The diagnostic process at early stage of Parkinsons disease
Parkinson disease is considered a progressive multisystem disorder involving dopaminergic, noradrenergic, serotoninergic and cholinergic systems, characterized by motor and non-motor (autonomic, sleep, sensory and neuropsychiatric) symptoms. These symptoms may precede motor manifestation by 5-20 years. The recognition of these biomarkers in the premotor phase of the disease is important to early diagnosis and treatment.