Normal Sleep

Cornelia Pinnell, Ph.D.Argosy University/Phoenix

Outline of Lecture

• Normal Sleep– Sleep-wake rhythm– REM & NREM sleep – physiological changes– Polysomnography – REM & NREM dreams– Developmental changes

• Sleep Disorders

Normal sleep

Sleep is a regular, recurrent, easily reversible state that is characterized by relative quiescence, and by a great increase in threshold of response to external stimuli, relative to the waking state.

Sleep research

1) Basic sleep mechanisms & sleep physiology

2) Sleep problems in clinical medicine

Sleep-wake rhythm

• Endogenous sleep-wake cycle = 25 hours (Michel Siffre, 1972); external clues (light, social cues) entrain people in 24-hour cycles

• Circadian rhythms and sleep – during different times of the day sleep patterns differ greatly in their proportion of REM & NREM sleep

Sleep patterns

•Sleep is cyclical: NREM & REM (rapid eye movement) sleep cycles

–NREM sleep – most physiological functions are markedly reduced; every 90-100 minutes of NREM sleep followed by REM sleep

–REM sleep – irregular patterns, similar toaroused waking patterns; periods increase from 10 minutes to up to 50 minutes throughout the night –up to a total of 2 ½ hours of REM activation/night

Lifespan changes in sleep patterns

• Neonate: sleep 16h/day; EEG moves from alert state directly to REM; REM > 50% of sleep time

• 4 month old infant: REM < 40% of sleep time

• Young adult: REM = 25%; NREM: st.1= 5%, st.2=45%, st.3=12%; st.4=13%

• Old age: reduction in REM and slow-wave sleep

Polysomnography

• Polysomnography is the monitoring of multiple electrophysiological parameters during sleep.

Polysomnographic studies

• Night time – conducted during sleep hours• Daytime – to monitor daytime sleepiness• Multiple Sleep Latency Test (MSLT) – instructed to

lie down in a dark room and not resist falling asleep; sleep latency is measured on each trial, 5x - an index of physiological sleepiness

• Maintenance of Wakefulness Test (MWT) –instructed to lie down in a quiet dimly lit room and remain awake – sleep latency is measured – index of ability to stay awake

Polysomnogram REM findings

• Thermoregulation – poik ilothermia (i.e., temperature varies with changes in the temperature of the surrounding medium).

• REM electromyograph – marked reduction in muscle tone – near total paralysis.

• Partial or full penile erection - (nocturnal penile tumescence study is one of the most frequently requested tests) accompanies almost every REM period.

Polysomnogram REM findings

• REM EEG - low voltage, random fast activity with sawtooth waves, similar to waking patterns; pulse, respiration, blood pressure are high.

• REM latency (time lapse from sleep onset until the first REM period) = 90 minutes in normal adults; shorter latency in individuals with depression or narcolepsy. (If awakened, people are disoriented, disorganized thinking)

Physiological changes during NREM sleep

• Respiration: regular, slowed down

• Cardiac function: regular pulse, reduced 5 -10 beats/min below the level of restful waking

• Blood pressure: lower, little variation

• Blood flow: slightly reduced

• Muscle tone: episodic involuntary body movements during NREM

• Temperature: slightly reduced

Physiological changes during REM sleep

• Respiration: high

• Cardiac function: high pulse

• Blood pressure: high

• Brain oxygen use: increased

• Temperature: poor thermoregulation (Poikilothermia = changes in body temperature related to environment)

• In men: partial or full penile erection

Stages of NREM sleep (electrophysiological criteria)

• Stage 1 – theta waves - low-voltage of 3-7 cycles/sec -lightest stage

• Stage 2 – sleep spindles – 12-14 cycles/sec. & K-complexes (slow triphasic waves)

• Stage 3 – delta (high amplitude slow) waves

• Stage 4 - delta (slow) waves ; most occurs during the first third of the night

Stage 1 of NREM sleep

Stage 2 of NREM sleep

Stages 3 & 4 – delta waves (slow)

REM sleep(electrophysiological criteria)

• Saw-tooth waves

• Theta waves activity

• Alpha waves activity

REM dreams

• People awakened during REM sleep frequently report dreaming (60 to 90%)

• REM dreams are typically absurd and surreal – ‘dream logic’

NREM dreams

People report occasional dreams during NREM sleep.

Typically NREM dreams are:• lucid

• purposeful

Expected changes in sleep quality with aging

• Insomnia• Sleep-disordered breathing• REM sleep-behavior disorder

Restorative functions of sleep

• Homeostatic functions– Role in protein synthesis & metabolism– Thermoregulation & energy conservation

• Hypothesized role in synthesizing information & making connections

Sleep requirements

• Short sleepers – < 6 hours (abbreviated need for sleep; no difficulty falling asleep)

• Long sleepers – > 9 hours; longer REM & high density REM, vivid dreams

• Sleep deprivation – prolonged periods lead to ego disorganization, hallucination, delusions, irritability, lethargy

Sleep regulation

• Serotonin & acethylcoline - sleep

• Melatonin = ‘sleep facilitator’• Dopamine – alerting effect• Depressed patients have marked REM sleep

disruptions: shortened REM latency; increased REM%, shift of REM to the first half of night– Antidepressants reduce REM sleep

Sleep Disorders

• DSM – IV- TR

• International Classification of Sleep Disorders (ICSD) –

• http://www.typesofsleepdisorders.net/international-classification-of-sleep-disorders.html

Outline of Lecture

• Sleep Disorders– Epidemiology– Major symptoms:

• Insomnia• Hypersomnia• Parasomnia• Sleep-wake disturbance

– Classification of sleep disorders

Outline of Lecture

• Primary Sleep Disorders– Dyssomnias

• 307.42 Primary Insomnia• 307.44 Primary Hypersomnia• 347 Narcolepsy• 780.59 Breathing-Related Sleep Disorder• 307.45 Circadian Rhythm Sleep Disorder• 307.47 Dyssomnia NOS

Outline of Lecture

• Primary Sleep Disorders– Parasomnias

• 307.47 Nightmare Disorder• 307.46 Sleep Terror Disorder• 307.46 Sleepwalking Disorder• 307.47 Parasomnia NOS

Outline of Lecture

• Sleep Disorders Related to Another Mental Disorder (Axis I or Axis II)

• Other Sleep Disorders– Due to a medical condition (indicate)– Substance Induced (use specific codes)

Epidemiology of sleep disorders

• More than 1/3 of US adults experience some type of sleep disorder

• Insomnia is the most common sleep disorder.

Major symptoms of SD

• Insomnia• Hypersomnia• Parasomnia• Sleep-wake disturbance

Insomnia

• Difficulty initiating or maintaining sleep. Often associated with apprehensive feelings or ruminative thoughts.

• Transient insomnia – may be related to grief, loss, stress, life changes

• Persistent insomnia – most often a difficulty falling asleep

Hypersomnia

• Hypersomnia manifests as excessive amount of sleep, excessive daytime sleepiness (somnolence), or sometimes both – less common than insomnia.

• Transient/situational hypersomnia may be in response to an identifiable recent life change, conflict, or loss.

Other symptoms of SD

• Parasomnia. Usually occurs in stages of deep sleep (3 & 4); strange behaviors may happen during sleep, associated with poor recall.

• Sleep-wake disturbance occurs when there is a displacement of sleep from its desired circadian period.

Classification of SD

• DSM-IV-TR –1) Primary sleep disorders; 2) Sleep disorders related to another mental disorder; 3) Other sleep disorders

• ICD-10 – only sleep disorders non-organic type are included

• ICSD - The American Sleep Disorders Association’s International Classification of Sleep Disorders: Diagnostic and Coding Manual – 1) Dyssomnias; 2) Parasomnias; 3) Sleep disorders associated with medical-psychiatric disorders; 4) Proposed sleep disorders

Primary sleep disorders

Cause significant distress or impairment in social, occupational, or other important area of functioning.

Not caused by another mental disorder, physical condition, or substance.

Primary sleep disorders

Dyssomnias• 307.42 Primary Insomnia• 307.44 Primary Hypersomnia• 347 Primary Narcolepsy• 780.59 Primary Breathing-Related Sleep Disorder• 307.45 Primary Circadian Rhythm Sleep Disorder• 307.47 Dyssomnias NOS

307.42 Primary Insomnia

• Prevalence in general adult population:1- 10%• Prevalence in the elderly:up to 25%• May include repeated Rapid Eye Movement

(REM) sleep interruptions & atypical polysomnographic features – poor sleep, nonrestorative.

DSM-IV Criteria for 307.42 Primary Insomnia • A - Chief complaint is difficulty initiating or

maintaining sleep or nonrestorative sleep for at least 1 month.

• B – Sleep disturbance causes significant distress or impairment in social, occupational, or other important areas of functioning

• C & D - Sleep disturbance does not occur exclusively during the course of other SDs or other mental disorder

• E – Not due to a substance or medical condition

Assessment of insomnia

• Sleep diaries• Sleep questionnaires• Sleep interview• Polysomnography

Treatment for chronic insomnia

• Pharmacotherapy:– Sedatives– Antidepressants– Anxiolytics (benzodiazepines)– OTC (over-the-counter) medication –

melatonin, valerian, antihistamines

• Non-pharmacological interventions:

Treatment for chronic insomnia

• Non-pharmacological interventions:– Sleep hygiene– Environmental (stimulus) control– Relaxation– Cognitive-behavioral therapy

307.44 Primary Hypersomnia

• Excessive sleep episodes or daytime sleep episodes occurring almost daily

• Sleep is normal in architecture and physiology.

• Specifier: Recurrent, if periods of excessive sleepiness of at least 3 days occur several times a year for at least 2 years.

DSM-IV Criteria for 307.44 Primary Hypersomnia

• A - Diagnosed when no other cause can be found for excessive somnolence which occurs for at least 1 month.

• B – Excessive sleepiness causes significant distress or impairment in social, occupational, or other important areas of functioning

• C, D, E – as for Primary Insomnia

347 Primary Narcolepsy

• Prevalence in adults: 0.02 – 0.16%

• Onset typically in adolescence - may occur at any age.

• Excessive daytime sleepiness & abnormal REM sleepdaily for at least 3 months. REM sleep onset within 10 minutes from sleep onset includes hypnagogic & hypnopompic hallucinations, cataplexy (i.e., sudden loss of muscle tone) & sleep paralysis(conscious, awake, unable to move)

DSM-IV Criteria for 347 Narcolepsy

• A – Irresistible attacks of refreshing sleep that occur daily over at least 3 months

• B – Presence of both of the following – Cataplexy (sudden loss of muscle tone, bilaterally –

often due to intense emotion)– Recurrent intrusion of elements of REM sleep during

the transition between sleep & wakefulness

• C – Not due to another substance or mental disorder

780.59 Primary Breathing-Related SD

• Sleep apnea is considered pathological if patients have at least 5 apneic episodes during the night.

• Obstructive sleep apnea syndrome – pure central sleep apnea (airflow and respiratory effort cease); pure obstructive sleep apnea (airflow ceases, but respiratory effort increases during the apneic episode).

DSM-IV Criteria for 780.59 Breathing-Related Sleep Disorder

• A - Sleep disruption leading to excessive sleepiness or insomnia related to apnea, hypopnea, or oxygen desaturation.

• B – Disturbance not better accounted for by another mental disorder, substance or medical condition

307.45 Primary Circadian Rhythm SD:• Delayed sleep phase type - sleep and wake

times that are intractably later than desired, inability to fall asleep and awaken at a desired earlier time

• Jet lag type– eastward travel more difficult to tolerate; disappears spontaneously in 2 to 7 days

• Shift work type - rapid change of work schedules & self-imposed chaotic sleep schedules lead to insomnia or excessive sleepiness

• Unspecified type

DSM-IV Criteria for 307.45Circadian Rhythm Sleep Disorder

• A- Persistent or recurrent pattern of sleep disruption leading to excessive sleepiness or insomnia that is due to a mismatch between the sleep-wake schedule required by a person’s environment and his or her circadian sleep-wake pattern.

• B - The sleep disturbance causes clinically significant distress or impairment in social, occupational, or other important areas of functioning

DSM-IV Criteria for 307.45Circadian Rhythm Sleep Disorder

• C - The disturbance does not occur exclusively during the course of another Sleep Disorder or other mental disorder.

• D - The disorder is not due to the direct physiological effect of a substance (e.g., a drug of abuse, or medication) or a general medical condition

Consequences of disturbed sleep patterns• Shorter and poorer quality of sleep of

night shift workers (as compared to day or evening shift workers)

• Frequent shift rotation has more detrimental effects on sleep quality and duration

Consequences of disturbed sleep patterns• Depression• Substance abuse• Anxiety• Decline in work performance• Disruption in interpersonal relationships

307.47 Dyssomnias NOS

Nocturnal myoclonus Restless leg syndrome Sleep drunkenness Insufficient sleep Menstrual-associated syndrome

Parasomnias

• Nightmare disorder - long, frightening dreams from which people awaken frightened, occur during REM sleep late in the night – prevalence: 50% of the population report occasional nightmares

• Sleep terror disorder - arousal in the first third of the night during deep non-REM sleep, accompanied by a piercing scream or cry and behavioral manifestations of intense anxiety bordering on panic – amnesia for the episode; polygraphic recordings similar to sleepwalking; prevalence: 1-6% of children

Parasomnias

• Seepwalking disorder (Somnambulism) - a sequence of complex behaviors that are initiated in the first third of the night during deep NREM sleep – walking about without full consciousness; onset: ages 4-8, peak prevalence at age 12; more common in boys – familial disorder

• Parasomnias NOS – bruxism; REM sleep behavior disorder (dream enacting); sleeptalking - somniloqui; sleep-related head banging; sleep paralysis

SD related to another mental disorder (Axis I or Axis II)

• Insomnia

• Hypersomnia

Other sleep disorders

• Due to a general medical condition - epileptic seizures; cluster headaches; sleep-related asthma, cardiovascular symptoms, gastroesophageal reflux, hemolysis

• Specify type:– Insomnia Type– Hypersomnia Type– Parasomnia Type– Mixed Type (multiple sleep sxs, no sx clearly predominates)

Treatment for sleep disorders

• Sleep medicine is a young discipline• Most common treatment: pharmacological

(undesired side effects)• Nonpharmacological:

– CBT - sleep hygiene, lifestyle changes– Relaxation, meditation, guided imagery– Dental guard (for bruxism)– Light therapy; exercise

Sleep hygiene

• Maintain regular bedtime and waking schedule; avoid daytime naps

• Discontinue CNS-acting substances (e.g., caffeine, nicotine, alcohol, stimulants)

• Exercise daily, early in the day• Avoid evening stimulating activities• Avoid large meals near bedtime• Relaxation & meditation routines, hot bath• Comfortable sleeping conditions

Treatment for sleep disorders

Primary insomnia the most difficult to treat: deconditioning techniques; relaxation, biofeedback, meditation; medication – benzodiazepines, hypnotics; sleep hygiene.

Primary Hypersomnia – With stimulant drugs.

Primary Narcolepsy – With stimulant drugs & forced naps at regular times during the day