Sleep Disorders

Overview

Sleep disorders can affect people of all ages and go unnoticed in many cases. Some sleep disorders are chronic, such as sleep apnea, while others may only occur occasionally, such as transient insomnia caused by stress or jet lag. Especially for chronic disorders, it is important to identify the underlying cause of the condition and seek the appropriate treatment so it will be possible to have a good night of sleep. Chronic sleep deprivation can lead to poor mental and physical health, and is associated with a number of illnesses such as heart disease and stroke.

What is sleep?

Sleep is a state in which the body’s mental and physical functions are suspended. Although the body appears to be at rest, the brain continues to be very active while one sleeps, just in a different way than when one is awake.

The brain normally passes through five phases of activity while one sleeps. The first four stages are known as non-REM sleep, and the final stage is known as REM sleep:

Stage 1 – sleep onset

• Can be awakened easily

• Eyes move slowly

• Muscle activity slows

Stage 2 – light sleep

• 50% of the total time one is asleep

• Eye movement stops

• Slow brain waves with bursts of electrical activity called spindles

Stage 3- deep sleep

• Very slow brain waves, called delta waves, with short bursts of slightly faster waves

• Difficult to awaken

• No eye movement

• No muscle activity

Stage 4 - deep sleep

• Exclusively delta waves

• Difficult to awaken

• No eye movement

• No muscle activity

Rapid eye movement (REM)

• 20% of the total time one is asleep

• Often remember dreams when awakened at this stage

• Eye movement is rapid

• Breathing becomes rapid and irregular

• Increased heart rate

• Limb muscles are signaled by the brain to become temporarily paralyzed

• REM sleep behavior disorder

o Limb muscles are not signaled by the brain to become temporarily paralyzed

o As a result, an individual may act out dreams

Sleep starts with stage one and progresses through stages one through four, then REM sleep, then back to stage 1. It takes anywhere from 90-110 minutes to complete one cycle. As the brain passes through the sleeping cycles, the REM phase becomes longer while the deep sleep phases (stages 3 and 4) become shorter.

How much sleep do you need during the day?

Sleep as much as needed so as not to feel tired during the day. How much sleep one actually needs varies from individual to individual and also changes with age. The approximate amounts of sleep that are characteristic for different age groups are:

• Infants: 14-16 hours

• Children: 9-12 hours

• Adolescents: 9 hours

• Adults: 7-8 hours

Sleep/Wake cycle

The sleep/wake cycle is controlled by the body’s innate timekeeper, or “biological clock,” that controls the circadian (daily) rhythms of the body. The cycle is about 24 hours long; in humans it is designed for the body to be awake during the day and at rest at night. There are many factors that control the circadian rhythms of the body. One of the most important factors that regulate the sleep/wake cycle is exposure to light:

• The biological clock in humans is largely controlled by a part of the brain called the suprachiasmatic nuclei (SCN), located at the base of the brain

• When light decreases, such as at dusk, the SCN signals the nearby pineal gland in the brain to secrete melatonin, a hormone that influences the desire to sleep.

• When the body is exposed to light, such as in the morning, melatonin levels decrease, resulting in a more awake feeling.

Why is sleep important?

Sleep is essential for normal physiological, physical and mental functioning. It also allows certain processes important for maintaining health to take place in the brain.

• Through entering the sleep state, cells in the brain called neurons have a chance to become repaired.
• The sleeping state of the brain may maintain certain connections between neurons, and may also allow connections to become repaired.
• REM sleep stimulates the region of the brain involved with learning and memory, allowing information to be stored properly
• Deep sleep coincides with
• The release of certain hormones, such as growth hormones
• Protein production and cellular repair throughout the body, which is particularly important for the cells of the immune system

Good Sleep habits

Proper sleep habits are important for good health, even when a sleep disorder is not an issue. Furthermore, good sleep habits can also alleviate some of the conditions associated with certain sleep disorders. To sleep better, try:

• Keeping to a regular sleep schedule
• Napping
• Don’t nap later than 3:00 p.m.
• Keep a regular napping schedule if you take naps often.
• Refraining from eating a lot before bedtime
• Exercising during the day can help one sleep better at night, but exercising too close to bedtime can hinder sleep
• Sleep where it is quiet
• Sleep at a comfortable temperature – the body cannot regulate temperatures as well when asleep, so extreme temperatures may interfere with quality sleep

DISORDERS

Sleep deficit

The body is designed to get a certain amount of sleep each night. Although humans have the capacity to mentally override the desire to sleep at a certain time, this does not eradicate the need for the body to sleep. In addition, some substances, such as caffeine, can be ingested to allow one to stay awake longer.

The body keeps track of sleep lost. If you do not get enough sleep one night, you will have to sleep more the next night in order make up for the accumulated sleep deficit. For some people who chronically miss a good night sleep, it is possible to partially ignore the sleep debt by becoming accustomed to the sleep-deprived state.

Symptoms

• Feeling tired during the day
• Experiencing microsleeps – brief episodes of sleep during the day, often unbeknownst to the person
• Difficulty with cognitive activities such as mathematical calculations
• Slower reaction rate – a sleep-deprived person drives as poorly as an intoxicated individual

Snoring

Snoring is a noise generated when a person inhales during sleep, causing the soft palate and uvula (structure that hangs down in the back of the throat) to vibrate against the tongue and upper throat. The vibration is a result of a partial or complete obstruction of the airway in the back of the throat or nose.

Causes of snoring

• Being overweight causes excessive bulkiness of throat tissue
• Poor muscle tone in tongue or throat, causing the tongue to fall back into the throat, or the sides of the throat to collapse in
• Long, soft palate and/or uvula or other deformities of the throat
• Obstructed nasal airway – e.g. from a cold or allergies
• Large tonsils or adenoids in children

Treatments

The treatment appropriate for an individual’s snoring depends on the conditions that cause the snoring. In less severe cases, the condition can be alleviated by changes in activity and sleeping patterns. In more severe cases, medical treatment may be necessary.

• Exercise –to develop good muscle tone
• Lose weight
• Do not take sedatives (e.g. sleeping pills, antihistamines) or ingest alcohol before going to sleep
• Sleep on your side
• There are a number of oral devices available that can aid in keeping the airways open during sleep by bringing the jaw forward, elevating the soft palate, or retaining the tongue so it will not fall back into throat
• Continuous positive airway pressure (CPAP) - a mask that blows air into the throat while one sleeps in order to prevent the airway from becoming obstructed
• Surgery – some procedures can remove extra tissue from the throat area and airway

Sleep apnea

Sleep apnea is a disorder that results in the interruption of breathing during sleep. The disorder is usually associated with loud snoring, and is characterized by breathing being periodically stopped during sleep, sometimes as often as hundreds of times per night in extreme cases. Lack of breath results in low blood oxygen, which causes a sufferer to briefly awaken in order to take a breath. The low blood oxygen levels and chronic disturbances of sleep can lead to more serious conditions such as high blood pressure, heart disease and stroke.

Obstructive sleep apnea

Obstructive sleep apnea occurs when the throat is blocked during sleep. It is evident by loud snoring and 10- to 60-second pauses between loud snores. This is the most common form of sleep apnea. The disorder is commonly caused by:

• Throat muscles collapsing during sleep as a result of reduced muscle tone.

• Physical characteristics, such as excess tissue in the back of the throat, large tongue or tonsils, characteristics of the nasal passage or structure of the jaw.

• Excess weight, fat buildup around the throat area

• Alcohol consumption

Central Sleep apnea

Central sleep apnea is the result of a neurological disorder where there is a delay in the signals from the brain telling the body to breathe. The inability to breathe causes a drop in blood oxygen levels, causing the body to briefly wake up in order to breathe again.

Symptoms of sleep apnea

• Loud snoring
• Breathing stops frequently during sleep, resulting in a pause in snoring while the individual is briefly awakened
• Excessive daytime sleepiness, having trouble staying awake during the day
• Waking up at night with the sensation of choking
• Waking up in the morning with headaches
• Decline in mental functioning, e.g. difficulty concentrating or remembering

Treatment

For mild sleep apnea, behavioral changes can often alleviate the symptoms:

• Losing weight

• Sleeping on one’s side

• Oral devices prevent airways from being blocked by bringing the jaw forward, elevating the soft palate and preventing the tongue from falling back into airway

For moderate to severe sleep apnea, more extensive medical treatments may be necessary:

• Continuous positive airway pressure (CPAP) – a nose mask that blows air into the airway to keep it open

• Surgery helps resolve obstruction from facial deformities or excessive tissue in the throat

Narcolepsy

Narcolepsy is a disorder in the brain’s ability to regulate the sleep-wake cycle, which can lead to an onset of REM sleep while awake. The condition is thought to be hereditary.

Symptoms

• Excessive daytime sleepiness
• Cataplexy – loss of muscle control (e.g. buckling of the knees, limpness throughout the whole body), especially during emotional situations
• Hallucinations or vivid dream-like images during sleep onset or awakening
• Temporary paralysis, unable to move or talk, when one awakes
• Disrupted nighttime sleep from frequent awakenings, leg jerks or tossing and turning
• Sleep attacks – excessive sleepiness while awake, regardless of how much sleep is attained at night. They can last from 30 seconds to more than 30 minutes.

Treatment

Some available drugs can alleviate, but no entirely eliminate, symptoms:

• Modafinil alleviates the urge to sleep

• Some antidepressants can alleviate cataplexy and REM-sleep symptoms

There are also some behavioral modifications that can alleviate symptoms:

• Keeping a good sleep schedule
• Improving diet
• Increasing exercise
• Avoiding exciting situations

Insomnia

Insomnia is a condition where one is not able to get a good night of sleep. Insomnia can take the form of:

• Difficulty falling to sleep
• No problem falling asleep, but difficulty staying asleep
• Waking up too early

The inability to sleep can lead to:

• Daytime sleepiness
• Anxiety
• Impaired concentration
• Impaired memory
• Depression
• Irritability

Insomnia is not usually a primary disorder; rather, it is a symptom of an underlying condition. In order to resolve insomnia, it is necessary to pinpoint the condition that is leading to the inability to sleep well.

Factors that may lead to insomnia include:

• Circadian disorders
• Physical pain
• Mental problems, such as depression
• Certain medications
• Excessive caffeine consumption
• Stress
• Caffeine
• Alcohol

Some factors that may perpetuate insomnia:

• Poor sleeping habits, in particular irregular sleep/wake schedules
• Anxiety about not being able to sleep
• Drinking alcohol before bed
• Excessive napping late in the day (after 3:00 p.m.)

There are three varieties of insomnia, characterized by the longevity of the symptoms. Insomnia can be the result of a number of factors or a combination of factors, and how long the symptoms persist depends on the underlying cause or causes and how those causes are addressed.

• Transient insomnia – lasting a few nights

Factors that commonly lead to transient insomnia:

o Stress

o Environmental noise

o Extreme temperature changes

o Jet lag

o Certain medications

• Short-term insomnia – two or four weeks of poor sleep

• Chronic insomnia – most nights; lasting a month or longer

Factors that commonly lead to chronic insomnia include:

o Depression

o Arthritis

o Kidney disease

o Heart failure

o Asthma

o Sleep apnea

o Restless legs syndrome

o Parkinson’s disease

o Hyperthyroidism

o Chronic stress

o Shift work or other nighttime activity

Treatment

• Good sleep habits

o Regular sleep schedule

o Reduce noise, light and extreme temperatures in bedroom

• Avoid substances such as caffeine, nicotine, alcohol and other drugs that interfere with sleep

• Reduce/manage stress

• Avoid napping during the day, especially late in the day

• Hypnotic drugs can be used for short term, but caution must be taken with these drugs since they can lead to addiction

Restless legs syndrome

Restless legs syndrome (RLS) is an unpleasant feeling in the legs, often characterized as a crawling, tickling, prickling sensation in legs and feet accompanied by an urge to move these parts of the body for relief. This is one of the most common sleep disorders, especially among older people. It is also associated with anemia, pregnancy and diabetes.

Common situations that can lead to symptoms

• Riding in a car

• Watching TV

• Reading

• Inactivity, sitting

• Lying in bed trying to sleep

Treatment

• Stimulating legs, e.g. by walking around

• Taking a hot shower

• Rubbing the legs

Periodic limb movements in sleep (PLMS)

PLMS is a variation of RLS, characterized by repetitive leg movements or jerks occurring every 20 – 40 seconds during sleep. The perpetual leg movements cause sleep to become disrupted, thus leading to daytime sleepiness.

Sleep disorders in children

Sleepwalking (somnambulism)

Sleepwalking results in a series of complex behaviors that start during deep sleep. These complex behaviors result in walking during sleep. Sleepwalking usually begins in pre-pubertal children, and occurrence usually decreases with age. Sleepwalking episodes are characterized by:

• Difficulty waking during an episode

• Amnesia following an episode

• Frequency can occur less than once per month to nightly

Treatments that can reduce the occurrence of sleepwalking include:

• Getting enough sleep

• Avoiding stress

• Calming down before going to bed

• Sleeping in a bedroom on the ground floor and being sure doors and windows cannot be opened

• Being aware of medications that may induce sleepwalking

• Hypnosis

• Psychological evaluation

Also, benzodiazepines have been known to eliminate or considerably reduce episodes

Sleep terrors

Sleep terrors are characterized by a sudden awakening from deep sleep with a piercing scream or cry. In addition, autonomic (nervous system component that controls heart, lungs, etc.) functions and behavior resemble those of intense fear, such as a rapid heart beat and shortness of breath. These episodes usually occur during the first third of the night. Despite the apparent signs of intense fear, a sufferer exhibits partial or total amnesia for events during an episode.