[Cognitive dysfunction in patients with Parkinson's disease].

Neurocognitive functions have been studied in 100 patients with Parkinson's disease (PD). PD was associated with cognitive impairment due to frontal lobes dysfunction, with hippocampus and right hemisphere involvement in advanced stages of the disease. Severity of cognitive impairment increased simultaneously with severity of movement disorder. Patient's age correlated with cognitive abilities. Mild dementia developed in the oldest patients with advanced PD. Besides typical cognitive disturbances, there were more pronounced memory impairment and speech disorders in some patients that might be related to concomitant pathology.