[Comparative study of Parkinson's disease and dementia with Lewy bodies]

Comparative investigation of motor and neuropsychological functions was conducted in 17 patients with clinically established diagnosis of dementia with Lewy bodies (DLB), 21 patients with Parkinson's disease (PD) without dementia and 26 patients with dementia (PDD). No significant differences were found in overall severity of parkinsonian features. However, comparing to PD, patients with DLB rarely had resting tremor, bilateral parkinsonism onset and good response to levadopa medication but more frequently exhibited gaze up palsy and myoclonus. Patients with PDD had more prominent akinesia, rigidity and axial disturbances, as compared to the PD patients without dementia, but there were no significant differences in these variables between patients with DLB and PDD. Comparing to PDD patients, those with DLB poorly performed on the tests measuring attention, verbal fluency and visual-spatial functions. Behavioral disturbances (especially apathy, aspontaneity, euphoria, obsessive-compulsive syndrome, dysinhibition, environment dependence) were severer in the patients with DLB and PDD, but no significant differences were found between these two groups. All the patients with DLB, 14 patients with PDD (53.8%) and 2 patients without dementia (7.4%) had psychotic disorders, which emerged later and were less pronounced in the patients with DLB compared to PDD patients. However, no significant differences were found in motor and neuropsychological impairment between DLB and PDD with psychotic disorders. The results may indicate a typological similarity of clinical manifestations of DLB and PDD that suggest nosologic proximity of these conditions included to synucleinopathies group.