Sleep and sleep disorders

LIGULA REFERRAL HOSPITAL
Issah kiswagala
M.B.B.S

 Sleep is a state of unconsciousness in which the brain is relatively
more responsive to internal than external stimuli.
 The predictable cycling of sleep and the reversal of relative external
unresponsiveness are features that assist in distinguishing sleep
from other states of unconsciousness.
 The brain gradually becomes less responsive to visual, auditory,
somatosensory, and other environmental stimuli during the
transition from wake to sleep.
 Homeostatic factors (factor S) and circadian factors (factor C)
interact to determine the timing and quality of sleep.

 The sleep-wake cycle itself is a circadian rhythm, i.e., an endogenous
cyclic change occurs in an organism with a periodicity of roughly 24
hours.
 The cycle is regulated by the superchiasmatic nucleus (SCN).
 The REM cycle, which is approximately 90 minutes, is an example of
an ultradian rhythm, occurring with a periodicity of less than 24
hours.
 This biological clock determines the release of neurochemicals that
either initiate sleep or chase it away.

“SANDman”
1. Serotonin: helps initiate sleep
2. Acetylcholine (ACh): higher during REM sleep (associated with
erections in men)
3. Norepinephrine (NE): lower during REM sleep
a. Ratio of ACh and NE is the biochemical trigger for REM sleep.
b. NE pathway begins in the pons, which regulates REM sleep.
4. Dopamine: produces arousal and wakefulness. Rises with waking
5. Melatonin is not related to sleeping, but rather to feelings of
sleepiness: Release is inhibited by daylight, and, at nighttime, levels rise
dramatically

Changes in First 3 Hours of Sleep

 Sleep consists of two distinct states: NREM and REM.

 Divided into 4 stages on the basis of EEG criteria
 Alternates with REM sleep throughout the sleep period and is
characterized by:
i. Slowing of the EEG rhythms
ii. Higher muscle tone
iii. Absence of eye movements
iv. Absence of “Thought - like” mental activity
 Is an idling brain in a movable body.

 Slow-wave sleep occurs for longer stretch in babies and young
children, also with increase in growth hormones, prolactin and
serotonin
 Most of NREM Stages 3 and 4 (the deepest sleep levels) occur during
the first half of the night.
 The average adult spends most sleep time in Stage 2 and least in
Stage 1.
 Stage 3 is also the stage when sleepwalking and sleep talking are
most likely to occur.
 Duration of delta sleep (deep sleep) is 65% inherited.

 Characterized by:
i. An aroused EEG pattern
ii. Sexual arousal
iii. Saccadic eye movements
iv. Elaborate visual imagery (dreaming)
v. Associated with pons
 Is an awake brain in a paralyzed body.

 Most REM sleep occurs during the last half of the night. REM sleep
gets progressively longer as the night goes on.
 Adults most commonly wake out of REM or Stage 2 sleep.
 REM sleep appears to increase somewhat in both children and
adults after learning, especially the learning of complex material, in
the previous waking period.
 REM sleep is essential to get the most out of studying. It is
when most long-term memories are consolidated by the
hippocampus.
 A newborn baby may spend about 80% of his/her total sleep time in
REM-stage compared to adults in about 20 – 25% in REM sleep.

Sleep deprivation, also known as insufficient sleep or sleeplessness, is
the condition of not having enough sleep. It can be either chronic or
acute and may vary widely in severity.
A chronic sleep-deprivation state adversely affects the brain and
cognitive function.
The cerebral cortex shows the greatest effects of sleep deprivation but
has the capacity to cope with one night’s sleep loss.
Only about one-third of lost sleep is made up.
 80% of lost Stage 4 is recovered.
 About one-half of the missing REM is recovered.

 If getting 5 hours of sleep or less per night, person functions at level
of someone legally drunk!
 The longer the prior period of wakefulness, the more Stage 4 sleep
increases during the first part of the night and the more REM
declines.
 Short sleepers lose the latter part of REM sleep.
REM deprivation
a. Does not impede the performance of simple tasks
b. Interferes with the performance of more complex tasks
c. Makes it more difficult to learn complex tasks
d. Decreases attention to details but not the capacity to deal with
crisis situations

 A sleep disorder, or Somnipathy, is a medical disorder of the sleep
patterns of a person or conditions that disturb normal sleep patterns.
 Most people occasionally experience sleeping problems due to stress,
hectic schedules, and other outside influences. However, when these
issues begin to occur on a regular basis and interfere with daily life,
they may indicate a sleeping disorder.
 While some sleep disorders have a clearly identifiable cause, others
emerge from a combination of factors. Often, sleep disorders are the
unwelcome side effect of some other mental or physical medical
condition.
 When sleep disorders aren’t caused by another condition, treatment
normally involves a combination of medical treatments and lifestyle
changes

 There are many conditions, diseases, and disorders that can cause
sleep disturbances. In many cases, sleep disorders develop as a
result of an underlying health problem
Sleep disorder can be due to
 Other conditions, such as heart disease, lung disease, nerve
disorders, and pain
 Mental illnesses, including depression and anxiety
 Medicines/Drugs
 Genetics
 Allergies and Respiratory Problems
 Nocturia

Sometimes the cause is unknown.
There are also some factors that can contribute to sleep problems,
including
 Caffeine and alcohol
 An irregular schedule, such as working the night shift
 Aging. As people age, they often get less sleep or spend less time
in the deep, restful stage of sleep. They are also more easily
awakened

 There are over 90 different types of sleep disorders. The most
common include:
 Insomnia
 Narcolepsy
 Sleep Apnea
 Circadian Rhythm Disorders
 Restless Leg Syndrome

Insomnia refers to the inability to fall asleep or to remain asleep.
It’s the most common sleep disorder, and it comes in two varieties:
a) Primary insomnia: This is not caused by an underlying medical
condition.eg, stress and anxiety, hormones, or digestive problems
b) Secondary insomnia: This type stems from another medical problem.
Insomnia is usually classified as one of three types:
 chronic, which is when insomnia happens on a regular basis for at
least one month
 intermittent, which is when insomnia occurs periodically
 transient, which is when insomnia lasts for just a few nights at a
time

 Problems falling asleep, staying asleep, or sleeping all the way
through the night
 Feeling sleepy or fatigued during the day
 Feeling cranky or moody
 Problems with concentration or memory

 Establishing and sticking to a consistent sleep schedule
 Taking prescription sleep aid
 Avoiding alcohol or caffeine near bedtime
 Treating mental or physical health problems that may be
contributing to insomnia
 Regular exercise
 Behavioral therapies designed to help overcome specific sleep-
related struggles—like problems falling asleep

 Narcolepsy is a neurological disorder in which the brain doesn’t
properly manage the body’s sleep-wake states. There are two types:
 Type 1 narcolepsy: This term is used to describe patients who either
have low levels of a brain chemical called hypocretin, which helps
regulate the body’s sleep-wake cycles, or those who experience some
specific narcolepsy symptoms.
 Type 2 narcolepsy: Patients with this condition do not have low levels
of hypocretin, but experience other narcolepsy symptoms. e.g. sleep
paralysis in a lying supine person without a pillow.
 Narcolepsy is a disorder of REM sleep: onset of REM within 10
minutes.

1. Sleep attacks and excessive daytime sleepiness (EDS)
2. Cataplexy (pathognomonic sign)- Sudden loss of muscle tone,
which leads to weakness or loss of muscle control. This often
occurs when a person is exposed to intense emotions such as
laughter and anger.
3. Hypnagogic hallucinations - Vivid and terrifying nightmares
(hypnopompic can occur, but not pathognomonic)
i. Hypnagogic: while falling asleep
ii. Hypnopompic: while waking up
4. Sleep paralysis which is an inability to move or speak even when
partly awake.

I. Prescription medications
a) Modafinil or psychostimulants for excessive daytime
sleepiness
 Inhibits DA re-uptake
 Activates glutamate; inhibits GABA
b) Antidepressants (TCA, SNRI)
c) Gamma hydroxybutyrate (GHB) to reduce daytime
sleepiness and cataplexy
II. Establishing and sticking to a consistent sleep schedule
III. Avoiding alcohol or caffeine near bedtime
IV. Short daytime naps to prevent unexpected bouts of sleep

Sleep apnea is a condition in which a person repeatedly stops breathing
during the night, which harms the depth and quality of his or her sleep.
In some cases, these breathing stoppages can occur hundreds of times
each night. There are 3 types:
 Obstructive sleep apnea: This is caused by the partial or total blockage of
breathing airways during sleep. It’s the more common type of sleep
apnea. Occurs in Middle-aged, Overweight and Rasping snoring
 Central (diaphragmatic) sleep apnea: The type of sleep apnea in which
the muscles that control a person’s breathing don’t work properly during
sleep. This is often a result of "signaling problems" in a person’s brain, or
as a result of other conditions, like heart failure and stroke. Occurs in
Elderly, Overweight and Cheyne-Stokes (60-second hyperventilation,
followed by apnea)
 Mixed sleep apnea

 Heavy snoring with frequent pauses
 Kicking, punching of sleeping partner
 Obesity is often part of the clinical picture, but not always
 Short sleep duration, frequent waking, insomnia, decreased Stage 1,
decreased delta and REM
 EDS and insomnia often reported
 High risk of sudden death during sleep, development of severe
nocturnal hypoxemia, pulmonary and systemic hypertension (with
elevated diastolic pressure)
 Nocturnal cardiac arrhythmias (potentially life-threatening)
 Males outnumber females by 8 to 1

 Weight loss (if applicable)
 Behavioral conditioning to change sleep position (Side-sleeping)
 Continuous positive airway pressure (CPAP). which is a mask-like
device that keeps airways open by gently forcing air into the
sleeper’s nose or mouth
 For severe obstructive and mixed apnea: Surgery to repair or
remove structural causes of airway blockages e.g. tonsillectomy or
tracheostomy
 Using breathing strips or nasal sprays to open up airways

 This group of related sleep issues is caused by disruptions to a
person’s internal circadian rhythm, or sleep clock. For people with a
circadian rhythm disorder, there’s a mismatch between their internal
clocks and their desired sleep-wake schedule, and this leads to
problems sleeping.
 Circadian rhythm disorders come in a variety of subtypes. These
include:
 Shift work disorder: This occurs among people who work irregular
schedules or night shifts, and are often trying to stay awake or fall
asleep at times that don’t align with their body’s internal clocks.

 Delayed sleep phase disorder: This could be thought of as "night
owlism." It’s most common among teens and young adults, and it’s
defined as an inability to fall asleep until very late at night—2 or 3
a.m.—and a desire to sleep until midday or later. While this may not
seem like a problem for some, it can be a considerable challenge if a
person’s work or school obligations require them to go to bed and get
up at earlier hours.
 Advanced sleep phase disorders: This is basically the opposite of
delayed sleep phase disorder. This type, which is most common
among the elderly, typically involves going to bed at a very early
hour—sometime between 6 and 9 p.m.—and rising in the middle of
the night.

 Problems falling asleep, staying asleep, or sleeping all the way
through the night. Other reasons can be due to addicted video
games, movies etc.
 Feeling sleepy or fatigued during the day
 Feeling cranky or moody
 Problems with concentration or memory

 Establishing and sticking to a consistent sleep schedule
 Improving bedtime routines or “sleep habits”
 Taking prescription sleep aid
 Avoiding alcohol or caffeine near bedtime
 Regular exercise
 Behavioral therapies

 Restless leg syndrome (RLS) is just what it sounds like: a strong
inclination or urge to move your legs while they’re at rest. RLS
usually happens once a person lies down in bed or after they’ve been
sitting for long periods.
 For some, RLS can be so severe that it becomes difficult to fall or
stay asleep. This can lead to excessive daytime drowsiness and
insomnia.

 Tingling, burning, numbness, pain or other unpleasant sensations in
the legs
 Experiencing these symptoms in bed or after long stretches of
inactivity

 Iron supplements to treat a deficiency
 Prescription medications
 Warm baths
 Massages

 [1] https://www.cdc.gov/sleep/index.html
 [2] https://www.cdc.gov/sleep/about_sleep/chronic_disease.html
 [3] https://my.clevelandclinic.org/-
/scassets/files/org/neurological/sleep-disorders/sleep-disorder-
treatment-guide-2016.ashx?la=en
 [4] https://emedicine.medscape.com/article/1188226-
overview#showall

Sleep and sleep disorders

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