History of the development of sleep medicine in the United States.

Sleep Medicine has only recently been recognized as a specialty of medicine. Its development is based on an increasing amount of knowledge concerning the physiology of sleep, circadian biology and the pathophysiology of sleep disorders. This review chronicles the major advances in sleep science over the past 70 years and the development of the primary organizations responsible for the emergence of Sleep Medicine as a specialty, sleep disorders as a public health concern and sleep science as an important area of research.

Benefits and risks of pharmacotherapy for narcolepsy.

Narcolepsy is a life-long central nervous system (CNS) syndrome characterised by excessive sleepiness, cataplexy, sleep paralysis, hypnagogic hallucinations and disturbed night-time sleep. Unsuccessfully treated narcolepsy confers increased risks on patients and on society due to the patient's increased chance of becoming involved in vehicle crashes and workplace mishaps. The syndrome may be diagnosed by a clinical history positive for cataplexy and excessive daytime sleepiness and negative for other more common sleep disorders such as sleep apnoea and sleep deprivation. Night-time polysomnography and multiple sleep latency testing are helpful in differentiating narcolepsy from other sleep problems. Recent data from canine, murine, and human forms of narcolepsy indicate that genetically or developmentally mediated deficits in the hypocretin neurotransmitter system may cause some, but not all, forms of narcolepsy. Pharmacotherapy for narcolepsy is required to control symptoms and involves the use of CNS stimulants or modafinil to control sleepiness and antidepressant medications or sodium oxybate to control cataplexy. Modafinil and sodium oxybate have been developed and approved specifically for the indication of narcolepsy based on large, double-blind, placebo-controlled, parallel group efficacy and safety studies. The efficacy of drugs in the treatment of narcolepsy is variable from patient to patient and usually associated with adverse effects that can limit patient compliance and, therefore, symptom control. Nevertheless, the benefits of pharmacotherapy are judged to outweigh the risks to the patient. The favourable benefit-risk ratio of pharmacotherapy is greater if one considers the reduced risk to society of vehicle crashes and workplace mishaps that might be precipitated by attentional lapses or sleep attacks in the untreated or under-treated patient with narcolepsy.

Mortality in Obstructive Sleep Apnea: Association with Impaired Wakefulness.

Sleep fragmentation from obstructive sleep apnea (OSA) is correlated with a shortened sleep latency on the Maintenance of Wakefulness Test (MWT) and the Multiple Sleep Latency Test. Whether impairment of wakefulness is associated with increased mortality in OSA patients is unknown. We evaluated survival over an average timespan of 7.5 years from the date of diagnosis in a consecutive series of 322 OSA patients who had undergone nocturnal polysomnograpy and the MWT. Evaluable survival data were obtained in 142 patients. Twenty two had died. Deaths were predominantly due to cardiovascular disease. A comparison of the demographic and sleep study data between the alive and dead groups was significant for differences in MWT sleep latency and in age at time of diagnosis. The MWT mean sleep latency, when adjusted for age, was significantly shortened in the dead patients (28 +/- 11 min vs. 21 +/- 10 min, p < 0.005). Also, there was a significant decrease in survival in the patients whose MWT mean sleep latency was less than 20 min. These findings demonstrate an association between impairment of wakefulness and long-term mortality in OSA patients. This association was not evident for the other measures used to assess OSA severity.