[Cognitive disorder in Parkinson's disease]

Over the course of Parkinson's disease, a substantial percentage of patients not only develop motor und vegetative disorders, but also significant cognitive deficits that can, in isolated cases, take on the proportions of dementia. Additionally, affective and emotional dysregulations extending to depressive disorders may become manifest. These impairments can be explained by the underlying neuropathology and the Parkinson-associated transmitter imbalances as well as by the changes this disease causes in the patients' daily lives. According to Gifford and Cummings [21], up to 75 percent of patients with moderate to severe dementia are not diagnosed by their general practitioners; this number proving much higher in patients with mild cognitive impairments and affective and emotional problems. Due to the masking symptoms of a Parkinson's condition, it can be assumed that these numbers are probably even higher in this patient group. Accordingly, cognitive, affective and emotional disorders should be included as an integral part of Parkinson's disease diagnostics.