A lot of brain disorders and neurodegenerative diseases like Alzheimer’s disease are associated with sleeping problems and disturbances like insomnia, hypersomnia, sleep-wake rhythm disturbance, and so on. This can lead to worse symptoms including impaired motor and cognitive skills, headaches, and depression. Scientists are studying what causes these sleep disturbances, and what brain areas are responsible for controlling sleep and are damaged during disease.
Chokroverty S. Sleep and Neurodegenerative Diseases. Semin Neurol 2009;29:446-468.