Introduction: Most patients with Parkinson's disease have cognitive and behavior disorders during the course of their illness.
Objective: In this study we consider practical aspects of the treatment of patients with Parkinson's disease who have such problems.
Development: Better understanding of both normal and abnormal physiology of the basal ganglia and their connections makes it possible to suggest hypotheses regarding the cause of these disorders. The combination of lesions of multiple subcorticocortical systems with different degrees of direct cortical pathology due to Lewy bodies and neuritic plaques may explain most of the changes, from depression to dementia.
Conclusions: It is necessary to test these concepts using studies based on specific predictions derived from pathophysiological models. Until this is done, the clinical treatment of cognitive and compartmental disorders in Parkinson's disease will continue to be symptomatic, complex and controversial.