Clinical Features of Parkinson's Disease in Early Stages. Diagnostic Errors of Different Forms

The article describes the clinical picture of Parkinson's disease (PD) with indication of disease stages according to classifications by different authors. Criteria for clinical diagnosis of PD are provided. Difficulties in making correct diagnosis are indicated. Clinical examples demonstrate cases of erroneous diagnosis, confirming the diversity of clinical symptoms of PD onset and indicating the necessity for thorough patient examination and history taking.