Sleep Disorders Flashcards (Chapter 2, Part 2)

Flashcards providing vocabulary definitions for sleep disorders, including Central Disorders of Hypersomnolence, Circadian Rhythm Sleep-Wake Disorders, Parasomnias, and Sleep-Related Movement Disorders.

Central Disorders of Hypersomnolence

A category of sleep disorders defined by a primary complaint of daytime sleepiness that is not caused by disturbed nocturnal sleep or misaligned circadian rhythms.

Narcolepsy

A chronic neurological disorder characterized by "sleep attacks" and the inability to regulate REM sleep boundaries.

Narcolepsy Tetrad

The four hallmark clinical features of narcolepsy: Excessive Daytime Sleepiness (EDS), Cataplexy, Sleep Paralysis, and Hypnagogic/Hypnopompic Hallucinations.

Excessive Daytime Sleepiness (EDS)

The most common symptom of narcolepsy, which manifests as difficulty concentrating, memory loss, and unintended "microsleep" periods.

Cataplexy

A bilateral loss of muscle tone triggered by strong emotions (such as laughing or anger), ranging from mild weakness to complete limb atonia and a resulting fall.

Sleep Paralysis

Partial or total skeletal muscle paralysis occurring at sleep onset (hypnagogic) or awakening (hypnopompic).

Hypnagogic/Hypnopompic Hallucinations

Vivid, often frightening dreamlike experiences occurring during the transition between sleep and wakefulness.

Automatic Behavior

Subconscious performance of activities (such as talking out of context) seen in $20\text{--}40\%$ of narcolepsy patients.

Sleep Onset REM Periods (SOREMPs)

Entering REM sleep almost immediately after falling asleep.

Narcolepsy Type I

Formerly known as Narcolepsy with Cataplexy; caused by hypocretin-1 signaling deficiency with CSF Hypocretin-1 $< 110\,\text{pg/mL}$ and MSLT criteria showing MSL $< 8\,\text{min}$ and $> 2$ SOREMPs.

Narcolepsy Type II

Formerly known as Narcolepsy without Cataplexy; characterized by normal hypocretin levels (CSF Hypocretin-1 $> 110\,\text{pg/mL}$ or not measured) and MSLT criteria showing MSL $< 8\,\text{min}$ and $> 2$ SOREMPs.

Idiopathic Hypersomnia

A disorder characterized by an irrepressible need to sleep for at least $3\,\text{months}$, nonrefreshing naps, a mean sleep latency (MSL) $\le 8\,\text{minutes}$ on MSLT, no cataplexy, and commonly a 24-hour sleep duration $\ge 11\,\text{hours}$.

Kleine-Levin Syndrome (Recurrent Hypersomnia)

A rare disorder primarily affecting adolescent males, involving episodes of excessive sleep ($16\text{--}18\,\text{hours/day}$) lasting $2\,\text{days}$ to $5\,\text{weeks}$ (average $10\,\text{days}$), associated with hyperphagia, hypersexuality, and confusion.

Insufficient Sleep Syndrome

Chronic sleep deprivation due to lifestyle choices, diagnosed using sleep logs and actigraphy to confirm total sleep time is less than expected for age.

Circadian Rhythm Sleep-Wake Disorders (CRSWD)

Disorders that occur when the internal biological clock is misaligned with the external environment or required schedule.

Delayed Sleep-Wake Phase Disorder

A significant delay in the sleep period where patients cannot fall asleep until very late and struggle to wake in the morning; common in adolescents.

Advanced Sleep-Wake Phase Disorder

An early shift in the sleep period where patients fall asleep early (e.g., 7:00 PM) and wake extremely early; common in older adults.

Irregular Sleep-Wake Rhythm Disorder

A disorder with no defined circadian rhythm where sleep occurs as variable episodes across $24\,\text{hours}$; often associated with neurological or developmental disorders.

Non-24-Hour Sleep-Wake Rhythm Disorder

A "free-running" cycle not entrained to the 24-hour light-dark cycle, with an internal clock often $> 24\,\text{hours}$; highly prevalent in blind individuals.

Shift Work Disorder

A circadian disorder characterized by excessive daytime sleepiness during night shifts and insomnia during daytime sleep attempts.

Jet Lag Disorder

A circadian disorder occurring when traveling across two or more time zones, with severity depending on the number of zones crossed and direction of travel.

Confusional Arousals

An NREM Stage N3 arousal disorder involving awakening in a confused state with slow speech and cognition, without fear or leaving the bed.

Sleepwalking (Somnambulism)

An NREM Stage N3 arousal disorder involving complex behaviors ranging from sitting up to walking or running.

Sleep Terrors

An NREM Stage N3 arousal disorder characterized by sudden awakenings with a loud scream, intense fear, autonomic activation (tachycardia, sweating), unresponsiveness, and no recollection in the morning.

Sleep-Related Eating Disorder (SRED)

Nightly compulsive eating of high-calorie/junk foods during Stage N3 arousals, where patients are difficult to awaken and have amnesia regarding the event.

REM Sleep Behavior Disorder (RBD)

Failure of REM muscle atonia leading patients to physically act out dreams (isomorphism), often violently; highly correlated with Parkinson's disease and most common in males age $50+$.

Recurrent Isolated Sleep Paralysis

Inability to move at sleep onset or offset in the absence of a narcolepsy diagnosis, often triggered by sleep deprivation.

Nightmare Disorder

Frequent, frightening dreams that cause distress in daytime functioning; highly associated with Post-Traumatic Stress Disorder (PTSD).

Exploding Head Syndrome

A parasomnia involving an imagined loud noise or flash of light at sleep-wake transitions without physical pain; more common in women (average age $58$).

Sleep Enuresis

Involuntary urination in patients $> 5\,\text{years}$ old occurring $> 2\,\text{times/week}$ for $> 3\,\text{months}$.

Primary Sleep Enuresis

A classification of sleep enuresis where the patient has never been consistently dry.

Secondary Sleep Enuresis

Sleep enuresis occurring after at least $6\,\text{months}$ of dryness; highly correlated with Obstructive Sleep Apnea (high RDI) and PTSD.

Restless Legs Syndrome (RLS)

A clinical diagnosis based on an irresistible urge to move the legs usually accompanied by creeping/crawling sensations; symptoms worsen at rest and in the evening/night, and movement provides temporary relief.

Periodic Limb Movement Disorder (PLMD)

Involuntary, repetitive limb movements during sleep (primarily Stage N2) meeting specific scoring criteria, defined by a PLM Index $> 15/\text{hour}$ in adults or $> 5/\text{hour}$ in pediatric patients.

Sleep-Related Rhythmic Movement Disorder

Repetitive body rocking or head banging at sleep onset; common in infants, but abnormal if persisting past age $5$ or causing injury.

Benign Sleep Myoclonus of Infancy

Repetitive leg jerks in infants (birth to $6\,\text{months}$) that resolve spontaneously.

Sleep Starts (Hypnic Jerks)

Sudden muscle contractions occurring at sleep onset, often accompanied by a sensation of falling.

Excessive Fragmentary Myoclonus (EFM)

Frequent small twitches of fingers or toes showing brief EMG amplitude increases ($50\text{--}100\,\mu\text{V}$); usually benign.

Hypnagogic Foot Tremor

Rhythmic leg or foot movements occurring at sleep onset.