Parasomnias

Parasomnias

The parasomnias are a group of disorders characterized by dis-turbances of either physiological processes or behavior associ-ated with sleep, but not necessarily causing disturbances of sleep or wakefulness.

Nightmare Disorder

The essential feature of this disorder is the repeated occurrence of frightening dreams that lead to full awakenings from sleep. The dreams or awakenings cause the individual significant dis-tress or dysfunction. By DSM-IV-TR definition, the disorder is excluded if the nightmare occurs in the course of another men-tal or medical disorder or as a direct result of a medication or substance. Many, but not all, nightmares occur during REM sleep; REM nightmares take place most often during the last half of the night when REM sleep is most common (see nightmares in post traumatic stress disorder). Whereas more than half of the adult population probably experiences an occasional nightmare, nightmares start more commonly in children between the ages of 3 and 6 years. The exact prevalence is unknown

Treatment

The disorder is usually self-limited in children but can be helped sometimes with psychotherapy, desensitization, or rehearsal instructions. Secondary nightmares, as in post traumatic stress disorder (PTSD), can be difficult to treat.

Sleep Terror Disorder

This disorder is defined as repeated abrupt awakenings from sleep characterized by intense fear, panicky screams, autonomic arousal (tachycardia, rapid breathing and sweating), absence of detailed dream recall, amnesia for the episode, and relative un-responsiveness to attempts to comfort the person. Because sleep terrors occur primarily during delta sleep, they usually take place during the first third of the night. These episodes may cause dis-tress or impairment, especially for caretakers who witness the event. Sleep terrors may also be called night terrors, pavor noc-turnus, or incubus.

The prevalence of the disorder is estimated to be about 1 to 6% in children and less than 1% in adults. In children, it usually begins between the ages of 4 and 12 years and resolves spontaneously during adolescence. It is more common in boys than in girls. It does not appear to be associated with psychi-atric illness in children. In adults, it usually begins between 20 and 30 years of age, has a chronic undulating course, is equally common in men and women, and may be associated with psychiatric disorders, such as PTSD, generalized anxi-ety disorder, borderline personality disorder and others. An increased frequency of enuresis and somnambulism has been reported in the first-degree relatives of patients with night terrors.

Treatment

Nocturnal administration of benzodiazepines has been reported to be beneficial, perhaps because these drugs suppress delta sleep, the stage of sleep during which sleep terrors typically occu

Sleepwalking Disorder

This disorder is characterized by repeated episodes of motor be-havior initiated in sleep, usually during delta sleep in the first third of the night. While sleepwalking, the patient has a blank staring face, is relatively unresponsive to others, and may be con-fused or disoriented initially on being aroused from the episode. Although the person may be alert after several minutes of awak-ening, complete amnesia for the episode is common the next day. Sleepwalking may cause considerable distress, for example, if a child cannot sleep away from home or go to camp because of it. By DSM-IV definition, pure sleepwalking is excluded if it occurs as a result of a medication or substance or is due to a medical dis-order. However, sleepwalking may be an idiosyncratic reaction to specific drugs, including tranquilizers and sleeping pills.

Most behaviors during sleepwalking are routine and of low-level intensity, such as sitting up, picking the sheets, or walk-ing around the bedroom. More complicated behaviors may also occur, however, such as urinating in a closet, leaving the house, running, eating, talking, driving, or even committing murder. A real danger is that the individual will be injured by going through a window or falling from a height.

Whereas about 10 to 30% of children have at least one sleepwalking episode, only about 1 to 5% have repeated episodes. The disorder most commonly begins between the ages of 4 and 8 years and usually resolves spontaneously during adolescence. Genetic factors may be involved, because sleepwalkers are re-ported to have a higher than expected frequency of first-degree relatives with either sleepwalking or sleep terrors. Sleepwalking may be precipitated in affected patients by gently sitting them up during sleep, by fever, or by sleep deprivation. Adult onset of sleepwalking should prompt the search for possible medical, neurological, psychiatric, pharmacological, or other underlying causes, such as nocturnal epilepsy.

Treatment

No treatment for sleepwalking is established, but some patients respond to administration of benzodiazepines or sedating antide-pressants at bedtime. The major concern should be the safety of the sleepwalker, who may injure herself or himself or someone else during an episode.

REM Sleep Behavior Disorder

This disorder, like sleepwalking, is associated with complicated behaviors during sleep such as walking, running, singing and talking. In contrast to sleepwalking, which occurs during the first third of the night during delta sleep, REM sleep behavior disorder usually occurs during the second half of the night during REM sleep. It apparently results from an intermittent loss of the muscle atonia that normally accompanies REM sleep, thus allowing the patient to act out her or his dream. Also, in contrast to sleepwalk-ing, memory for the dream content is usually good. Furthermore, the idiopathic form typically occurs in men during the sixth or seventh decade of life. The cause or causes remain unknown. It has been reported in a variety of neurological disorders and dur-ing withdrawal from sedatives or alcohol; during treatment with tricyclic antidepressants or biperiden (Akineton); and in various neurological disorders including dementia, subarachnoid hemor-rhage and degenerative neurological disorders.

Treatment

Nocturnal administration of clonazepam, 0.5 to 1 mg, is usually remarkably successful in controlling the symptoms of this dis-order. Patients and their families should be educated about thnature of the disorder and warned to take precautions about injur-ing themselves or others.

Nocturnal Panic Attacks

The typical daytime panic attack, as bizarre and frightening as it may seem to the patient experiencing it, is often fairly obvi-ous to the assessing psychiatrist. Symptoms of anxiety, sweating, tremor, dizziness, chest pain and palpitations occur “out of the blue” with or without specific behavioral or associational stim-uli. Once it has been diagnosed, treatment options may include pharmacotherapy with one of several classes of drugs, behavioral therapy, or a combined approach.

When these symptoms occur at night, the task of the as-sessing psychiatrist is greatly complicated. The patient may as-sume that the cause is a nightmare or a night terror and may be resistant to the diagnosis of an anxiety disorder, particularly if the symptoms are absent or mild during the daytime. Patients with panic disorder often have not only disturbed subjective sleep but also panic attacks during sleep. Psychiatrists should remem-ber that panic attacks could occur exclusively during sleep, with-out daytime symptoms, in some patients. Conversely, a report of “awakening in a state of panic” may be associated with a va-riety of other disorders including obstructive sleep apnea, gas-troesophageal reflux, nocturnal angina, orthopnea, nightmares, night terrors and others.

Sleep-related Epilepsy

Some forms of epilepsy occur more commonly during sleep than during wakefulness and may be associated with parasom-nia disorders. Nocturnal seizures may at times be confused with sleep terror, REM sleep behavior disorder, paroxysmal hypno-genic dystonia, or nocturnal panic attacks (Culebras, 1992). They may take the form of generalized convulsions or may be partial seizures with complex symptoms. Nocturnal seizures are most common at two times: the first 2 hours of sleep, or around 4 to 6 AM. They are more common in children than in adults. The chief complaint may be only disturbed sleep, torn up bedsheets and blankets, morning drowsiness (a postictal state), and muscle aches. Some patients never realize they suffer from nocturnal epilepsy until they share a bedroom or bed with someone who observes a convulsion.

Sleep Disturbances Related to Other Psychiatric Disorders

Subjective and objective disturbances of sleep are common fea-tures of many psychiatric disorders. General abnormalities in-clude dyssomnias (such as insomnia and hypersomnia), paras-omnias (such as nightmares, night terrors and nocturnal panic attacks) and circadian rhythm disturbances (early morning awakening). Before assuming that a significant sleep complaint invariably signals a psychiatric diagnosis, mental health special-ists should go through a careful differential diagnostic procedure to rule out medical, pharmacological, or other causes. Even if the sleep complaint is primarily related to an underlying psychi-atric disorder, sleep disorders in the mentally ill may be exacer-bated by many other factors, such as increasing age; comorbid psychiatric, sleep and medical diagnoses; alcohol and substance abuse; effects of psychotropic or other medications; use of caf-feinated beverages, nicotine, or other substances; lifestyle; past episodes of psychiatric illness (persisting “scars”); and cognitive, conditioned and coping characteristics such as anticipatory anxi-ety about sleep as bedtime nears. Some features of these sleedisorders may persist during periods of clinical remission of the psychiatric disorder and may be influenced by genetic factors. Finally, even if the sleep complaint is precipitated by a nonpsy-chiatric factor, psychiatric and psychosocial skills may be useful in ferreting out predisposing and perpetuating factors involved in chronic sleep complaints.

Although signs and symptoms of sleep disturbance are common in most psychiatric disorders, an additional diagnosis of insomnia or hypersomnia related to another mental disorder is made according to DSM-IV-TR criteria only when the sleep dis-turbance is a predominant complaint and is sufficiently severe to warrant independent clinical attention. Many of the patients with this type of sleep disorder diagnosis focus on the sleep complaints to the exclusion of other symptoms related to the primary psychi-atric disorder. For example, they may seek professional help with complaints of insomnia or oversleeping when they should be at work, excessive fatigue, or desire for sleeping pills, but initially, they minimize or strongly deny signs and symptoms related to poor mood, anxiety, obsessive rumination, alcohol abuse, or a personality disorder.

Sleep Disturbances in Psychiatric Disorders: “Chicken or Egg?”

Whether sleep disturbances “cause” psychiatric disorders can be debated. At one level, this hypothesis seems unlikely because normal subjects vary considerably in their amount and type of sleep. Occasional extreme short sleepers, “needing” and sleeping as little as an hour a day for many years, have been reported, who appeared to be psychologically and medically normal in other re-spects. Furthermore, prolonged partial or selective sleep depriva-tion in normal volunteers does not apparently precipitate major psychiatric disorders. Normal control subjects have been kept awake for as long as 11 consecutive days in experiments to test the effect of sleep deprivation. Such experiments may cause dyspho-ria and dysfunction but not depression or dementia. Moreover, pa-tients with narcolepsy or depression have been deprived of REM sleep for more than a year while being treated with high doses of MAOIs; if anything, they were better because their primary mood disorder improved during the course of treatment. Finally, total or partial sleep deprivation for one night has antidepressant effects in about half of depressed patients, including severely depressed melancholic, endogenous, or delusional patients.

These observations neither prove nor disprove the hypoth-esis that sleep disturbance does not cause psychiatric disorders. After all, experimental disruption of sleep in normal control sub-jects is highly artificial, usually conducted in supportive environ-ments in well-screened, self-selected, healthy subjects. Likewise, people may vary in their sleep needs, but as far as we know, eve-ryone needs to sleep; it may just be that individuals vary in the threshold of sleep disturbance beyond which they can go before manifesting psychiatric symptoms. Most important, chronic sub-jective sleep disturbances may be risk factors for certain vulner-able individuals. Thus, specific sleep characteristics may predis-pose to, or be a risk factor for, later development of psychiatric or substance abuse disorders. Again, the complaint of chronic insomnia or hypersomnia or normal short sleep cannot always be equated with objective sleep abnormalities, but it should at least alert the psychiatrist to the possibility that the patient deserves careful monitoring for a time.

Sleep disruption may be particularly harmful to some per-sons, for example, bipolar disorder patients, whether euthymic or depressed, in whom sleep deprivation may precipitate a manicepisode. Mania is not uncommon with jet lag or work-related sleep deprivation in bipolar disorder patients. Behavioral and ap-parent personality changes with sleep deprivation are probably common but more often ignored in everyday life. The irritability of sleep-deprived children is known to most parents; and who of us has not had a “bad day” after a “bad night”?

Whereas insomnia is probably the most common sleep complaint in most psychiatric disorders, hypersomnia is not in-frequently reported, especially in association with the following: bipolar mood disorder during depressed periods; major depres-sive disorder with atypical features (i.e., hypersomniac, hyper-phagic patients with “leaden paralysis” and loss of energy); sea-sonal (winter) depression; stimulant abusers during withdrawal; some patients with personality disorders; and patients who are heavily sedated with anxiolytic, antipsychotic, or antidepressant medications, among other disorders.