., 2010; Touchette et al., 2007; Nixon et al., 2008) .
problemi di apprendimento (Beebe et al., 2010)
Umore depresso
Uso di caffeina e stimolanti
Gruber R, Michaelsen S, Bergmame L, Frenette S, Bruni O, Fontil L, Carrier J.
Short sleep duration is associated with teacher-reported inattention and
cognitive problems in healthy school-aged children. Nature and Science of
Sleep 2012:4 33–40
• Short sleep duration was
found to be related to
teacher-derived reports of
ADHD-like symptoms of
inattention and cognitive
functioning in healthy
children.
• No significant association
between sleep duration and
hyperactivity symptoms
was evident.
Sleep <10 h associated with 86% increased risk of accident in
3-5 years old
Children with sleep
problems had more
accident proneness
Sleep-Obesity
• Five years old children sleeping<11 hours were significantly more obese
(adjusted OR 1.4 (1.1-1.9) (Locard et al, 1992)
• Spanish adolescents < 6 hrs of sleep had higher risk of obesity (OR 0.43)
(Vioque et al, 2000)
• Japanese 6-7 yrs old children who sleep < 8 hrs had increased risk for
obesity (OR 2.87) (Sekine et al 2002)
• Sleep duration < 10 hrs at 30 months was associated with increased risk of
obesity at 7 yrs (Reilly, 2005)
• Short sleep duration across early childhood increased by almost 3 times
the risk for overweight or obesity at 6 years vs. ch. who slept around 11 h
per night (Touchette et al., 2008).
Risk for overweight or obesity was
almost 4.2 times higher for short
persistent sleepers (Touchette et
al., 2009)
Parent’s health and infant’s sleep
• 70% of mothers with colicky infants have aggressive
thoughts/fantasies towards their children
• 26% admit to toughts of infanticide during colic episodes
(Levistsky et al., Clin Pediatr, 2000)
• Increased maternal depression and disorganized parent
attachment (Stifter et al., Infancy, 2002; Armitage, 2009)
• Life stress and symptoms of depression and anxiety in the
mothers were negatively related to preschool child's sleep
duration (Caldwell Radekers, 2014)
• Infant sleep problems were associated with poor general health in
mothers and in fathers and with severe psychological distress
(Hiscock et al., 2007)
SLEEP and Maternal Depression
Armitage R; Flynn H; Hoffmann R; Vazquez D;
Lopez J; Marcus S. Early developmental changes
in sleep in infants: the impact of maternal
depression. SLEEP 2009;32(5):693-696.
Mindell JA; Telofski LS; Wiegand B; Kurtz ES.
A nightly bedtime routine: impact on sleep
in young children and maternal mood.
SLEEP 2009;32(5):599-606
• Maternal depression is
associated with significant
sleep disturbance in
infancy at 2 weeks
postpartum that continues
through 24 weeks. It
remains to be determined if
sleep disturbance in infancy
confers a greater risk of
developing early-onset
depression in childhood.
• These results suggest that
instituting a consistent
nightly bedtime routine, in
and of itself, is beneficial in
improving multiple aspects
of infant and toddler sleep,
especially wakefulness after
sleep onset and sleep
continuity, as well as
maternal mood.
• 20/2/2007: Madre uccide figlio di un anno
(ANSA) - VERONA, 20 FEB - Una donna ha ucciso il proprio figlio di
un anno e ha poi tentato di suicidarsi.
• 2/12/2008: L’infanticidio di Catanzaro e depressione post
partum
– La morte della neonata di appena due settimane, sbattuta sul pavimento
dalla madre perché piangeva troppo, avvenuta a Catanzaro è l’ennesimo
infanticidio commesso da una mamma.
• 20/7/2009: Madre uccide figlio di 4 anni
(ANSA) MILANO, 20 LUG - E' stata arrestata la donna di 36 anni
che nel pomeriggio ha ucciso il proprio bambino di 4 anni
• 26/8/2009 Genova, madre uccide figlio neonato poi si toglie la
vita
• Early childhood sleep disturbance is more closely
associated with anxiety, whereas adolescent sleep
problems are closely linked to depression (Dahl, 1996;
Alfano et al., 2009).
• Chronic poor sleep in adolescents was associated with
depression (Roberts et al, 1995; 2001), with anxiety or
depression (67%) (Manni et al, 1997; Morrison et al, 1992)
and/or somatic concerns (Marks and Monroe, 1976) and
lower self-esteem (Price et al, 1978; Kirmil-Gray, 1984)
• The magnitude of depressive symptoms in adolescents are related
to the presence of sleep problems
Come cambia il sonno in adolescenza?
Gogtay, et al. (2004)
During adolescence
extensive brain
reorganization driven by
synaptic elimination 
NREM decrease
• Ritardo ora di addormentamento
– ↓ durata del sonno di 3 hrs in circa 2 anni (da 10 a 7 h)
• Anticipo ora entrata a scuola
• Irregolarità del ritmo sonno-veglia:
– Discrepanza sonno weekday/weekend
– “Weekend oversleep” = perpetual “jet lag”
• Aumento fisiologico della sonnolenza (23% naps)
Initial insomnia
INSOMNIA IN ADOLESCENCE
6632 students: 2645 M, 3987 F; 13,8-19,2 y
(Giannotti, Cortesi, 2007)
25%
 Problemi di sonno nelle ragazze
20%
 Irregolarità del sonno nei ragazzi
 > uso di ipnotici nelle femmine
15%
14
 > uso di stimolanti nei maschi
MASCHI
15
16
FEMMINE
17
M
• use of alcohol, cannabis, and other drugs;
depression; suicide ideation (Roane & Taylor,
2008) and risk for somatic health problems,
psychological problems (Roberts et al., 2008)
Substance
BDZ
44%
NSAIDs
10%
OTC
33%
?
13%
7%
6%
5%
4%
3%
2%
1%
M
F
Initial insomnia
18
F
20,2 % 22,2%
p
ns
Night wakings(>2)
8,1%
11,5%
<.01
Awakenings > 30’
4,3%
6,9%
<.01
Early awakening
17%
25%
<.001
Sonnolenza aumenta con età
M
60%
F
50%
40%
30%
20%
10%
14
15
16
17
18
Mobile phones?
• 34% of US adolescents reported text messaging and 44% talking on
the telephone after 9 pm (Calamaro et al., 2009)
• 30% woken up by text messages [Van den Bulck, 2003, 2007]
• Mobile phone use associated with shorter sleep duration, later
wake-up times (Punamaki et al. 2007; Harada et al. 2002) and with
school bullying in adolescents (Tochigi et al., 2012)
• 64% of children had one or more electronic devices in their
bedroom  shortened sleep duration, excess body weight, and
lower physical activity (Chalal et al., 2012)
• Unlike passive technological devices (e.g., TV, mp3), the more
interactive technological devices (i.e., computers, cell phones)
before bed, the more likely difficulties falling asleep and
unrefreshing sleep (Gradisar et al., 2013)
IMPACT OF TECHNOLOGY ON ADOLESCENT SLEEP
Delayed bedtime
shorter TST.
Cain M, Gradisar M. Sleep Medicine, 2010
Mechanisms of technology affecting sleep
1. Reduce sleep length (Custers & Van den Bulck, 2012), increase sleep
latency (Higuchi et al., 2005) delay bedtimes (Van den Bulck, 2004).
2. Directly displace sleep, and replace activities that promote good
sleep (< physical activity  obesity) (Stepanski & Wyatt, 2003).
3. Cause physical discomfort, such as muscular pain and headache,
which can negatively affect sleep (Thomée et al., 2010).
4. The bedroom is not sleep-inducing stimuli (Hauri & Fisher, 1986).
5. Induce cognitive and emotional arousal and impair sleep (Cain &
Gradisar, 2010; Gellis & Lichstein, 2009; Higuchi, 2005)
6. Bright light emitted by many electronic devices, especially with
short wavelengths, can cause phase delays, (Cain & Gradisar, 2010;
Bjorvatn & Pallesen, 2009; Khalsa, et al., 2003; Zeitzer, et al. 2000).
Fossum, et al. The Association Between Use of Electronic Media in Bed Before Going to Sleep and Insomnia
Symptoms, Daytime Sleepiness, Morningness, and Chronotype. Behav Sleep Med, 2014; 12:343-357
Fossum, et al. The Association Between Use of Electronic Media in Bed Before Going to Sleep
and Insomnia Symptoms, Daytime Sleepiness, Morningness, and Chronotype, Behavioral Sleep
Medicine, 2014; 12:343-357
Bruni O, et al. Technology use and sleep quality in preadolescence and
adolescence. JCSM, 2015
• Adolescents reported more sleep problems, more eveningness,
increase of internet, social network and phone activities, while
preadolescents were more involved in gaming console and TV.
• The transition from preadolescence to adolescence should be
considered at high risk for the development of sleep problems
Hysing et al. Sleep patterns and insomnia among
adolescents: a population-based study. J Sleep Res. (2013)
• To obtain the recommended sleep duration of 8–
9 h, which was also in accordance with their selfperceived sleep need, they should have gone to
bed at around 22:00 hours.
• At weekends, their sleep duration was in
accordance with their subjective sleep need,
with a shift towards later bedtime of more than
2 h and an even later rise time.
Sleep deprivation affects frontal areas and
executive functioning especially in infants
• The impact of sleep deprivation is more prominent in
frontal than posterior brain areas (Cajochen, et al., 2001) and
frontal brain regions seem to have a higher need for
recovery during sleep than posterior areas (Beebe & Gozal,
2002; Dahl, 1996; Horne, 1993).
• Given that major advances in EF take place between 1 and
6 years of age (Zelazo et al., 2008), and that neural density of
the frontal lobes begins to decline at about 7 years of age
(Huttenlocher, 2002), the potential impact of sleep on
frontal⁄executive functions may be especially potent
earlier in development, when the brain shows substantial
dynamic plasticity (Singer, 1995).
The mechanisms by which sleep deprivation and disruption,
determine neurocognitive deficits are similar to those of
intermittent hypoxia
• Sleep-deprivation determined cellular injury (Everson,
2005), hippocampal oxidative stress (Gopalakrishnan et
al., 2004; Silva et al., 2004), suppression of neurogenesis
and long-term potentiation in the hippocampus
(Hairston, 2005) and affect brain structures involved in
motivation, goal direction, reward, and attentional
capacity.
• In the developing brain, exposure to sleep deprivation
during sensitive periods may result in morbid and
potentially irreversible changes in neural organization in
these brain sectors (Frank et al., 2003)
Blunden and Beebe. The contribution of intermittent hypoxia, sleep
debt and sleep disruption to daytime performance deficits in children:
Consideration of respiratory and non-respiratory sleep disorders. Sleep
Med Rev (2006) 10, 109–118
Similar deficits in hypoxia and sleep deprivation!!!!!
Thanks for
your
attention!