Sleep-Wake Disorders

Question 1

describe the 3 stages of non-REM sleep

Answer 1

• stage 1: transitional
• stage 2: light sleep (non-restorative)
• stage 3: “slow wave”, “delta”, “deep” sleep
  
  • restorative sleep
  • disorientation upon awakening
  • amneisa for a brief awakening

Question 2

describe diagnostic criteria for insomnia disorder

Answer 2

• difficulty initiating or maintaining sleep for ≥ 3 months
• etiology: classical conditioning
  
  • the bed gets associated with wakefulness (due to poor sleep habits, aka “poor sleep hygiene”)

Question 3

describe stimulus control technique in treating insomnia

Answer 3

• stimulus control technique
  
  • make the bed a cue for rapid sleep-onset
    
    • use the bed only as place to sleep
    • lie down only when tired
    • if not asleep in 10 min, depart bed
    • return only when tired

Question 4

describe sleep hygiene methods

Answer 4

• consistency in bedtime/awakening
• no naps (unless always taken)
• no caffeine past noon
• avoid noise and excessive temps during night
• exercise (more than 2 hrs before bedtime)
• hot bath (within 2 hrs of bedtime)

Question 5

describe pharmacological approaches to treating insomnia

Answer 5

• sedatives (benzodiazepines, like diazepam)
  
  • 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 to decreased slow wave sleep and REM
    • tolerance and withdrawal
• benzodiazepine-like drugs (zolpidem) usually have fewer side effects

Question 6

describe hypersomnolence disorder

Answer 6

• excessive sleepiness despite sufficient sleep (at least 7 hrs) for ≥ 3 months
• features
  
  • average sleep episode = 9.5 hours
  • unrefreshing naps
  • normal PSG
• neuropath
  
  • idiopathic
  • exclude other causes (narcolepsy)
• treatment: stimulants (modafinil to promote wakefulness)

Question 7

describe diagnostic criteria for narcolepsy

Answer 7

• recurrent irresistible sleep occurring within the same day, several times/week, for ≥ 3 months
  
  • AND
• at least 1 of the following:
  
  • cataplexy
  • hypocretin deficiency
  • characteristic PSG abnormalities

Question 8

describe cataplexy

Answer 8

• sudden loss of muscle tone while awake
• typically precipitated by emotion
• considered an aberrant manifestation of REM sleep

Question 9

describe hypocretin (orexin) deficiency seen in narcolepsy

Answer 9

• hypocretin (orexin) deficiency (spinal tap needed)
  
  • hypothalamic neuropeptide
  • deficiency may be autoimmune related

Question 10

describe characteristic PSG abnormalities seen in narcolepsy

Answer 10

• nocturnal PSG
  
  • short REM-sleep latency (“sleep-onset REM”)
• daytime PSG (multiple sleep latency test)
  
  • short REM-sleep latency AND
  • short sleep-onset latency

Question 11

describe polytherapy used in narcolepsy treatment

Answer 11

• stimulatants for somnolence (modafinil)
• antidepressants for cataplexy

Question 12

describe monotherapy used in narcolepsy treatment

Answer 12

• monotherapy: Xyrem (sodium oxybate) aka GHB = gamma hydroxybutyrate
  
  • GHB (schedule 1 drug) except when marketed as Xyrem and used for narcolepsy
  • Xyrem (schedule III drug) treats cataplexy AND somnolence
  • available via a restricted distribution system

Question 13

describe obstructive sleep apnea hypopnea (OSAH)

Answer 13

• 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

Question 14

why do apneas/hypoapneas cause sleepiness?

Answer 14

• the rise of CO2 during apneas 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

Question 15

describe a treatment for OSAH

Answer 15

• CPAP (continuous positive airway pressure)
  
  • a device that maintains an open airway by deliverying compressed air at a specific air pressure to the mask’s nasal pillow

Question 16

describe central sleep apnea (CSA)

Answer 16

• multiple episodes of cessation of breathing per night caused by CNS dysregulation of breathing
• multiple causes:
  
  • primary (idiopathic)
  • opioid use

Question 17

how do you distinguish between OSA and CSA and what are treatments for CSA?

Answer 17

• a PSG distinguishes OSA from CSA based on whether thoracic movements occur at the start of apneic episode:
  
  • OSAH = thoracic effort occurs
  • CSA = no thoracic efforts occur
• treatment: varies depending on the cause
  
  • respiratory stimulants (acetazolamide), nocturnal O2

Question 18

describe circadian rhythm sleep-wake disorder (CRSWD) and name an example

Answer 18

• 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

Question 19

describe treatment for CRSWD

Answer 19

• phototherapy at strategic times during the day to adjust the timing of the sleep-wake cycle
• light –> SCN –> inhibits pineal gland –> decreases melatonin –> alert
• no light –> SCN –> activates pinearl gland –> increases melatonin –> drowsy

Question 20

describe non-REM sleep arousal disorder (N-RSAD)

Answer 20

• repeated episodes of incomplete awakening from sleep with either of the following:
  
  • sleep walking (somnambulism): rising from bed and walking with a blank and staring face, relative unresponsiveness and difficulty awakening
  • sleep terrors: abrupt terror arousal (usually with panicky scream), intense fear and autonomic arousal, and unresponsiveness to comforting by others
• episodes occur within first 1/3 of sleep (during slow wave sleep) with amnesia of episodes
  
  • benzos side effect is less slow wave sleep, so it could help reduce episodes

Question 21

describe nightmare disorder

Answer 21

• 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
• treatment: if needed, antidepressants to decrease REM

Question 22

describe REM sleep behavior disorder (RSBD)

Answer 22

• vocalization 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
• RSBD features:
  
  • typically action-filled, violent dreams
  • immediately awake, oriented and alert with detailed dream recall

Question 23

what is RSBD associated with and what are some treatment?

Answer 23

• loss of motor inhibition during REM is associated with neurodegenerative disease (Parkinson’s, Lewy body dementia)
• treatment:
  
  • clonazepam (a benzo)
  • modification of sleep environment for safety

Question 24

describe restless legs syndrome (RSL) and treatment for it

Answer 24

• urge to move legs in response to uncomfortable sensations with all of the following features:
  
  • occurs/worsens during inactivity
  • nocturnal worsening of symptoms
  • temporary relief from discomfort by moving
• patient is aware of symptoms and complains of insomnia
• treatment:
  
  • anti-Parkinson’s drugs to increase DA

Question 25

describe periodic limb movements (PLMs)

Answer 25

• repetitive muscle contracts during sleep, usually of the lower limb
  
  • associated with multiple sleep stage arousals
  • pt complains of daytime sleepiness but is unaware of movements
  • electromyogram during PSG confirms diagnosis
  • treat using similar drugs as for RLS

Question 26

summarize sleep-wake disorders

Answer 26