Sleep and Sleep Disorders

A set of vocabulary flashcards covering key terms and concepts related to sleep, sleep architecture, various sleep disorders like insomnia and obstructive sleep apnea, and their management, based on lecture notes.

Sleep

A state in which a person lacks conscious awareness of environmental surroundings but can be easily aroused, essential for healthy mood, behavior, physical functioning, and survival.

Sleep insufficiency

A condition where the amount of sleep does not support optimal alertness, functioning, and health.

Sleep deprivation

Too little sleep to meet needs.

Sleep fragmentation

Frequent awakenings or arousal during sleep (almost waking up).

Sleep disturbance

Conditions of poor sleep quality caused by health-related or environmental factors.

Sleep disorders

Abnormalities unique to sleep, such as insomnia, OSA, or narcolepsy, which are often missed or unreported and cause considerable health and safety consequences.

Sleep Architecture

The pattern of nighttime sleep, recorded with polysomnography (PSG).

Polysomnography (PSG)

A diagnostic tool used to record sleep architecture, measuring muscle tone (EMG), eye movements (EOG), and brain activity (EEG).

EMG (electromyogram)

A measurement used in polysomnography to measure muscle tone.

EOG (electrooculogram)

A measurement used in polysomnography to record eye movements.

EEG (electroencephalograph)

A measurement used in polysomnography to measure brain activity.

NREM Sleep

Non–rapid eye movement sleep, accounting for 75% to 80% of sleep time and divided into three stages (N1, N2, N3).

N1 (NREM Stage 1)

The first stage of NREM sleep, marking the beginning transition from wakefulness to sleep, characterized by slow eye movements, and the patient is easily awakened.

N2 (NREM Stage 2)

The second stage of NREM sleep, representing most of the night’s sleep, where heart rate and temperature decrease, and the EEG depicts specific brain wave forms.

N3 (NREM Stage 3)

The third and deepest stage of NREM sleep, also known as slow wave sleep (SWS), where the EEG shows delta waves that measure sleep intensity.

REM Sleep

Rapid eye movement sleep, accounting for 20% to 25% of sleep time, where brain waves resemble wakefulness, postural muscles are inhibited, and most vivid dreams occur.

Insomnia

The most common sleep disorder, characterized by difficulty falling asleep, difficulty staying asleep, waking up too early, or waking up feeling unrefreshed.

Short-term insomnia disorder

Problems falling asleep or remaining asleep for at least 3 nights/week for less than 3 months.

Chronic insomnia disorder

Difficulty falling asleep or remaining asleep for at least 3 nights/week for 3 months or more.

Sleep hygiene

A variety of practices important to normal, quality nighttime sleep and daytime alertness.

Cognitive-behavioral therapy for insomnia (CBT-I)

A non-pharmacological treatment for chronic insomnia that focuses on identifying and changing thoughts and behaviors that prevent sleep.

Rebound insomnia

The worsening of sleep that occurs from abruptly stopping certain sleep medications.

Sleep-Disordered Breathing (SDB)

Abnormal respiratory patterns associated with sleep, including snoring, apnea, and hypopnea.

Apnea

Absent respiratory airflow, defined as more than 90% cessation of airflow lasting greater than 10 seconds.

Hypopnea

Reduced respiratory airflow, defined as a 30-90% decrease in airflow lasting greater than 10 seconds.

Obstructive Sleep Apnea (OSA)

The most diagnosed sleep-disordered breathing problem, characterized by partial or complete upper airway obstruction during sleep, usually occurring during the REM cycle.

Obstructive Sleep Apnea-Hypopnea Syndrome (OSAHS)

Another term for Obstructive Sleep Apnea, indicating a partial or complete upper airway obstruction during sleep.

Apnea-Hypopnea Index (AHI)

The hourly average of apneic events or hypopneas lasting at least 10 seconds’ duration, used in the diagnosis of OSA (e.g., AHI > 5 events/hour with a 3-4% decrease in O2 saturation).

Continuous Positive Airway Pressure (CPAP)

A medical device for severe sleep apnea that delivers continuous positive airflow through a nasal or oral-nasal mask to splint the airway open, preventing obstruction.

Bilevel Positive Airway Pressure (BiPAP)

A medical device for sleep apnea that delivers higher inspiration pressure and lower expiration pressure, which may be better tolerated than CPAP.

Uvulopalatopharyngoplasty (UPPP or UP3)

A surgical procedure for sleep apnea involving the removal of obstructing tissue from the tonsillar pillars, uvula, and posterior soft palate.

Genioglossal advancement and hyoid myotomy (GAHM)

A surgical procedure for sleep apnea that advances the attachment of the muscular part of the tongue on the mandible, often performed with UPPP.

Radiofrequency ablation (RFA)

The least invasive surgical technique for sleep apnea, which can be done alone or in combination with other surgical procedures.

Circadian Rhythm Disorders

Conditions where the body's circadian time-keeping system loses synchrony with the environment, disrupting the sleep-wake cycle and quality of sleep.

Jet lag disorder

A circadian rhythm disorder most commonly occurring when crossing at least 3 time zones, with severity and recovery time increasing with the number of zones crossed.

Shift work sleep disorder

A circadian rhythm disorder common in individuals with alternating or rotating shifts, characterized by symptoms like insomnia and excessive sleepiness.

Sleep debt

The accumulated sleep deficit from repeated inadequate sleep.