Jameel Adnan, MD. Community & Primary Health Care KAAU-RABEG BRANCH Normal Sleeping Jameel Adnan, MD. Community & Primary Health Care KAAU-RABEG BRANCH

Round Map Introduction Sleep Stages Sleep Architecture REM Latency vs Sleep latency Changes with age Function of Sleep

Introduction Thousands of articles about sleep and sleep disorders appear each year in medical and psychological journals >80 different sleep disorders have been described. Despite the intensive efforts that these publications reflect, there is still no definitive explanation for why we sleep.

Introduction Sleep is not a passive process, but rather an active state that is as complex as wakefulness. The brain is not "at rest" during sleep; it is involved in a wide variety of activities.

Sleep Stages  

Sleep Stages Two general states: Rapid Eye Movement sleep (REM) Non-Rapid Eye Movement sleep (NREM). NREM sleep is further subdivided into four NREM stages.

1. REM Sleep

1. REM Sleep A low voltage, fast frequency EEG pattern The brain is active, and the body is inactive. three main features: A low voltage, fast frequency EEG pattern The presence of rapid eye movements An atonic electromyogram (EMG) Rapid Eye Movement (REM) sleep is a normal stage of sleep characterized by the rapid movement of the eyes. REM sleep is classified into two categories: tonic and phasic.[1] It was identified and defined by Kleitman and Aserinsky in the early 1950s Physiologically, certain neurons in the brain stem, known as REM sleep-on cells, (located in the pontine tegmentum), are particularly active during REM sleep, and are probably responsible for its occurrence. The release of certain neurotransmitters, the monoamines (norepinephrine, serotonin and histamine), is completely shut down during REM[citation needed]. This causes REM atonia, a state in which the motor neurons are not stimulated and thus the body's muscles do not move. Lack of such REM atonia causes REM Behavior Disorder; sufferers act out the movements occurring in their dreams. Heart rate and breathing rate are irregular during REM sleep, again similar to the waking hours. Body temperature is not well regulated during REM. Erections of the penis (Nocturnal Penile Tumescence or NPT) normally accompany REM sleep. If a male has erectile dysfunction (ED) while awake, but has NPT episodes during REM, it would suggest that the ED is from a psychological rather than an organic cause. In females, erection of the clitoris (nocturnal clitoral tumescence or NCT) causes enlargement, with accompanying vaginal blood flow and transudation (i.e. lubrication). During a normal night of sleep the penis and clitoris may be erect for a total time of from one hour to as long as three and a half hours during REM. Research urologists have found that the increased blood flow during NPT and NCT episodes may prevent excessive collagen from forming in the erectile tissues (sinusoids) of the clitoris and penis. They are aware that the increased fiber formation in the erectile tissues could lead to tissue-cell death and eventual loss of erectile function.

1. REM Sleep 1. A low voltage, fast frequency EEG pattern, resembles an active, awake EEG pattern. So, REM sleep is sometime called paradoxical sleep. 2. The presence of rapid eye movements. The chances are high that the patient will report dreaming if awakened during this period. During REM, the activity of the brain's neurons is quite similar to that during waking hours; for this reason, the sleep stage may be called paradoxical sleep.

1. REM Sleep 3. An atonic ElectroMyoGram (EMG) Consistent with inactivity of all voluntary muscles except the extraocular muscles The individual is paralyzed during REM sleep. Result from direct inhibition of alpha motor neurons. All three primary characteristics of REM sleep are not always present simultaneously. In humans, the lack of appropriate muscle atonia during REM sleep is considered to be abnormal, causing a potentially dangerous sleep disorder called REM Behavior Disorder (RBD) The extraocular muscles are the six muscles that control the movements of the (human) eye. The actions of the extraocular muscles depend on the position of the eye at the time of muscle contraction. Superior inferior medial lateral rectus Superior inferior obliqiue

1. REM Sleep Phasic and tonic REM sleep REM sleep consists of two different states, based on the occurrence of rapid eye movements Phasic REM sleep. Tonic REM sleep.

1. REM Sleep REM sleep is a predominantly parasympathetic (vagal) state, but during phasic REM sleep, there are sudden bursts of sympathetic nervous system (SNS) activity associated with rapid eye movements. These bursts of SNS activity have been reported to be associated with sudden increases in arterial blood pressure, cardiac or cerebral ischemia (frequently in the early morning hours) cardiac arrhythmias, and sudden changes in heart and respiratory rates .

1. REM Sleep Short central apneas and hypopneas are also common during phasic bursts of rapid eye movements. Long cardiac asystoles have been noted to occur in otherwise healthy young individuals during phasic bursts of REMs.

2. NREM Sleep 

2. NREM Sleep consists of 4 sleep stages defined primarily by the frequency and amplitude of the EEG The brain is inactive, the body is active. Stage 1 sleep It is the transition from wakefulness to deeper sleep characterized by fast EEG frequencies in the theta range (4 to 7 Hz). It is the lightest stage of sleep, patients awakened from stage 1 sleep typically do not perceive that they were actually asleep. 2-5 % of total sleep time in young adults Stage 1 sleep typically accounts for 2 to 5 percent of total sleep time in young adults. An increased amount or percentage of stage 1 sleep typically suggests sleep fragmentation due to a sleep disorder.

NREM Sleep Stage 2 sleep Called intermediate sleep A true physiologic stage of sleep. 40-50 % of total sleep time. is characterized by a slowing of EEG frequency and an increase in EEG amplitude. Benzodiazepines typically increase stage 2 sleep at the expense of stages 3 and 4 sleep.

NREM Sleep Two distinct features of NREM sleep appear on the EEG for the first time in this sleep stage: Sleep spindles. transient "spindle" shaped features of the EEG frequency of 12-14 Hz lasting at least 0.5 seconds. They are most prominent at the vertex of the scalp. k-complexes. These consist of a well delineated negative sharp wave immediately followed by a positive component standing out from the background EEG with a total duration ≥0.5 seconds, usually maximal in amplitude over the frontal regions.

NREM Sleep Stages 3 and 4 sleep (combined) deep sleep or slow wave sleep, 20 % of total sleep time in young adults. characterized by a transition to an EEG with high amplitude delta EEG waves (1.5 to 3 Hz).

Sleep Architecture

Sleep Architeture  Sleep stages occur in cycles lasting 90-120 min each. 4-5 cycles occur during a typical night of sleep. During the first half of the night, the individual typically passes from wakefulness briefly into stage 1 sleep and then to stages 2, 3, and 4. Stages 3 and 2 reappear, after which REM sleep is observed for the first time. During the second half of the night, stage 2 and REM sleep alternate.

Abnormalities of sleep architecture Narcolepsy REM sleep occurring earlier than 90 to 120 minutes Irregular sleep/wake organization, Withdrawal from certain medications (e.g., tricyclic antidepressants, MAOI) Depression. Sleep disorders will increase the number of sleep stage changes and may completely disrupt the normal cycling of sleep. Narcolepsy is a chronic sleep disorder, or dyssomnia. The condition is characterized by excessive daytime sleepiness (EDS) in which a person experiences extreme fatigue and possibly falls asleepيغفو ) ) at inappropriate times, such as while at work or at school. A narcoleptic will most likely experience disturbed nocturnal sleep and also abnormal daytime sleep pattern, which is often confused with insomnia. When a person with narcolepsy falls asleep or goes to bed they will generally experience the REM stage of sleep (rapid eye movement/dreaming state), within 10 minutes; whereas for most people, this shouldn't occur until generally 30 minutes of slumber.

REM Latency vs Sleep latency The period lasting from the moment of fall asleep to the first REM period. Last app. 90 min Depression and narcolepsy are examples of shorten REM latency Sleep Latency: The time needed before actually fall asleep .last app. 15 min Insomnia is an example of increase sleep latency

Changes with age  Quantity and Quality of sleep change significantly with aging. Deep or slow wave sleep (stages 3 and 4) declines Light sleep (stage 1) increases. The number of arousals and the amount of wakefulness also increase in later years.

Multiple sleep latency test an objective measure of daytime sleepiness used for >15 years the sleepier an individual is, the faster he will fall asleep. The following protocol is typically used: The patient is given 4-5 opportunities to nap, usually at two hour intervals during the day. On each occasion, the individual is asked to lie down on a bed in a quiet, darkened sleep room and fall asleep as quickly as possible. The EEG, eye movements, and muscle tone are measured during the test.

The latency from wakefulness to sleep onset is measured to determine the "sleep latency." Each session is terminated after 15 minutes of sleep. The process is repeated during each of the four to five naps, and a mean sleep latency across all the naps is computed.

Severe 0-5 Troublesome 5-10 Manageable 10-15 Excellent 15-20 sleepiness Minutes Severe 0-5 Troublesome 5-10 Manageable 10-15 Excellent 15-20

Polysomnogram Polysomnographic record of REM Sleep. EEG highlighted by red box. Eye movement highlighted by red line. Polysomnography (PSG), also known as a sleep study, is a multi-parametric test used in the study of sleep and as a diagnostic tool in sleep medicine. The test result is called a polysomnogram, also abbreviated PSG. The name is derived from Greek and Latin roots: the Greek 'poly' for multi-channel (many), the Latin 'somnus' (sleep), and the Greek 'graphein' (to write). The PSG monitors many body functions including brain (EEG), eye movements (EOG), muscle activity or skeletal muscle activation (EMG) and heart rhythm (ECG) during sleep. After the identification of the sleep disorder sleep apnea in the 1970s, the breathing functions respiratory airflow and respiratory effort indicators were added along with peripheral pulse oximetry.

Function of Sleep

Function of Sleep   The Restorative Theory of Sleep, states that some process during sleep restores tissue and prepares the body for the next day. The Adaptive Theory of Sleep proposes that sleep increases survival. The Energy Conservation Theory states that a low metabolism for energy conservation is the function of sleep. There is no general agreement about the possible function(s) of sleep The most prominent theory is the Restorative Theory of Sleep, states that some process during sleep restores tissue and prepares the body for the next day. This theory certainly appears to have validity on face value, as a night without sleep does not leave one prepared for the next day. The Adaptive Theory of Sleep proposes that sleep increases survival. In its simplest form, it states that sleep immobilizes animals during the most dangerous time of the day, decreasing their chances of becoming another animal's prey.