Environmental toxic factors and clinical pattern of Parkinson’s disease

Abstract

Background: Parkinson’s disease (PD) – the most common neuro-degenerative movement disorder – is considered a result of a multifactorial pathogenic process modulated by cumulative and interactive effects of genes and exposures. An environmental exposure could enhance or create dopaminergic neurons vulnerability and increase PD risk. The purpose of the study was to find if excessive exposure to toxic environmental factors may influence clinical pattern of PD. Material and methods: The study was conducted on 111 patients diagnosed with PD, study group being defined as PD exposed to toxins (33 patients), control group including PD patients without toxin exposure (78 patients). General epidemiological data and clinical data were recorded. Results: Toxin exposure was found in 33 patients (29.73%), more of them – men and rural residents. Toxin exposed PD patients had an insignificantly younger age. The most common disease phenotype in the study group was the akinetic-rigid phenotype (64.7%, p = 0.040), bradykinesia being the most common sign at the disease onset (57.6%, p = 0.008). Levodopa equivalent daily dose also was higher in the study group (659.02 ± 232.46, p = 0.042). Conclusions: Excessive exposure to toxic environmental factors may influence the clinical pattern of PD. In this study the akinetic-rigid type was the predominant disease phenotype associated with toxin exposure. Doses needed for treatment were higher in PD patients exposed to toxins, as an indicator of a more severe motor impairment in this group.