Sleep and Its Disorders

Question 1

Sleep

Answer 1

The natural periodic suspension of consciousness during which the powers of the body are restored; the intermediate state between wakefulness and death; a reversible behavioral state of perceptual disengagement from unresponsiveness to the environment

Question 2

Physiologic functions in sleep

Answer 2

The body temperature is at a lower set point, decreased ventilation, and dominance of parasympathetic drive

Question 3

NREM sleep

Answer 3

Active body, physical restoration, stages N1, N2, and N3

Question 4

REM sleep

Answer 4

Active brain, atonia, mental restoration

Question 5

Normal sleep - mammals

Answer 5

All mammals have NREM/REM sleep. All species have REM sleep in early life that tends to decrease with age

Question 6

What is one of the most important determinants of sleep?

Answer 6

Age

Question 7

What are the two variables of sleep in human?

Answer 7

The developmental course of Wake/Sleep cycle; the developmental course of the REM/NREM

Question 8

What is the ratio of REM:NREM sleep for normal sleep in humans?

Answer 8

Infants - 50:50. Adults spend 20-25% in REM and 75-80% in NREM

Question 9

Slow wave sleep

Answer 9

Largest decline in the second decade of life, stage 2 sleep increases to adult level of 45-55%

Question 10

Normal sleep in children

Answer 10

Sleep onset REM periods until 3 months old, NREM stages 3-6 months

Question 11

Normal sleep in adults

Answer 11

Sleep entered through NREM sleep, REM cycles every 90-120 minutes

Question 12

Normal sleep

Answer 12

NREM sleep predominates in the first half of sleep and is linked to prior level of wakefulness; REM predominates in last half of sleep and is circadian linked

Question 13

Hypnogram

Answer 13

A graph with the cyclic alteration of wake, REM sleep, and NREM sleep during the sleep period

Question 14

Homeostatic sleep drive

Answer 14

Sleep responses are proportional to the duration of prior wakefullness - increased sleepiness, increased sleep, increased depth and maintenance of sleep

Question 15

Circadian rhythms

Answer 15

When isolated from time cues such as sunlight, most creatures show intrinsic rhythms of nearly, but rarely exactly, 24 hours. Generated by the circadian pacemaker located in the syprachiasmatic nuclei (SCN) of the hypothalamus

Question 16

What do the circadian rhythms include?

Answer 16

Wake/sleep, hormones, temperature, immune function, drug metabolism, renal function, airway function cardiovascular activity, hematoloigcal function, and neoplastic cells

Question 17

Entrainment

Answer 17

How circadian rhythms are synchronized to the external environment. It is done through presentation of stimuli that signal the time of day called Zeitgebers.

Question 18

Zeitgebers

Answer 18

Stimuli the signal the time of day; a stimulus capable of shifting the phase of the circadian clock in a systemic manner (photic and non-photic)

Question 19

Opponent Process Model

Answer 19

The SCN enhances wakefulness and opposes the homeostatic rhythm

Question 20

Two Process Model of Sleep Regulation (Borbly)

Answer 20

The circadian rhythm, goverened by SCN controls the regulation of awareness/alertness (process C). The sleep-wake homeostasis, or Process S, the accumulation of hypnogenic (sleep-inducing) substances in the brain, generates a homeostatic sleep drive.

Question 21

Fxn of sleep and sleepiness

Answer 21

Sleep affects all organs of the body, and it remains a biological enigma. Sleep deprivation disrupts biological rhythms.

Question 22

Determinants of sleepiness

Answer 22

Sleep quantity/sleep quality/circadian factors. The primary determinants of alertness/sleepiness: circadian, homeostatic, age, drugs, sleep disorders. Total sleep requirement and the timing of the wake/sleep cycle are inherent characteristics of an individual

Question 23

Societal sleep deprivation - chronic and pervasive

Answer 23

As a society, we now get 20% less sleep than our ancestors only 100 years ago. College students oversleep their alarms 50% of the time

Question 24

Sleep debt

Answer 24

Sleep deprivation is also cumulative. A person does not come to require less sleep or get used to being sleep deprived. Getting less than the necessary amount of sleep starts to create a “sleep debt” which must be paid off. The payback requirement is less than the debt.

Question 25

Consequences of sleep deprivation

Answer 25

Car accidents, errors in judgement

Question 26

Safety issues with sleep deprivation.

Answer 26

58% of EM residents reported near crashes driving, 80% of which were post night-shift; increased with the number of night shifts/month. 50% greater risk of blood-borne pathogen exposure incidents (needlestick, laceration, etc) in residents between 10p-6a

Question 27

Epworth Sleepiness Scale

Answer 27

0 = no chance of dozing; 1 = slight chance of dozing; 2 = moderate chance of dozing; 3 = high chance of dozing. 8 questions about situational chance of dozing and a score of 9 or higher is indicative of sleepiness.

Question 28

Sleep Testing

Answer 28

Polysomnography; uses EEG, EOG, EMG, leg EMG, airflow, respiratory effort, ECG, and pulse Ox

Question 29

Visual rules - scoring of sleep stages

Answer 29

Stages of sleep: Stage W (wakefullness); NREM contains: Stage N1 (NREM1), Stage N2 (NREM2), Stage N3 (NREM3). Stage R (REM)

Question 30

Multiple sleep latency test (MSLT)

Answer 30

Well-validated test of the underlying physiologic tendency to fall asleep during the usual waking hours. It is performed under very controlled conditions. An all night in-lab PSG must precede the MSLT. 5 20min nap opportunities are given at 2hr intervals. Average latency to sleep onset and appearance of REM sleep are measured.

Question 31

Norms of sleep latency for the MSLT

Answer 31

0-5 minutes indicative of severe hypersomnia; 5-10 minutes is borderline, 10-20 minutes is normal. 2 or more naps with REM periods are abnormal.

Question 32

Maintenance of Wakefulness Test

Answer 32

Designed to test the patient’s ability to stay awake, The patient is seated upright in bed in a dimly lit room and asked to stay awake for 40 minutes. The test is repeated 4 times throughout the day

Question 33

Actigraphy

Answer 33

A small recording device worn on the wrist to measure sleep

Question 34

Sleep disorders

Answer 34

Insomnia, sleep related breathing disorders, hypersomnias of central origin, circadian rhythm sleep disorders, parasomnia

Question 35

Insomnia

Answer 35

Present for at least a month, evidence of conditioned sleep difficulty or heightened arousal in bed. Treatment includes cognitive behavioral therapies like stimulus control and sleep restriction as well as medications

Question 36

Obstructive sleep apnea

Answer 36

Symptoms and signs include loud snoring, observed apneas, daytime sleepiness, elevated BMI, crowded oropharynx, hypertension, morning sore throat or headache. Diagnoses is through the polysomnography

Question 37

Treatment of sleep apnea

Answer 37

Using a positive airway pressure device (CPAP

Question 38

Restless leg syndrome

Answer 38

Unpleasant limb sensations with the urge to move, symptoms precipitated by rest but get better with movement and get worst in the evening or at night. It causes sleep disturbances and consequences

Question 39

Hypersomnias of Central Origin: Narcolepsy

Answer 39

Characterized by sleepiness and symptoms due to the abnormal regulation of REM sleep. Symptoms include excessive daytime sleepiness, cataplexy, hypnagogic hallucinations, and sleep paralysis

Question 40

Narcolepsy

Answer 40

Prevalence is 0.03-0.05% and the most common age of onset is adolescence. Secondary nacrolepsy can occur in patients with head trauma, stroke, MS, brain tumors, and CNS infections. MSLT found that the mean sleep latency, less than 8 minutes, and 2 or more REM periods in 5 naps is characteristic of narcolepsy

Question 41

Circadian Rhythm sleep disorders

Answer 41

Delayed sleep phase type, advanced sleep phase type, irregular sleep-wake type, non-entrained type (free running), jet lag type, shift work type, or due to medical condition, substance use, or alcohol

Question 42

Parasomina

Answer 42

Disorders that intruse into the sleep process and are not primarily disorders of sleep and wake state. Parasomnias are undesirable physical events or experiences that arise from sleep or the sleep-wake transition. It encompasses movements, behaviors, emotions, perceptions, and dreaming

Question 43

Sleepwalking

Answer 43

Complex automatic motor activity from deep sleep with amnesia of the event, presents with communication difficulty. Major concern for safety/injury because it can encompass a wide range of behaviors, like getting dressed, leaving the house, and driving.

Question 44

Sleep terrors

Answer 44

Sudden arousals from deep sleep, include screaming, terror, or confusion. Present with extreme autonomic arousal and it is more common in children, as well as males. It can present with variable motor activity (includes extreme agitation)

Question 45

REM sleep behavior disorder

Answer 45

Dream enactment behavior associated with loss of muscle atonia in REM sleep; includes verbalizations, singing, walking, running, and violent/agitated behaviors (often hitting bed partner)

Question 46

Sleep related eating disorder

Answer 46

Subcategory of sleepwalking, more common in women than men. It arises from NREM sleep, pt will prepare and eat food, occasionally non-edible objects, but will have total amnesia for the event.