Sleep

Organization

1. Physiology of the normal sleep2. Sleep Disorders

Definition

REST- a state of calmness, relaxation without emotional stress, and freedom from anxiety

SLEEP- an altered state of consciousness in which the individual’s perception of and reaction to the environment are decreased.

Theories on Sleep

1. ELECTROPHYSIOLOGIC 2.HORMONAL 3. NEURAL

Neural approach

Views sleep as an active process involving the RETICULAR activating system (RAS) and the interaction of Neurotransmitters.

The RAS is a network of neurons in the medulla, pons and midbrain with projections to the spinal cord, hypothalamus, cerebellum and cerebrum.

The reticular activating system (or ARAS, for Ascending Reticular Activating System)

The reticular activating system (or ARAS, for Ascending Reticular Activating System) is the name given to the part of the brain (the reticular formation and its connections) believed to be the center of arousal and motivation in mammals (including humans).

Functions The activity of this system is crucial for maintaining the state of

consciousness.

It is involved with the circadian rhythm; damage can lead to permanent coma.

It is thought to be the area affected by many psychotropic drugs. General anesthetics work through their effect on the reticular

formation.

The reticular activating system (or ARAS, for Ascending Reticular Activating System)

Functions contThe functioning of this system is a

prerequisite for consciousness to occur The reticular activating system controls our

sexual patterns.

Neural approach

SEROTONIN is said to be the MAJOR neurotransmitter associated with sleep, produced in the median raphe nuclei of the brainstem.

Serotonin decreases the activity of the RAS inducing sleep.

REM sleep appears to be due to the influence of norepinephrine.

Hormonal approach

Views sleep as a pattern affected by hormones.

MELATONIN from the pineal gland in the brain is secreted in enormous quantities during sleep.

Its activity is influenced by the relationship of darkness and light.

Hormonal approach

ACTH is also high during the early period of sleep and CORTISOL rises toward the end of the nighttime sleep period.

GROWTH HORMONE and PROLACTIN also increase during deep sleep.

FUNCTIONS OF SLEEP

1.Restores normal levels of activity and normal balance among parts of the nervous system

2. Necessary for protein synthesis

Phases of Sleep

A. REM (Rapid Eye Movement) sleepB. NREM (Non-Rapid Eye Movement) sleep

Normal sleep stages

NREM sleep is divided in to four stages according to changes in biophysiological changes

NREM sleep is followed by REM sleepSleep pattern is usually NREM sleep stages 1

to 4 followed by REM sleep

NREM SLEEP

Also referred to as the SLOW wave sleep, because the brain waves of the client are slower than the brain waves of an awake or alert person.

It is a deep, restful sleep There is a decreased physiologic functions All metabolic processes are reduced.

NREM Stages

STAGE 1- the stage of very light sleep, sleeper can readily be awakened, lasts for a few minutes. The eyes tend to roll slowly from side to side, and muscle tension remains absent.

STAGE 2- the stage of light sleep, body processes continues to slow down, and lasts about 10-15 minutes. Constitutes 40-45% of TOTAL sleep!

NREM Stages

STAGE 3-refers to a medium-depth sleep where vital signs and metabolic processes slow further because of the PARASYMPATHETIC nervous system influence. The sleeper is difficult to arouse.

STAGE 4-this is the deepest sleep or delta sleep. It is the stage where the heart rate and respiratory rate drop 20-30% below those exhibited during waking hours.

This stage is thought to restore the body physically. Some dreaming may occur here. This stage may be absent in the elderly.

20

EEG Stages of Wakefulness and Sleep

NREM sleep

NREM (Non Rapid Eye Movements) consists of relatively long stretches of dreamless sleep in contrast to REM sleep. REM sleep is typically characterized by dreams

Eye movements in NREM sleep are slow and rolling in contrast to REM sleep, in which the eye movements are rapid and conjugate

NREM Sleep-changes in EEG and consciousness (cerebral function)

Divided into four stagesStages are divided according to the depth of

unconsciousnessGreater depth of unconsciousness as sleep

progresses from stage 1 to 4EEG becomes progressively slower and

shows higher-voltage pattern ( also called slow wave, delta wave )

NREM-Thinking and Body Activities

Thinking in NREM is brief, rudimentary and readily forgotten

Muscle tone is presentDTR can be elicitedEMG activities can be detected in chin and

limb muscles

NREM sleep-autonomic changes

Characterized by generalized decrease in autonomic activities

Decrease in autonomic activities causes hypotension and bradycardia

Decreased generalized metabolic activity

NREM sleep-Hormonal changes

Growth Hormone is secreted almost entirely in NREM sleep (due to hypothalamic-pituitary activity)

GH is secreted in 30 to 60 minutes after the beginning of sleep

Prolactin is secreted in NREM sleep (at the beginning of sleep)

Cortisol is secreted in NREM sleep (late at night)

NREM sleep

Important characteristics of NREM sleep like slow wave, decreased generalized metabolic activities and deep unconsciousness help revitalize the body

Occurs predominantly in the early nightRemaining sleep becomes lighter and dream

filled predominantly characterized by REM sleep in the late phase

THE REM SLEEP

This sleep type usually recurs about every 90 minutes and lasts 5 to 30 minutes.

Other name: PARADOXICAL Sleep

The EEG pattern resembles that of the “awake” state. This is not as restful as NREM sleep

Most dreams take place during this period and the dreams are usually remembered or consolidated to memory

28

Normal Sleep Cycles

REM Sleep characteristics

DreamingFlaccid limb paralysisEye movements- rapid, conjugate and

predominantly horizontalIncreased autonomic activities

REM sleep-changes in autonomic activities

Increased pulseIncreased blood pressureIncreased intracranial pressureIncreased cerebral flowIncreased muscle metabolismIn men, erectionsThese increase in autonomic activities are

considered responsible for increased incidence of myocardial infarctions and ischemic CVA

EEG/EMG characteristics of sleep

EEG-more active in REM similar to wakefulness. EEG shows low voltage fast with ocular movement artifact

EMG is silent in REM sleep corresponding to flaccid muscles

Paradoxical muscle tone, all other body activities are as active as the wakefulness state in REM sleep

Sleep patterns-Latencies Definitions

Sleep latency- the interval to fall asleep after retiring. Normal range is 10-20 minutes

REM latency- once asleep, normal individual enter NREM sleep and pass in succession through four stages. The interval from falling asleep to the first REM sleep is called REM latency.

Normal range is 90-120 minutes

SHORTENED SLEEP LATENCY

Alcohol and drug induced sleepNarcolepsySleep apneaSleep deprivation

Prolonged Sleep Latency

Delayed sleep phase syndromeInadequate sleep hygienePsychiatric disorders-Acute schizophrenia,

Major depression, and ManiaRestless leg syndrome

Causes of shortened REM sleep

Alcohol, sedative and hypnoticsDepressionNarcolepsySleep apneaSleep deprivation

Effects of age on sleep

NREM sleep reduces in the elderly.The slow wave phase disappears in people

older than 75 years of age

Sleep disorders in Elderly

Leg movement disordersREM behavior disorderSleep apnea syndromeMedication induced sleep disordersMedical disorders especially cardiovascular

disturbances and painDementiaNeurological disordersDepression

Sleep Disorders

A. Dyssomnias-

Dyssomnias are a broad classification of sleeping disorders that make it difficult to get to sleep, or to stay sleeping.

Sleep Disorders

B. Parasomnias:

Parasomnia is a broad term used to describe various uncommon disruptive sleep-related disorders.

They are intense, infrequent physical acts that occur during sleep.

Include sleepwalking, sleep talking, sleep terrors, nightmares, and teeth grinding

Dyssomnias-characteristics

Patients may complain of: difficulty getting to sleep or staying asleep intermittent wakefulness during the night, early morning awakeningor combinations of any of these. Transient episodes are usually of little

significance. Stress, caffeine, physical discomfort, daytime

napping, and early bedtimes are common factors

Dyssomnias-causes

There are over 30 recognized kinds of Dyssomnias. Major groups of Dyssomnias include:

Intrinsic sleep disorders - 12 disorders recognized, including narcolepsy, periodic limb movement disorder, restless legs syndrome, sleep apnea.

Extrinsic sleep disorders - 13 disorders recognized, including alcohol-dependent sleep disorder, food allergy insomnia, inadequate sleep routine.

Circadian rhythm sleep disorders - 6 disorders recognized, including advanced sleep phase syndrome, delayed sleep phase syndrome, jetlag, shift work sleep disorder

Dyssomnias-conditions-Narcolepsy

Narcolepsy is a neurological condition most characterized by Excessive Daytime Sleepiness (EDS).

A narcoleptic will most likely experience disturbed nocturnal sleep, confused with insomnia, and disorder of REM or rapid eye movement sleep.

The main characteristic of narcolepsy is

overwhelming excessive daytime sleepiness (EDS), even after adequate nighttime sleep.

Dyssomnias-conditions-Narcolepsy

A person with narcolepsy is likely to become drowsy or to fall asleep, often at inappropriate times and places

Four other classic symptoms of narcolepsy, which may not occur in all patients, are cataplexy, sleep paralysis, hypnogogic hallucinations, and automatic behavior.

Narcolepsy treatment

Treatment is individualized depending on the severity of the symptoms, and it may take weeks or months for an optimal regimen to be worked out.

Complete control of sleepiness and cataplexy is rarely possible

Treatment is primarily by medications, but lifestyle changes are also important.

The main treatment of excessive daytime sleepiness in narcolepsy is with a group of drugs called central nervous system stimulants.

For cataplexy and other REM-sleep symptoms, antidepressant medications and other drugs that suppress REM sleep are prescribed.

Periodic Limb Movements

Periodic Limb Movement Disorder (PLMD), also called nocturnal myoclonus, is a sleep disorder where the patient moves involuntarily during sleep

It is related to restless leg syndrome (RLS) in that 80% of people with RLS also have PLMD. However, most people with PLMD do not experience RLS

These medications are also successful for the treatment of RLS restless leg syndrome.

Dyssomnias-Restless Leg Syndrome

Criteria

(1) an urge to move the limbs with or without sensations (2) worsening at rest (3) improvement with activity (4) worsening in the evening or night

Restless Leg Syndrome- Medicinal approach

Dopamine agonists such as ropinirole, pramipexole, carbidopa/levodopa or pergolide

Opioids such as propoxyphene, oxycodone, or methadone, etc.

Benzodiazepines, which often assist in staying asleep and reducing awakenings from the movements

Anticonvulsants, which often help people who experience the RLS sensations as painful, such as gabapentin

Parasomnias

A sleep disorder is a physical and psychological condition or disturbance of sleep and wakefulness caused by abnormalities that occur during sleep or by abnormalities of specific sleep mechanisms

Although the sleep disorder exists during sleep, recognizable symptoms manifest themselves during the day

Parasomnias

Accurate diagnosis requires a polysomnogram, widely known as a "sleep test.“

Some common Parasomnias include sleepwalking, sleep talking, sleep terrors, nightmares, and teeth grinding

Parasomnias-classifications

A. Arousal-Sleep terrors, Sleepwalking or Somnambulism

B. Sleep-Wake Transition-Rhythmic movement disorders

C. Parasomnias with REM sleep-Nightmares, Sleep paralysis, and REM sleep Behavior disorders

D. Other Parasomnias- Bruxism and Enuresis

Sleep Disturbances in Alcoholism

Is associated with both insomnia and excessive daytime sleepiness (EDS)

They have a short sleep latency, less REM sleep and increased slow wave sleep in the first half of night

In the second half, they have increased REM and periods of wakefulness, as though emerged into delirium

Alcohol withdrawl leads to insomnia and REM rebound

Dyssomnias

Parasomnias

Lack of Sleep

Disturbed sleep Excessive Sleep

VS

Lack of Sleep

Insomnia Sleep Deprivation

Insomnia

Insomnia is the inability to fall asleep.

It is common problem that most people

experience at least occasionally.

Why?Consequently, insomnia often disrupts

daily life. It can result from

- Diet (intake of caffeine or alcohol) - Stress- Emotional Difficulties - Underlying Disease

Result

When it occurs, people feel tired much

of the time and often worry a lot about

not getting enough sleep.

Sleep Deprivation

Actually sleep deprivation is not a Disorder.

It just indicates that a person has not been getting enough sleep.

Result

It’ll affect person’s judgment,

reaction-time, hand-eye coordination,

memory, general well-being and immune

system.

How can I know that I am a Sleep Deprived patient?

Feeling drowsy during the day?Falling asleep for very short period of

time(5 min or so) ?Regularly falling asleep immediately after

lying down?

It means you need more SLEEP!!!

Go to bed NOW !!!

Disturbed Sleep

Sleep Apnea

Restless Leg Syndrome(RLS) and Periodic limb movement Disorder

REM sleep behavior Disorder

Sleep Apnea

Sleep Apnea is interrupted breathing during sleep.

It usually occurs because of a mechanical problem in the windpipe.

But it also indicates a neurological disorder involving nerve cells (neurons).

Process

1) As people age, muscle tone relaxes, which may cause the windpipe to collapse.

2) This condition is called Obstructive Sleep Apnea.

3) It results in loud snoring and blocked air flow through the windpipe.

4) It lasts from 10 to 60 seconds.

5) People may be gasping or snorting.

6) And then the brain quickly reacts to the sudden lack of oxygen, the muscles tighten.

7) Windpipe opens.

Why?

Narrow nasal passages, enlarged tonsils, and obesity are factors that may contribute to obstructive sleep apnea.

It also may be related to alcohol, tobacco, or sedatives.

Result

The sleep cycle can be interrupted as many as 100 times a night.

Every time the windpipe closes, the brain is deprived of oxygen.

This lack of oxygen eventually can cause problems morning headaches and decreased mental function.

High risk for heart disease and stroke

REM Sleep behavior disorder

It causes disruptions in the brain during REM sleep.

ProcessREM SLEEP

Pons

Signal

Signal

Cerebral Cortex

Muscles

Thinking&

Organizing Information

Result

It causes a type of temporary paralysis.

In a person with REM sleep behavior disorder, these signals translate into images that make up dreams.

If the signals are interfered with, the person may physically act out dreams during sleep. For example, if a patient with REM sleep behavior disorder dreams about running, he or she might actually get up and run.

As a result of this condition, patients may injure themselves or others.

BUT !!! REM sleep behavior disorder is rare.

Restless leg syndrome (RLS) and periodic limb movement disorder (PLMD)

It is a common sleep disorder, especially in the elderly.

Also RLS is a genetic disorder

Result

It causes patients to want to move their legs.

It often results in insomnia.

PLMD causes jerking in the legs or arms that occurs frequently during resting or sleeping.

Jerking may occur as many as 3 times in a minute and each jerk can wake the patient.

Excessive Sleep Disorder

Narcolepsy

Cataplexy

Sleep paralysis

Hypnagogic hallucinations

Narcolepsy

It is a condition that causes patients

to fall asleep uncontrollably throughout

the day for periods lasting less than a

minute to more than half an hour.

These sleep attacks can occur at anytime,

even while the person is engaged in an activity !!!

Process

During sleep, narcoleptics have an abnormal sleep pattern:

They enter REM sleep prematurely without going through the normal sequence of sleep stages.

Narcolepsy usually is a genetic (inherited) disorder, although it may be associated with brain damage or neurological disease.

When?

age : 15 - 30

When people get pregnant, ill, a fever, or stress.

Result

often feel tired most of the time.

cataplexy, and sleep paralysis.

Cataplexy

Cataplexy is weakness or paralysis of the muscles.

When cataplexy occurs, persons who are standing may fall down.

In narcoleptic patients, it may be

triggered by tiredness and intense

emotions and may be accompanied by

short, sudden episodes of laughter or

anger.

Sleep paralysis

Sleep paralysis is the inability to move the arms, legs, or entire body that occurs when a person is falling asleep or waking up.

Result

o People who experience sleep paralysis

May become:

very anxious and often regain movement onlyif they hear a loud noise or another stimulus.

Hypnagogic hallucinations or pre-sleep dreams

Hypnagogic hallucinations or pre-sleep dreams, are dream-like hallucinations that occur in the transition between being awake and being asleep.

Often, they are very vivid, frightening dreams.

Insomnia-causes

Medical and neurological conditionsDrug and alcohol abusePsychiatric disordersPatients older than 65 years of age

Treatment of Insomnia

Limited course of hypnotic is effective for the insomnia due to the transient disturbances such as grief

People with neurological conditions like Alzheimer’s disease can develop “paradoxical reaction” to hypnotics

Non-prescription hypnotics like antihistamines are more hazardous than prescription hypnotics like benzodiazepine

In the elderly, the benzodiazepines can cause anterograde insomnia, insomnia in the early morning, daytime anxiety and psychomotor impairments

STUDY OF NORMAL SLEEP

There are mainly two ways to define the stages of sleep

A. Clinical observationsB. Physiologic informationPolysomnography is a common method

employed to study these changes

Recording of Polysomnography

Simultaneous recordings of EEG, EOG, EMG, EKG, vital signs and breathing

What answers to expect from Polysomnography ?

Polysomnography is a comprehensive recording of the biophysiological changes that occur during the sleep

Polysomnography is usually performed during the night when patient sleeps

Recording of Polysomnography