Sleep–wake disturbances in common neurodegenerative diseases : a closer look at selected aspects of the neural circuitry

There is a growing appreciation regarding the relationship between common neurodegenerative diseases, such as Alzheimer's and Parkinson's and sleep–wake disturbances. These clinical features often herald the onset of such conditions and certainly appear to influence disease phenotype and progression. This article reviews some of the pathophysiological processes underlying specific disruptions within the neural circuitry underlying sleep–wake disturbances and explores how clinicopathological relationships commonly manifest. It is proposed that a greater understanding of these relationships should allow insights in to the efficacy of currently available treatments and help in the development of future therapies targeting disruptions within the sleep–wake neural circuitry.