Sleep/Wake disorders Flashcards
Sleep vs Coma
● Sleep
○ When sleep-promoting neurons are stimulated and wake-promoting
regions are inhibited.
○ Controlled by the body’s “internal clock” and by external forces.
○ Reduced responsiveness, but can be interrupted by sensory or other
stimuli
○ Also defined by typical Electroencephalographic (EEG) Patterns
● Coma - Unresponsive to the environment and cannot be interrupted by
stimuli, including pain
Physiologic changes during sleep
● ↑ Parasympathetic tone
● ↓ Sympathetic tone
● Constant neuronal activity
● Reduced overall Metabolism
Regulatory Neurons and Neurotransmitters of Arousal
Histamine (HA), Serotonin (5-HT), Noradrenalin (NA), Dopamine (DA),
Acetylcholine (ACH), Glutamate (GLU), Hypocretin/orexin (HCT)
Regulatory Neurons and Hormones of Sleep
○ Ventrolateral preoptic nucleus (VLPO)/Median preoptic nucleus (MnPO)
○ Melatonin
○ Adenosine (AD)
Ventrolateral preoptic nucleus (VLPO)/Median preoptic nucleus (MnPO)
Promotes sleep through monosynaptic GABAergic
inhibition of monoamine neurons
Suprachiasmatic Nucleus (SCN) is part of the_____
anterior hypothalamus and is
the “master clock” of the body
“master clock” of the body.
Suprachiasmatic Nucleus
Melatonin
: Helps regulate circadian rhythm
○ Produced in the pineal gland and controlled by light input as processed
by the SCN
Sleeps effects on the CNS
○ Assists with brain plasticity, neural maturation, memory consolidation,
and learning. This leads to improved cognition.
○ There is evidence that clearance of neurotoxic waste in the CNS occurs
Sleeps effect on General Restoration, Rejuvenation, and Energy conservation
○ Mitigates adverse consequences of stress
○ Physical growth, including muscle growth
○ Assists the immune system functions
○ Tissue repair
○ Protein and Hormone synthesis
Adults 18 to 60 years should sleep
_____ hours a night on a regular basis
seven or more
Prolonged Sleep Deprivation (ie, little or
no sleep):
● Decreased cognition and memory
● Abnormal moods and decreased
inhibition
● Potential psychosis
Microsleeps
Short episodes of uncontrollable sleep
lasting between a fraction of a second to 30 seconds. There is complete lapse of consciousness and no ability to respond to stimuli.
Fatal Familial Insomnia (FFI)
- Progressive genetically linked insomnia with loss of the normal
circadian sleep-activity pattern - FFI is a rapidly fatal disease with a mean duration of 13 months. There
is no specific treatment for FFI. Management is generally supportive
Electroencephalogram (EEG)
● Electrical activity is recorded from standardized placement sites on the scalp (usually 10 to 20)
● The electrical activity is described in terms of amplitude and frequency
Beta Waves Patterns
High frequency & low amplitude &
more desynchronous than other waves
Alpha wave EEG Patterns
Brain waves become slower (low
frequency), increase in amplitude
(high amplitude) & become more
synchronous
What waves are typical when you are awake?
Beta or alpha (calm wakefulness)
Stage 1 sleep EEG findings
Theta waves (lower frequency)
and greater amplitude
Stage 2 EEG findings
● EEG Findings: Theta waves continue,
interspersed with 2 phenomenon:
○ Sleep spindles: short bursts of ↑ wave
frequency
○ K-complexes: sudden ↑ wave amplitude
Sudden twitches or hypnic jerks are
common happen in this stage
Stage 1
Stage 3 (Slow Wave Sleep) EEG findings
Delta waves (slowest & highest
amplitude)
Rapid Eye Movement (REM) sleep (Stage R) EEG findings
Low voltage, mixed EEG pattern and “Sawtooth” waves.
○ These are similar to wakeful EEG findings
Atonia
inactivity of all voluntary muscles (except extraocular muscles,
diaphragm). Result of inhibition of alpha motor neurons.
Happens in REM sleep
T/F Brain is activity is high in Rem Sleep
T
Stage 1 is not repeated, but is replaced by ____
REM
Rapid onset to REM, occurring quickly after sleep begins, suggests
_____
narcolepsy or a circadian rhythm disorder
Sleep deprivation may increase ____
stage N3 and REM sleep
In Lab Polysomnography (PSG) indications
obstructive sleep apnea (OSA), central apnea, periodic limb movements,
parasomnias, narcolepsy, and excessive daytime sleepiness
In Lab Polysomnography (PSG) procedure
- Patients are connected to a variety of monitoring devices during a PSG,
including an EEG. Then they sleep while being observed. - Information is collected on the patient’s sleep stages, EKG findings, respiratory
effort/airflow, oxygen saturation, snoring, body position, and limb movements. - Additional conclusions can be made about Sleep efficiency, Sleep latency,
Apneas/Hypopneas, Cheyne-Stokes breathing, and EEG abnormalities
Central disorders of hypersomnolence
Narcolepsy and Idiopathic hypersomnia
Circadian rhythm sleep-wake disorders
Sleep-wake phase disorders, Non-24-hour sleep-wake rhythm disorder, and Shift work/jet lag disorders
Sleep-related movement disorders
Restless legs syndrome, Periodic limb movement disorder, Bruxism
Insomnia
Difficulty initiating sleep, maintaining sleep, or both, despite adequate
sleep opportunity, with associated daytime impairment
Acute vs Chronic insomnia
- Acute: Can be a symptom of adjustment
- Usually lasts a few days or weeks (Less than 3 months)
- Chronic: Occur at least 3 times a week and persist for at least 3 months
Insomnia
- Increasing age
- Separated or divorced
- Low socioeconomic status
- Associated with medical & psychiatric disorders
- Use of alcohol, drugs, and certain medications
Ideal room temperature for sleeping
- Cool (60-68 degrees!)
Progressive Relaxation Therapy
- Tensing & relaxing muscles systematically from head to toe
- Guided imagery & meditation
- May combine with bio-feedback to give patients immediate input as to their
stress levels & its response to therapy
Recommended Initial Treatment for Insomnia (after lifestyle changes)
Sleep Restriction Therapy/ CBT-I
- Sleep restriction therapy initially limits the _____
total time allowed in bed, including naps
and other sleep periods outside of bed
* ↑ the drive to sleep
* Leads to sleep consolidation & improved sleep efficiency (Percentage of time in bed spent sleeping)
Pharmacotherapy for insomnia
- Nonbenzodiazepine BZRAs
- Melatonin agonists
- Hypnotic Benzodiazepines
- Anxiolytic benzodiazepines
- Orexin Receptor Antagonists:
- Antidepressants
- Antipsychotics
- OTCs
Narcolepsy
A neurologic disorder that affects control of sleep & wakefulness.
- Characterized by chronic daytime sleepiness, cataplexy, hypnagogic
hallucinations, and sleep paralysis (most patients won’t have all of them)
Epidemiology of narcolepsy
- Typically begins in the teens and early
twenties - Some genetic risk
- 40 - 70 cases per 100,000
Pathogenesis of narcolepsy
- Defective REM sleep regulation**
- Loss of orexin (hypocretin) neuropeptides, made in the lateral hypothalamus.
- Orexin neurons are most active during
waking and almost stop firing during slow
wave and REM sleep. - Possible autoimmune etiology
- Rarely due to damage to the hypothalamus.
Clinical Presentation: 4 Cardinal Symptoms of Narcolepsy
- Daytime sleepiness: Moderate to severe daytime sleepiness
- Cataplexy: Emotionally-triggered transient muscle weakness. Often partial,
can cause transient facial weakness or falls - Hypnagogic Hallucinations: Hallucinations when falling asleep or awakening
- Sleep paralysis: Inability to move for one or two minutes immediately after
awakening or when falling asleep.
Orexin neurons are most active during
____ and almost stop firing during ____
waking; slow wave and REM sleep
Evaluation Almost always performed before diagnosing narcolepsy
Multiple sleep latency test (MSLT): Measures a person’s tendency to sleep during the day
Narcolepsy subtypes
Type 1: With Cataplexy
Type 2: Without Cataplexy
Polysomnogram (PSG) findings for narcolepsy
Looking for fragmented sleep stages and rapid onset REM
Management of narcolepsy
- Napping and Sleep Hygiene
- Psychosocial Support
- Medications
Idiopathic Hypersomnia
Chronic excessive daytime sleepiness (daily periods of irrepressible
need to sleep or daytime lapses into sleep) and often difficulty waking
up from nocturnal sleep or daytime naps
Must exclude narcolepsy and apnea before making this diagnosis
Idiopathic Hypersomnia
Alterations of the circadian system
- Delayed sleep-wake phase disorder
- Advanced Sleep-wake phase disorder
- Non-24-hour sleep–wake phase disorder (lack light/dark cycle input)
- Shift work Disorder
Lack light/dark cycle input
Non-24-hour sleep–wake phase disorder
Circadian Rhythm Disorder treatments
- Sleep hygiene, synchronize sleep & wakefulness
- Appropriate time cues (timed exposure to bright lights)
- Blackout curtains
- Melatonin is effective in jet lag & shift work
Bright Light Therapy
- Exposure to bright light can be used to treat
circadian rhythm sleep disorder - The goal is to combine a healthy sleep pattern with
an appropriately timed circadian rhythm - Light therapy can help “set” the internal clock
Hypnic Jerks
Brief jerk of a part or all of the body as a person falls asleep. A
common example is the feeling of falling accompanied by jerking up in bed.
Bruxism
Teeth clenching and grinding. Occur during micro-arousals from sleep
accompanied by an activation of the autonomic nervous system. Can lead to sleep disruption, tooth wear, jaw soreness, and headaches. Oral devices can help
Nocturnal Leg Cramps
These are painful muscle contractions that often last for
over a minute. Occur anytime during the night
Parasomnias
Complex Movements/Behaviors during sleep
Disorders of arousal
A mixture or combination of NREM and wakefulness.
Characterized by minimal cognitive functioning, amnesia of the events, and behaviors that make the person appear awake.
– Confusional arousals
– Sleepwalking
– Night or Sleep terrors
– Sleep-related eating disorder (SRED)
Somnambulism
Sleepwalking
Sleep Terror Disorder
Incomplete arousal from NREM stage 3 & 4 (usually first 1/3 of the night)
* Appears to abruptly awaken from sleep with panicky scream, tachycardia,
rapid breathing, sweating.
* Unresponsiveness to others, amnesia of the episode (nightmares are remembered)
Restless Leg Syndrome (RLS)
● Results in an urge to move the legs, usually associated with
unpleasant sensations. The urge to move the legs is worse at
rest and at night and is relieved by movement.
● Commonly associated with sleep disturbance
● Periodic limb movement disorder (PLMD)
Sleep Apnea
Defined as abnormal ventilation during sleep, manifested by apnea and/or hypopnea
* Apnea - Breathing cessation for ≤10 seconds or
* Hypopnea - Still breathing but there is partial airway obstruction
Central Apnea:
No ventilatory effort during an apneic episode
Obstructive Apnea:
Ventilatory effort continues during an episode but no
airflow occurs.
* Usually due to transient obstruction of the upper airway
Sleep Apnea screening : STOP-Bang
● Snoring loudly (or been told they snore)
● Tired during the day
● Observed choking/gasping or not breathing
● Pressure (Hypertension)
● BMI greater than 35
● Age older than 50
● Neck Size greater than 16 inches
● Gender (Male
