371.1 🎓 醫孞生版

371.1.0.1 📌 䞀頁重點

371.1.0.1.1 Normal Sleep

371.1.1 Stages

  • NREM (75-80%):
    • N1: light, 5%
    • N2: 50%; spindles + K-complexes
    • N3: slow wave (deep), 20-25%; growth hormone release
  • REM (20-25%):
    • Dreaming
    • Atonia
    • Eye movements

371.1.2 Cycles

  • ~ 90 min
  • 4-6 cycles per night
  • REM ↑ in latter half of night

371.1.3 Sleep Duration

  • Adults 7-9 hr
  • Older may need less
  • Adolescents need more
371.1.3.0.1 ICSD-3 Categories

371.1.4 1. Insomnia

  • Chronic: difficulty falling/staying asleep ≥ 3 nights/week for ≥ 3 months
  • Daytime consequences (fatigue, mood, cognitive)
  • Causes: psychophysiological, comorbid (anxiety, depression, pain), medication, substance

371.1.5 2. Sleep-Disordered Breathing

  • OSA (obstructive sleep apnea) — most common
  • CSA (central sleep apnea)
  • Sleep-related hypoventilation

371.1.6 3. Central Disorders of Hypersomnolence

  • Narcolepsy type 1 (with cataplexy, ↓ orexin)
  • Narcolepsy type 2 (without cataplexy)
  • Idiopathic hypersomnia
  • Kleine-Levin syndrome

371.1.7 4. Circadian Rhythm Disorders

  • Delayed sleep phase (DSPD — adolescents)
  • Advanced sleep phase (ASPD — elderly)
  • Shift work disorder
  • Jet lag
  • Irregular sleep-wake
  • Non-24 (blind)

371.1.8 5. Parasomnias

  • NREM: sleepwalking, sleep terrors, confusional arousal
  • REM: REM behavior disorder (RBD), nightmares, sleep paralysis
  • Other: enuresis, sexsomnia

371.1.10 Definition

  • Recurrent partial (hypopnea) or complete (apnea) airway collapse during sleep
  • Cyclical desaturations
  • Arousals

371.1.11 Risk Factors

  • Obesity (BMI > 30; ↑ neck circumference > 17 men, > 16 women)
  • Male
  • Age
  • Anatomic (retrognathia, tonsillar hypertrophy, narrow oropharynx)
  • Family history
  • Acromegaly, hypothyroid, PCOS
  • Smoking, alcohol

371.1.12 Symptoms

  • Loud snoring (witnessed by bed partner)
  • Witnessed apneas + gasping
  • Excessive daytime sleepiness (Epworth ≥ 10)
  • Morning headache
  • Non-restorative sleep
  • Nocturia
  • Cognitive impairment
  • Depression

371.1.13 Consequences

  • CV: HTN, AF, CAD, stroke, HF, sudden death
  • Metabolic: insulin resistance, NAFLD
  • Cognitive
  • Daytime sleepiness → motor vehicle accidents
  • Mortality (if untreated severe)

371.1.14 Diagnosis

  • Polysomnography (PSG) — gold standard
  • Home sleep apnea test (HSAT) — for high pretest probability without comorbidities
  • AHI (apnea-hypopnea index): events per hour
    • 5-15: mild
    • 15-30: moderate
    • ≥ 30: severe
  • Diagnosis: AHI ≥ 5 + symptoms OR AHI ≥ 15

371.1.15 Treatment

Lifestyle: - Weight loss (significant impact) - Positional therapy - Alcohol/sedative avoidance - Smoking cessation - Treatment of nasal congestion

Positive Airway Pressure (PAP): - CPAP (continuous) — first-line - APAP (auto-adjusting) - BPAP (bilevel) - Adherence challenges

Alternative: - Mandibular advancement device (MAD) — mild-moderate - Positional therapy - Surgical (UPPP — uvulopalatopharyngoplasty, maxillomandibular advancement, tonsillectomy in children) - Hypoglossal nerve stimulation (Inspire) — moderate-severe with PAP intolerance, BMI < 32, no concentric collapse

Adjunctive: - Modafinil/armodafinil for residual sleepiness - Solriamfetol (Sunosi) for residual sleepiness - Pitolisant for residual sleepiness

371.1.15.0.1 Central Sleep Apnea (CSA)

371.1.16 Causes

  • Heart failure (Cheyne-Stokes)
  • Opioids
  • Stroke
  • High altitude
  • Idiopathic

371.1.17 Treatment

  • Treat underlying
  • Adaptive servo-ventilation (ASV) — contraindicated in HFrEF with EF < 45% (SERVE-HF)
  • Oxygen
  • Acetazolamide
371.1.17.0.1 Narcolepsy

371.1.18 Type 1 (with Cataplexy)

  • ↓ Orexin/hypocretin (autoimmune destruction)
  • HLA-DQB1*06:02 association
  • Cataplexy (sudden brief loss of muscle tone with strong emotion)
  • Sleep paralysis
  • Hypnagogic hallucinations
  • Excessive daytime sleepiness
  • PSG + MSLT (multiple sleep latency test): mean sleep latency < 8 min, ≥ 2 SOREMPs

371.1.19 Type 2 (without Cataplexy)

  • Normal orexin
  • Otherwise similar

371.1.20 Treatment

Excessive Daytime Sleepiness: - Modafinil/armodafinil — first-line - Methylphenidate, amphetamines - Solriamfetol (Sunosi) — dopamine + NE reuptake inhibitor, FDA 2019 - Pitolisant (Wakix) — H3 antagonist, FDA 2019 - Sodium oxybate (Xyrem) / mixed-salt oxybate (Xywav) — also for cataplexy

Cataplexy: - Sodium/mixed-salt oxybate (Xywav lower sodium) - SNRIs (venlafaxine) - SSRIs - Pitolisant

371.1.20.0.1 REM Behavior Disorder (RBD)

371.1.21 Features

  • Loss of REM atonia
  • Acting out dreams (kicking, punching, falling out of bed)
  • Often violent
  • Older men
  • Sleep partner reports

371.1.22 Diagnosis

  • PSG with EMG: REM without atonia

371.1.23 Significance

  • Prodrome of synucleinopathy (PD, DLB, MSA)
  • 80%+ develop within 15 years
  • Counsel patients

371.1.24 Treatment

  • Safety (clear bedroom, partner separate bed if needed)
  • Clonazepam 0.25-1 mg HS
  • Melatonin 3-12 mg HS (less side effects)
371.1.24.0.1 NREM Parasomnias

371.1.25 Sleepwalking, Sleep Terrors, Confusional Arousal

  • Out of slow-wave sleep
  • Early in night
  • Children > adults
  • Genetic predisposition
  • Triggers: sleep deprivation, fever, stress

371.1.26 Treatment

  • Safety
  • Sleep hygiene
  • Treat triggers
  • Clonazepam (selected)
371.1.26.0.1 Insomnia

371.1.27 Approach

  • CBT-I (cognitive behavioral therapy for insomnia) — first-line
  • Sleep hygiene
  • Stimulus control
  • Sleep restriction
  • Relaxation

371.1.28 Pharmacologic (Short-Term)

  • DORAs (dual orexin receptor antagonists):
    • Suvorexant (Belsomra)
    • Lemborexant (Dayvigo)
    • Daridorexant (Quviviq) — FDA 2022
  • Z-drugs: zolpidem, eszopiclone, zaleplon (use shortest duration)
  • Benzodiazepines: temazepam, triazolam (avoid chronic, fall risk elderly)
  • Melatonin receptor agonists: ramelteon, tasimelteon
  • Doxepin (low dose): Silenor 3-6 mg
  • TCAs: amitriptyline, mirtazapine (sleep + mood)
  • Trazodone: off-label common
  • Antihistamines: limited evidence
371.1.28.0.1 Circadian Rhythm Disorders

371.1.29 Treatment

  • DSPD (delayed phase): melatonin in evening, light therapy in morning
  • ASPD (advanced phase): light therapy in evening, melatonin in afternoon
  • Shift work: scheduled bright light, modafinil, melatonin
  • Jet lag: melatonin, light timing
  • Non-24 in blind: tasimelteon (Hetlioz)

371.1.29.1 🩺 床邊速查

  • Normal sleep: NREM (N1, N2, N3) + REM cycles 90 min; adults need 7-9 hr
  • OSA: AHI ≥ 5 + symptoms or AHI ≥ 15; CPAP mainstay
  • Narcolepsy: ↓ orexin (type 1 with cataplexy); modafinil + oxybate + pitolisant + solriamfetol
  • RBD: prodrome of synucleinopathy (80% within 15 years); clonazepam or melatonin
  • Insomnia: CBT-I first-line; DORAs new class (daridorexant)
  • RLS: see Ch369