Currently there is no known cause of Parkinson’s or understanding of why some people develop Parkinson’s and not others. This is the reason Parkinson’s is often referred to as Idiopathic (or typical) Parkinson’s.
There are many theories as to the causes of Parkinson’s and it’s generally thought that multiple factors are responsible.
Through research, our understanding of the possible causes of Parkinson’s is increasing all of the time. Areas of current research include ageing, genes, environmental factors, chemical exposure, and viruses.
Genes and Parkinson’s
Genetic or hereditary Parkinson’s is very rare. Current research suggests that 5 per cent of Parkinson’s may have a genetic cause. In the rare examples where Parkinson’s does seem to be passed on from one generation to the next, genetic abnormalities appear to be involved. Even when an abnormal gene is present the chances of going on to develop Parkinson’s are very low.
Genetic testing is available only for people where a genetic cause is strongly thought to relate to their diagnosis, i.e. several family members living with Parkinson’s. Your neurologist is the only person who can arrange for a genetic test, and this will only occur after genetic counselling.
Environment and Parkinson’s
There is limited evidence that toxins in the environment may cause dopamine-producing neurons to die, leading to the development of Parkinson’s. In particular, there has been a great deal of speculation about the link between the use of herbicides and pesticides and the development of Parkinson’s.
A number of scientific studies have established a clear association between the herbicide paraquat and development of Parkinson’s disease¹.
Learn more about Fight Parkinson’s position on paraquat and Parkinson’s disease.
There are many other examples of different environmental factors leading to the development of Parkinson’s, but as yet the evidence is inconclusive.
Other factors that increase the risk of Parkinson’s
Advancing age, being male and head injuries are potential factors which may increase the risk of Parkinson’s.
Unfortunately, it is generally impossible to determine the cause of Parkinson’s in an individual. Parkinson’s is a chronic and slowly progressive disorder.