The differential diagnoses of parkinsonism: Findings from a cohort of 1528 patients and a 10 years comparison in tertiary movement disorders clinics

ObjectiveTo investigate the etiologic diagnoses of parkinsonism, underlining aspects of each form and comparing our findings with those published in a similar setting, 10 years before.MethodsA large cohort of 1528 patients with parkinsonism was analyzed, gathering data on demography, motor and non-motor characteristics, as well as the final etiologic diagnoses based on established criteria.ResultsParkinson's disease (PD) was the most common diagnosis representing 74.7%, followed by drug-induced parkinsonism (DIP) in 7.9%, vascular parkinsonism (VP) in 3.9%, other neurodegenerative disorders in 10%, and rare sporadic causes, divided as genetic, infectious and others, that summed 3.5%. Comparative analysis of these groups showed that each has particularities that extend beyond their diagnostic criteria.ConclusionsThe main conclusions are that the most important causes of parkinsonism in this setting are typical, with PD been the most common diagnosis, although other causes were frequent, encompassing one fourth of all cases. Although DIP was identified in a particularly large part of this cohort, this proportion is smaller than demonstrated previously in a Brazilian study conducted in the 90s. This decrease probably reflects higher awareness regarding the risk of this motor complication and the more widely used newer antipsychotics.