Parasomnias Clinical Presentation

The history can help differentiate among the various parasomnia subtypes.

Nightmare disorder

In nightmare disorder, patients complain of a frightening dream (in addition to fear, patients can also experience anger, embarrassment, sorrow). Nightmares typically occur in the latter third portion of the night. Arousal during the dream is common. The presence of a dream is the essential feature that differentiates nightmare disorder from sleep terror disorder.

Nightmares can lead to either sleep onset or sleep maintenance insomnia, which may be a presenting complaint. There is often a history of traumatic experiences (this is a key symptom of posttraumatic stress disorder [PTSD]).

Sleep terror disorder

Sleep terror disorder (pavor nocturnus) is characterized by a sudden arousal from non–rapid eye movement (NREM) sleep (usually from slow-wave sleep) and associated autonomic and behavioral manifestations of fear. Commonly, patients let out a piercing scream, followed by fear, crying and inconsolability. In adults, agitation is often seen. Significant autonomic hyperactivity is present, with tachycardia, tachypnea, flushing, diaphoresis, and increased muscle tone.

The patient is routinely unresponsive to external stimuli and, when awakened, is confused, disoriented, and amnestic regarding the event. It should be cautioned that confrontation of an individual during an episode may be dangerous, in that the individual may become violent. Incoherent vocalizations or micturition have been reported to accompany the event.

Sleepwalking

Episodes of sleepwalking (somnambulism) are associated with behaviors that range from simply sitting up in bed to walking, possibly with associated complex behaviors such as eating. Talking behavior also has been noted during these episodes. Upon awakening, the patient is most often confused and amnestic regarding the event; however, patients may be able to recall simple motivations (such as the desire to urinate) if awakened during an episode. Individuals typically have their eyes open during an event.

The sleepwalking event occurs during NREM sleep (usually slow-wave sleep) and may be more common after sleep deprivation. The event may spontaneously terminate, or the patient may return to bed or lie down somewhere else and return to sleep without ever awakening.

Rapid eye movement sleep behavior disorder

The hallmark of rapid eye movement (REM) sleep behavior disorder is the acting out of dreams. The behavior can include punching, kicking, leaping, and running from the bed. The most common reason for medical consultation is injury to the bed partner, though the effects of sleep disruption also can precipitate such consultation. The event occurs during REM sleep (the dreams), hence the name.

In patients with REM sleep behavior disorder, arousals from sleep to alertness and orientation occur rapidly, and patients usually have a vivid recall of their dreams. After awakening, the patient exhibits normal behavior and interactions. Despite nocturnal behavior, few patients develop excessive daytime sleepiness or fatigue.

Acute and chronic forms exist. The acute form can emerge during withdrawal from ethanol or sedative-hypnotic abuse and with anticholinergic and other drug intoxication states.

Restless legs syndrome and periodic limb movement disorder

Patients with restless legs syndrome (RLS) describe discomfort in lower extremities, using terms such as “pulling, searing, crawling, creeping, and boring” to describe sensations. The symptoms usually occur at bedtime or during other periods of inactivity. These distressing symptoms are relieved by moving the legs, walking about, rubbing the legs, squeezing or stroking the legs, and by taking hot showers or baths. The symptoms may wax or wane over the patient’s lifetime.

Patients with RLS commonly present with complaints of insomnia (difficulty initiating sleep), and, in severe cases, the disorder may cause depression and suicidal thoughts.

Periodic limb movement disorder (PLMD) primarily occurs during the first half of the night and progressively declines as the night goes on; episodes typically take place while the individual is asleep. PLMD is described as rhythmic extension of the great toe, associated with dorsiflexion of the ankle and light flexion of the knee and hip. The upper extremity may be involved, as manifested by intermittent flexion of the elbow.

Because PLMD occurs during sleep, these symptoms are often not appreciated by the patient. Patients often present with symptoms of excessive daytime sleepiness, initially during passive activities such as watching television, being a passenger in a car, or reading. In later stages, patients may have excessive daytime sleepiness during activities requiring alertness, such as driving, operating machinery, or talking with people.

RLS and PLMD may occur even during childhood and present as attention deficit hyperactivity disorder (ADHD) or as growing pains. These disorders are present in a significant proportion of pregnant women, and exacerbations are observed during menstruation and menopause.

RLS and PLMD are associated with numerous neurologic conditions, such as peripheral neuropathy, postpolio syndrome, spinal cord pathology, and various causes of myelitis. They affect 20-40% of patients with chronic renal failure who are on dialysis. A history of iron-deficiency anemia is also quite common in these patients.^[35] RLS and PLMD should be considered if a patient complains of insomnia or excessive daytime sleepiness.

A related phenomenon is sleep-related leg cramps, which can occur while awake or asleep. These are characterized by involuntary, nonperiodic, and painful contractions in the calf or foot. Although RLS can mimic the painful sensations experienced in this condition, a useful distinction can be made. Because leg cramps involve actual spasms, they are usually isolated to specific muscle groups; accordingly, they are alleviated only by stretching, not just by simple movement (as in RLS).

In patients with parasomnias that are not attributable to a general medical condition, physical findings are either absent or nonspecific. The only physical findings that can be specific to one of these parasomnias would be those findings associated with complications of the sleep disorder (eg, falling, for a sleepwalker).

Patients with RLS and PLMD may have physical signs of peripheral neuropathies and other neurologic disorders, such as radiculopathy and spinal cord pathology. Thus, a detailed neurologic and musculoskeletal examination must be performed. For diagnosis of REM sleep behavior disorder after a complaint from the patient or bed partner, a complete neurologic and psychiatric examination should be conducted.

Diagnostic guidelines for primary RLS include the following:

• Discomfort is present in both legs (tingling, prickling, tension, or aching), accompanied by irresistible movements of the limbs
• Symptoms appear at rest, show a circadian pattern by occurring mainly in the evening, and can interfere with sleep onset
• The severity may vary from week to week and may occur in upper limbs
• Partial or complete relief is obtained by physical maneuvers (eg, rubbing, shaking, stomping, or walking)
• Neurologic symptoms or signs are absent

Diagnostic Statistical Manual of Mental Disorders, Fourth Edition, Text Revision (DSM-IV-TR) diagnostic criteria for nightmare disorder include the following:

• Repeated awakenings from the major sleep period or naps occur, with detailed recall of extended and extremely frightening dreams, usually involving threats to survival, security, or self-esteem; the awakenings generally occur during the second half of the sleep period
• Upon awakening from the frightening dreams, the person rapidly becomes oriented and alert (in contrast to the confusion and disorientation observed in patients with sleep terror disorder and some forms of epilepsy)
• The dream experience, or the sleep disturbance resulting from the awakening, causes clinically significant distress or impairment in social, occupational, or other important areas of functioning
• The nightmares do not occur exclusively during the course of another mental disorder (eg, delirium or PTSD) and are not due to the direct physiologic effects of a substance (eg, a drug of abuse or a medication) or a general medical condition

DSM-IV-TR diagnostic criteria for sleep terror disorder include the following:

• Recurrent episodes of abrupt awakening from sleep occur, usually during the first third of the major sleep episode, and begin with a panicky scream
• Intense fear and signs of autonomic arousal (eg, tachycardia, rapid breathing, and sweating) occur during each episode
• Patients demonstrate relative unresponsiveness to efforts by others to comfort the person during the episode
• No detailed dream is recalled, and amnesia develops regarding the episode
• The episodes cause clinically significant distress or impairment in social, occupational, or other important areas of functioning
• The disturbance is not due to the direct physiologic effects of a substance (eg, a drug of abuse or a medication) or a general medical condition

DSM-IV-TR diagnostic criteria for sleepwalking disorder include the following:

• Repeated episodes of rising from bed during sleep and walking about occur, usually during the first third of the major sleep episode
• While sleepwalking, the person has a blank staring face, is relatively unresponsive to the efforts of others to communicate with him or her, and can be awakened only with great difficulty
• Upon awakening (either from the sleepwalking episode or the next morning), the person has amnesia regarding the episode
• Within several minutes after awakening from the sleepwalking episode, mental activity or behavior is not impaired, though a short period of confusion or disorientation may be present
• The sleepwalking causes clinically significant distress or impairment in social, occupational, or other important areas of functioning
• The disturbances are not due to the direct physiologic effects of a substance (eg, a drug of abuse or a medication) or a general medical condition

A Mental Status Examination of patients suffering from parasomnias is useful because medical disorders, psychiatric disorders, and stress may precipitate or aggravate parasomnias. A careful assessment for alcohol or drug use, anxiety disorders, depression, and delirium should be performed. Relevant mental status findings are those associated with the following conditions:

• Delirium
• Depression
• Depression (in children)
• Alcohol and Substance Abuse
• Adjustment Disorders
• Anxiety Disorders
• Anxiety Disorders (in children)
• Posttraumatic Stress Disorder

Patients found to have an underlying psychological or psychiatric disorder should be seen by a psychologist or psychiatrist, and appropriate therapy should be offered. Depression or atypical affective disorders may well be masked and not apparent to a casual observer. Furthermore, the Mental Status Examination of Sleep provides a framework for assessing a broad range of consequences of parasomnias and facilitating the formulation of target symptoms to be controlled with treatment.

Accidental injury to self or others can occur, particularly in patients with sleepwalking disorder (injury to self), sleep terror disorder (injury to self or others because the patient sometimes moves violently while trying to escape the terror), and REM sleep behavior disorder (the patient may act out a complex series of dream-related violent behaviors).

Reports exist of patients eating during episodes of sleepwalking, with partial or complete amnesia for the event. Excessive intake of food can be considered a complication of this disorder.

Parasomnias can adversely affect obstructive sleep apnea by interfering with nasal continuous positive-pressure therapy.