At present, it is widely accepted that genes, environmental toxins, and other factors, such as aging and lifestyle, combine to cause PD. But it is controversial to classify genetic factors as the primary cause of PD, as the genetic factors can only explain a few cases, and 90% of PD patients have no family history ( 16). So far, 23 loci and 19 disease-causing genes related to PD have been found. The environmental hypothesis and the genetic hypothesis are frequently discussed in the etiology of PD. In recent years, the etiology of PD has been discussed in many studies, where aging, genetic, and environmental factors are the main concerns ( 15). The current treatment methods have limited efficacy on the loss of dopaminergic neurons but only alleviate the symptoms partially and unsustainably ( 14). However, until now, the etiopathogenesis of PD has not been clearly understood.
#Center for environmental visualization full#
The features of PD have been mentioned in Indian texts for thousands of years, and the full syndrome was described in the early nineteenth century ( 13). In addition, there are some non-motor symptoms in PD patients, including depression, cognitive impairments, and gastrointestinal dysfunction, which may appear years or even decades before motor symptoms ( 12). As a chronic progressive neurodegenerative disorder, the clinical manifestations of PD include many motor symptoms, such as static tremor, bradykinesia, and rigidity ( 11). Mitochondrial dysfunction, oxidative stress, protein aggregation, and inflammation play indispensable roles in the pathogenesis of PD ( 10), each of which could lead to the degeneration of dopaminergic neurons. Sporadic PD is also characterized by the presence of Lewy bodies and Lewy neurites, which consist primarily of misfolded and aggregated protein α-synuclein in the remnant neurons ( 7– 9).
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However, the main neuropathological features of PD are the progressive loss of dopaminergic neurons in the substantia nigra pars compacta (SNpc) ( 6). Pathological studies of several rare hereditary parkinsonism cases found no Lewy body or deposition of α-synuclein ( 5). It is assumed that the annual cost of PD in the US alone would exceed $50 billion by 2040 ( 4). Consequently, the cost of PD will skyrocket. PD patients in France are estimated to be 260,000 in 2030, corresponding to an increase of 65% compared with 2010 ( 3). China has the largest number of PD patients in the world, which are estimated to grow to 5 million in 2030 ( 2).
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With the global trends in aging, the number of people affected by PD is expected to increase significantly. In America, the incidence of PD among people over 65 years old is about 1.6%, with 50,000 to 60,000 new cases diagnosed annually ( 1). Parkinson's disease (PD) is one of the most common neurodegenerative diseases, mainly affecting the middle-aged and the elderly. To the best of our knowledge, this is the first study to specifically visualize the relationship between pesticide exposure and PD, and forecast research tendency in the future. The hot topics, valuable articles, and productive authors in this research field could be found after that. Based on 1767 articles from the Web of Science Core Collection and PubMed database, this study carried out the analysis from the keywords, cited references, countries, authors, and some other aspects by using Citespace. This paper aims to explore the knowledge structure, analyze the current research hot spots, and discuss the research trend through screening and summarizing the present literature. Some pesticides have been demonstrated to be associated with PD by many previous studies and experiments, and an increasing number of researchers have paid attention to this area in recent years. Both genetic and environmental factors contribute to the onset and progression of PD. The etiology and pathogenesis of Parkinson's disease (PD) have not yet been clearly described. 3School of Information and Safety Engineering, Zhongnan University of Economics and Law, Wuhan, China.2Department of Neurology, Renmin Hospital of Wuhan University, Wuhan, China.
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1Research Center for Environment and Health, Zhongnan University of Economics and Law, Wuhan, China.Chaoyang Liu 1,2,3 *, Zehua Liu 1,3, Zhentao Zhang 2, Yanan Li 1,3, Ruying Fang 1,3, Fei Li 1,3 and Jingdong Zhang 1,3