The role of exposure to pesticides in the etiology of Parkinson’s disease: a 18F-DOPA positron emission tomography study
Susceptibility to Parkinson’s disease (PD) is believed to involve an interaction between genetic and environmental factors. The role of pesticides as a risk factor of PD and neurodegeneration remains controversial. An asymmetric decrease in ligand uptake on 18F-DOPA positron emission tomography (PET), especially in the dorsal putamen, is a sensitive marker of PD. The aim of this study was to examine the pattern of ligand uptake on 18F-DOPA PET in patients with PD exposed or not exposed to pesticides. The main sample included 26 Israeli patients with PD, 13 who were exposed to pesticides and 13 who were not, matched for age and disease duration. All underwent 18F-DOPA PET imaging, and an asymmetry index of ligand uptake between the ipsilateral and contralateral caudate, putamen, and whole striatum was calculated. No significant between-group differences were found in demographic variables, clinical asymmetry index (P = 0.15), or asymmetry index of ligand uptake in the putamen (P = 0.84), caudate (P = 0.78) and striatum (P = 0.45). Comparison of the 18F-DOPA results of the Israeli cohort with those of 17 non-pesticide-exposed patients with PD from Austria yielded no significant differences, further validating our findings. Our observations suggest that although exposure to pesticides might be a risk factor for PD, it does not have an effect on the asymmetry pattern in the nigrostriatal system over non-exposure. We assume that once the disease process is initiated in pesticide-exposed patients, the pathogenic mechanism does not differ from that of idiopathic PD.
KeywordsPesticides Parkinson's disease Asymmetry index 18F-DOPA PET
Magnetic resonance imaging
Positron emission tomography
Unified PD Rating Scale
RD study design, interpretation of data and drafted the manuscript. AS study design, technical equipment and data acquisition. AR statistical analysis and drafted the manuscript. CS data acquisition. WP data acquisition. YR technical assistance and revision of manuscript. LG study design and drafted the manuscript. ML data acquisition and drafted the manuscript. All authors approved the final article.
This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.
Compliance with ethical standards
Conflict of interest
The authors declare that they have no conflict of interest.
This study has been approved by our Institution’s Ethics Committee and has therefore been performed in accordance with the ethical standards laid down in the 1964 Declaration of Helsinki and its later amendments.
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