RPSGT Registered Polysomnographic Technologist Vocabulary Review

Comprehensive vocabulary flashcards covering sleep abbreviations, EEG waveforms, respiratory event scoring, and sleep-related pathologies for the RPSGT exam.

AI (Apnea Index)

The average number of apnea events per hour of sleep.

AHI (Apnea-Hypopnea Index)

The sum of apneas and hypopneas per hour of sleep; used to determine the severity of obstructive sleep apnea.

Alpha Waves

EEG waves with a frequency of $8-13\,Hz$; prominent during deep relaxation or when eyes are closed while awake.

Beta Waves

EEG waves with a frequency of $13-35\,Hz$; present during normal wakefulness when the patient is alert.

Delta Waves

Slow EEG waves with a frequency of $0.5-4\,Hz$ and high amplitude (> 75\,\mu V); characteristic of Stage N3 sleep.

Theta Waves

EEG waves with a frequency of $4-7\,Hz$; commonly observed in Stage N1 sleep and during daydreaming.

Narcolepsy

A sleep disorder characterized by repeated periods of falling asleep during waking hours, often including cataplexy and immediate entry into REM sleep.

Cataplexy

A sudden loss of muscle tone, often triggered by strong emotions, frequently associated with narcolepsy.

Obstructive Sleep Apnea (OSA)

A disorder caused by the passive collapse of the pharynx during sleep, resulting in breath cessation despite continued respiratory effort.

Central Sleep Apnea (CSA)

A breathing-related sleep disorder involving apneic episodes where inspiratory effort is absent, usually resulting from cardiac or neurological conditions.

Cheyne-Stokes Respirations

A periodic breathing pattern characterized by a crescendo-decrescendo variation in tidal volume followed by a period of apnea.

Restless Legs Syndrome (RLS)

A neurological disorder characterized by an irresistible urge to move the legs, usually accompanied by uncomfortable sensations at rest.

Periodic Limb Movements in Sleep (PLMS)

Repetitive, stereotypical limb movements (usually legs) that occur during sleep in a series of four or more.

Electrooculogram (EOG)

A recording of eye movements; used in sleep studies to identify REM sleep through vertical and horizontal movement detection.

Electromyogram (EMG)

A recording of electrical activity in muscles; chin EMG helps identify REM atonia, while limb EMG identifies periodic movements.

Sleep Spindles

Sudden bursts of $12-14\,Hz$ electrical activity lasting $0.5-1.5$ seconds; a hallmark of Stage N2 sleep.

K Complexes

Sharp negative EEG waves followed by a slower positive wave, lasting at least $0.5$ seconds; characteristic of Stage N2 sleep.

REM Sleep Behavior Disorder (RBD)

A parasomnia occurring during Stage R sleep where the normal muscle atonia is absent, allowing patients to act out their dreams.

Hypnopompic Hallucinations

Sensory perceptions (usually visual) that occur during the transition from sleep to wakefulness.

Hypnagogic Hallucinations

Sensory perceptions that occur during the transition from wakefulness to sleep.

Sleep Efficiency (SE)

The ratio of total sleep time to the total time spent in bed, expressed as a percentage: $\frac{\text{TST}}{\text{TBT}} \times 100$.

Sleep Onset Latency (SOL)

The amount of time in minutes required to transition from an awake state to the first epoch of sleep.

Expiratory Positive Airway Pressure (EPAP)

The lower pressure level used in Bi-level PAP therapy to maintain airway patency during exhalation.

Inspiratory Positive Airway Pressure (IPAP)

The higher pressure level used in Bi-level PAP therapy to support ventilation during inhalation.

RERA (Respiratory Effort-Related Arousal)

A sequence of breaths lasting at least 10 seconds characterized by increasing respiratory effort or flattening of the nasal pressure waveform leading to an arousal.

Pulse Oximetry ($SpO_2$)

A non-invasive method to measure the percentage of hemoglobin saturated with oxygen using light waves.

Mixed Apnea

A respiratory event that begins with an absence of inspiratory effort (central) but concludes with the resumption of effort (obstructive).

Hypercapnia

An abnormally high level of carbon dioxide ($CO_2$) in the blood.

Hypoxemia

An abnormally low level of oxygen in the blood.

Wicket Spikes

A normal EEG variant of $6-11\,Hz$ occurring in single spikes or runs, primarily in older adults during drowsiness or Stage N1.