Sleep Wake Disorders Flashcards
What are the stages of sleep stages?
1) Non-REM
N1: Transitional
N2: Light sleep (non-restorative)
N3: (“slow wave”, “delta”, “deep” sleep) ‒ Restorative sleep ‒ Disorientation upon awakening ‒ Amnesia for a brief awakening ‒ N3 length decreases across cycles
2) REM (Rapid Eye Movement) ‒ Physiological activation ‒ Dreaming, paralysis ‒ Rapid orientation upon awakening ‒ Memories for a brief awakening ‒ REM length increases across cycles
What are the Sleep Wake Diorders?
- Insomnia disorder
- Hypersomnolence disorder
- Narcolepsy
• Breathing-Related Sleep Disorders
– Obstructive sleep apnea hypopnea
– Central sleep apnea
• Circadian rhythm sleep-wake disorder
• Parasomnias ‒ Non-REM sleep arousal disorder ‒ Nightmare disorder ‒ REM sleep behavior disorder ‒ Restless legs syndrome ‒ Periodic limb movements
In these disorders, the problem is NOT due to another mental disorder, medical condition or drug. If so, the diagnosis will specify the causal medical condition
What are the diagnostic tools for sleep wake disorders?
➢ To differentiate the SWDs, an interview is conducted and often followed by polysomnography (PSG)
➢ PSG involves measuring a variety of physiological parameters including brain waves, muscle contractions, breathing, etc. during sleep
Explain the insomnia disorder
Difficulty initiating or maintaining sleep
➢ Etiology: Insomnia is a learned arousal response to bedtime and other cues associated with the sleep environment. The learned arousal derives from inappropriate sleep hygiene (e.g., using the bed for wakeful activities)
What behavioral strategies are used to treat insomnia ?
Improve Sleep Hygiene: Behavioral strategies
such as:
• Use bed only to sleep (incl. rapid falling asleep and staying asleep) – Lie down only when tired – If not asleep in 10 min, depart bed – Return only when tired – If early awakening, don’t stay in bed
- Maintain consistent sleep schedule
- Avoid caffeine, esp. after noon
- Exercise more than 2 hrs before bedtime
- Take hot bath within 2 hrs of bedtime
What are the Pharmological approaches to treat insomnia ?
➢ Pharmacological Approaches
a. Sedatives (benzodiazepines like temazepam)
• Induces sleep and increases sleep duration
• Recommended only for short-term use (2-4 wks) due to long-term side effects:
– Poor sleep quality due ↓ slow wave sleep (N3) and REM
– Tolerance and withdrawal b. Nonbenzodiazepine Hypnotics (e.g.,
zolpidem) usually have fewer side effects
What is hypersomnelence disorder?
➢ Excessive sleepiness despite sufficient sleep (at least 7 hrs)
• Features
– Average sleep episode = 9.5 hrs
– Unrefreshing naps
– Normal PSG
• Neuropathology
– Unknown etiology (idiopathic form)
– Exclude other causes (e.g., narcolepsy)
Describe the treatment of hypersomnelence disorder
Treatment: Stimulants (e.g., methylphenidate) or stimulant-like drugs (e.g., modafinil) to promote wakefulness
What are the characteristics of narcolepsy?
- Recurrent irresistible sleep occurring within the same day, several times per week
AND - At least 1 of the following: a) Cataplexy
b) Characteristic polysomnography (PSG) abnormalities c) Hypocretin deficiency
(See next slides for elaboration of each of these)
a) Cataplexy
– Sudden loss of muscle tone while awake
– Typically precipitated by strong emotion
– Considered a REM-related behavior occurring
outside of REM sleep
Note: Other REM-related behaviors occurring outside of REM sleep may be present but are NOT diagnostic criteria:
– Sleep paralysis
– Hypnagogic (upon falling asleep) hallucinations
– Hypnopompic (upon awakening) hallucinations
What are the characteristics of PSG abnormalities in Narcolepsy?
b) Characteristic PSG abnormalities
Either of the following:
1) Nocturnal PSG
– Short REM-sleep latency (“sleep-onset REM”)
2) Daytime PSG (Multiple Sleep Latency Test [MSLT] involving forced
daytime naps every 2 hrs)
– Short REM-sleep latency AND
– Short sleep-onset latency
c) Hypocretin (orexin) deficiency (spinal tap needed)
– Hypothalamic neuropeptide
– Deficiency may be autoimmune-related
Describe the Narcolepsy treatment
➢ Polytherapy
• Stimulants (e.g., dextroamphetamine) or stimulant-like drugs to promote wakefulness (e.g., modafinil)
&
• Antidepressants for cataplexy
➢ Monotherapy
• Sodium oxybate (aka: gamma hydroxybutyrate [GHB])
– GHB (schedule I drug) except when marketed for narcolepsy (schedule III drug)
– Available via a restricted distribution system
– Complex dosing (bedtime, repeat ~4 hrs later)
– Treats cataplexy and somnolence
What are the breathing related sleeping disorder?
➢ Excessive sleepiness or insomnia that is due to a sleep-related breathing condition:
- Obstructive Sleep Apnea Hypopnea
- Central Sleep Apnea
What is Obstructive Sleep Apnea Hypopnea?
Multiple episodes of breathing cessation/reduction occur per night due to an upper airway obstruction
– Obstruction usually occurs when the soft tissue in the back of the throat collapses during sleep
How do Apneas/hypopneas cause sleepiness ?
Apneas/hypopneas cause sleepiness
– The rise in CO2 during apnea causes temporary arousal (not awakening) from sleep, which bumps the person from a deep to a light stage of sleep
– Duration of sleep may be adequate, but the sleep is unrefreshing
Classic Profile: Middle-aged, overweight male who snores loudly and intermittently
Describe OSAH treatment
➢ Continuous Positive Airway Pressure (CPAP): A device that maintains an open airway by delivering compressed air at a specific air pressure to the mask’s nasal pillow
➢ Additional approaches to maintaining open airway at night include: – weight loss – avoiding back sleeping – orthodontic devices – surgery
What is central sleep apnea?
Multiple episodes of cessation of breathing per night caused by CNS dysregulation of breathing
➢MultipleCauses: Examples-
– Primary(idiopathic)
– Opioiduse(diagnosticlabelwouldthen
indicate that CSA was “opioid-induced”)
What causes central sleep apnea?
A PSG distinguishes OSAH from CSA based on whether thoracic movements occur at the start of apneic episode:
– OSAH (thoracic effort occurs)
– CSA (no thoracic effort occurs)
How is Central Sleep Apnea be treated?
➢ Treatment: Varies depending on the cause (e.g., respiratory stimulants such as acetazolamide; nocturnal oxygen)
What is Circadian Rhythm Sleep disorder (CRSWD)?
➢ Excessive sleepiness or insomnia resulting from a mismatch between a person’s circadian sleep- wake pattern and the sleep-wake schedule required by the environment
Example
CRSWD, Delayed Sleep Phase Type
– Delayed sleep onset and awakening times, with the inability to fall asleep and awaken at a desired earlier time
How is CRSWD treated?
Phototherapy at strategic times during the day to adjust the timing of the sleep-wake cycle
Setting of Circadian Clock
(governed by the suprachiasmatic nucleus [SCN])
Light→SCN→inhibits pineal gland→decreases melatonin → alert
No light→SCN→activates pineal gland→ increases melatonin→drowsy
What are Parasomnias?
Disorders characterized by abnormal behaviors associated with sleep
- Non-REM sleep arousal disorder
- Nightmare disorder
- REM sleep behavior disorder
- Restless legs syndrome
- Periodic limb movements
What is Non-REM Sleep Arousal Disorder (NSR-AD)?
Repeated episodes of incomplete awakening from sleep with either of the following:
a) Sleepwalking (somnambulism): Rising from bed and walking about with a blank and staring face, relative unresponsiveness, and difficulty awakening
b) Sleep terrors: Abrupt terror arousals (usually with panicky scream), intense fear and autonomic arousal, and unresponsiveness to comforting by others
What are the subtypes and characteristics of NRS-AD?
Subtypes
– Sleepwalking type
– Sleep terror type
Characterized by
– Episodes occurring within first 1/3 of sleep (during slow wave sleep [SWS])
– Difficulty awakening/orienting
– No (or little) dream imagery
– Amnesia for the episode the next morning
What are the treatment methods of NRS-AD?
Treatment: If needed, benzodiazepines to ↓ SWS; If patient sleepwalks, then consider environmental safety
What is Nightmare Disorder?
➢ Extremely dysphoric dreams that typically involve threats to survival, security or physical integrity
➢ Characterized by – Awakening in the 2nd half of sleep period (during REM sleep) – Rapid alertness upon awakening – Dream content is well remembered – Good recall of the awakening the next morning
What is nightmare disorder treated?
Treatment: If needed, antidepressants to ↓ REM
What is REM Sleep behavior disorder?
➢ Vocalizations and/or complex motor movements occur during REM sleep
– REM sleep without atonia is confirmed by PSG
– The disturbance is not induced by a substance
➢ Characterized by:
– Typically action-filled, violent dreams
– Immediate awakening, orientation, and alertness with detailed dream recall
What are The treatments of REM sleep behavior disorder?
Treatment
•Clonazepam (a benzodiazepine)
‒ Reduces motor movements
‒ Unclear therapeutic mechanism of action
Modification of sleep environment for safety
Note: Loss of motor inhibition during REM is associated with future neurodegenerative disease (e.g., Parkinson’s disease, Lewy body dementia)
What is Restless Leg Syndrome?
Urge to move legs in response to uncomfortable sensations with all the following features:
– Occurs/worsens during inactivity
– Nocturnal worsening of symptoms
– Temporary relief from discomfort by
movement
➢ Patient is aware of symptoms and complains of insomnia
How is Restless Leg Syndrome treated?
Parkinson’s disease drugs (also, benzos, anticonvulsants, etc.)
Drugs only get rid of uncomfortable feeling
Describe the periodic limb movements of restless leg syndrome
Repetitive muscle contractions during sleep, usually of the lower limb
– Associated with multiple sleep stage arousals
– Patient complains of daytime sleepiness but is
unaware of movements
– PSG electromyogram confirms diagnosis
– Treat using similar drugs as for RLS
Note: Sleep starts (AKA hypnic or myoclonic jerks) are muscle
contractions that occur only upon falling asleep; these are
normal and not diagnosable
