Movement disorders and parasomnias
Sleep is not always as quiet and peaceful as we’d like it to be. Some people are troubled by uncontrollable limb movements, while others experience parasomnias (unusual behaviors during sleep).
Sleepers typically shift position every 15 to 30 minutes, and it’s normal for muscles to jerk at the onset of sleep. But people with certain neurological disorders that trigger excessive limb movements may find it impossible to obtain a restful night’s sleep.
Restless legs syndrome
Restless legs syndrome (RLS) is a neurological disorder characterized by strange sensations in the lower legs, knees, and occasionally the arms, accompanied by an uncomfortable urge to move the limbs. Motion may relieve the discomfort temporarily. RLS affects about 10% of people ages 30 to 70, two-thirds of them women.
As many as half of people with RLS note that other members of their family have similar symptoms, and each child of an affected person has a 50% chance of inheriting the condition. In 2007, two research teams identified specific genes linked to the development of RLS that may account for up to half of all cases of the disorder.
Sleep deprivation is a major problem for individuals with RLS, as the symptoms are most prominent at night — or, in many cases, only occur at night. RLS symptoms may compel the person to get in and out of bed many times. In recognition of the restless nights suffered by people with RLS, the nonprofit Restless Legs Syndrome Foundation titled its newsletter NightWalkers (see “Resources”).
During the day, symptoms are worse when sitting still, and the irresistible urge to move can make it difficult for some people with RLS to take car or plane trips, enjoy a movie, or even hold a desk job. People develop a variety of coping strategies, such as pacing, doing knee bends, rocking, or stretching the leg muscles. Some people get temporary relief by rubbing or squeezing their leg muscles, wrapping their legs in bandages, or applying cold or warm compresses. The daytime symptoms sometimes abate for a few hours, days, or even years.
Because the symptoms sound bizarre or vague, and the need to be constantly mobile seems like nervousness, people with RLS are frequently thought to have psychiatric problems. In the past, they were often misdiagnosed as having hypochondria, manic-depressive illness, or a stress-related disorder. Children who have RLS are often diagnosed as having attention deficit hyperactivity disorder. Some people report that their symptoms started in adolescence and that adults attributed the problem to growing pains or back trouble.
RLS usually worsens with age (see Figure 7). Many people don’t seek medical attention until their late 30s. Women may find that symptoms flare up during menstruation, pregnancy, or menopause. At least one in four pregnant women experiences restless legs.
Restless legs can be a complication of alcoholism, iron-deficiency anemia, diabetes, heart failure, or kidney failure. In some people, caffeine, stress, nicotine, fatigue, or prolonged exposure to a cold or very warm environment worsens the symptoms. Certain medications — including antihistamines, antidepressants, or lithium — can exacerbate RLS.
|Figure 7: Prevalence of restless legs syndrome by ageRLS can occur at any age, but it tends to be more common and severe in people over 50.
Adapted from Archives of Internal Medicine, June 13, 2005, pp. 1286–92.
Periodic limb movement disorder
A neurological condition called periodic limb movement disorder (PLMD) causes people to kick and jerk their arms and legs throughout the night. Their leg and arm muscles involuntarily contract about every 20 to 40 seconds, so the same movement — involving the hip, knee, or ankle — may be repeated hundreds of times a night. These repetitive movements are called periodic limb movements of sleep and can cause brief arousals. PLMD results when the movements disrupt sleep enough to produce daytime sleepiness.
Most people with RLS also have PLMD, but the reverse is not true. In fact, the two disorders have several key distinctions (see “RLS and PLMD: What’s the difference?” below).
According to some estimates, as many as 30% to 50% of people ages 65 and older have PLMD. However, that figure is based on observations of leg twitches alone, and not all of these people experience the brief, unconscious awakenings that disrupt sleep.
Episodes of PLMS may last only a few minutes, or they may continue for hours, with intervals of sound sleep in between. They usually don’t occur continuously throughout the night, but instead cluster in the first half of the night and occur mainly during non-REM sleep. Instead of proceeding smoothly through all the sleep stages in regular cycles, people with PLMD awaken for a few seconds at a time (generally without realizing it) and frequently skip back to the lighter stages of sleep. Unless a bed partner complains, people with PLMD are often oblivious to the movements and may wake up baffled at why they feel exhausted despite getting what they thought was a full night’s rest.
RLS and PLMD: What’s the difference?
|Restless leg syndrome (RLS)||Periodic limb movement disorder (PLMD)|
|Occurs while awake, sometimes preventing sleep.||Occurs during sleep, causing partial arousals that disrupt sleep.|
|Involves voluntary movements — pacing, knee bends, rocking, or stretching — performed to relieve uncomfortable sensations in the lower legs and knees. Often worse after periods of inactivity and at bedtime.||Involves involuntary movements, usually repetitive flexing of the big toe, ankle, knee, and hip, typically occurring every 20 to 40 seconds. Episodes last anywhere from a few minutes to several hours.|
|People with RLS are aware of their symptoms, which include aching, burning, tingling, and “creepy, crawly” sensations in the legs.||Affected people usually aren’t aware of their symptoms unless a bed partner complains.|
|Diagnosis is based on a patient’s description of symptoms.||Diagnosis usually requires a sleep study.|
Treatments for movement disorders
Doctors diagnose RLS and PLMD based on the individual’s description of symptoms and, in some cases, observations during an overnight sleep study. Standard neurological examinations often reveal no abnormality.
Several small studies suggest that exercise can ease both RLS and PLMD; walking or other moderate exercise, such as biking or swimming, are good choices.
Some people find that cold showers are beneficial, but others prefer heat. Finally, some people with mild RLS may be able to get to sleep by simply massaging their calves or stretching their legs in bed. But most people with moderate to severe RLS need medication.
Drugs that ease the tremors of Parkinson’s disease also reduce the number of leg movements and thus improve quality of life for people with RLS and PLMD (see Table 5). These include bromocriptine (Parlodel), levodopa-carbidopa (Sinemet), pramipexole (Mirapex), and ropinirole (Requip), which in 2005 became the first drug approved by the FDA to treat RLS. Although the drugs used to treat RLS and PLMD are the same as those used in treating Parkinson’s disease, people with these sleep disorders are no more likely to develop Parkinson’s disease than other individuals.
People with mild movement disorders may be prescribed clonazepam (Klonopin) or temazepam (Restoril), which may help them stay asleep during leg movements. Most people who take these medications for insomnia develop a tolerance to them after a few weeks, but this doesn’t seem to happen when such drugs are taken for RLS. Anti-seizure medications such as gabapentin (Neurontin), which are used to treat epilepsy, are also prescribed for RLS. A related medication called Horizant Was FDA-approved in 2011 to treat moderate to severe RLS. Horizant contains gabapentin enacarbil, which becomes a long-acting version of gabapentin in the body. Opiates (opium-derived drugs) such as oxycodone (OxyContin) may be used to treat people with severe RLS symptoms who don’t respond to other treatments. Opiates decrease the discomfort of RLS and, for some, dramatically reduce leg movements at night. But because of the potential for addiction, most physicians are reluctant to treat sleep disturbances with these drugs. However, when properly used, they may provide long-term benefit with little risk of addiction.
Table 5: Medications for movement disorders
|clonazepam (Klonopin)temazepam (Restoril)||Clumsiness or unsteadiness, dizziness, lightheadedness, daytime drowsiness, headache||Should be used with caution by people with sleep apnea or other breathing difficulties; not to be used with alcohol or other depressants; habit-forming; withdrawal symptoms may occur if stopped abruptly.|
|bromocriptine (Parlodel)levodopa-carbidopa (Sinemet)pramipexole* (Mirapex)
|Abnormal movements, depression, mental changes, nausea, dizziness||Certain drugs in this class should not be used by people who are sensitive to ergot drugs, who have hypertension, who take monoamine oxidase inhibitors (MAOIs), or who have glaucoma.|
|oxycodone (OxyContin, Percocet)||Depressed breathing and circulation, dizziness or lightheadedness, next-day sedation, constipation, nausea, vomiting||Risk of addiction; not to be used by persons with sleep apnea; should not be used with alcohol or other depressants.|
|carbamazepine (Tegretol)gabapentin (Neurontin)gabapentin enacarbil (Horizant)
valproic acid (Depakene)
|Unsteadiness, vision problems, body aches, congestion||Tegretol may reduce the number of blood cells produced by your body.|
|*Ropinirole, pramipexole, and gabapentin enacarbil are FDA-approved to treat RLS. Other medications in this chart are not approved to treat RLS or PLMD, but physicians have found that they help people with these conditions.|
People with parasomnias may wake up enough to carry out complex behaviors, but not enough to realize what they are doing. These sleep-disrupting behaviors include sleepwalking, sleep eating, and night terrors, among others.
Somnambulism and somniloquy
Somnambulism, or sleepwalking, occurs during partial awakening from deep sleep. Sometimes sleepwalkers carry out complex actions; at other times they simply pace or sit on the edge of the bed performing repetitive behaviors. They can be difficult to awaken and typically have no memory of the episode in the morning. There have been reports of somnambulists committing murder, although this is extremely rare. Episodes of sleepwalking are usually brief and benign, with few people endangering themselves or others. Scientists used to believe that sleepwalkers were acting out their dreams, but experts have determined that sleepwalking does not occur during dreaming.
Sleepwalking is common in children and probably occurs because their brains have not yet mastered regulation of sleep and waking. The tendency seems to be inherited. Although people are more likely to sleepwalk when they’re anxious or fatigued, there is little correlation between somnambulism and psychological problems. If the condition continues beyond puberty, the individual should be evaluated to determine whether sleepwalking is the result of nighttime epilepsy or a reaction to medication, extreme stress, or another sleep disorder. If the condition presents a risk of injury, a doctor may prescribe medications such as benzodiazepines.
Somniloquy, or talking in one’s sleep, is nothing to worry about. People are more likely to talk in their sleep during times of stress or illness. Talking can occur during any or all stages of sleep. When awakened, people who talk in their sleep rarely remember what they said. Only occasionally can someone who talks in his or her sleep hear and respond to what someone else says.
Nocturnal eating disorders
The two types of nighttime eating disorders are nocturnal eating syndrome and sleep-related eating disorder.
Nocturnal eating syndrome occurs most commonly in people with daytime eating disorders or depression. They are usually light sleepers and wake frequently. Within minutes after getting out of bed, people with this condition raid the refrigerator and begin wolfing down food. Although they aren’t really hungry, they can’t go back to sleep without eating. In some people with this disorder, overeating occurs only during sleep hours, not during the daytime. The person is awake and fully alert during the episode and can recall it the next day. Nocturnal eating syndrome should be treated as an eating disorder.
Sleep-related eating disorder is a combination of a sleep disorder and an eating disorder. People with this disorder experience partial arousals similar to sleepwalking, but respond by eating. Often they consume unhealthful, high-calorie food, such as cookie dough. They report being half-awake or asleep during the episodes and have very poor memory of the events or no recollection at all. Sleep-related eating disorder occurs more frequently in people with eating disorders and depression. However, treatment should address both the sleep disorder and the existing eating disorder.
Sleep-related eating disorder occurs in children and adults and sometimes can be traced to an illness or traumatic event. A medical evaluation may reveal an ulcer, a history of strict dieting, bulimia, or a sleep problem such as narcolepsy, sleepwalking, sleep apnea, or periodic limb movement disorder. Sometimes medications prescribed for depression or insomnia can cause this disorder. A number of medicines have been tried to treat these disorders, including dopaminergic agents, anticonvulsants, antidepressants, and opiates, but results have been mixed.
Bedwetting, known medically as sleep enuresis, is common among children. It’s considered a problem, however, if it’s still occurring by age six. Statistically, 80% to 85% of children are consistently dry throughout the night by age 5. After that, the number of children who continue to wet the bed decreases by about 15% per year, even without treatment, and only 1% to 2% of children still wet the bed by the time they’re 15. Almost all bedwetting children eventually stay dry at night.
Bedwetting, which occurs more frequently among boys than girls, is usually due to slow maturation of bladder control. Occasionally, it results from psychological stress. When a specific physical problem such as a structural abnormality of the urinary tract, diabetes, a urinary tract infection, or a nervous system defect leads to bedwetting, the child will also have difficulty with daytime bladder control.
It’s important for adults to understand that, initially, children have little control over bedwetting and that admonishments and punishments won’t solve the problem. Parents should remain calm as they change the bed sheets and underpants. Don’t show disgust or disappointment.
Reminding the child to urinate before going to bed and limiting liquids in the last two hours before bedtime may reduce or eliminate the problem. Other options include setting up a token-and-reward system to motivate the child to stop wetting the bed; using an alarm that wakes the child upon the first sign of wetness; bladder training exercises; and, as a last resort, medications. Consult your pediatrician for further details.
Bedwetting occurs in a very small percentage of adults and is often due to an underlying medical problem or excessive caffeine or beer consumption. In men, an enlarged prostate gland that presses against the bladder may be to blame. Bedwetting may be a side effect of diuretic pills or a sign of diabetes, a bladder or kidney problem, epilepsy, or serious obstructive sleep apnea. Treatment for adult bedwetting depends on the cause.
REM sleep behavior disorder
Most people make subtle twitching movements during REM sleep, but occasionally sleepers shout, punch, or otherwise act out their dreams. This phenomenon — known as REM sleep behavior disorder — was identified in the 1980s. It’s estimated to occur in one in 200 people (0.5%), and nine out of 10 people who have it are men. The disorder nearly always arises after age 50, but there are occasional reports of it occurring in younger adults and children.
Approximately 70% of people with REM sleep behavior disorder go on to develop Parkinson’s disease, suggesting that similar brain structures are involved in both conditions.
If the person is at risk of harming himself or others or is having daytime sleepiness from the sleep disruption, a medium-acting benzodiazepine may help suppress symptoms. Until the problem is under control, people can protect themselves and loved ones by sleeping in a separate room and putting sharp or breakable objects out of reach.
Nightmares, sleep terrors, and panic attacks
Nightmares, sleep terrors, and sleep-related panic attacks can interrupt sleep.
Nightmares. Nightmares, which usually occur early in the morning, are bad dreams that become so threatening that a person wakes in a state of fear and agitation. Nightmares occur mainly during REM sleep, when the body barely moves.
Nightmares can be a side effect of certain medications, such as antidepressants, narcotics, and barbiturates. Nightmares can also occur when a person stops taking drugs that temporarily reduce REM sleep, such as benzodiazepines. Alcoholics who stop drinking often experience dream disturbances and nightmares.
If you experience frequent nightmares that aren’t linked to medication use, counseling may help. The most common approach is a type of behavioral therapy known as desensitization, in which the sufferer recalls the details of the nightmare and uses relaxation techniques to overcome fear. The therapist may guide you through typical dream sequences — for example, helping you imagine confronting or driving off a pursuer. A psychoanalytically oriented therapist, on the other hand, may focus on identifying and resolving past and present emotional issues that play themselves out in nightmares.
Sleep terrors. A sleep terror can be quite dramatic to witness. The sleeper may let out a bloodcurdling scream, sit bolt upright, and attempt to fight or flee. During an episode, which may last as long as 15 minutes, a person may seem confused and agitated. After the spell is over, he or she is likely to go right back to sleep and later may not remember what happened.
Unlike nightmares, sleep terrors occur during non-REM sleep, usually in the first hour or so after going to bed. They appear to run in families and occur most often in children. Adults with sleep terrors tend to be more agitated, anxious, and aggressive than children who have this problem. When the episodes involve violent or injurious behavior, medical treatment may be recommended. Some doctors prescribe medications such as benzodiazepines that suppress deep sleep. Hypnosis or a relaxation technique known as guided imagery may also be helpful.
Sleep-related panic attacks. People with this condition awaken suddenly because of episodes of intense panic characterized by a racing heartbeat, sweating, trembling, breathlessness, or the feeling that they may be dying. Anti-anxiety drugs are often useful for both daytime and nighttime attacks.