Cognitive Deficits in Parkinson’s Disease

Motor abnormalities dominate the clinical picture of Parkinson’s disease. Bradykinesia, caused by severe damage to the ascending nigrostriatal dopaminergic projection, leads to a slight hesitancy in initiating voluntary acts, a difficulty in performing repetitive movements with a progressive reduction in their amplitude, a poorly defined fatigue and possibly an additional defect of motor intention. Many patients also have an inability to attend to two motor commands simultaneously, and more complex perceptual-motor abnormalities have also been detected. Muscle rigidity, a coarse resting tremor and postural instability compound the patient’s incapacities, all of which are exquisitely influenced by the emotions.