Sleep Medicine

When we sleep, the heart continues to beat, the lungs exchange gases, the gut absorbs nutrients, the integument serves as a barrier, the immune systems guards against infection and so on. But the brain does something extraordinarily different in sleep, compared to when awake: it changes it's physiology of function dramatically.

During wakefulness, our brains are profound sensory detectors, critical thinkers, in control of thoughts and actions. Each night, our brains shift away from thoughts, actions, and perceptions. The physiology that results leads to profound changes and substantial advantages across all body systems that can rest, repair, and recover.

What causes sleep disruption and what happens when the elegant and complex system of sleep is disrupted? These two fundamental questions address both cause and consequence. Imbedded in all chapters of this special issue of Seminars in Neurology, the fundamental relationships between disease and sleep are addressed. A common theme among the chapters is that many disorders cause sleep problems, and in turn, the sleep problems can make that very disorder itself worse (i.e., bidirectional).

We open this special issue with striking examples of the bidirectional relationships of sleep and brain disorders: dementia, epilepsy, autism, and traumatic brain injury. We then pivot to disorders of sleep that a neurologist is often called upon to address: insomnia, restless legs syndrome, narcolepsy, and REM sleep behavior disorder. Although these are exemplary topics, they are not exhaustive. Finally, this special issue closes with a chapter that unveils the unique and substantial impact that sleep plays in the practice of medicine of acute emergencies, introducing the concept of emergency sleep medicine.

Although this issue was a work of pleasure for us, I would like to express tremendous gratitude to the contributors for their diligence and expertise in their thoughts and writing, as well as to the Editor-in-Chief, David Greer, for his leadership, guidance, and advice that optimized this issue. I am grateful for the opportunity to be a part of this terrific team. Candidly, now that the work is complete, I am looking forward to a good night's sleep.