Common Sleep Disorders
Sleep-related complaints are second only to complaints of pain as a cause to seek medical attention.
We classify sleep disroders broadly into three categories:
Sleep disorders are a 24-hour condition that affect the person all day, not just at night. They lead to an inferior quality of life as patients feel stressed and sleepy during the day. There are dozens of different disorders.
Signs You Have A Sleep Disorder
Signs that you may have a sleep disorder
Only a doctor can give a medical diagnosis. Sleep diaries, actigraphy, EEGs, and polysomnograms are among the diagnostic tools employed.
Insomnia is a blanket term for many phenomena. Everyone has insomnia occasionally. Some people have it often. Other have it chronically, which is not fun at all. The National Institutes of Health estimates that 60 million people in the US have it in any given year. See our section on insomnia.
One of the most dangerous disorders is apnea, a cessation of breathing during sleep. The fat buildup and loss of muscle tone from aging and obesity can allow the windpipe to collapse, preventing the flow of air to the lungs. Apnea is associated with loud snoring (although not everyone who snores has apnea) and can also occur if the neurons that control breathing malfunction during sleep. A person with apnea may struggle to breathe (with a surge in blood pressure and heart rate) for 10 seconds to more than a minute, awaken, snort or gasp then resume snoring. This cycle may be repeated hundreds of times a night. Although most sufferers will not remember these brief awakenings, they can leave the person sleepy and possibly irritable and depressed. This and the disruption of a bed partner’s sleep can cause a strain on relationships.
The type of apnea described above is called obstructive sleep apnea. Another type, though much less common is called central sleep apnea, in which the airway is not blocked but the brain fails to signal the body to breathe. Some people suffer from both types of apnea.
Apnea is associated with coronary heart disease, heart attack, high blood pressure, congestive heart failure, pulmonary hypertension, stroke, neuropsychiatric problems and mental impairment. People with severe, untreated sleep apnea are two to three times more likely to have automobile accidents than the general population. The National Center on Sleep Disorders Research estimates that sleep apnea accounts for $42 million in hospital bills yearly.
Apnea can only be diagnosed through a medical evaluation, usually an overnight study at a sleep laboratory. It is estimated that 18 million people in the US have it, although many are unaware and undiagnosed. Mild sleep apnea can often be overcome by a person losing weight, not sleeping on his or her back and/or wearing special dental or oral appliances. Severe cases may be treated with special devices such as CPAP machines worn over the nose or surgery. People with sleep apnea should never take sleeping pills or sedatives because these could prevent them from awakening enough to breathe.
Snoring can be a nuisance and can signal the very serious problems of sleep apnea and upper airway resistance. Simple snoring (without apnea) is sometimes considered to be at the mildest end of the sleep disordered breathing spectrum. Snoring is associated with the hypertension, cardiovascular disease, and diabetes. The only intervention strategy accepted at present is weight loss. More on snoring.
Narcolepsy cause frequent daytime sleepiness and falling asleep spontaneously even if the afflicted person gets a normal amount of sleep at night. These “sleep attacks” can last from several seconds to more than 30 minutes and can include cataplexy (loss of muscle control during emotional situations), hallucinations and temporary paralysis upon awakening. Excessive daytime sleepiness is also a symptom. The disorder is usually hereditary though it can be brought on by brain damage or neurological disease. Symptoms usually appear during adolescence. In the United States, an estimated 250,000 people have this disorder. Stimulants, antidepressants and other drugs can help control the symptoms. Behavioral measures to control symptoms include strategically timed naps, regular timing of nighttime sleep and avoidance of alcohol and heavy meals. Although it can be a difficult condition to live with (and some narcoleptics have to quit their jobs), most manage their illnesses with medical help.
In the popular imagination, narcolepsy is often confused to cataplexy and sudden loss of muscle down and falling asleep. Most narcoleptics do not have cataplexy, and both narcolepsy and cataplexy come in varying degrees of severity. People who collapse all of the sudden are pretty rare.
Narcoleptics have frequent nighttime awakenings that may be imperceptible to the patient (microarousals) but which can show up on EEGs. The level of sleep fragmentation corresponds to the level of daytime sleepiness. Like most people, narcoleptics experience increased sleep fragmentation as they get older, but this increase in fragmentation does not appear to affect daytime sleepiness levels.
Narcolepsy is usually treated with stimulants, including amphetamine or amphetamine-like compounds modafinil. The most common amphetamine-like drugs are dextroamphetamine, pemoline methamphetamine, and methylphenidate (Ritalin). These are classified as Central Nervous System (CNS) stimulants. Modafini is marketed as Provigil and Nuvigil. Dextroamphetamine has a varying duration of action while methamphetamine and modafinil have a longer duration of action. Modafinil is well tolerated by the body and fewer sympathomimetic and side effects although it is generally lower potency than the amphetamine-like drugs. Another treatment strategy takes a different route: sodium oxybate is prescribed for narcoleptics to make them sleep deeper during the night in hopes they will not experience excessive daytime sleepiness during the day.
There is a genetic predisposition to narcolepsy and less than 0.2% of the population has the condition. The gene for narcolepsy in dogs has been identified and it appears to code for a family of neuropeptides called orexins or hypocetinc . The brain cells that contain secrete orexins make connections with many brain regions involved in regulating the sleep-wake cycle. There are only about 20,000 of these cells in a brain. The brains of narcoleptics may have damage to these cells. That, at least, is the dominant hypothesis today.
When patients are evaluated with the Multiple Sleep Latency Test and the sleep latency is fewer than eight minutes, this is diagnostic support for narcolepsy. The difference between hypersomnia and narcolepsy on the MSLT is that the narcoleptics will have two or more sleep-onset rapid eye movements.
Restless Legs Syndrome (RLS) is an unpleasant crawling, prickling or tickling sensation in the legs and feet and the urge to walk or move them to find relief. Although not considered serious medically, RLS makes it difficult to fall asleep and stay asleep. It is estimated that 12 million people in the US have RLS.
Most people with RLS also have Periodic Limb Movement Disorder (PLMD) or repetitive movements of the toe, foot and sometimes the knee and hip during sleep. Sufferers may be unaware of sleep disturbances but their bed partners often are not so lucky.
These conditions are associated with other medical conditions such as iron-deficiency anemia, pregnancy and diabetes. There is evidence that blood iron levels are correlated with RLS. People experiencing them should consult a health care professional. Severe RLS is most common among the elderly but symptoms can develop at any age.
ADHD and Sleep Disorders
Not surprisingly, people with ADHD often to have sleep disorders. The symptoms of ADHD, inattention and hyperactivity, play out differently. People with high scores on inattention tend to need more sleep. Hyperactive ADHD sufferers tend to need less sleep.