Sleep Disorders

Restless Legs Syndrome

• First-line treatments include dopamine agonists (pramipexole and ropinirole) and benzodiazepines.
• Other treatments include muscle relaxants, opioids, and gabapentin/pregabalin.

Sleep Startles

• Occur during the transition from stage 3 NREM to REM sleep.
• The motor center is excited, causing muscles to activate suddenly.
• Characterized by a feeling of falling.

Sleep Paralysis

• A state of awareness where a person is unable to move or speak.
• Triggered by sleep deprivation, psychological stress, or abnormal sleep cycles.
• Experienced by 8% to 50% of people at some point in their lives.
• Occurs during REM sleep.
• Characterized by an imbalance in neural functions regulating sleep, causing overlap of sleep states.
• Can be accompanied by hallucinations.

How to Measure Brain Activity

• An electroencephalogram (EEG) measures brain activity by recording electrical signals from the scalp.
• 24 electrodes are placed on the scalp at standard positions.
• Differences in electrical charges recorded by each electrode are plotted on a graph versus time.
• While individual neuron activity cannot be measured, the activity of neuron groups can be observed.
• Polysomnography (PSG) is used in sleep medicine to measure brain activity.

Circadian Rhythm Sleep Disorders

• Common features include insomnia, excessive daytime sleepiness, irritability, frequent waking during abnormal hours, headaches, and impaired concentration.

Parasomnias

• Include sleepwalking disorder, sleep terror disorder, and nightmare disorder.

Sleepwalking Disorder (Somnambulism)

• Occurs during non-REM sleep, resulting in no memory of the event.
• Affects 2% of adults and 20% of children.
• Etiology is unknown but thought to be genetic.
• Characterized by sitting up, walking, or eating during sleep.
• Patients often have a blank stare and difficulty arousing during episodes.
• Treatment includes education and reassurance, and benzodiazepines (clonazepam).

Sleep Terror Disorder

• Occurs during non-REM sleep, resulting in no memory of the event.
• Affects 7% of adults and 30% of children.
• Associated with sleep deprivation, irregular sleep schedules, and medications like sedatives, hypnotics, lithium, and anticholinergics.
• Etiology is either idiopathic or genetic (inherited in 80% of cases).
• Characterized by recurrent episodes during the first third of the sleep cycle, including sitting up, walking, or eating.
• Patients have a blank stare and difficulty arousing during the episode.
• Treatment includes education and reassurance, and benzodiazepines (clonazepam).

Nightmare Disorder

• Occurs during REM sleep, causing the patient to remember the dream.
• Affects 2% of adults, typically during early adulthood.
• Characterized by recurrent frightening dreams during the second half of the sleep cycle.
• Patients remember the dream after awakening.
• Treatment includes therapy and antidepressants (prazosin and antidepressants).

Narcolepsy

• Characterized by excessive daytime sleepiness, cataplexy, sleep paralysis, and hallucinations.
• More common in males than females.
• Etiology is a decreased ability to regulate sleep-wake cycles due to low levels of orexin, a wakefulness-promoting neuropeptide.
• Caused by lesions to the posterior hypothalamus and midbrain.
• Treatment options include sodium oxybate (drug of choice), antidepressants, stimulants, and modafinil.

Obstructive Sleep Apnea

• A chronic breathing-related disorder characterized by repetitive episodes of breathing cessation or reduced airflow during sleep.
• Affects 1-2% of children, 15% of middle-aged adults, and over 20% of older adults.
• Etiology includes obesity, increased neck circumference, and airway narrowing.
• Clinical features include excessive daytime sleepiness, snoring, frequent awakenings, nonrefreshing sleep or fatigue, morning headaches, and hypertension.
• Treatment options include continuous positive airway pressure (CPAP), weight loss, exercise, and surgery.

Non-benzodiazepines

• Melatonin, zolpidem, eszopiclone, zaleplon, and suvorexant are effective for short-term insomnia treatment.
• These medications have a low incidence of daytime sleepiness and orthostatic hypotension.
• Zolpidem can increase the risk of falls in older adults and may cause cognitive impairment in women with doses over 10 mg.

Antidepressants

• Trazodone, amitriptyline, and doxepin can be used to treat insomnia but are off-label.
• Mirtazapine in low doses is often prescribed for sleep in patients with co-existing depressive disorders.
• Common side effects include sedation, dizziness, and psychomotor impairment.

Hypersomnolence Disorder

• Excessive daytime sleepiness despite sufficient sleep duration, characterized by:
  • Recurrent sleep episodes within the same day
  • Prolonged, non-restorative sleep exceeding 9 hours
  • Difficulty achieving full wakefulness after awakening
• These symptoms must occur at least three times a week for three months.
• Non-restorative sleep, automatic behaviors, and difficulty waking up in the morning are common complaints.

Chronic Insomnia

• Persists for at least three months and can extend to years.
• Reduces quality of life and increases the risk of mental illness.
• Often diagnosed with a subjective sleep tracking measure - Consensus Sleep Diary.
• DSM-5 criteria includes:
  • Difficulty initiating or maintaining sleep, or early-morning awakenings with inability to return to sleep
  • Symptoms occur at least three days a week for at least three months.
  • Causes clinically significant distress or functional impairment.
  • Occurs despite adequate opportunity to sleep.
  • Not solely due to another sleep-wake disorder, substance, or medication.
  • Coexisting mental and medical conditions do not adequately explain the symptoms.

Chronic Insomnia Epidemiology

• Prevalence rates range from 6-10%.
• The most common sleep-wake disorder.

Chronic Insomnia Etiology:

• Subclinical mood or anxiety disorders.
• Preoccupation with perceived inability to sleep.
• Unfavorable bedtime routines (poor sleep hygiene).
• Idiopathic.

Chronic Insomnia Treatment

• First-line treatment is Cognitive Behavioral Therapy (CBT).
• Sleep hygiene measures are essential.
• Chronotherapy (bright light therapy) entrains the circadian rhythm and is supported for insomnia treatment.
• Pharmacotherapy (hypnotic medications) should only be used in cases not responding to CBT.

Benzodiazepines

• Reduce sleep latency and nocturnal awakenings.
• Effective for short durations (4-8 weeks).
• Insufficient evidence to support long-term efficacy.
• Side effects include tolerance, addiction, daytime sleepiness, and rebound insomnia.
• Older adults are at risk for falls, confusion, and dizziness.

Obstructive Sleep Apnea

• The most common hypersomnia.
• Characterized by repeated episodes where breathing is interrupted during sleep due to blockage of the upper airway.
• Frequent awakenings, daytime sleepiness, snoring and witnessed apneas are key symptoms.
• Diagnosis is made with Polysomnography.

Obstructive Sleep Apnea Prevalence:

• Most common in middle-aged men and women.
• Male to female ratio is 2:1 to 4:1.
• Incidence:
  • Children: 1-2%
  • Middle-aged adults: 2-15%
  • Older Adults: >20%

Obstructive Sleep Apnea Treatment

• Positive Airway Pressure (CPAP) continuous or bi-level (BiPAP).
• Behavioral strategies (weight loss, exercise).
• Surgical interventions: tonsillectomy and selective upper airway stimulation implants.

Central Sleep Apnea

• Characterized by five or more central apneas per hour of sleep.
• Can be idiopathic or caused by:
  • Cheyne-Stokes breathing associated with heart failure, stroke, or renal failure.
  • Opioid use.
• Insomnia and daytime sleepiness are associated symptoms.

Central Sleep Apnea Prevalence

• Idiopathic subtype is rare.
• Cheyne-Stokes subtype is more prevalent in patients with reduced ejection fraction and acute stroke.
• 30% of chronic opioid users experience central sleep apnea.
• Higher frequency in men compared to women.

Central Sleep Apnea Course

• Tied to coexisting medical conditions and can be transient.
• Chronic in opioid users.

Central Sleep Apnea Treatment:

• Treat the underlying condition.
• CPAP/BiPAP.
• Supplemental Oxygen.
• Medications:
  • Acetazolamide (Diamox)
  • Theophylline
  • Sedative-hypnotics

Sleep-Related Hypoventilation

• Polysomnography shows decreased respiration and elevated CO2 levels.
• Individuals experience frequent arousals, morning headaches, insomnia, and excessive daytime sleepiness.
• Often co-occurs with medical or neurological disorders, medication use, or substance use disorders.
• Long-term consequences include pulmonary hypertension, cor pulmonale, cardiac arrhythmias, polycythemia, neurocognitive dysfunction, and respiratory failure due to severe blood gas abnormalities.

Sleep-Related Hypoventilation Prevalence:

• Very uncommon.

Sleep - Related Hypoventilation Course:

• Slowly progressive

Sleep-Related Hypoventilation Treatment:

• Treat underlying condition.
• CPAP/BiPAP.
• Medications to stimulate breathing:
  • Bronchodilators
  • Theophylline