A High Density EEG Comparison of Sleep Patterns in Insomnia

Insomnia, defined as a subjective report of difficulty initiating sleep, maintaining sleep, and/or non-restorative sleep, leads to significant daytime dysfunction and increased health risks. A commonly held hypothesis is that insomnia is caused by a state of hyperarousal, but the neurobiological mechanisms of hyperarousal in insomnia are poorly understood, in part because of limitations in our ability to image the brain during normal human sleep with sufficient temporal resolution. Furthermore, the efficacy of insomnia treatment is judged by subjective report of the patient and demonstration of changes in sleep latency and/or sleep amount which are generally small in magnitude; there are currently no data to demonstrate that insomnia treatments correct any functional abnormalities in the sleep process that likely contribute to neurobehavioral abnormalities and health risks. The goals of the proposed study are to use high density EEG to define abnormalities in specific aspects of sleep in insomnia patients compared to healthy sleeping control subjects to define biomarkers that will both increase our understanding of the pathophysiology of insomnia as well as provide targets to assess treatments for insomnia.