Transcript Sleep and the Brain

Importance of Sleep
Lisa Medalie, PsyD, RPSGT, CBSM
Behavioral Sleep Medicine Specialist
The University of Chicago
Sleep Medicine
Sleep Introduction
How sleep is defined and measured
What is Sleep?
Definition:
-A complex reversible state characterized by diminished responsiveness to external stimuli
and a stereotypical species-specific posture.
-Sleep is generated and maintained by central nervous system (CNS) networks that use specific
neurotransmitters located in specific areas of the brain.
Characteristics:
-Active and highly regulated process
-Composed of two fundamentally different states: REM sleep & NREM sleep
Purpose
Not understood
Hypotheses: Restoration and recovery of body systems; immune system support; learning and
memory consolidation; protection from predators; brain development; discharge of emotions
Kryger, Roth, Dement (2005); National Institute of Health, National Center on Sleep Disorders Research (2003)
How do we study sleep?
Kryger, Roth, Dement (2005); National Institute of Health, National Center on Sleep Disorders Research (2003)
EEG Characterization
Wake: alpha, frequency 9-12 hz
Stage 1: smaller amplitude and irregular
frequency, theta waves with vertex spikes
Stage 2: Stage N2 sleep is defined by the
presence of either K complexes or sleep
spindles
Stage 3: large amplitude, very slow waves,
delta waves
REM: low-amplitude mixed-frequency EEG
activity,
Kryger, Roth, Dement (2005); National Institute of Health, National Center on Sleep Disorders Research (2003)
Sleep Stage Distribution
Stage 1
REM
Sleep
Stage 2
90-120 min
Stage 2
Stage 3
Proportion of sleep
stages in normal sleep:
 REM:25%
 NREM: 75%
Stage 1: 5%
Stage 2: 45%- 50%
Stage 3: 20%- 25%
Kryger, Roth, Dement (2005); National Institute of Health, National Center on Sleep Disorders Research (2003)
Non-REM vs. REM Sleep
NREM
REM
Synchronized EEG activity
Paradoxical sleep since EEG resembles a
waking pattern
Slow or no eye movements and tonically
active EMG
Muscles are atonic except the diaphragm
and extraocular muscles
Intact thermoregulatory response to
changes in ambient temperature
Absent thermoregulatory response to
ambient temperature
Regular respiratory pattern
Irregular breathing pattern with variable
RR
Heart rate and BP are lower than relaxed
wakefulness
HR and BP are similar to relaxed
wakefulness
Unfocused thought with occasional short
dream
Abundant long dreaming with clear
recollection of its content
Kryger, Roth, Dement (2005); National Institute of Health, National Center on Sleep Disorders Research (2003)
Physiology of Sleep:
The Two-Process Model
Sleep homeostasis (Process S) :
-A process that keeps track of how much time has
passed awake (or asleep)
-SWS increases when sleep pressure is high and
decreases when sleep pressure is low.
-Adenosine (neurotransmitter) regulates
homeostatic sleep drive.
Circadian rhythm (Process C):
-A clock that keeps time irrespective of what
happens in the environment
Peaks in alertness = late morning and early evening
Troughs in alertness= early morning and early
midafternoon
Borbély (1982); Daan et al. (1984); Borbély & Achermann (2005)
Sleep Patterns and Age
Average total sleep time
REM percentage
Common Sleep Disorders
Obstructive
Sleep Apnea
• 12 million Americans
• Interrupted breathing during sleep
• Drops in oxygen and partial arousals
• Excessive daytime sleepiness
Restless Leg
Syndrome
• Neurologic movement disorder
• Unpleasant leg sensations – urge to move legs
• Worse at rest
• Associated with Periodic Limb Movement Disorder
Narcolepsy
Insomnia
• 250,000 affected, fewer than half diagnosed
• Excessive and overwhelming sleepiness – sleep attacks
• Cataplexy, Sleep Paralysis, Hypnogogic/Hypnopompic Hallucinations
• One third symptoms, 6-10% diagnosis
• Difficulty falling and or staying asleep
• Impaired daytime functioning and /or distress
Sleep and Cognition in Adults
Effects of Sleep Deprivation and
Sleep Disorders
Sleep Deprivation and Cognition
A: Correct scores on CPT
B: Error scores on CPT
Level: Increases with difficulty
SD: 24 h sleep deprivation
Joo et al. (2012). J Clin Neurol; 8(2): 146-150
Insomnia and Cognition
Studied 20 patients with Primary
Insomnia (mean age, 50 yrs; 18
females) and 20 Age-, gender-,
and education matched Good
Sleepers
Noh et al. (2012). J Clin Neurol
Sleep Apnea and Cognition
Canessa et al. (2011). Amer J of Resp and Crit Care Med
Sleep and Cognition in Children
Sleep and Attention Deficit
Hyperactivity Disorder (ADHD):
A Causal Conundrum
Hyperarousal Theory
• Hyperactivity in children with ADHD is caused by
overstimulation of the central nervous system
• The state of physiological arousal in children with ADHD is
drastically elevated
• Hyperactive behavior in children with ADHD is related to a
deficiency in effectively censoring information signaled from
the environment
• Too much information comes in, and individuals are unable to
modulate the impact of overflowing stimulation which
presents as hyperactivity
(Busby, Firestone & Pivik, 1982; Hastings & Barkley, 1978)
Hypoarousal Theory
• A low level, not high level, of central nervous system arousal
causes difficulty inhibiting sensory input and behaviors
• Excessive, unproductive behavior is caused by inhibited
control of sensory input
• Hyperactivity in children with ADHD is a compensatory
mechanism for a system which processes external stimulation
too slowly
• When individuals are processing too slowly to function in
their environment, the system overcompensates to speed up
the system with fast production of behavior
(Satterfield, 1975)
Relevance to Sleep
• Hyperarousal Theorists: Individuals with ADHD have
difficulty settling because of their hyperaroused
central nervous system activity. Difficulty settling
makes for difficulty sleeping
• Hypoarousal Theorists: Sleep disturbance leads to
excessive sleepiness which slows processing.
Hyperactivity is a compensatory behavior to keep
children awake in the face of sleep deprivation
Sleep and Cognitive Functioning
• PSG on 82 healthy children randomized to sleep deprivation or optimal
sleep
• Found patients in sleep deprived group exhibited increased symptoms of
ADHD the following day
(Fallone et al. 2001)
Sleep Disorders and ADHD
Disorder
Findings
Insomnia
Increased bedtime resistance, increased sleep-onset difficulties,
increased instability of sleep onset, difficulties settling down,
interruptions during bedtime routines and anxiety (Corkum et al.,
2001; Owens et al. 2000; Cortese et al., 2009; Hvolby et al. 2009;
Corkum et al. 1999)
RLS
RLS has incidence of 0.5% in general public (Picchietti et al., 2007).
Approximately 44% of children with ADHD have been found to have
restless legs syndrome (RLS) or RLS symptoms, and up to 26% of
subjects with RLS have been found to have ADHD or ADHD
symptoms (Cortese et al. 2005)
OSA
In healthy 3-5 year olds apnea–hypopnea index is 0.90 ± 0.78
(range: 0–3.6) and in 6–7-year-olds is 0.68 ± 0.75 (range: 0–6.6),
while a range of 0–1.7 has been reported in children with
attention-deficit/hyperactivity disorder of comparable age ranges
(Goraya et al, 2009)
(Spruyt & Gozal, 2011)
Study of Sleep Habits and Stimulant Usage in
College Students
• Participants: 19 college students (18-22 years old)
diagnosed with ADHD and receiving
accommodations through Academic Support
• Instrumentation: Participants completed a 3 week,
medication form and daily medication/academic
functioning/sleep habits log
– Self report – 0-5 likert scale items
(0 = poor, 5 = excellent)
Sleep Onset Latency in Medicated vs. NonMedicated College Students with ADHD
Variable
Sleep Onset
Latency (Min)
Non Med
Med
M
M
T (17)
P
27.50
70.22
2.0
.03
-Sleep onset latency difference between medicated and non-medicated groups
reached significance.
There was a non-reported trend towards significance for medicated students to
sleep approximately 60 minutes less than their non-medicated counterparts.
- Average total sleep time in medicated group was 6 hours and non-medicated
group was 7 hours
•
50% of medicated students in this study increased their prescribed stimulant dose
Review of ADHD-Sleep Relationship
•
•
•
•
1. Sleep problems may mimic ADHD symptomatology
2. Sleep problems may exacerbate underlying ADHD symptoms
3. Sleep problems may be associated with or exacerbated by ADHD
4. Psychotropic medications used to treat ADHD may result in sleep problems.
• In any individual, the relationship between ADHD treatment and sleep may be:
– 1. Direct effect (i.e., improve, worsen sleep)
– 2. Indirect effect (i.e., ADHD medications or treatment improve comorbid condition or
functioning, and sleep subsequently improves)
– 3. May be a moderator of response (e.g., sleep problems may limit dosing necessary to achieve
an optimal response
(Owens, 2005; Stein, Weiss & Hlavaty, 2012)
Parent/school report of ADHD symptoms
Screen: BEARS, Clinical Interview
RLS
OSA
Sleep Study
Insomnia
Sleep Logs, Actigraphy
If (+) Sleep Disorder
If (-) Sleep Disorder
Treat Sleep Disorder then re-evaluate
ADHD symptoms
Consider ADHD Treatment Options: If use
of medication (particular stimulant)
educate on sleep hygiene and consider
dose timing issues
Summary
• We are still unsure exactly why we sleep
• How we sleep is best explained by shift in EEG activity
and by taking into account sleep homeostasis and
circadian rhythmicity.
• The importance of sleep is at least somewhat
confirmed by negative cognitive consequences of
insufficient sleep.
• Screening of sleep disorders in patients with ADHD
seems warranted
• Treatment for sleep disorders are available. Patients
with complaints of sleeplessness or sleepiness have
options.
Sleep Complaints
Behavioral Sleep Medicine
Sleep Medicine
Insomnia
Circadian Rhythm Disorders
Inadequate Sleep Hygiene
Nightmare Disorder
Night Eating Syndrome
Sleep Apnea
Periodic Limb Movement
Disorder
Narcolepsy
Idiopathic Hypersomnia
Actigraphy
Sleep Logs
Cognitive Behavioral
Treatment for Insomnia
Overnight Sleep Study
Daytime Nap Study
CPAP
Medication Management