SLEEP
SLEEP STAGES
• Normal sleep is divided into
• Non–rapid eye movement (NREM) and
• Rapid eye movement (REM) sleep.
• The stages of sleep are
– stage I (light sleep)
– stage II
– stages III
– Stage IV (deep or delta-wave sleep) and
– REM sleep
• REM latency – average time to first REM period
is 90 min.
• Waking usually transitions into NREM sleep.
• REM follows NREM sleep and occurs 4-5 times
during a normal 8- to 9-hour sleep period.
• The first REM period of the night may be less
than 10 minutes in duration, while the last may
exceed 60 minutes.
• REM rebound
• For the purpose of analysis,
• Overnight sleep has been divided into 3
equal time periods:
• sleep in the first third of the night, more of
NREM;
• Sleep in the middle third of the night;
• Sleep in the last third of the night, the
majority of which is REM.
• Awakening after a full night's sleep is
usually from REM sleep.
• Awake stage
– Alpha (8-12 cps)and beta waves
• Stage I
– transition between wake and sleep.
– usually accounts for 5-10% of total sleep time
– low voltage theta-3 to 7 cycles/sec
• Stage II
– occurs throughout the sleep period
– represents 40-50% of total sleep time
– 12 -14 cycles/sec-sleep spindle and saw tooth k
complexes
– bruxism
• Stages III and IV
– delta sleep occur mostly in the first third of the
night.
– They are distinguished from each other only
by the percentage of delta activity and
– represent up to 20% of total sleep time.
• REM represents 20-25% of total sleep time
• Sleep walking, somnambulism, enuresis
&night terror.
Sleep in infants
• Infants have an overall
• Sleep the most, 14-16 hours a day
• Over the first several months of life, sleep
time decreases;
• By age 5-6 months, sleep consolidates
into an overnight period with at least 1 nap
during the day
• REM sleep in infants represents a larger
percentage of the total sleep at the
expense of stages III and IV.
• By young adulthood REM sleep reduced
to 25% of sleep
Sleep in elderly persons
• Time spent in stages III and IV sleep
decreases by 10–15% and the time in
stage II increases by 5% compared to
young adults
• Overall decrease in total sleep duration.
• Latency to fall asleep and the number and
duration of overnight arousal periods
increase.
• Thus to have a fully restorative sleep, the
total time in bed must increase.
Neurotransmitters in Sleep
• Serotonin and Acetylcholine promote
sleep
• Increased serotonin associated with
increased sleep time
• Melatonin a metabolite of Serotonin
released from pineal gland during
darkness thought to aid sleep
• However external supplementation has not
showed desired benefits in trials.
• Acetylcholine associated with inducing
REM sleep
• From Reticular formation
• In Alzheimer's decreased ACh is
associated with decreased REM sleep
• Norepinephrine and dopamine promote
arousal and wakefullness.
• Increased levels of NE in anxious patients
increased sleep latency
• Increased levels of dopamine in mania
and psychosis associated with decreased
sleep time
• Antipsychotics block dopamine and
promote sleep, antidepressants increase
serotonin and promote sleep.
Sleep Disorders
• Dyssomnias
• Parasomnias,
• Medical/psychiatric disorders
Dyssomnias
• Dyssomnias are disturbances in the
amount, timing, or quality of sleep
resulting in excessive daytime sleepiness
or insomnia.
• Insomnia , hypersomnia
• Breathing related sleep disorders
• Narcolepsy
• Circadian rhythm disturbances
• Restless leg syndrome
• Nocturnal myoclonus
INSOMNIA
• Difficulty in falling asleep or staying asleep
3 times /week for at least one month
• Caffeine, Alcohol, and other Substances
• Partner's Sleep Habits
• Medications
• Environmental Factors
Psychophysiological insomnia
• People with psychophysiological insomnia react
to situations that are psychologically stressful
with bodily tension or other physical complaints,
and they learn to associate certain things with
emotions that prevent sleep.
• People with this disorder typically have a
focused absorption on their sleep problems,
which itself interferes with sleep.
Sleep state misperception
• This disorder involves an honest complaint
of insomnia or excessive sleepiness when
there is no objective evidence that sleep is
disturbed or lacking. Often seen in people
in middle or late adulthood. They feel they
are not able to sleep as long or as well as
they could in former years.
Idiopathic insomnia
• Idiopathic insomnia is a lifelong inability to
get adequate sleep that has no observable
cause.
• It is assumed that this difficulty is due to
an abnormality of sleep-wake control
systems in the brain.
• It may also be due to a problem in the
sleep-inducing and -maintaining systems,
or hyperactivity in the arousal systems.
NARCOLEPSY
• Narcolepsy is a chronic neurological disorder that
impairs the ability of the central nervous system to
regulate sleep. People with narcolepsy experience:
• excessive daytime sleepiness and
• intermittent, uncontrollable episodes of falling asleep
during the daytime.
• Other symptoms typically associated with narcolepsy
include:
• cataplexy (short-lived intermittent muscle weakness),
• hypnagogic hallucinations (hallucinations while falling
asleep )
• sleep paralysis (paralysis while falling asleep or waking),
and
• automatic behavior.
Primary Hypersomnia
• Kleine –Levin Syndrome – recurrent bouts
of sleepiness , daily for at least 1 month.
• Not relieved by day time napping
• Hyperphagia
• Treatment – stimulants , fluoxetine
Extrinsic sleep disorders
• Outside the body and are due most commonly to
behavioral or environmental factors.
• Common extrinsic sleep disorders include:
– inadequate sleep hygiene
– environmental sleep disorder
– insufficient sleep syndrome
– stimulant-dependent sleep disorder
– alcohol-dependent sleep disorder
– hypnotic-dependent sleep disorder.
Circadian rhythm sleep
disorders
• Disruption of the sleep cycle in a 24-hour
period.
• Common circadian rhythm sleep
disorders include: jet lag, shift-work sleep
disorder, irregular sleep-wake pattern,
delayed sleep phase syndrome, and
advanced sleep phase syndrome.
Time zone change (jet lag)
syndrome
• Result of rapidly changing time zones,
usually as the result of jet flight.
• The difference between the body's internal
clock and local time causes
– trouble getting to sleep at night
– daytime sleepiness and
– physical problems like stomach upset.
Shift-work sleep disorder
• Transient insomnia or excessive
sleepiness that results when work
schedules change or are incompatible with
nonwork sleep-wake cycles.
Irregular sleep-wake pattern
• A disorder in which individuals do follow
set times for sleeping and for waking up.
They find it difficult to sleep or wake up
when they try to do either.
Delayed-sleep-phase syndrome
• A disorder in which nightly sleep is
delayed until long after the desired sleep
time.
• This results in sleep-onset association
disorder and trouble waking up at the
desired time.
Advanced-sleep-phase
syndrome
• This is a disorder in which nightly sleep
and irresistible sleepiness come before the
desired time.
• The patient wakes up earlier than desired
in the morning.
24-hour sleep-wake syndrome
• People with this syndrome sleep as if they
have a free-running biological clock, and
have a daily sleep delay of 1 to 2 hours
after the previous night's sleep time.
Breathing related sleep disorder
• Sleep apnea is a breathing problem during sleep that creates a
sleep disorder. Sleep apnea occurs when a person's breathing is
interrupted during sleep. Distinctive signs of sleep apnea include:
• frequent waking episodes at night
• disrupted breathing, gasping, gagging, or choking for air during
sleep
• There are three types of sleep apnea:
• Obstructive sleep apnea (OSA): Obstructive sleep apnea is the
most common type of sleep apnea and is caused by an obstruction
in the airway, which actually stops the air flow in the nose and
mouth.
– Throat and abdominal breathing continue normally.
– commonly accompanied by snoring and causes the sleeper to wake up, gasping
or snorting, and then go back to sleep again.
• PIckwickan Syndrome – daytime sleepiness results from airway
obstruction
• Central sleep apnea (CSA):
– much less common type than Obstructive sleep apnea.
– Due to a brain signal problem: the brain signal that instructs the
body to breathe is delayed.
– oral breathing and throat and abdominal breathing all cease at
the same time.
– breathing may be too shallow to provide oxygen to the blood and
tissues.
– irregular heartbeat,
– high blood pressure,
– heart attack, and/or
– stroke.
• Mixed sleep apnea:
– combination of Obstructive sleep apnea and Central
sleep apnea,
– most commonly found in infants or young children
who have abnormal breathing control.
• Treatment of sleep apnoea –CPAP,
uvulopalatoplasty, permanent tracheostomy
Restless legs syndrome (RLS) and periodic limb
movement in sleep (PLMS)
• Restless legs syndrome (RLS) is a neurological disorder
characterized by uncomfortable, tingly or creeping sensations in
your legs, which create an uncontrollable urge to keep them moving.
• Symptoms of RLS include:
• irritating sensations in your legs that give you an overwhelming urge
to walk around and move them
• little movements of the toes, feet or legs may be visible when you
rest
• very restless sleep
• Similarly, people with periodic limb movement in sleep (PLMS)
experience rhythmic jerking of the feet or legs, which interrupts
sleep.
• While there is no cure for these disorders, treatment is highly
effective – 90% of those treated experience relief of their symptoms
through lifestyle changes and medication( L-dopa, iron supplements
& magnesium supplements)
PARASOMNIAS
• Parasomnias are disorders of partial arousal or
disorders that interfere with sleep stage
transitions. Abnormal events occur during sleep.
Bruxism, night mare, sleep terror, sleep
walking and REM sleep behavior disorder
• Parasomnias usually associated with rapid
eye movement (REM) sleep occur during the
REM sleep stage.
• Common examples include: nightmares, sleep
paralysis, and REM sleep behavior disorder
• Bruxism
– Tooth grinding
– Stage II sleep
– Leads to tooth damage
– Treat with Corrective dental appliance
• Nightmare Disorder
– Repetitive frightening dreams
– Occur in REM sleep
– Recalled on awakening
• Sleep Terror Disorder
– Repetitive experience of fright
– Screams but cannot be awakened (occur in
NREM sleep)
– No memory of dream
• Sleepwalking Disorder
– Repetitive walking during sleep
– No memory of walking (occurs in delta sleep)
– Begins in childhood
– Associated with enuresis
• REM sleep Disorder
– Sleep and dream without skeletal muscle
atonia
– Patients can harm themselves or others
– Anticonvulsants and benzodiazepines for
treatment
• Often, a person does not recall their
experience of the parasomnic event the
following day.
• Often attributed to stress, depression, or
other psychological and medical
conditions.
• Treatment for parasomnias may involve
lifestyle changes, medication(TCA,BZD,
CBZ- Tegrital)
Medical/psychiatric sleep
disorders
• Sleep disorders associated with medical disorders.
Common examples include: alcoholism, chronic
obstructive pulmonary disease, asthma, sleep-related
gastroesophageal reflux, peptic ulcer, and fibrositis
syndrome.
• Sleep disorders associated with neurological
disorders. Common examples include: degenerative
brain disorders, dementia, sleep-related epilepsy, and
sleep-related headaches.
• Sleep disorders associated with psychiatric
disorders. Psychoses, anxiety, depression, and panic
disorders can result in excessive sleepiness, insomnia,
or other disruptions in the sleep cycle
• Sleeping sickness-
– African sleeping sickness, Gambina trypanosomiasis.
– This is a chronic protozoan brain infection that
produces excessive sleepiness.
• Cerebral degenerative disorders such as Huntington's
disease, Alzheimer's disease, Pick's disease,
Parkinson's disease, ALS, and others can disrupt sleep
at night.
• Fatal familial insomnia is a rare, inherited
degenerative disorder that begins with sleep
troubles and progresses within a few months to a
total lack of sleep, and then death(prion protein
gene).
Assessment
• Epworth Sleepiness Scale – This sleep
questionnaire asks you to rank whether certain
situations make you sleepy and, if so, how
sleepy. Your responses will assist your doctor in
providing a formal diagnosis.
• Nocturnal polysomnogram - This test will
measure the electrical activity of your brain
(electroencephalogram) and heart
(electrocardiogram), and the movement of your
muscles (electromyogram) and eyes (electro-
oculogram) and usually requires an overnight
stay at a sleep clinic for observation purposes.
contd
• Multiple sleep latency test (MSLT) – This test
measures how long it takes for you to fall asleep during
the day. Sleep specialists will observe your sleep
patterns.
• Repeated test of sustained wakefulness (RTSW) –
This test measures how long it takes for you to fall
asleep by challenging your ability to stay awake. During
the test, you will likely be placed in a quiet room with dim
lighting and asked to stay awake.
• Blood test – Depending on your description of your
symptoms and personal and family medical histories, a
blood test may also be conducted. The blood test may
not be conclusive but can be helpful in establishing the
possibility and probability of certain sleep disorders
RISK FACTORS
• poor sleep environment (i.e., noisy or brightly lit)
• excessive caffeine or alcohol intake
• use of certain medications and drugs
• smoking or chewing tobacco
• anxiety, depression, or other mood disorder
• stressful situation such as death of a loved one or job pressure
• counter-productive sleep routine
• daytime napping
• early or late-night bed times
• traveling between time zones
• shift workers with rotating schedules
• physical illness
• obesity
Sleep hygiene
• .Environment manipulation
• Fixed bed time schedule
• Exercise early in the day
• milk
• Avoid caffeine / alcohol /stimulants