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Evaluation of sleep disorders. The history will provide the diagnosis in 90% of the cases. A good interview and a sleep diary are useful. A sleep diary consists of daily recording of what they do during the day: what they eat, what caffeinated beverages they use, when they try to go to sleep, when they wake up, when they set the alarms, when they go to work. The diary can demonstrate temporal relationships to behaviors, habits, activities and sleep function. Filling out a questionnaire may facilitate your questioning. If you really want to get high-tech you can refer somebody to a sleep laboratory, even though most people already know the answer before they send somebody to a sleep laboratory. In the sleep lab, doing an EEG and polysomnography can confirm breathing patterns, muscular patterns, EEG patterns and the rest. Or you can directly visually observe somebody while they are sleeping which can be a very time intensive thing, to go to their home and watch them sleep for one or two nights. But there are ways you can do it, either in sleep laboratories or by using a still camera.
The elderly have the greatest number of sleep difficulties. The elderly as a group often have insomnia. The elderly usually need to spend more more time in bed. They have more nocturnal awakenings, that is, they have more fragmented sleep. Their total sleep time in a 24-hour day and during the night time when they tend to be asleep is reduced from when they were younger. They have an increased sleep onset latency. That is the time when their head hits the pillow to when they actually fall asleep.
An awake EEG tracing is characterized by global activity. As I start to drone on you start to get drowsier and drowsier then you start to get 8-12 cycles per second alpha waves. As you start to get more and more sleepy you enter stage I sleep, you’ll have 3-7 cycles per second beta waves, which to the untrained eye, and even to many trained eyes, it doesn’t look that much different than the rest of the tracing, but that’s why most of us are not electroencephalographers. Stage II sleep has these characteristic bursts of activity called sleep spindles with 12-14 cycles per second activity and these very high amplitudes, low frequency, K-waves. If this were an electrocardiogram it would be reminiscent of a premature ventricular contraction.
Hygiene. And this doesn’t mean when you brush your teeth before you go to sleep. It’s the biologic factors and the environmental factors that contribute to a good night’s sleep or a bad night’s sleep. Exercise tends to have an important relationship to sound sleep. Those of you that are athletic or do a lot of exercise tend to have more delta sleep than those of you who are couch potatoes. You will probably find you’ll have better sleep if your exercise is done in the late afternoon or early evening as it would just before bedtime because it will interfere with sound sleep.
Now lets turn to the sleep disorders themselves. Going back to the first classification system of primary sleep disorders, secondary sleep disorders and parasomnias. Among the primary sleep disorders there are a whole bunch. The two most important and the two most frequent and the ones we will spend some attention on are narcolepsy and sleep apnea. Nobody really cares very much about primary insomnia. Those are the people that have never slept well from the time they were born, or people who have primary hypersomnia, the people who have always slept more than everybody else. There are those people who have nocturnal myoclonus where they get these rhythmic myoclonic jerks throughout the night’s sleep which generally don’t interfere too much with their night’s sleep as much as with the bed partner’s night sleep.
Some people for some unknown reason have periodic hypersomnia. Every so often they just need more sleep, and it is unclear exactly all the parameters that cause this. There are other conditions like the Kleine-Levin syndrome, which is phenomenologically just the opposite of anorexia nervosa. Whereas anorexia nervosa happens more in young women.
So let’s focus on narcolepsy. Narcolepsy is common. Narcolepsy is always asked about on boards. It’s asked about on the boards because it’s got these characteristic four features. That is, characteristic features are: there are three attacks. These 10-15 minute irresistible attacks of sleep that may occur in inappropriate circumstances. Sleep paralysis is the third feature of this condition, where people awaken and find that they cannot move and they feel totally paralyzed. Now the good news is that 5 % of the general population who does not have narcolepsy has this phenomenon.
The fourth feature is that they have hypnagogic and hypnopompic hallucinations. That is hallucinations that occur upon falling asleep or upon awakening. Now you might say, "How am I possibly going to remember the tetrad of symptoms associated with narcolepsy?" and that is where the common thread of the pathophysiology of narcolepsy.
The next of these disorders we are going to talk about it sleep apnea. But not all the patients with sleep apnea are obese _ individuals. As people age even the thin bodies have sleep apnea, either central or peripheral obstruction types, can occur. Sleep apnea is diagnosed by having more than 30 apneic episodes that occur in that second hour of night’s sleep. The manifestations are that people have the absence of breathing when they fall asleep. During the daytime they have excessive daytime sleeping because they never get restful deep sleep because they are always falling asleep then partially awakened, sleep, partially awakened. But because they are never getting this full restful sleep they have decreased attention, irritability, they have depression. They have abnormal behaviors that occur during sleep, that is they have parasomnias.
Other types of secondary sleep disorders: anything that affects the neurologic axis, that affects the sleep wave REM system can disrupt sleep. Endocrine disorders, primarily thyroid disorders, can disrupt sleep. Hyperthyroidism gives you fragmented sleep, hypothyroidism gives you increased sleepiness and, interestingly enough, decreased delta sleep, which is associated possibly with decrease in muscular _ in hypothyroid individuals. Acute renal failure gives you short fragmented sleep.
When it comes to the prescription of many medicines, keep in mind the principles of pharmacodynamics and pharmacokinetics and think about whether the drug you are prescribing will be absorbed. How it is going to be distributed. How it’s going to be eliminated. Whether the kidneys are working, whether the liver is working. All these factors do have an impact on the prescription of medicines and the dosing frequency and the total daily dose that you do.
On a typical night’s sleep, you fall asleep, you are in delta sleep in 30 minutes. Every 90 minutes you do REM. Delta sleep decreases as the night goes on. A 17-year-old insomniac comes into your office. He doesn’t sleep at all for an hour and a half. And it takes three or four hours before he gets some sleep, right here. So you say, "I’m going to help him out. He really wants to sleep." So you give him short acting barbiturates. The first night he’s asleep solidly in 20 minutes.
Secondary sleep disorders. We know that depression is one of the DSM criteria for major depression. Frequently, but not always, associated with early morning awakening and with the reduced REM. Every year for the last five years this question has been asked, which is, "What helps the REM sleep during depression - reduced latency."
The parasomnias. The parasomnias are always asked about on the boards because they have discreet questions that can be asked about them. Some of the types of parasomnias that exist are somnambulism or sleep-walking. It’s a non-REM delta sleep phenomenon. It’s not usually associated with dreaming and it is difficult to arouse these patients during their sleep walking. And they usually do not remember sleep walking. When my son was younger he used to sleep-walk and sleep-talk. In the morning we would tell him he did these things and he was totally disbelieving that he had done these things. Night terrors, a subset of parasomnias, where there is absolutely extreme arousal during a night’s sleep.
One percent of navy recruits still have bed-wetting. Maybe it’s because they want to be near the sea, I don’t know, but people do outgrow it. And that’s because the sleep hygiene curve that I showed you earlier on, people have less delta sleep as they age and remember, delta sleep is more dense, more frequent when you are younger and it more common early in the night’s sleep rather than in later sleep. So my son would always have these things in the first hour and a half after falling asleep.
The elderly. The biggest problem you can face in the elderly is that of sleep apnea. Fifty percent of referrals to most sleep disorder centers are for sleep apnea, even though they may not report it, many of these complainants are aware that they are not breathing during sleep.
If somebody comes in complaining or excessive daytime sleepiness, the differential will include: narcolepsy and sleep apnea will be two of the most common causes. Anything that affects the sleep-wake REM neurologic axis, metabolic disturbances, toxins and drugs, especially hypnotics that are being prescribed for them. Questions to ask somebody when they have excessive daytime somnolence include, "Have you ever had unusual muscular experiences?" do you have cataplexy, in other words.
What things destroy sleep? Noisy rooms, hot rooms, the use of hypnotics, caffeine, alcohol before bedtime and tobacco. But to be more optimistic, how do you improve somebody’s sleep? Sleep only until refreshed. Establish a regular arousal time which will then train your circadian rhythm. Maintain steady daily exercise which not only helps you sleep.