Sleep-Wake Disorders

N1

What stage of sleep is being described?

-5% of time asleep, transition from wakefulness to sleep

-Lightest stage of sleep

N2

What stage of sleep is being described?

-50% of time spent asleep, characterized by specific EEG waveforms (sleep spindles, K complexes)

N3

What stage of sleep is this?

-20% of total sleep, AKA slow wave/delta sleep

-Deepest stage of sleep

REM Sleep

What stage of sleep is this?

-20-25% of total sleep, increases as time asleep lengthens, awake brain + paralyzed body

-Deepest stage of sleep

-Associated with dreaming, memory, consolidation, and learning

-EEG waves resemble that of an awake person, rapid side-to-side eye movement

-Muscles temporarily paralyze to prevent acting-out dreams

Dyssomnias

Disorders that make it difficult or to fall or remain asleep, or of excessive daytime sleeping

Insomnia

Dissatisfaction with sleep quality/quantity (1+): difficulty initiating sleep, difficulty maintaining sleep, early morning awakening with inability to return to sleep

• Occurs > 3x/week for > 3 months

• Occurs despite adequate opportunity for sleep

• Causes clinically significant distress or functional impairment

• Not due to substance/medication

• Not explained by coexisting medical disorders

CBT

What is the first line treatment for chronic insomnia?

Hypersomnolence Disorder

Excessive sleepiness despite > 7 hours of sleep with 1+ sx:

• Recurrent periods of sleep within same day (naps)

• Sleep episode >9 hours that is nonrestorative

• Difficulty being fully awake after awakening

• Occurs >3x/wk for > 3 months

• Causes significant distress or impairment in functioning

Modafinil

What is one drug that can be used to treat hypersomnolence disorder?

Narcolepsy

Recurrent periods of irresistible need to sleep, lapsing into sleep, or napping during the day >3x/wk for > 3 months. Characterized by 1+ sx:

• Cataplexy (brief episodes of sudden bilateral loss of muscle tone often precipitated by laughter)

• CSF hypocretin deficiency

• REM sleep latency < 15 min or mean sleep latency <8 min

Sodium oxybate

What is the treatment of choice for cataplexy?

Obstructive Sleep Apnea

Must meet 1 of 2 criteria (measured via polysomnography):

• > 5 obstructive apneas/hypopneas per hour of sleep + either of the following: nocturnal breathing disturbance or daytime sleepiness

• > 15 obstructive apneas/hypopneas per hour of sleep, regardless of other sx

Central Sleep Apnea

> 5 central apneas per hour of sleep measured on PSG

• Idiopathic rate, Cheyne-Stokes type, comorbid with opioid use

Sleep-Related Hypoventilation

PSG shows episodes of decreased respiration associated with increased CO2 levels