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INTRODUCTION — Abnormal movements and behaviors during sleep are part of a larger group of nocturnal events that may occur during sleep, wake, or the transitions into or out of sleep. These events are most common early in life, affecting approximately 15 to 20 percent of children and 4 percent of adults [1-4].
Nocturnal events are typically divided into simple behaviors (eg, single movements, repetitive or periodic movements, rhythmical movements) and complex behaviors (eg, sleep talking, sleepwalking, sleep terrors, dream enactment) (table 1).
A detailed history, including a clear description from the patient and ideally a bed partner or family witness, is the cornerstone of establishing clues about the underlying etiology. The challenge for the clinician is to recognize when certain nocturnal events signal an underlying, treatable disorder, an emerging neurological abnormality, or a benign age-appropriate episode.
An approach to the evaluation and diagnosis of abnormal movements and behaviors during sleep is presented here. Additional topics on the diagnosis and treatment of specific parasomnias, sleep-related movement disorders, and other paroxysmal neurological events in both children and adults can be found elsewhere. (See "Sleepwalking and other parasomnias in children" and "Disorders of arousal from non-rapid eye movement sleep in adults" and "Rapid eye movement sleep behavior disorder" and "Clinical features and diagnosis of restless legs syndrome/Willis-Ekbom disease and periodic limb movement disorder in adults" and "Restless legs syndrome/Willis-Ekbom disease and periodic limb movement disorder in children" and "Sleep-related epilepsy syndromes".)
TYPES OF NOCTURNAL EVENTS
Classification — Although classification and nomenclature of sleep-related movements and behaviors have varied over time, most schema attempt to classify behaviors according to the type of movement (ie, simple or complex) and the underlying sleep physiology, ie, whether movements are associated with transitions of sleep and wake, non-rapid eye movement (NREM), or rapid eye movement (REM) sleep (table 1).
Most simple movements occur during the transition from wake to sleep or sleep to wake or during light, NREM sleep (figure 1). Complex behaviors can result from disruption of the control mechanisms of the three normal states of being: wake, NREM sleep, and REM sleep.
Occasionally, simple or complex motor patterns during sleep are a manifestation of seizures, dissociative psychiatric events, or even physiological states such as hypoglycemia. Therefore, clinicians should be aware that nocturnal events may be a manifestation of specific neurologic, medical, psychiatric, or sleep disorders. On the other hand, some of these behaviors, specifically the disorders of arousal and nightmares, may be normal in childhood.
Simple or single movements — Simple movements during sleep are typically quick, single movements involving only one body area (table 2A). They tend to occur in the transition periods between sleep and wakefulness (figure 1) and are classified by the International Classification of Sleep Disorders, Third Edition (ICSD-3), as movement disorders of sleep .
●Hypnic jerks – Hypnic jerks are a common example of simple sleep-related movements. They consist of a sudden, brief jerk of the whole body or one or more segments at sleep onset, often associated with the sense of falling. Hypnic jerks can occur at any age and are a benign phenomenon, sometimes related to sleep deprivation or excessive caffeine or other stimulant intake.
Some hypnic jerks are accompanied by sensory phenomena, most commonly a kinetic sensation of falling but sometimes a brief visual, auditory, or tactile sensation. These sensory starts or sleep-related hallucinations can also occur without a motor accompaniment. Such symptoms can be distressing to patients and may lead to sleep avoidance or delayed sleep onset.
A more dramatic, primarily sensory phenomenon that also occurs at sleep onset is called exploding head syndrome, consisting of a painless sensation of head explosion [5-7]. The ICSD-3 classifies this event under "other parasomnias," but due to its clinical features, it is sometimes confused with a headache syndrome and even subarachnoid hemorrhage. There is typically no actual movement associated with this phenomenon.
●Propriospinal myoclonus – Propriospinal myoclonus at sleep onset consists of flexion or extension jerks in the abdomen, trunk and/or neck during relaxed wakefulness and drowsiness, as an individual attempts to fall asleep. Propriospinal myoclonus that persists throughout the day has been linked to spinal cord pathology in a minority of patients; however, there is no evidence that propriospinal myoclonus that is limited to sleep onset is associated with structural nervous system damage. Magnetic resonance imaging (MRI) of the spine is usually normal, but approximately one fifth of patients may show focal lesions of unclear significance . (See "Symptomatic (secondary) myoclonus", section on 'Propriospinal myoclonus'.)
●Epileptic myoclonus – Sudden jerks of the limbs that occur with waking or soon after waking in children or adolescents may represent epileptic myoclonic jerks, a type of seizure that is common in patients with juvenile myoclonic epilepsy (JME). These patients usually have other types of generalized seizures as well; with careful history taking, nearly all patients with JME have myoclonic seizures, but almost never in isolation. (See "Juvenile myoclonic epilepsy", section on 'Clinical features'.)
●Benign sleep myoclonus of infancy – Benign sleep myoclonus of infancy, also called benign neonatal sleep myoclonus, refers to brief jerks of the limbs during NREM sleep in young infants. The jerks are usually bilateral and symmetric. They typically occur during the first few weeks of life and resolve by two to three months of age. The movements are benign but can be confused with seizures. However, unlike the jerks of myoclonic seizures or severe myoclonic epilepsy syndromes of infancy, benign myoclonus occurs exclusively during sleep, does not continue when the infant is awoken, and is associated with normal neurologic development. (See "Nonepileptic paroxysmal disorders in infancy", section on 'Benign neonatal sleep myoclonus'.)
●Bruxism – Bruxism (teeth grinding) consists of quick jerks or grinding movements involving the muscles of mastication. Bruxism typically occurs at sleep onset or in association with arousals from sleep and may recur multiple times per night. Primary consequences include dental pathology, temporomandibular joint dysfunction, and morning headaches. (See "Sleep-related bruxism (tooth grinding)" and "Polysomnography in the evaluation of abnormal movements during sleep", section on 'Sleep-related bruxism'.)
●Nocturnal leg cramps – Nocturnal leg cramps are painful, sustained muscle contractions, most commonly in the calf, foot, or thigh, that may occur at any time during the night. They typically last from seconds to minutes and are relieved by forceful stretching of the affected muscles. The main differentiating feature compared with other sleep-related leg movements is the presence of sustained muscle contraction. (See "Nocturnal leg cramps".)
Periodic or rhythmic movements — Periodic or rhythmic movements that may occur in or around sleep include body or head rocking or banging, hypnagogic foot tremor, and periodic limb movements of sleep (table 2B).
●Sleep-related rhythmic movement disorder – Rhythmic movements involving large muscle groups at sleep onset (eg, body rocking and rolling, head rocking and rolling) may occur in early childhood as the child is trying to fall asleep. In most cases, the movements are not associated with significant clinical consequences and are considered developmentally normal.
When the movements or behaviors significantly interfere with normal sleep or daytime function, or result in self-harm or injury, they are classified as a sleep-related rhythmic movement disorder . Sleep-related rhythmic movement disorder rarely occurs in adolescents and adults, sometimes in association with other sleep disorders such as obstructive sleep apnea or restless legs syndrome/Willis-Ekbom disease (RLS/WED), in which case it may improve with treatment of the sleep disorder.
●Hypnagogic foot tremor – Hypnagogic foot tremor is a rapid, rhythmic movement of one foot that occurs at the onset of sleep or during light NREM sleep. It is believed to be a physiologic phenomenon; in one series of 375 consecutive adults undergoing polysomnography for other reasons, hypnagogic foot tremor was noted in 8 percent of patients and was not associated with disrupted sleep .
Alternating leg muscle activation (ALMA) is a related phenomenon that consists of brief activation of the anterior tibialis in one leg in alternation with similar activity in the other leg during sleep or arousals from sleep . Most individuals are unaware of the movements. ALMA has been identified primarily in patients with sleep-related breathing disorders and periodic limb movements. There may be an association with antidepressant use.
●Periodic limb movements of sleep – Periodic limb movements of sleep are episodes of repetitive and highly stereotyped limb movements occurring every 5 to 90 seconds, primarily during the first half of the night and during NREM sleep. Most people who have periodic limb movements do not have any symptoms associated with them. They occur with increased frequency in older adults with and without other sleep or neurologic disorders. In particular, most patients with RLS/WED have evidence of these movements in sleep. (See "Clinical features and diagnosis of restless legs syndrome/Willis-Ekbom disease and periodic limb movement disorder in adults", section on 'Periodic limb movements of sleep' and "Polysomnography in the evaluation of abnormal movements during sleep", section on 'Periodic limb movements of sleep'.)
Complex movements and behaviors (parasomnias) — Complex movements and behaviors during sleep, or parasomnias, encompass common or bizarre behaviors as well as seemingly purposeful movements, perceptions, dreaming, and autonomic output during sleep or sleep transitions. While the simple movements described above tend to occur during the transition between sleep and wakefulness, more complex behaviors may occur in a variety of sleep states.
The ICSD-3 categorizes parasomnias into three major groups: events associated with NREM sleep, events associated with REM sleep, and other parasomnias .
During NREM sleep — Events associated with NREM sleep include disorders of arousal (eg, sleepwalking, sleep terrors, confusional arousals) and sleep-related eating disorder (table 2C).
●Disorders of arousal – Sleepwalking, confusional arousals, and sleep terrors are a mixture of NREM sleep and wake states, such that the features of the two states are combined . These disorders represent a continuum of behaviors evoked from deep NREM sleep, possibly related to compromised ability to inhibit or fully permit arousal from sleep [9,10]. All three are characterized by minimal cognitive functioning, amnesia for the events, and features of appearing awake, such as eyes open. Some patients report a memory of vague, visual imagery and auditory impressions.
Events are often triggered by stimuli, occur after acute sleep deprivation or psychosocial stressors, and involve a variety of nonstereotyped behaviors. Sleep-disordered breathing events such as an apnea or other sleep disorders may also serve as a trigger. Disorders of arousal occur most commonly in children and adolescents. (See "Sleepwalking and other parasomnias in children", section on 'Clinical features' and "Disorders of arousal from non-rapid eye movement sleep in adults".)
●Sleep-related eating disorder (SRED) – SRED is similar to other disorders of arousal and occurs due to a mixture of wake and NREM sleep. SRED is characterized by episodes of recurrent involuntary and amnestic eating during the sleep period. Patients often consume peculiar forms of food (eg, raw hamburger, cake mix) with partial or no memory of the event. In many cases, SRED may be related to treatment with a hypnotic agent or a comorbid sleep disorder such as RLS/WED. (See "Disorders of arousal from non-rapid eye movement sleep in adults", section on 'Sleep-related eating disorder'.)
During REM sleep — REM sleep-related parasomnias include recurrent isolated sleep paralysis, nightmares, and REM sleep behavior disorder (RBD) (table 2C).
●Recurrent isolated sleep paralysis – Recurrent isolated sleep paralysis is characterized by the intrusion and persistence of REM sleep-related atonia into wakefulness [10,11]. Patients with sleep paralysis are completely unable to move or call out, yet many will have a dramatic sense of impending doom or urgency to flee. Individuals may remember these events for years. Some of these events may also be accompanied by hallucinations. Although sleep paralysis can occur as part of the classic narcolepsy tetrad, in most cases, sleep paralysis is an isolated symptom and is related to sleep deprivation. (See "Clinical features and diagnosis of narcolepsy in adults", section on 'Clinical features'.)
●Nightmare disorder – Complex visual imagery during REM sleep is the hallmark of nightmare disorder. Nightmares are distressing dreams that have an emotional carryover into wakefulness. While nightmares usually do not have a motor component, they may end abruptly with the patient screaming or, less frequently, experiencing a sudden jerk or brief movement [12,13]. True, more complex or violent dream enactment is not consistent with nightmare disorder, but rather RBD. The latter is more common in older adults compared with children. Nightmares should also be distinguished from sleep terrors (table 3). (See "Sleepwalking and other parasomnias in children", section on 'Sleep terrors' and "Disorders of arousal from non-rapid eye movement sleep in adults", section on 'Sleep terrors'.)
●REM sleep behavior disorder (RBD) – RBD is characterized by complex movements or behaviors during REM sleep that occur due to a pathologic loss of muscle paralysis (atonia) that normally occurs during REM sleep. The movements often correspond to a dream in which the individual is being attacked or needs to defend him/herself or others [14,15]. Movements range from relatively brief limb movements to more complex, violent movements such as punching or leaping out of bed. Associated vocalization is common, and language may be laden with expletives. (See "Rapid eye movement sleep behavior disorder", section on 'Clinical features'.)
RBD is most commonly seen in older males in association with Parkinson disease, multiple system atrophy, and dementia with Lewy bodies [14,15]. The disorder may predate other symptoms of alpha-synuclein neurodegeneration by decades. In younger patients, the gender distribution is more equal, and medications are often implicated (particularly the serotonergic antidepressants). (See "Rapid eye movement sleep behavior disorder", section on 'Etiology'.)
Vocalization — Vocalization during sleep is a common nocturnal event. Vocalization can be simple or more complex and can be associated with a variety of sleep-related movements and behaviors, both physiologic and pathologic.
Most vocalizations are utterances or short phrases, such as those seen in the normal variant of sleep talking. Talking can also be a feature of the disorders of arousals (sleepwalking, sleep terror, or confusional arousals) or RBD. The key distinction between physiologic sleep talking and disorders of arousal or REM sleep is the inclusion of other motor behaviors.
Monotonous expiratory groaning during sleep may indicate a sleep-related breathing disorder called catathrenia. Catathrenia is characterized by prolonged expirations, primarily during REM sleep, that can be very distressing to the bed partner and family members . The disorder can be treated with continuous positive airway pressure (CPAP).
Nocturnal epilepsy — The differential diagnosis of abnormal movements or behaviors during sleep includes nocturnal seizures. While a generalized tonic clonic seizure out of sleep is usually obvious by history and not easy to confuse with a sleep disorder (bilateral tonic clonic movements, often with tongue biting and/or urinary incontinence, postictal drowsiness and confusion), some patients have focal seizures involving stereotyped, complex behaviors that occur predominantly or exclusively at night.
Behaviors associated with epileptic seizures can range across a wide spectrum and they can be difficult to distinguish from parasomnias. The main clue that events are seizures rather than parasomnias is the stereotyped nature of seizures [17,18]. Nocturnal frontal lobe epilepsy, also called sleep-related hypermotor epilepsy, is one example of an epilepsy syndrome involving predominantly nocturnal seizures with complex behaviors. Onset of seizures is typically in late childhood or adolescence. (See "Sleep-related epilepsy syndromes", section on 'Nocturnal (sleep-related) focal epilepsies'.)
As discussed above, brief myoclonic jerks upon awakening are another type of seizure that occurs in relation to sleep-wake transitions, usually in association with juvenile myoclonic epilepsy. (See 'Simple or single movements' above.)
Panic or dissociative events — Some psychiatric symptoms, such as panic or dissociative events, occur during the night [19-22]. In the majority of patients, however, symptoms are not limited to the sleep period. Most patients with dissociation or panic have diurnal symptoms, a history of traumatic events, or other symptoms of major mood disorders . (See "Disorders of arousal from non-rapid eye movement sleep in adults", section on 'Others'.)
EVALUATION — The goal of the evaluation of a patient with abnormal movements or behaviors during sleep is threefold:
●Obtain a clear description of the events, including a direct description from a bed partner when possible
●Assess whether the patient is at risk for harm to self or others as a result of the movements or behaviors
●Determine what may be driving the appearance of the events and whether the events are indicative of an underlying, treatable disorder
History — Clinical features are the cornerstone of differentiating nocturnal events (table 2A-C). In addition to the event description, the history should also focus on recognition of any provocative factors (eg, sleep deprivation, medications, certain medical or neurologic disorders) and clues to an underlying sleep disorder.
Event description — An event description should be obtained from a bed partner when possible, as many nocturnal events cannot be recalled by the individual. The witness should be asked to describe or even act out the behaviors that occur during the events to help identify important features such as eyes being open or closed, posturing of one hand, specific facial posture, or stereotypic behavior. Patients and witnesses also should be asked if the events have caused injury or near-harm to self or others.
In addition to the behavioral characteristics of the events, historical features that can help distinguish the type of event include the following:
●Time of night – The time of night when events occur is a clue to the sleep stage out of which the event arises (figure 1). (See "Stages and architecture of normal sleep", section on 'Sleep staging'.)
•Simple movements, such as hypnic starts, occur during the transition from drowsiness to sleep, or in the early stages of non-rapid eye movement (NREM) sleep.
•For more complex movements and behaviors, the sleep stage may provide a clue to whether the event is a disorder of arousal (associated with NREM sleep, which predominates in the first hour or two of the sleep period) or rapid eye movement (REM) sleep behavior disorder (RBD, associated with REM sleep, which predominates in the second half of the sleep period).
•Nocturnal seizures and psychiatric events can occur at any time of night.
●Duration of the event – This can help distinguish NREM from REM complex behaviors.
•Most movements associated with RBD are brief, lasting seconds. Disorders of arousal can last seconds to several minutes.
•Frontal lobe seizure duration is more variable: some seizures are brief (eg, posturing lasting several seconds), whereas others may consist of bizarre behaviors lasting from 30 to 60 seconds.
•Prolonged events (ie, lasting over thirty minutes to an hour) are more likely psychiatric in origin.
●Variable versus stereotyped behaviors – Events that have the same behavior each time (stereotypic and monomorphic), especially at the start of the events, are more likely to be seizures, with some exceptions (eg, rhythmic movement disorder, periodic limb movements). Events that vary in behavior (polymorphic) from one event to the next are less likely to be seizures.
●Eyes open or closed – Most disorders of arousal (eg, sleepwalking, night terrors) are associated with open eyes, whereas the complex movements and behaviors of RBD are associated with closed eyes.
●Memory recall – Most patients with RBD have dream recall that is congruent with the behaviors performed. Patients with disorders of arousal have either partial recall or no recall of the events. Patients with seizures may have recall if the events are brief, the patient awakens, and the seizure does not involve both hippocampi; once both hippocampi are involved, however, the patient may not have complete memory for the event.
●Age of onset – Most of the NREM-related parasomnias begin during early childhood and resolve by adolescence. By contrast, RBD primarily affects older adults, usually males, except when the disorder is related to a medication or another sleep disorder such as narcolepsy.
●Family history of nocturnal events – Many of the disorders of arousal (eg, sleepwalking, night terrors) are hereditary, and a family history of similar events in siblings or parents can provide reassurance of the benign nature of the events. Some forms of nocturnal epilepsy also have a strong genetic component.
There are several partially-validated questionnaires that can help identify patients with specific parasomnias or distinguish among types of parasomnias.
●The Mayo Sleep Behavior Questionnaire is a 16-item questionnaire designed to predict the likelihood of RBD as well as other disorders (eg, restless legs syndrome) . It is available online for clinical use. The single question, "Have you ever seen the patient appear to 'act out his or her dreams' while sleeping?", has also been validated in a community-based sample .
●The Frontal Lobe Epilepsy and Parasomnia (FLEP) scale can help to distinguish frontal lobe seizures from parasomnias and may be helpful in directing which study to order next (table 4) . Those with scores suggesting frontal lobe epilepsy may benefit from video electroencephalography (EEG) recording, while those more likely to have parasomnia should have video polysomnography. Although somewhat helpful, the scale has a significant gray zone that demonstrates its limitations for seizures originating from locations other than the frontal lobe and some parasomnias.
Provocative factors — Some nocturnal events can be provoked or exacerbated by poor sleep quality, medications, or other related factors. The history should include questions about a broad range of possible provocative factors, such as :
●Poor sleep hygiene
●Circadian rhythm disturbances (eg, jet lag)
●Fever or other illnesses
●Ingestion of alcohol or sedatives before sleep onset
If provocative factors are not immediately obvious, patients with nocturnal events should be asked to keep an event diary listing events and any associated changes in activity, medications, herbs, supplements, or other potentially inciting issues.
A variety of nocturnal events can be caused or exacerbated by medications or other neurologic, psychiatric, or medical disorders [26-31]. Some hypnotics with short half-lives, such as zolpidem, have been implicated in initiating complex sleep-related behaviors such as sleep-related eating, sleepwalking, and even driving . (See "Treatment of insomnia in adults", section on 'Risks and side effects' and "Disorders of arousal from non-rapid eye movement sleep in adults", section on 'Sleep-related eating disorder'.)
Medical problems that provoke arousals, such as chronic obstructive pulmonary disease (COPD), hypoglycemia, gastroesophageal reflux, congestive heart failure, or renal disease, and neurologic issues ranging from head trauma, brain tumors, and encephalitis, have been reported to initiate complex sleep-related movements or behaviors.
Symptoms of other sleep disorders — Patients with abnormal movements in sleep should also be questioned regarding symptoms of other sleep disorders, which can exacerbate nocturnal events. The history should therefore probe for symptoms of specific sleep disorders:
●Obstructive sleep apnea (OSA) – Does the patient have loud snoring or witnessed pauses in breathing (apneas)? Are there other symptoms or risk factors suggestive of OSA, such as obesity? Sleep apnea can aggravate disorders of arousal, bruxism, epilepsy, and rhythmic movement disorder. (See "Clinical presentation and diagnosis of obstructive sleep apnea in adults", section on 'Clinical features'.)
●Narcolepsy – Particularly in patients who describe sleep paralysis or dream enactment behavior, are there additional cardinal features of narcolepsy such as cataplexy, daytime sleep attacks, and hypnagogic hallucinations? (See "Clinical features and diagnosis of narcolepsy in adults", section on 'Clinical features'.)
●Periodic limb movement disorder – Patients are usually unaware of periodic limb movements of sleep, and therefore bed partners should be queried. Such patients should also be asked about associated daytime symptoms such as impaired functioning or excessive daytime sleepiness. (See "Clinical features and diagnosis of restless legs syndrome/Willis-Ekbom disease and periodic limb movement disorder in adults", section on 'Diagnosis'.)
Physical examination — Most individuals presenting with abnormal movements or behaviors during sleep will have a normal physical and neurologic examination. The goal of the exam is to detect any signs of trauma from the events themselves (eg, tooth wear associated with bruxism, bruises or injuries from complex sleep-related behaviors) and to detect signs of an underlying medical or neurologic disorder that may be associated with the events.
A history suggestive of a disorder of arousal such as sleepwalking should prompt a search for signs of a sleep-fragmenting disorder such as OSA (eg, elevated blood pressure, increased body mass index, crowded airway, enlarged tonsils, large neck circumference).
Individuals with dream enactment behaviors suggestive of RBD or older adults with nighttime confusion should have a complete neurologic examination to look for signs of cognitive impairment, cogwheeling, lack of arm swing, mask-like facies, orthostatic hypotension, hypokinesis, or other features of parkinsonism [17,32]. Patients suspected of having epileptic seizures also should be evaluated for focal neurologic findings, suggesting a cerebral hemisphere lesion.
Overnight video polysomnography — Polysomnography (PSG) can provide important information in determining the etiology of the nocturnal events, with the goal of capturing the physiology of each sleep state and evaluating the possibility of other contributing sleep disorders . While many patients can be diagnosed and treated based on the history alone, overnight PSG should be obtained if the history is atypical (eg, unusual age of onset, high frequency of events, stereotypic behaviors, or a mixture of symptoms), if the patient reports significant daytime sleepiness, when other sleep disorders are suspected (eg, OSA, narcolepsy), or the patient is at risk for harming themselves or others (table 5) .
PSG performed to investigate nocturnal events should include all of the following components (see "Polysomnography in the evaluation of abnormal movements during sleep"):
●Complete respiratory monitoring
●Time-synchronized high definition video monitoring
●Electromyographic recording from all four limbs ("expanded EMG/RBD/parasomnia montage")
●A complete 10-20 set of cephalic EEG electrodes
●Ability to extensively review the electroencephalogram
Patients with disorders of arousal are relatively unlikely to have events in the laboratory but may demonstrate suggestive PSG features such as continuation of slowing, or prolonged sleep inertia (partial and prolonged confusion) when arousing from slow wave sleep [34,35]. Patients with RBD more commonly have events in the laboratory and demonstrate increased muscle activity in isolated muscle groups, such as the forearm musculature, during REM sleep, often exceeding established norms for REM sleep. (See "Rapid eye movement sleep behavior disorder", section on 'Polysomnography'.)
The presence of wakefulness on PSG prior to and during the nocturnal events may suggest a dissociative disorder, although panic events may occur out of light sleep.
Other testing — Neuroimaging is not necessary in the majority of patients presenting with abnormal movements or behaviors during sleep.
A magnetic resonance imaging (MRI) study of the brain and referral to neurology is indicated in patients diagnosed with nocturnal seizures as part of a broader evaluation to determine the underlying etiology. When the diagnosis of seizure is in doubt, sleep-deprived EEG and ambulatory or inpatient video EEG monitoring may be useful. (See "Clinical and laboratory diagnosis of seizures in infants and children" and "Evaluation and management of the first seizure in adults" and "Video and ambulatory EEG monitoring in the diagnosis of seizures and epilepsy".)
Neuroimaging should also be considered when the onset of a parasomnia is associated with abnormal neurologic signs or symptoms, as rare cases of secondary RBD or narcolepsy related to pathologic processes in the diencephalon or rostral pons have been described. (See "Rapid eye movement sleep behavior disorder", section on 'Pontine lesions' and "Clinical features and diagnosis of narcolepsy in adults", section on 'Secondary narcolepsy'.)
As RBD may be a prodromal symptom of neurodegeneration, patients with events consistent with the disorder should undergo a careful neurologic examination and may require additional studies depending upon the clinical context (eg, structural and/or metabolic neuroimaging, neuropsychological testing, formal neurology consultation). (See "Rapid eye movement sleep behavior disorder", section on 'Evaluation'.)
MANAGEMENT — Management strategies vary according to the type of movement or behavior, its frequency and severity, and whether or not an underlying sleep or other medical or neurologic disorder is present.
Simple sleep-related movements such as hypnic starts and infrequently occurring disorders of arousal (eg, sleepwalking, confusional arousals, sleep terrors) rarely need to be treated. Patients should be educated about triggers for events, including sleep deprivation, and counseled about ensuring a safe sleep environment. Medications that may be implicated in the behaviors (eg, serotonergic antidepressants for rapid eye movement (REM) sleep behavior disorder (RBD), short-acting hypnotics for complex sleep-related behaviors) should be discontinued if possible. (See "Sleepwalking and other parasomnias in children", section on 'Management' and "Disorders of arousal from non-rapid eye movement sleep in adults", section on 'Management'.)
Patients with periodic limb movements associated with arousals and significant daytime sleepiness can respond to pharmacologic therapy with a dopamine agonist, alpha-2-delta calcium channel ligand, or other medications used to treat restless legs syndrome/Willis-Ekbom disease. RBD tends to be very responsive to either melatonin or clonazepam, and all patients should be educated about maximizing environmental safety (eg, removing sharps from the bedroom). (See "Treatment of restless legs syndrome/Willis-Ekbom disease and periodic limb movement disorder in adults", section on 'Periodic limb movement disorder' and "Rapid eye movement sleep behavior disorder", section on 'Treatment'.)
For most parasomnias and abnormal movements, however, patients will continue to have minor occurrences, despite medication or behavioral modification. The overarching goal of therapy is to keep the patient and others safe from current and future harm. If there are minor residual movements that do not impact safety, patients should be reassured and clinicians should resist the urge to over treat.
Treatment of patients with ongoing, frequent abnormal nocturnal movements or behaviors can be challenging. Clinicians may find themselves baffled as to how to proceed or what metric to use to determine success. One simple tool is the event diary. Patients or families can keep a log of the events, including the timing of the event. In this way, potential provocative factors can be examined for possible linkage. The patient or bed partner can be asked to grade the severity of the event, noting if the patient was at risk for harm, or if the event was disruptive to the family. This simple mechanism connects the patient as an active participant in the process of guiding therapy.
Some patients do not respond to therapy. For these patients, the event calendar may also provide further clues leading to an alternative diagnosis or underlying treatable sleep disorder. The history described above should be repeated in order to identify additional clues (see 'History' above):
●Patients with very frequent events may benefit from video electroencephalography (EEG) monitoring, so that several events can be captured and analyzed in more detail.
●In patients with disorders of arousal, the re-emergence of events may signal new or worsening sleep apnea or inadequate therapy of a medical disorder that is causing frequent arousals from sleep.
●Confusional events at night in older adults may be a sign of medication intolerance or progression of an underlying neurocognitive disorder.
●Abnormal movements and behaviors during sleep are part of a larger group of nocturnal events that may occur during wakefulness, the transition into or out of sleep, or during sleep itself (table 1). (See 'Introduction' above.)
●Events can be initially characterized into brief or simple events versus events that contain more complex behaviors such as talking, multipart movements, and emotional expression. Simple, single movements or sensory events are usually not associated with major pathophysiological consequences, although they may be distressing to patients. Complex events typically require further investigation to determine the underlying etiology and possible link to other sleep, medical, neurologic, or psychiatric disorders. (See 'Types of nocturnal events' above.)
●A clear description of the events is key to the evaluation of all abnormal movements and behaviors during sleep (table 2A-C). The history should include a detailed description of the witnessed movements or behaviors, timing during the night (figure 1), duration, and frequency of the event, the individual's memory for the event, dream recall, whether eyes are open or closed, and any stereotypic features. (See 'Event description' above.)
●Bed partners and patients may also note certain provocative factors such as sleep deprivation, alcohol, medications, or stimuli associated with the events. Other key characteristics include age of onset, family history for similar events, and symptoms of other neurologic, medical, psychiatric, or sleep disorders. (See 'Provocative factors' above and 'Symptoms of other sleep disorders' above.)
●Video polysomnography with extended electroencephalography (EEG) is useful when the history is atypical, when there are symptoms suggestive of an underlying sleep or neurologic disorder, or the patient or family is at risk for injury. (See 'Overnight video polysomnography' above.)
●Management strategies vary according to the type of movement or behavior, its frequency and severity, and whether or not an underlying sleep or other medical or neurologic disorder is present. Simple sleep-related movements such as hypnic starts and infrequently occurring disorders of arousal do not need to be treated. Effective pharmacologic therapy is available for certain disorders, such as REM sleep behavior disorder (RBD). In all cases, patients should be counseled on common provocative factors (eg, sleep deprivation, alcohol) and the establishment of a safe sleeping environment. (See 'Management' above.)
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