These are some of the sleep disorders we see in our Sleep Disorders Clinic:
Sleep apnea involves abnormal breathing during sleep, where people either pause their breathing or breathe significantly less, causing them to wake up, sometimes hundreds of times during the night. This often results in severe fatigue during the day. Snoring is often a symptom of apnea. People are more likely to suffer from sleep apnea if they are overweight. Apnea is more common in men, and it’s also more likely to occur as we get older.
Insomnia is the inability to get to sleep or stay asleep, which leaves people fatigued and interferes with their ability to function during the day. Insomnia is considered chronic when it goes on for longer than six months.
Narcolepsy is characterized by excessive daytime sleepiness. It is a potentially disabling sleep disorder whereby the person may fall asleep uncontrollably in any situation. Often, people with narcolepsy also have cataplexy, the sudden loss of muscle power at times of emotion such as when laughing.
Sleep paralysis is when a person loses the ability to move when falling asleep or waking up. The paralysis can last from seconds to several minutes. Sometimes a person experiencing sleep paralysis sees dreamlike images (called hypnagogic hallucinations or hypnopompic hallucinations), which are often very frightening. These may be confused with or misdiagnosed as psychiatric hallucinations, but they are not the same.
REM behaviour disorder is the acting out of dreams. Not to be confused with sleep walking, this disorder occurs during REM (rapid eye movement) sleep. Normally our bodies are paralyzed during REM sleep so that we won’t act out our dreams. With REM behaviour disorder, the body isn’t paralyzed, so the person can act out their dreams. People with this disorder often can remember their dream; it usually affects men over the age of 60.
Sleepwalking (somnambulism) occurs during deep sleep when part of the brain becomes awake while the other part remains asleep. Someone who sleepwalks usually doesn’t remember anything about the event. Sleepwalking is most common in children, who usually outgrow the condition.
Sleep talking (somniloquy) is most commonly found in children, and is normal. It’s most likely to occur during brief arousals from the non-REM (NREM) stages of sleep. Sleep talking can be caused by factors such as stress, illness (fever), or another sleep disorder such as sleep apnea or night terrors.
Night terrors refer to a disorder of partial arousal (like sleepwalking) in which part of the brain wakes up while the other part remains in deep sleep. The person usually bolts upright in bed and lets out a bloodcurdling scream or shout. The individual is not aware of the event, he or she eventually returns to sleep and awakes the next day with no memory of the terrors and usually no memory of dreaming. This makes night terrors generally more distressing to those who witness them than to those who experience them. Night terrors are common in children and the condition is usually outgrown.
Periodic limb movements (PLMs) are sporadic and repetitive contractions of the leg (and sometimes the arms) during sleep. As with sleep apnea, these abnormal movements may cause a person to awaken up to hundreds of times during the night and, as a result, they cause fatigue during the day. They are more likely to occur as one ages.
Restless legs syndrome occurs at rest, usually in the evening or before falling asleep. With this disorder, a person’s legs feel uneasy, as though they have itchy, crawly feelings in them. Patients often relieve these sensations by moving the legs, which is why it’s called ‘restless’ legs syndrome, although the arms can also be affected. Most people with restless legs also have periodic leg movements (PLMs) during sleep.
Circadian rhythm disorder occurs when the body’s internal clock is offset, such as sleeping at a time when you want to be awake. Sunlight and other time cues seem to play a role in setting the circadian clock. Factors such as jet lag and shift work cause our natural rhythms to be upset. Changes in age also affect our bodies’ response to time cues. For example, the older adults have an advanced sleep phase, so they fall asleep early in the evening and wake early in the morning. Teenagers, on the other hand, have a delayed sleep phase so they tend to fall asleep late at night and can sleep until noon.