Sleep Disorders PDF

Sleep Disorders https://www.clevelandclinicmeded.com/medicalpubs/diseasemanageme... Menu Sleep Disorders Li Ling Lim, MD Nancy Foldvary-Schaefer, DO, MS Published: November 2012 L...

Sleep Disorders https://www.clevelandclinicmeded.com/medicalpubs/diseasemanageme... Menu Sleep Disorders Li Ling Lim, MD Nancy Foldvary-Schaefer, DO, MS Published: November 2012 Last Reviewed: May 2017 Contents Definition Sleep is a normal recurring state that manifests as loss of responsiveness to the external environment. Sleep had been seen as a passive state that ensues in the absence of wakefulness. However, it is now known to be an active physiologic state involving dynamic changes in neural, metabolic, and cardiorespiratory function. Sleep disorders encompass a wide range of conditions that have been most recently categorized in the International Classification of Sleep Disorders, Second Edition (ICSD-2).1 The ICSD-2 lists more than 80 distinct sleep disorders sorted into 8 categories, including the insomnias, sleep-related breathing disorders, hypersomnias of central origin, circadian rhythm sleep disorders, parasomnias, and sleep-related movement disorders. Back to Top Pathophysiology Normal sleep and wake states are generated by a complex neuronal network in the brain and are regulated by homeostatic and circadian mechanisms. Sleep may be divided into 2 main stages: rapid eye movement (REM) and non-REM (NREM) sleep. REM sleep is also known as paradoxical sleep because it resembles wakefulness with desynchronized electroencephalography (EEG) activity, phasic events such as REM, and bursts of muscle activity. REM sleep also is characterized by dreaming. NREM sleep is characterized by synchronized EEG activity, muscle relaxation, and decreased heart rate, blood pressure, and tidal volume. Sleep homeostasis refers to the regulatory mechanism that maintains an overall constancy of sleep intensity and duration. Sleep deprivation creates a sleep debt that must be repaid, resulting in compensatory heightened pressure to sleep and eventual increased sleep intensity and duration. Conversely, excessive sleep reduces sleep propensity and amount of sleep. Sleep physiology changes with age as the brain matures and eventually degenerates. With advancing age, there is a decline in the percentage of sleep that is deep, more frequent awakenings, and sleep fragmentation. In the elderly, sleep disorders such as obstructive sleep apnea (OSA) occur more frequently. Sleep needs also vary with age, decreasing from 16 hours a day in infancy and stabilizing at 7½ to 8 hours for most normal adults. Back to Top Signs and Symptoms A suggested practical approach when assessing patients with sleep-related disturbances is to elicit symptoms 1 of 18 12/8/24, 4:26 PM Sleep Disorders https://www.clevelandclinicmeded.com/medicalpubs/diseasemanageme... and signs according to the 3 cardinal clinical presentations of sleep disorders: insomnia, excessive daytime sleepiness, and abnormal movements or behavior in sleep. Insomnia Patients with insomnia most commonly describe difficulty with falling asleep and, less commonly, difficulty maintaining sleep or a perception of unrefreshing sleep. Regardless of the cause, insomnia often results in daytime fatigue, general malaise, and, in severe cases, cognitive and mood disturbances. Chronic insomnia often affects social and occupational functioning and diminishes quality of life. In patients with insomnia related to medical and psychiatric conditions, associated manifestations include chronic pain or other physical discomfort, depression, anxiety, and, often psychosocial stressors. Neurodegenerative disorders, such as Parkinson disease and dementia, are commonly associated with sleep disturbance. Medications such as steroids, bronchodilators, and some antidepressants can cause insomnia, so taking a careful drug history from the patient is important. Chronic insomnia is often multifactorial, encompassing components related to psychophysiologic issues, drugs, and underlying disease, as well as maladaptive behaviors. Inadequate sleep hygiene, a common problem of patients with chronic insomnia, is classified in the ICSD-2 as a distinct insomnia diagnosis. This term refers to a range of well-recognized sleep-incompatible behaviors, which include excessive use of substances that disrupt sleep (eg, caffeine, nicotine, and alcohol), mentally or physically arousing activities close to bedtime, excessive napping or time in bed, irregular sleep-wake times, and preoccupation with sleep difficulty. Excessive Daytime Sleepiness Excessive daytime sleepiness refers to the inability to stay alert during the major awake period of the day, resulting in falling asleep at inappropriate times. Excessive daytime sleepiness is more likely to occur in monotonous situations when alerting stimuli are absent, and it is associated with increased risk of accidents, such as when operating motor vehicles or other machinery. The severity of sleepiness can be quantified subjectively using scales such as the Epworth Sleepiness Scale (Table 1) or can be measured objectively in the sleep laboratory using the multiple sleep latency test (MSLT) or maintenance of wakefulness test (MWT).2 The MSLT measures the physiologic tendency to fall asleep in quiet situations, and the MWT measures the ability to stay awake in quiet situations. Table 1. Epworth Sleepiness Scale* How likely are you to doze off or fall asleep in the following situations, in contrast to feeling just tired? (This refers to your usual way of life in recent times. Even if you have not done some of these things recently try to work out how they would have affected you.) Use the following scale to choose the most appropriate number for each situation: 0 = no chance of dozing 1 = slight chance of dozing 2 = moderate chance of dozing 3 = high chance of dozing Situation Score 2 of 18 12/8/24, 4:26 PM Sleep Disorders https://www.clevelandclinicmeded.com/medicalpubs/diseasemanageme... Sitting and reading Watching television Sitting inactive in a public place (e.g. a theater or a meeting) As a passenger in a car for an hour without a break Lying down to rest in the afternoon when circumstances permit Sitting and talking to someone Sitting quietly after a lunch without alcohol In a car, while stopped for a few minutes in traffic Total score: *A score of ≥10 indicates sleepiness. Abnormal Movements or Behavior in Sleep These conditions encompass the NREM and REM parasomnias, sleep-related movement disorders (mainly, restless leg syndrome [RLS] and periodic limb movement disorder [PLMD]), and sleep-related epilepsy. The NREM parasomnias are disorders of arousal seen usually in the pediatric population and include confusional arousals, sleepwalking, and sleep terrors. The REM parasomnias include nightmare disorder and REM sleep behavior disorder (RBD). Because the synchronized state of NREM sleep facilitates epileptic activity in general, some epileptic syndromes have a marked tendency to manifest predominantly during sleep and must be distinguished from the parasomnias, which usually requires EEG documentation of epileptiform discharges. Epileptic phenomena are characterized by repetitive stereotypic behavior, but they can be difficult to distinguish clinically from nonepileptic phenomena. Back to Top Diagnosis Most sleep disorders can be diagnosed by a comprehensive sleep history, which includes a detailed account of routine sleep-related habits (eg, bedtime, wake time, and number of awakenings), sleep duration, sleeping environment, daytime activities, psychosocial stressors, current drug use, and abnormal behavior in sleep. Important collateral information is often provided by a bed partner, other observer, or family member regarding behavior that the patient may be unaware of, such as snoring or acting out dreams. Sleep questionnaires detailing pertinent sleep-related information and sleep logs are often useful, especially in documenting sleep-wake patterns in the circadian-rhythm sleep disorders. The Epworth Sleepiness Scale is often used to assess the level of daytime sleepiness and to monitor the response to therapeutic interventions.2 A score of 10 or more indicates that the patient is considered sleepy. Diagnosis of most sleep disorders can be made on the medical history alone, which is based on pattern recognition of clinical characteristics determined from the comprehensive sleep history and a physical examination. Sleep Disorders Manifesting with Insomnia 3 of 18 12/8/24, 4:26 PM Sleep Disorders https://www.clevelandclinicmeded.com/medicalpubs/diseasemanageme... Patients with sleep-onset difficulty might have one of the insomnias as classified in the ICSD-2. Restless leg syndrome should be considered, and a careful history should be taken to rule out drugs and underlying medical problems that cause insomnia. The circadian rhythm disorders are less common causes of sleep-onset insomnia. Also uncommon are sleep-maintenance problems alone causing unrefreshing sleep (without snoring or marked excessive daytime sleepiness) due to OSA or abnormal behavior in sleep. These strikingly abnormal sleep phenomena are usually evident from the history. Psychophysiologic Insomnia Psychophysiologic insomnia, also known as primary insomnia, occurs in about 12% to 15% of patients seen at sleep disorders clinics and affects 1% to 2% of the general population. It is characterized by a physiologic heightened-arousal state that predisposes patients to learned sleep-preventing associations, usually in the setting of social and environmental psychosocial stressors. Persons with psychophysiologic insomnia are typically light or poor sleepers, and can develop chronic insomnia after an initial episode of acute insomnia that failed to resolve following a precipitating stressful event. A counterproductive over-concern with sleep and the consequences of lack of sleep ensue, leading to a mental hyperarousal state (racing mind) and a form of conditioned insomnia associated with the person's habitual bedtime rituals and sleeping environment. Such patients typically report sleeping better while away from home and their usual routines, such as on vacation or during a business trip. This form of insomnia is often perpetuated because habits incompatible with healthy sleep develop, such as excessive time in bed tossing and turning, watching the clock, intense preoccupation with sleep, and abuse of prescription sleep aids. It is also associated with an increased risk of depression and dependence on hypnotics. Insomnia Due to Mental Disorder Insomnia due to underlying psychopathology (usually depression or anxiety) is one of the most frequently encountered problems at sleep disorders clinics, affecting about 3% of the general population. This condition is usually seen more in women and in middle-aged patients. Insomnia may be a presenting symptom in a variety of psychiatric conditions, including mood, anxiety, psychotic, and personality disorders.3 Insomnia is the most common sleep disturbance associated with major depression, which is seen in 80% to 85% of patients, usually manifesting as recurrent or early morning awakenings. In anxiety disorders, difficulty falling asleep is more typical and accompanies excessive worrying about a range of activities or events. In contrast to psychophysiologic insomnia, where anxiety is typically focused on sleep difficulty alone, patients with anxiety disorder manifest more pervasive anxiety symptoms attributable to a broader range of reasons. In this diagnostic category, which can closely resemble psychophysiologic insomnia, the underlying mental disorder plays a key role in the insomnia, with greater persistence and severity of the mood or anxiety disorder. Adjustment Insomnia Adjustment insomnia or acute insomnia refers to sleep disturbance of relatively short duration (