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
