The pathogenesis and treatment mechanism of Parkinson's disease from the perspective of traditional Chinese medicine

Parkinson disease (PD) is the most common neurodegenerative movement disorder. In Europe, prevalence and incidence rates for PD are estimated at approximately 108-257/100 000 and 11-19/100 000 per year, respectively. Risk factors include age, male gender and some environmental factors. The aetiology of the disease in most patients is unknown, but different genetic causes have been identified. Although familial forms of PD account for only 5%-15% of cases, studies on these families provided interesting insight on the genetics and the pathogenesis of the disease allowing the identification of genes implicated in its pathogenesis and offering critical insights into the mechanisms of disease. The cardinal motor symptoms of PD are tremor, rigidity, bradykinesia/akinesia and postural instability, but the clinical picture includes other motor and non-motor symptoms. Its diagnosis is principally clinical, although specific investigations can help the differential diagnosis from other forms of parkinsonism. Pathologically, PD is characterized by the loss of dopaminergic neurons in the pars compacta of the substantia nigra and by accumulation of misfolded α-synuclein, which is found in intra-cytoplasmic inclusions called Lewy bodies. Currently available treatments offer good control of motor symptoms but do not modify the evolution of the disease. This article is intended to provide a comprehensive, general and practical review of PD for the general neurologist.

This article reviews and summarizes 200 years of Parkinson's disease. It comprises a relevant history of Dr. James Parkinson's himself and what he described accurately and what he missed from today's perspective. Parkinson's disease today is understood as a multietiological condition with uncertain etiopathogenesis. Many advances have occurred regarding pathophysiology and symptomatic treatments, but critically important issues are still pending resolution. Among the latter, the need to modify disease progression is undoubtedly a priority. In sum, this multiple-author article, prepared to commemorate the bicentenary of the shaking palsy, provides a historical state-of-the-art account of what has been achieved, the current situation, and how to progress toward resolving Parkinson's disease. © 2017 International Parkinson and Movement Disorder Society.

The past 25 years have seen a major expansion of knowledge concerning the cause of Parkinson's disease provided by an understanding of environmental and genetic factors that underlie the loss of nigral dopaminergic neurons. Based on the actions of toxins, postmortem investigations, and gene defects responsible for familial Parkinson's disease, there is now a general consensus about the mechanisms of cell death that contribute to neuronal loss in Parkinson's disease. Mitochondrial dysfunction, oxidative stress, altered protein handling, and inflammatory change are considered to lead to cell dysfunction and death by apoptosis or autophagy. Ageing is the single most important risk factor for Parkinson's disease, and the biochemical changes that are a consequence of aging amplify these abnormalities in Parkinson's disease brain. What remains to be determined is the combination and sequence of events leading to cell death and whether this is identical in all brain regions where pathology occurs and in all individuals with Parkinson's disease. Focusing on those events that characterize Parkinson's disease, namely, mitochondrial dysfunction and Lewy body formation, may be the key to further advancing the understanding of pathogenesis and to taking these mechanisms forward as a means of defining targets for neuroprotection. Copyright © 2011 Movement Disorder Society.