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Parkinson´s Disease (PD) is the second most common neurodegenerative disease and affects more than 1.6-1.8% worldwide over the age of 65. Although the disease is clinically diagnosed by the emergence of motor dysfunctions, an increasing awareness of the complex and multifaceted nature of PD has emerged recently. Circadian and sleep disturbances are among the most debilitating non-motor symptoms and occur in virtually all PD patients. Despite this well established association, the neuropathophysiology of circadian and sleep symptoms in PD patients is not yet well understood. The studies described in this book aim at investigating the nature and the extend of circadian alterations in PD using both mice and non-human primate models of PD.

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Karim Fifel Ph.D. is currently a postdoc researcher at Leiden University Medical Center. His main research interest is the investigation of the neurobiology of sleep and circadian rhythms. Recently he has been working on circadian alterations in neurological disorders characterised by dysfunction of the dopaminergic system (i.e.Parkinson´s disease)

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