SLEEP DISORDERS

All humans follow similar sleeping patterns. A typical night’s sleep seems to consist of the repetition of 90 -110 minute cycles of rapid eye movement (REM) sleep, and periods when there is no REM (NREM).  The first period of REM usually lasts 5 to 10 minutes, but this tends to lengthen in successive cycles. There are four main stages of sleep.

Stage One Sleep is the lightest of all the stages where a person’s brain wave patterns are similar to those when he or she is awake.  The body is very active during this period; brain temperature rises, heart rate and blood pressure fluctuates, breathing is irregular and the brain uses more oxygen.  A person returns to Stage One several times during the sleep cycle after going through the first four stages.

Stage Two Sleep begins soon after falling asleep, usually within the first 5 to 10 minutes.  This is the period where sleepwalking and sleeptalking takes place although this is not really a true ‘dream state’.  The time spent in Stage Two tends to get shorter and shorter with each 90 – 110 minute sleep cycle.

Stage Three Sleep (REM). Here breathing is slow and even, the heart rate has slowed down and the body temperature has dropped. This is when a person is in the ‘Alpha’ brain wave state where images are in colour. During this period, the brain generates up to five times as much electricity as when a person is awake. The brain not having to deal with input from the senses can account for some of this, but there is no understandable reason why the rest of the increase is necessary.

During Stage Three, a person is often hard to awaken and this is also the time when most dreaming is done. (NREM dreams have been recorded. Research indicates that it is possible to have some eye movement during NREM stages although dreamers awakened at such times have less coherent and non-visual reports of their dreams) (Rickards).

The rapid eye movement that gives this stage its name involves both eyes moving quickly from side to side, although research suggests that this movement has nothing to do with the actual content of the dreams.  During this period the body has shut down to an almost paralysed level as the brain sends messages to the spinal column to suppress muscle responsiveness. And, as the brain believes what it sees, this is one of the reasons people often feel they cannot run or cry out during a nightmare.

The first REM period of sleep is usually the shortest, lasting 10 to 15 minutes, but by the end of the night it can be lasting from 40 to 60 minutes.  With each cycle the REM period grows longer and Stage Four Sleep gets shorter, or even disappears altogether.  A person will tend to have 4 or 5 REM periods each night and these will range from 5 to 45 minutes each in duration. The last REM period of the night usually produces the most vivid and easily remembered dreams, specially if a person wakes just as a Stage Three has been completed.

Stage Four Sleep is the deepest level of sleep.  The first cycle of the sleep period will usually involve 20 minutes or more in this stage, but the more exhausted the body, the more Stage Four Sleep it needs. Stage Four Sleep is the only time when growth hormones are released into the body, so teenagers need more of this than adults.  People over 70 might have almost no Stage Four Sleep in their cycle, which would leave them cranky.

Stage Four becomes shorter and shorter over the progress of the entire sleep period and by the end of it, as time to wake up comes closer, a person might not be spending any time in Stage Four at all. Stage Four Sleep is the period when Sleep Terror Disorder (also known as Night Terrors or pavor nocturnes) occurs.

Some research suggests that there are variations within these stages according to the individual and that these differences may vary again within an individual from night to night. These patterns may be affected by a person’s mental state (Rickards). Sleep disorders may be the primary presenting problem or they may be a response to something else such as an anxiety disorder or depression

Sleep Terror Disorder is an experience of extreme anxiety from which a person usually awakens screaming.  This most often occurs during the first third of the night and may last for 10 to 20 minutes after which time normal sleep returns.  The sufferer will commonly experience sweating, confusion, rapid heart rate, be difficult to awaken fully or comfort, be unable to explain what has happened and have no recall of bad dreams or nightmares if they do awaken fully or when they awaken the next day.  To be diagnosed as a disorder these episodes must be recurrent and not be the result of drug abuse, medication or some other medical condition. They must also cause significant distress or impairment of abilities in social, work or other important areas of functioning. (DSM-IV). This disorder most often occurs in pre-adolescent boys, although girls do suffer too, and is fairly common in children between the ages of 3 and 5. When it occurs in the very young, the incidence usually reduces greatly after the age of 5, (other research says 10).  It can run in families. When it occurs in adults it could be the result of emotional tension or stress, and/or excessive use of alcohol. This disorder is not dangerous. In children, this disorder doesn’t generally point to psychological problems and they usually outgrow it.  It might be eased in an adult by the sufferer reducing stress levels. Some form of counselling could also be appropriate.  Benzodiazepines are sometimes used to treat the problem although this doesn’t seem to be a recommendation.


REM Sleep Behaviour Disorder

The brain has mechanisms that protect us from hurting others or ourselves during sleep; however, if someone with sleep problems is coming close to causing such injuries, this might be a feature of another problem, such as a brain stem dysfunction, and professional help should be sought. This is called REM Sleep Behaviour Disorder (acting out dreams). Here, sufferers can have violent behaviour during sleep. The person may punch, kick, leap out of bed; even run from the bed as he or she tries to enact the dream. This might occur 3 or 4 times a night on consecutive nights.  This disorder can start at any age, but is more common in male adults (NSDC). The NSDC site suggests that this disorder often has no known cause, but might also occur due to withdrawal from alcohol, sedatives or anti-depressant medication, or be due to neurological conditions such as dementia or a previous stroke.  Short acting benzodiazepines seem to be the treatment of choice.


Sleep Starts

This problem involves sudden jerks, which occur at the beginning of sleep and can be considered normal as it affect 60-70% of the population.  ‘Severe increased exertion’, emotional stress and too much caffeine can increase the frequency of sleep starts.  These movements can involve the arms or the legs or the whole body and there might also be feelings of falling or imbalance (newcastle).


Nightmare Disorder

Nightmare Disorder varies from Sleep Terror Disorder in a number of ways: it occurs during REM sleep, it will involve an extended and extremely frightening dream, usually including threats to personal survival, security or self-esteem.  It generally occurs during the second part of the night and the person wakes with vivid recall of the dream and quickly becomes alert. It can affect people at any age. To be classed as a disorder the problem must involve clinically significant distress or impairment in social, work or other important areas of function. The problem must also not be generated by another mental disorder, drug abuse, medication or a general medical condition (DSM-IV). Other research suggests that to be classed at disorder level it has to last at least six months and the disturbing dream has to occur at least once a week.  Research also suggests that people do not necessarily awaken so often as a response to the nightmare if they have had the problem for a long time.


The ‘Nightmare Quiz’ site says that if all the following situations apply, a Chronic Nightmare Disorder is likely.

• I experience disturbing or unpleasant dreams on a regular basis – that is, at least every week or every month.
  
  
• I’m certain that my nightmares were caused by bad things that happened to me in the past.
  
  
• My sleep is disturbed by my bad dreams.
  
  
• Occasionally or more often, I sense some anxiety and fear about going to sleep because I am concerned I will have a bad dream.
  
  

• If I think about these nightmares, I sometimes re-experience the disturbing emotions in the dreams, and these emotions linger during the day.
  
  
• During my waking hours, I have noticed on several occasions that I will suddenly recall some part or the whole of a bad dream that I may have experienced the night before, or some other bad dream from a time in the past.
  
  
• My bad dreams almost always include some emotion which disturbs me, for example, fear, anxiety, anger, sadness, guilt, shame, frustration, confusion.
  
  
• Upon awakening from these unpleasant dreams, I may not remember the whole dream, but I can usually remember some part of it.
  
  
• Occasionally or more often, I will actually delay my bedtime because I am sure I’m going to have a bad dream.
  
  
• If I wake up in the night because of a bad dream, I will sometimes feel anxious or fearful about going back to sleep.
  
  
• Occasionally or more often, if I have had a disturbing dream, I feel unrested upon awakening in the morning.
  
  
• During the daytime I feel fatigued, sleepiness, or low energy if I’ve had bad dreams or nightmares the night before.