The Clinical Approach to the Patient with Sleep Disorders

There have always been sleep disorders, many of which have been recognized for centuries and some of our treatments have even been dated from the decades ago. In the last 20 years, however, there has been a dramatic increase in knowledge about sleep disorders and their treatments. It is now possible to objectively diagnose most sleep disorders and new, specific treatments can be instituted. The recent recognition of chronobiology has led us to be able to explain alterations in the sleep-wake pattern of humans. Genetic causes of sleep disorders, such as advanced sleep phase syndrome have shed new light on disorders that were previously believed to be primarily associated with an individual’s behavior. Neurochemical changes have led to a better understanding of the pathophysiology of some disorders such as narcolepsy. Despite advances in our understanding of sleep disorders, however, accurate diagnosis and treatment always requires a detailed understanding of the patient’s sleep-wake and medical history. The art of good sleep medicine still lies in the ability of the clinician to take a thorough history, develop a differential diagnosis and formulate a treatment plan. This chapter details the important elements of the clinical evaluation. A variety of sleep complaints are extremely common in our society. Most of these complaints can be grouped under the categories of insomnia, excessive daytime sleepiness (EDS), or abnormal events occurring during sleep. Approximately, 10% of the general population has a complaint of insomnia that occurs every night for two weeks or more.¹ Yet, only 5-6% of patients will ever seek a physician in order to address their sleep problem.² In fact, a majority of patients with insomnia never discuss their complaints with a physician, and usually resort to over-the-counter medications, or self-remedies in order to alleviate their sleep disturbance. Excessive daytime tiredness and sleepiness are also commonly reported complaints, with prevalence in the community estimated to be as high as 10-25%.³ Further, around 30% of the general population has some sleep disturbance a few nights every month, ⁴ and nearly everyone has had some type of abnormal intrusion into sleep, such as nightmares, sleepwalking or some other psychological, or physiological intrusion into sleep. Nevertheless, despite this prevalence of sleep disorders in the society most remain under diagnosed and undertreated. With better understanding of sleep disorders, significant morbidity as a sequela of sleep disruption has been recognized. For example, insomnia can lead to the development of depression⁵ or EDS can be a manifestation of obstructive sleep apnea (OSA) that, at its worse, can lead to sudden death during sleep. Even lesser degrees of disturbed sleep and daytime sleepiness can lead to impaired functional ability during the daytime, and a tendency for mood disturbances that might include irritability, anxiety, and depressive feelings. There has also been a growing concern regarding the possibility of sleepiness impairing functional ability often leading to motor vehicle and/ or industrial accidents.⁶ Several major catastrophic events that have affected society have been ascribed to disturbances of the sleep-wake cycle in the individuals responsible. The Exxon Valdez ship accident in Alaska that led to a major environmental oil disaster, challenger space shuttle accident, the Chernobyl nuclear power station accident, or more recently, the Metro-North train derailment in New York are some examples of major accidents that were in part caused by human errors associated with an inadequate sleep-wake pattern.