[Sleep disturbances in the elderly: pathology, symptoms and treatment].

Although sleep disturbance is common among the elderly, such elderly patients have been considered difficult to treat because the underlying mechanisms are complicated. However, these patients often exhibit adverse effects such as daytime somnolence, poor motor coordination, and an increased risk of falls. This article reviews the pathology, symptoms, and management of sleep disturbances in elderly patients. As a consequence of aging, elderly people exhibit alterations in the sleep architecture and sleep-wake rhythm. Many studies employing polysomnography have demonstrated a shortened total sleep time; decreases in sleep efficiency, and time spent in slow wave sleep and rapid eye movement (REM) sleep; and increases in nocturnal arousal and in the proportion of stage I sleep. Furthermore, these patients usually exhibit a multiple sleep-wake rhythm, and an advanced sleep phase. For the treatment of sleep disturbances in the elderly, it is necessary to perform appropriate multidimensional assessment of the patient, such as the assessment of psychosocial factors, as well as medications and diseases that may cause sleep disturbances. Benzodiazepine (BZP) hypnotics have been the primary treatments for sleep disturbances, and are effective and safe when prescribed within the recommended guidelines. Hypnotic drugs should be used carefully to avoid causing delirium, amnesia, and falls. There have also been reports demonstrateing the effectiveness and tolerability of non-BZP hypnotics, antidepressants with fewer anticholinergic effects, atypical neuroleptics, and herbal prescriptions. In addition to alterations in the sleep architecture and sleep-wake rhythm, several sleep disorders become more prevalent in the elderly. These late-life sleep disorders include periodic limb movement disorder (PLMD), restless legs syndrome (RLS), and parasomnias such as REM sleep behavior disorder. As these disorders become more severe, it becomes more difficult to fall asleep and/or maintain sleep continuity, which results in a poorer subjective sleep quality. These disorders have a pathology distinct from those of primary insomnia, and require a different treatment strategy. Furthermore, these disorders are usually refractory to BZP hypnotics. Adequate evaluations and diagnoses are, therefore, essential for successful management.