Tremor palsy, also known as Parkinson’s disease, is a common neurodegenerative disorder that develops after middle age and is characterized by resting tremor, muscle tonicity, and bradykinesia. The exact cause of Parkinson’s disease is still unknown. Genetic factors, environmental factors, ageing, and oxidative stress may all be involved in the degenerative death of dopaminergic neurons in PD. The incidence and prevalence of age-aging PD increases with age, and PD tends to develop over the age of 60, suggesting that aging is associated with the onset of the disease. Data suggest a progressive decrease in nigrostriatal dopaminergic neurons in normal adult brain with age. However, the prevalence of PD in older adults over 65 years of age is not high; therefore, aging is only one of the risk factors for the development of PD. Genetic factors The role of genetic factors in the pathogenesis of PD has received increasing attention from scholars. Since the discovery of the first Parkinson’s disease causative gene, alpha-synuclein (PARK1), in the late 1990s, there are now at least six causative genes associated with familial Parkinson’s disease. However, only 5-10% of Parkinson’s disease has a family history, and most of them are still disseminated cases. Genetic factors are also only one of the factors in the development of PD. Environmental factors In the 1980s American scholars such as Langston found that some drug users would rapidly develop typical Parkinson’s-like symptoms and were effective with levodopa preparations. It was found that synthetic heroin smoked by drug users contains a neurotoxic substance called 1-methyl-4 phenyl-1,2,3,6-tetrahydropyridine (MPTP). This substance is converted to the highly toxic 1-methyl-4phenyl-pyridinium ion MPP+ in the brain and selectively enters nigrostriatal dopaminergic neurons, inhibiting mitochondrial respiratory chain complex I activity and promoting oxidative stress, which leads to degenerative death of dopaminergic neurons. This led scholars to suggest that mitochondrial dysfunction may be a causative factor in PD. In subsequent studies it was also demonstrated that mitochondrial respiratory chain complex I activity is selectively decreased in the substantia nigra in patients with primary PD. The chemical structures of some herbicides and insecticides are similar to MPTP. With the discovery of MPTP, it was realized that some MPTP-like chemicals in the environment could be one of the pathogenic factors of PD. However, only a few of the many drug users exposed to MPTP developed the disease, suggesting that PD may be the result of a combination of factors.
Support Us
Discussion
Share your experience, or seek help from fellow patients.
