RPSGT Sleep Disorders & Pathophysiology Flashcards

Periodic limb movements of sleep (PLMS) are scored when individual limb movements last:

Answer: 0.5–10 seconds

AASM criteria define individual PLMS as lasting 0.5–10 seconds, occurring in a series of ≥4 movements separated by 5–90 second intervals.

Upper airway resistance syndrome (UARS) differs from OSA primarily in that:

Answer: Arousals occur from increased respiratory effort without meeting apnea/hypopnea criteria

UARS is characterized by increased upper airway resistance causing EEG arousals and sleep fragmentation without meeting standard apnea or hypopnea scoring thresholds.

Which neurotransmitter deficit is central to the pathophysiology of narcolepsy type 1?

Answer: Hypocretin (orexin)

Narcolepsy type 1 results from autoimmune destruction of hypothalamic neurons producing hypocretin (orexin), a wake-promoting neuropeptide.

Sleep-related hypoventilation is defined by AASM as arterial PCO2 (or surrogate) exceeding:

Answer: 50 mmHg during ≥25% of total sleep time

AASM defines sleep-related hypoventilation as arterial PCO2 >50 mmHg occurring during ≥25% of total sleep time.

Recurrent isolated sleep paralysis is classified under which category of sleep disorders?

Answer: REM-related parasomnias

Recurrent isolated sleep paralysis is classified as an REM-related parasomnia because it represents persistence of REM atonia during the transition to or from wakefulness.

Delayed sleep-wake phase disorder (DSWPD) is most prevalent in which population?

Answer: Adolescents and young adults

DSWPD is most common in adolescents and young adults, affecting approximately 7–16% of this population due to biological circadian shifts during puberty.