Parkinson’s disease is a devastating neurodegenerative disease that affects approximately 1 million patients in the US. It’s expected that there will be 60,000 new cases this year. There is no known cure and a recent study from the Mayo Clinic shows that the incidence of Parkinson’s disease and parkinsonism increased significantly in 30 years from 1976 to 2005. This trend was especially true for men age 70 and older. According to the study authors, this is the first study to show such an increase.
The study was conducted using data from the Rochester Epidemiology Project. This databases allowed the researchers to look at the complete medical records — from birth to death — of anyone in Olmsted County, Minnesota, who received at least one of the diagnoses related to parkinsonism. The records were reviewed by a movement disorders specialist to confirm the diagnosis and to classify different types of parkinsonism, including the most common type, Parkinson’s disease.
The terminology is a key part of the study. Parkinsonism includes Parkinson’s disease, but may include other disorders. The diagnosis of parkinsonism requires slowness of movement and at least one other symptom, such as muscle rigidity, a tendency to fall, or a tremor while a person is at rest. Parkinson’s disease has the manifestations of parkinsonism, but without any other known causes, and it is the most common type of parkinsonism.
Rodolfo Savica, M.D., Ph.D., lead author and neurologist at Mayo Clinic was confident that the study showed a true increase in cases and could possibly be related to lifestyle factors or environmental exposure. He said in a press release,“We have reasons to believe that this is a real trend. The trend is probably not caused merely by changes in people’s awareness or changes in medical practice over time. We have evidence to suggest that there has been a genuine increase in the risk of Parkinson’s disease. There has been a dramatic change in exposure to some risk factors in the United States. We know that environmental agents like pesticides or smoking or other agents in the environment have changed in the last 70 years or so. Changes in exposure to a number of risk factors may have caused Parkinson’s disease to rise”
The study results are contrary to previous studies on the incidence of parkinsonism. Tw earlier studies done in the United States and one conducted in Canada showed no trends toward increased or decreased incidence of the disease. Of particular note is how opposite the Mayo Clinic results were from three previous studies in the United Kingdom that showed a trend towards fewer cases over time.
The research is important step in looking for a cure for Parkinson’s. By studying the trends in diagnoses of the disease, which populations are more impacted than others and even decades that show spikes in the incidence of cases can give scientists valuable insight into how the disease develops. Knowing more about how many cases and who they affect can lead to better research towards a cure or treatments. The video below explains more about the study and what researchers hope to gain from the results.
Sources: Mayo Clinic, Parkinson's News Today