Disorders of Sleep: An Overview 305 Leon Ting and Atul Malhotra

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1 SLEEP MEDICINE Preface Robert D. Ballard and Teofilo L. Lee-Chiong Jr xiii Disorders of Sleep: An Overview 305 Leon Ting and Atul Malhotra Only recently has the medical profession focused on the importance of sleep and health. There are increasing numbers of studies linking sleep disorders with neurobehavioral and cardiovascular morbidity and possibly mortality. Although sleep disorders are diverse and affect a substantial number of patients, they are often misdiagnosed or underdiagnosed. Common presenting symptoms to physicians include hypersomnia and insomnia. A systematic workup helps to diagnose the underlying cause. Evaluation of the Patient Who Has Sleep Complaints: A Case-Based Method Using the Sleep Process Matrix 319 Gerald Rosen There are four sleep symptoms that patients can have: difficulty with sleep onset, problems occurring during sleep, difficulty awakening from sleep, and daytime sleepiness. These symptoms develop when there is a problem in one or more of the nine fundamental process domains that control sleep. These fundamental sleep process domains are: circadian, homeostatic, ultradian, developmental, cardiorespiratory, neurological, psychiatric/behavioral, drugs/alcohol, and other medical problems. Successful treatment of the sleep problems depends on the correct identification of the underlying sleep processes that are causing the sleep symptom. The sleep process matrix is a way of organizing one s thinking to accomplish this task. VOLUME 32 Æ NUMBER 2 Æ JUNE 2005 v

2 Obstructive Sleep Apnea-Hypopnea Syndrome 329 Eric J. Olson, John G. Park, and Timothy I. Morgenthaler Obstructive sleep apnea-hypopnea syndrome (OSAHS) is a common yet underdiagnosed condition of repetitive episodes of complete (apnea) or partial (hypopnea) airflow reduction during sleep as a result of adverse upper airway neuromuscular and anatomic factors. Cyclic hypoxemia and arousal may lead to several chronic physiologic perturbations that potentially link OSAHS with the initiation or exacerbation of many cardiac and vascular conditions commonly encountered by primary care providers. The cardinal features of OSAHS, such as snoring, daytime dysfunction, and being overweight, are common and nonspecific, so diagnosis rests on objective assessment of nocturnal breathing by polysomnography. First-line therapy is usually continuous positive airway pressure (CPAP), with lifestyle modifications, oral appliances, and upper surgery reserved for milder cases or CPAP failures. This article reviews terminology, clinical consequences, pathophysiology, epidemiology, diagnosis, and treatment pertinent to the perspective of the primary care provider. Central Sleep Apnea 361 M. Safwan Badr Central sleep apnea (CSA) is characterized by the periodic occurrence of apnea caused by loss of ventilatory motor output. CSA is often discussed as a minor variant of obstructive sleep apnea. However, this view obscures the critical contribution of CSA as an important manifestation of breathing instability in a variety of conditions with diverse causes. Central apnea can also be a physiologic phenomenon in healthy people during sleep onset. Conversely, patients who have obstructive apnea may also develop episodes of apparent central apnea, and apneas that begin as central may become obstructive as respiratory effort is restored ( mixed apneas ). Thus, there is a significant overlap between obstructive and central apnea. This article addresses the pathophysiology, clinical features, and management of normocapnic and hypercapnic CSA. Insomnia 375 David N. Neubauer Insomnia is among the most common concerns encountered in clinical practice. Generally insomnia is a complaint of insufficient or inadequate sleep, despite having the opportunity to sleep. Patients report difficulty initiating and maintaining sleep, and a sense that their sleep is not refreshing or restorative. Often patients describe daytime problems that they attribute to their poor nighttime sleep. Insomnia can result from a wide variety of psychologic and physiologic influences, and the contribution of these factors in promoting and perpetuating insomnia may shift over time. An insomnia disorvi

3 der may be diagnosed in some patients, especially when the sleep disturbance is chronic. Chronic insomnia is now recognized as a clinical problem with significant consequences and comorbidities. The identification and treatment of insomnia are important elements in the health management of patients in primary care settings. Narcolepsy and Disorders of Excessive Somnolence 389 Mark E. Dyken and Thoru Yamada In 1880, Jean Baptiste Gelineau gave the name narcolepsy to a syndrome associated with irresistible sleep attacks and episodic muscular atonia. Idiopathic narcolepsy is a central nervous system disorder that is evidenced as excessive daytime somnolence and the abnormal rapid eye movement sleep phenomena that are recognized as cataplexy, sleep paralysis, and hypnagogic hallucinations. In 1957, Yoss and Daly named this classic symptom combination the clinical tetrad. Although the symptoms of idiopathic narcolepsy generally begin in puberty, they have been reported in preteenaged children and in adults up to 68 years of age. Excessive sleepiness is mandatory for diagnosis and is usually the first symptom of a life-long problem that has the potential for producing major occupational, social, and psychologic problems. Parasomnias and Other Sleep-Related Movement Disorders 415 Teofilo L. Lee-Chiong Jr Parasomnias are undesirable physical phenomena that occur predominantly or exclusively during the sleep period. They are not principally abnormalities of the processes responsible for the states of sleep and wakefulness, and manifest as activation of skeletal muscle or the autonomic nervous system during sleep. They usually occur intermittently or episodically and may give rise to violent and potentially injurious behavior. Parasomnias have been classified as either disorders of arousal or disorders that are usually associated with rapid eye movement (REM) sleep. Restless Legs Syndrome 435 Ilia Itin and Cynthia L. Comella The clinical features of restless legs syndrome (RLS) include an urge to move the legs often associated with dysesthesia and motor restlessness. The symptoms occur or worsen at rest (eg, sitting, lying down) and are partially or completely relieved with action. The main clinical effect of RLS is to prolong sleep latency. Periodic limb movements in sleep consist of rhythmic extension of the big toe and dorsiflexion of the ankle occasionally accompanied by knee and hip flexion and occurring approximately every 20 to 40 seconds. vii

4 Similar movements can occur while awake, termed periodic limb movements while awake. Periodic limb movements may be associated with arousals or awakenings and may cause fragmented sleep. Sleep fragmentation and prolonged sleep latency may result in nocturnal sleep deprivation, leading to excessive daytime somnolence that can significantly affect the patient s quality of life. Circadian Rhythm Sleep Disorders 449 Kathryn J. Reid and Helen J. Burgess Circadian rhythm sleep disorders occur when there is a misalignment between the endogenous circadian clock and the external environment. The misalignment may be caused by an alteration in the endogenous circadian system or an alteration in the external environment relative to the endogenous circadian clock. However, the clinical presentation of most circadian rhythm sleep disorders is influenced by a combination of physiologic, behavioral, and environmental factors. Patients report complaints of insomnia and excessive daytime sleepiness, associated with impairment in important areas of functioning and quality of life. Current treatments use circadian synchronizing agents, such as light and exogenous melatonin, to realign the endogenous circadian clock to the external environment. Sleep Deprivation 475 Syed W. Malik and Joseph Kaplan Chronic sleep deprivation in the adult population has become a major problem in modern society. The consequences include excessive sleepiness, reduced school and work performance, and an increased risk for accidents. This article reviews the pertinent medical literature regarding the prevalence and assessment of sleep deprivation. Its impact on behavioral, physiologic, and occupational parameters is discussed, and specific interventions for combating sleep deprivation are provided. Medications and Their Effects on Sleep 491 J.F. Pagel Many medications disturb sleep or exacerbate the effect of chronic illnesses on sleep. Conversely, medications may be used therapeutically for specific sleep disorders. An understanding of the disorders of sleep and the effects of medications is required for the appropriate use of medications affecting sleep. One of the significant advances in sleep medicine has been the development and use of efficacious medications to treat sleep disorders medications with minimal side effects, low addiction potential, and limited toxicity in overdose. viii

5 Sleep and Medical Disorders 511 Robert D. Ballard Sleep disturbances are common manifestations of many medical disorders. Impaired sleep not only worsens quality of life but may also aggravate symptoms of the underlying disorders and possibly even worsen the prognosis of the primary disorders. This article reviews the interactions of sleep and sleep disorders with several medical disorders, including hypertension, heart disease, congestive heart failure, asthma, chronic obstructive pulmonary disease, gastroesophageal reflux, and renal disease. Sleep in Patients with Neurologic and Psychiatric Disorders 535 Brian D. Hoyt Given the widely recognized association between many neurologic and psychiatric disorders and significant sleep disturbances, the International Classification of Sleep Disorders Diagnostic and Coding Manual recognizes Sleep Disorders Associated with Mental, Neurologic, or Other Medical Disorders as one of four major classification categories. Such sleep disturbances may exacerbate symptoms of the underlying neurologic or psychiatric disorder or produce further adverse medical, behavioral, or psychosocial consequences. Therefore, adequate assessment and recognition of sleep disturbances in these populations is essential. This article includes a summary of neurologic systems influencing sleep that may be affected by neurologic and psychiatric disorders, followed by a brief review of sleep disturbances associated with many common neurologic and psychiatric disorders. Pediatric Sleep Disorders 549 Philip K. Capp, Phillip L. Pearl, and Daniel Lewin Disturbed sleep in a child is an understandably concerning issue for parents and a common reason for visits to a primary care clinician. Despite the prevalence of sleep disorders in children, there is a great disparity in physician training in sleep medicine and skill in diagnosing and treating sleep disorders. The sleep disorders that commonly present from infancy through adolescence range in severity from transient difficulties such as settling at night to life-threatening conditions that are essential targets for prevention and early intervention by clinicians. This article begins with a review of sleep architecture in children and progresses chronologically through sleep disorders in infancy, childhood, and adolescence. Sleep Disorders in the Older Patient 563 Alon Y. Avidan Many seniors have readily diagnosable sleep disorders that can be treated effectively to improve daytime somnolence and cognitive ix

6 impairments. Older patients often suffer from a variety of sleep disturbances that may be caused by age-related physiologic changes, polypharmacy, changes in circadian rhythm, retirement, and loss of spouse. This article discusses normal predictable age-related changes in sleep and sleep physiology and describes specific sleep pathologies common in older people in a case vignette format. Specific sleep disorders, including insomnia; obstructive sleep apnea; restless legs syndrome and periodic leg movement disorder of sleep; advanced sleep phase syndrome; and rapid eye movement sleep behavior disorder are discussed in the context of the older patient. Diagnostic criteria, clinical presentation, polysomnographic features (when appropriate), and treatment options are presented for each of these sleep disorders. Index 587 x