Parkinson´s disease is the second most common neurodegenerative disorder, behind Alzheimer’s disease, among the elderly with approximately 1.2 Mio European patients alone. It is characterized by typical key motor symptoms (bradykinesa, rigor, tremor and postural instability) resulting in slowness and stiffness of movements, imbalance and “shaking” of extremities and / or other parts of the body. Degeneration of dopaminergic neurons in specific parts of the brain (e.g. substantia nigra) are the pathological correlate of the motor symptoms in Parkinson´s disease.
Currently, there is no cure for the disease and existing therapeutic measures are mostly able to offer symptomatic relief.
Until recently, Parkinson´s disease was considered only a motor disease. Today, other non-motor symptoms have been well established correlating to non-motor functions such as sense of smell and sleep regulation (neuropsychiatric-, gastrointestinal-, autonomous symptoms). Interestingly, some of the non-motor symptoms start well before the classical motor symptoms is established. This changed scientist’s perception of the disease substantially. This new picture is not yet reflected in the way Parkinson´s disease is diagnosed. Therefore, scientists are looking for biological markers possibly supporting the diagnosis at an early disease stage, when only non-motor symptoms are detectable.