Update on nonapnea sleep disorders.

Much of the attention in the field of sleep disorders focuses on the obstructive sleep apnea syndrome. However, for the pulmonary physician interested in a wider breadth of sleep knowledge, important and interesting developments have been witnessed in the area of nonapneic sleep disorders. Exciting new breakthroughs have illuminated the pathogenesis of narcolepsy and are expected to lead to new treatment options for narcoleptic patients. For the surprisingly common but poorly understood restless legs syndrome (RLS), an expanding armamentarium of medications aids the knowledgeable physician in caring for his or her patients. The physiology of circadian rhythms is better understood due to basic scientific advances. Finally, new drugs used to treat insomnia offer more flexible treatment options and an old and previously vilified drug may allow sleep specialists to better understand the mechanisms of sleep.