• Non-REM arousal disorders
• REM sleep disorder
• Other REM related events
• Movement disorders
• Panic disorder
• Dissociative and conversion disorder
• Sleep attacks

Disorders of arousal from non-rapid eye movement (NREM) sleep are defined by the incomplete arousal from NREM sleep. Patients demonstrate behaviors usually associated with wakefulness while still asleep. Events such as sleepwalking, sleep terrors, and confusional arousals are common in children and to a lesser extent in adults. Approximately 30% of children have sleepwalking or sleep terror events, and the reported prevalence in adults ranges from 2% to 5%.35–37 The decrease in NREM events with increasing age raises the possibility that these disorders may represent an aberrance of maturation of sleep-wake regulation.

Frequently, patients with a NREM parasomnia disorder have a family history.38 First-degree relatives of a patient with sleepwalking have a tenfold greater incidence of sleepwalking.

Typically, NREM events are more common in the first one-third of the night. Patients are amnestic for the event, although a brief visual or auditory perception may occur.

Sleepwalking

Sleepwalking events can be very elaborate, including behaviors such as dressing, unlocking locks, cleaning, cooking, and driving. Some patients even describe events involving firearms and other potentially dangerous items.39 Patients can recall various feelings or impressions from the events and, rarely, some imagery.

A potential variant of this behavior is nocturnal eating disorder, in which patients arise during the night and eat high-calorie food. The patients generally have different eating habits than their usual daytime habits and have no memory for the events. Patients may eat raw meats, candies with the wrappers, or boxes of cookies. Patients may describe awakening in the morning to find a messy kitchen and food particles still on their bedclothes and in their hair. Occasionally, these events coincide with periods of restricted caloric intake.38

Sleep terrors

Sleep terrors are a more intense form of sleepwalking. Most patients with sleep terrors also have sleepwalking events. The predominance of autonomic expression during sleep terrors helps to distinguish these events from other partial arousals from NREM sleep. The sudden arousal from slow-wave sleep with a piercing scream or cry, accompanied by autonomic and behavioral manifestations of intense fear, is rarely forgotten by any witness. The onset of the events is abrupt, and patients have tachycardia, tachypnea, flushing, diaphoresis, and mydriasis. The patients are confused and disoriented, and attempts to intercede may result in harm to the person trying to wake the patient. Patients can become violent, resulting in injury to themselves and bed partners.

About 3% of children and fewer than 1% of adults may have these events.36,37

Confusional arousals

Confusional arousals can occur at any arousal from NREM sleep. They are characterized by disorientation, slow speech and mentation, or inappropriate behavior.40 The patients have memory impairment for the event, and the events can be induced with forced arousal. The course of these events usually improves with age and remains stable in adults.

Diagnosis

The diagnosis of NREM arousal disorder is usually made by history. If any atypical characteristics are present, video-EEG polysomnography should be performed to exclude seizure activity. Atypical characteristics include:

• adult onset
• lack of a family history
• spells not limited to the first one-third of the night
• spells that occur many times a night
• spells that occur during naps
• stereotyped features

Treatment

Treatment includes:

• avoidance of sleep deprivation, which can precipitate events
• creation of a safe environment for the patient (e.g., window locks, ground floor room)
• clonazepam or tricyclic antidepressants (occasionally)

Adapted from: Malow, BA, and Vaughn BV. Sleep disorders and epilepsy. In: Ettinger AB and Devinsky O, eds. Managing epilepsy and co-existing disorders. Boston: Butterworth-Heinemann; 2002;255–267. With permission from Elsevier (www.elsevier.com).

Reviewed and revised April 2004 by Steven C. Schachter, MD, epilepsy.com Editorial Board.

Rapid eye movement (REM) sleep behavior disorder (RBD) is characterized by intermittent loss of REM sleep–related atonia, with the appearance of elaborate motor activity associated with dream mentation. RBD was predicted by Jouvet in 1965, when he showed in cats that loss of the atonia that normally occurs during REM sleep could be produced experimentally by specific pontine tegmental lesions.41 In 1986, Schenck and Mahowald described RBD in humans.42

The behaviors in RBD can include punching, kicking, leaping, running, talking, yelling, and any behavior that could occur during a dream. Bed partners are frequently injured, and patients may go to great lengths to prevent injury to themselves or to bed partners. Patients usually have a vivid recall of the actual dreams that correlate to the witnessed behavior. (Dream recall is not uniformly noted, and patients may not be willing to talk about the dream that led them to seek medical attention.) These events occur more commonly in the latter half of the night but can occur any time the patient enters REM sleep.

Most cases begin in late adulthood, but children as young as age 2 years have presented with symptoms of RBD. It occurs most often in men.43

Causes

RBD can be induced by medication, and cases of tricyclic antidepressants, monoamine oxidase inhibitors, and serotonin reuptake inhibitors causing RBD-like behavior have been reported. Acute forms of RBD can also occur during alcohol withdrawal and, potentially, benzodiazepine withdrawal.

About 60% of patients have no clear identifiable cause for the disorder. In 40%, an identifiable neurologic disorder such as stroke, posterior fossa tumor, demyelination, or a degenerative disorder may prevent the induction of REM sleep–related atonia.44,45

Diagnosis

The diagnosis of RBD is made by a combination of history and polysomnography.43 Patients or witnesses should give the history of sleep behaviors that are disruptive, potentially harmful, or annoying, or there should be videotape documentation of excessive limb or body jerks, complex movements, or vigorous movements during REM sleep.

The polysomnogram should demonstrate excessive EMG tone in the chin or excessive twitching of the chin or limb leads during REM sleep. The addition of an extended EEG montage is important, to exclude epileptic seizures. The events in RBD are longer and less stereotyped than seizures.

Treatment

Patients with this disorder generally respond well to clonazepam. Dopaminergic compounds, antiepileptic drugs, clonidine, and even tricyclic antidepressants may be helpful in intractable cases.

Adapted from: Malow, BA, and Vaughn BV. Sleep disorders and epilepsy. In: Ettinger AB and Devinsky O, eds. Managing epilepsy and co-existing disorders. Boston: Butterworth-Heinemann; 2002;255–267.
With permission from Elsevier (www.elsevier.com).

Reviewed and revised April 2004 by Steven C. Schachter, MD, epilepsy.com Editorial Board.

Occasionally, patients present with the description of other REM-sleep fragmentary events as nocturnal behaviors. Patients with terrifying hypnagogic hallucinations may note recurrent scary imagery just as they are falling asleep. These events may be associated with screaming, yelling, or other frightened behavior. Patients have a clear memory for the events and can recall the visual imagery.46

Patients with recurrent sleep paralysis may also present with complaints of unusual spells. These individuals describe complete paralysis on awakening. They cannot move their extremities, and calling out may only produce a weak whisper. They can have concurrent visual imagery and a sense of impending doom or of being chased. These episodes may last seconds to minutes and can be aborted by another individual touching the patient. Patients may note that these spells are recurrent.47

A rare disorder, REM sleep sinus arrest can present as events of sudden arousal with a sense of impending doom. A sense of panic and fear can be a symptom. These patients may have histories compatible with isolated nocturnal panic attacks. Polysomnography shows sinus pauses of 2.5 seconds or longer during REM sleep. These patients need to be identified and referred for cardiac evaluation and pacemaker placement.48

Adapted from: Malow, BA, and Vaughn BV. Sleep disorders and epilepsy. In: Ettinger AB and Devinsky O, eds. Managing epilepsy and co-existing disorders. Boston: Butterworth-Heinemann; 2002;255–267.
With permission from Elsevier (www.elsevier.com).

Reviewed and revised April 2004 by Steven C. Schachter, MD, epilepsy.com Editorial Board.

Patients with rhythmic movement disorder can present with complaints of repetitive movements that occur before sleep onset.49 The movements are stereotyped, involving large muscles, usually of the head and neck, and are sustained into light sleep. Movements may include head banging, body rocking, leg rolling, humming, and chanting. Some patients are relatively unaware of the movement, and others describe the movement as a calming effect or a compulsion before sleep.

This behavior is frequently seen in infants and young children, and the prevalence diminishes with age. It is more commonly seen in individuals with mental handicaps or autism and is more prevalent in men. Emotional stress may provoke the movements.

Typical episodes are seen on polysomnography as episodes of rhythmic movement preceding sleep onset and during stage 1 sleep, although rhythmic movement disorder can occur out of any stage of sleep.

Sleep bruxism

Sleep bruxism can occur as a rhythmic or repetitive movement during sleep.22,50 Grinding or clenching of the teeth during sleep may produce bizarre sounds, and patients rarely can even vocalize with the episodes. Patients may have abnormal wear of the teeth, jaw pain, headache, facial pain, or tooth pain. They may have hundreds of events per night, and the events increase with emotional stress.

Some studies suggest as many as 85% of the population grinds its teeth to some degree.22 These events usually begin in the teen years. Occasionally a familial pattern can be ascertained.

The polysomnogram demonstrates repetitive bouts of increased temporalis muscle activity, particularly occurring before sleep onset and continuing through stage 2 sleep.

Patients should have a dental evaluation and be considered for bite plates.

Adapted from: Malow, BA, and Vaughn BV. Sleep disorders and epilepsy. In: Ettinger AB and Devinsky O, eds. Managing epilepsy and co-existing disorders. Boston: Butterworth-Heinemann; 2002;255–267.
With permission from Elsevier (www.elsevier.com).

Reviewed and revised April 2004 by Steven C. Schachter, MD, epilepsy.com Editorial Board.

Panic disorders range in prevalence between 1% and 3% of the general population. Approximately 6–14% of young adults report at least one spontaneous panic attack.51,52 Most of these events occur during the day, but as many as 2.5% of the attacks may occur exclusively as nighttime events. Two-thirds of patients with panic attacks have had one or more events at night.

Polysomnographic data demonstrate that panic attacks can occur at sleep onset or during stage 2 or slow-wave sleep, but the hallmark is that the event occurs after awakening. On polysomnography, patients have an abrupt arousal from sleep, followed by52–55:

• tachycardia
• tachypnea
• diaphoresis
• tremulousness
• feelings of impending doom
• clear memory of the events

Further systematic monitoring may be required to distinguish nocturnal panic attacks from other etiologies:

• other parasomnias
• nightmares
• gastroesophageal reflux
• REM sleep sinus arrest
• sleep-related laryngospasm
• paroxysmal nocturnal dyspnea
• nocturnal asthma
• seizures

Adapted from: Malow, BA, and Vaughn BV. Sleep disorders and epilepsy. In: Ettinger AB and Devinsky O, eds. Managing epilepsy and co-existing disorders. Boston: Butterworth-Heinemann; 2002;255–267.
With permission from Elsevier (www.elsevier.com).

Reviewed and revised April 2004 by Steven C. Schachter, MD, epilepsy.com Editorial Board.

Psychogenic events also must be included in the differential diagnosis of nocturnal events(see Table: Differential Diagnosis of Nocturnal Events). Among these are dissociative disorders. These disorders are relatively rare and may present initially as only nocturnal events.56 These fugue states may last hours, with loss of identity and memory. Patients usually have some diurnal symptoms and may have a history of physical or sexual abuse. They can occur in association with post-traumatic stress disorder.57

During polysomnographic monitoring, patients with dissociative disorders frequently demonstrate wakefulness before the onset of the spells.58 Simultaneous time-synchronized video monitoring is required to correlate the behavior with the electrographic data.

Conversion disorders also present as nocturnal events. Patients have significant underlying stressors or conflicts, which initiate or exacerbate the episodes.56 They may also have models to mimic epileptic spells. Although these events are unintentional, they have a clear impact on the patient's ability to function.56

Most patients with nocturnal events and conversion disorders have arousals before their events. They may or may not have memory for the events.

Adapted from: Malow, BA, and Vaughn BV. Sleep disorders and epilepsy. In: Ettinger AB and Devinsky O, eds. Managing epilepsy and co-existing disorders. Boston: Butterworth-Heinemann; 2002;255–267.
With permission from Elsevier (www.elsevier.com).

Reviewed and revised April 2004 by Steven C. Schachter, MD, epilepsy.com Editorial Board.

Sleep attacks due to excessive daytime sleepiness may result from a variety of causes. Intrinsic causes include narcolepsy and idiopathic hypersomnia. Sleep disruption and chronic sleep deprivation from disorders such as obstructive sleep apnea or restless legs syndrome also may produce sleep attacks. These sleep attacks may mimic epileptic seizures or the pseudoseizures characteristic of conversion disorders.59

A cardinal diagnostic feature of these sleep attacks is that they tend to occur in sedentary situations. Long-term video-EEG monitoring is sometimes necessary to exclude seizures. It typically documents drowsiness at the onset of the attack.

Adapted from: Malow, BA, and Vaughn BV. Sleep disorders and epilepsy. In: Ettinger AB and Devinsky O, eds. Managing epilepsy and co-existing disorders. Boston: Butterworth-Heinemann; 2002;255–267.
With permission from Elsevier (www.elsevier.com).

Reviewed and revised April 2004 by Steven C. Schachter, MD, epilepsy.com Editorial Board.