BACKGROUND- Insomnia is a symptom or set of symptoms, not a disease. It is the most common symptom in sleep medicine. Although psychiatric problems may cause such symptoms, other causes are common, particularly among older patients. It is important that neurologists know how to approach the statement, “Doctor, I can't sleep.”
REVIEW SUMMARY- Normal sleep physiology is discussed with basic insights into mechanisms of homeostatic and circadian rhythms and sleep electrophysiology. Diagnostic aids to sleep medicine are described and include the sleep log, the polysomnogram, and the multi-sleep latency test. The causes of insomnia and the relevant questions to ask in the sleep history are given. More detailed discussion of the epidemiology, clinical features, and management issues are presented for psychophysiological insomnia, sleep-wake cycle disorders, restless legs syndrome, periodic leg movements in sleep, and sleep apnea. In the final section, special attention is paid to problems of sleep in the elderly and in patients with Parkinson's disease and dementia.
CONCLUSION- This review allows the neurologist to better understand the potential causes of insomnia. This knowledge will enable the neurologist to approach the symptoms of insomnia with a clearer understanding of what questions to ask, how to sort out the differential, and what investigations are appropriate. Neurologists should feel more comfortable in treating and managing their own patients with physiological insomnia, restless legs syndrome, periodic leg movements of sleep, and sleep-wake cycle disturbances.