Abstract
Parkinson's disease (PD) is a serious neurodegenerative disease affecting one to two persons out of every 1,000 in the general population. In addiction to being a movement disorder characterized by progressive hypokinesia, rigidity, tremor at rest, and stance/gait disorders, PD is also often associated with mental changes.
Cognitive disorders, especially executive dysfunction, affect up to 90% of patients. Subcortical-type dementia develops in at least 20% of these patients.
Over the course of the disease, at least 50% of patients experience depression, which is often combined with anxiety. Psychotic complications of drug therapy affect realtively few patients, although patients with cognitive defects are at an increased risk.
In addiction to the crucial deficit of dopamine, disturbance in other neurotransmitters that participate in basal ganglia circuits and ascending pathways constitute the neurobiological background of the mental symptoms associated with PD. Consequently, not all of these disorders can be managed pharmacologically through dopamine replacement therapy.
Neuropsychological examinations help in the diagnosis and determination of the severity of various components of mental problems associated with PD. The recommended tests help in evaluation and long-term monitoring of global cognitive deficits, cognitive disorders (especially executive dysfunction), and depression.