Sleep Neurology Glossary
100 terms total — 24 showing — Last updated 15 Sep 2026
multiple sleep latency test MSLT
Daytime sleep study measuring the tendency to fall asleep, used primarily to diagnose narcolepsy and assess excessive daytime sleepiness.
actigraphy
Objective monitoring method using wrist-worn devices to track movement patterns and estimate sleep-wake cycles over exte...
alpha intrusion
Abnormal presence of alpha frequency waves during NREM sleep, often associated with non-restorative sleep.
alpha wave intrusion
Abnormal appearance of alpha waves (8-13 Hz) during non-REM sleep stages, often indicating poor sleep quality or arousal...
apnea-hypopnea index
Measurement of sleep-disordered breathing severity, calculated as the number of apneas and hypopneas per hour of sleep.
arousal index
Polysomnographic measure calculating the number of arousals per hour of sleep, indicating sleep fragmentation severity.
arousal threshold
The minimum stimulus intensity required to cause awakening or arousal from sleep.
BiPAP
Bilevel positive airway pressure device that provides different pressure levels for inspiration and expiration.
cataplexy
Sudden, temporary loss of muscle tone triggered by strong emotions, typically associated with narcolepsy.
central sleep apnea
A sleep disorder where breathing stops due to lack of respiratory effort from the central nervous system.
Cheyne-Stokes respiration
An abnormal breathing pattern characterized by crescendo-decrescendo cycles followed by apneas.
chronotherapy
Treatment approach that uses controlled manipulation of sleep-wake timing to treat circadian rhythm disorders.
circadian rhythm
The internal biological clock that regulates the sleep-wake cycle and other physiological processes over approximately 2...
circadian rhythm disorder
Sleep-wake disorders caused by misalignment between internal biological clocks and external environmental schedules.
confusional arousal
A parasomnia characterized by disorientation and confusion during partial awakening from deep sleep.
CPAP
Continuous positive airway pressure therapy device that delivers pressurized air to keep airways open during sleep.
CPAP titration
An overnight study to determine the optimal CPAP pressure setting for treating sleep apnea.
delta wave
Slow brain waves (0.5-2 Hz) characteristic of deep NREM sleep stages.
desynchronized sleep
Alternative term for REM sleep, referring to the desynchronized brain wave patterns observed during this stage.
epoch
A standardized 30-second segment used for sleep stage scoring in polysomnography.
exploding head syndrome
Benign parasomnia characterized by loud noise hallucinations during sleep-wake transitions, often described as explosive...
home sleep apnea test
A simplified sleep monitoring device used at home to diagnose obstructive sleep apnea.
hypersomnia
Excessive daytime sleepiness or prolonged nighttime sleep that significantly impairs daily functioning despite adequate...
hypnagogic hallucination
Vivid, often frightening sensory experiences that occur during the transition from wakefulness to sleep.
hypnogram
Graphical representation of sleep stages over time, showing the progression through different phases of sleep.