Parkinson’s Disease In Special Populations
Reviewed by: HU Medical Review Board
An estimated 10 million people worldwide are living with Parkinson’s disease (PD). One million of those people live in the United States, and about 60,000 Americans are diagnosed with PD every year.1
PD is most common in men over the age of 60. However, women can still develop PD. There is also a group of people who are diagnosed with PD before the age of 50. This is called young-onset Parkinson’s disease (YOPD). Roughly 5 to 10 percent of people in the United States living with PD have YOPD.2,3
Women and people with YOPD experience PD slightly differently.2,3
Young-onset Parkinson's disease
YOPD refers to any case of PD that is diagnosed before 50 years of age. There is an even smaller subset of people who are diagnosed before they turn 40 years old.3
The cause of PD is not fully understood. Experts believe it may have to do with environmental factors, such as exposure to pollution. However, there may be a genetic cause as well. People with YOPD are more likely to have stronger genetic factors of PD that can be passed down through families than cases of PD diagnosed after the age of 50.3
For many people with YOPD, an early symptom is involuntary muscle contractions that cause repetitive or twisting movement (dystonia). These contractions may affect one or more parts of the body or even the entire body. Uncontrolled, involuntary muscle movement (dyskinesia) is also more common in people with YOPD.3
YOPD often progresses slower than PD in other populations. Though symptoms begin younger, symptoms are not as severe or extensive. This means that those living with YOPD often are independent longer. People with YOPD are less likely to develop dementia too.3
People with YOPD also are less likely to have other health conditions. This makes them good candidates for new medical innovations to treat PD.3
PD in women
Overall, women are less likely to develop PD than men. They also experience PD differently than men. On average, they may experience different symptoms and tend to experience drug side effects more often. Unfortunately, in many cases, women with PD are not treated as effectively by doctors.5
Levodopa is the best treatment we currently have to treat the movement symptoms of PD. It is a molecule that the body can convert into dopamine to make up for the dopamine it cannot make.5
No medicine can stop the destruction of the dopamine-producing areas of the brain. Because of that, levodopa can be less effective the longer someone has PD.5
Some studies have shown that this drug stops working earlier for women than for men. Women also report side effects of levodopa more often. The most common side effect women report is dyskinesia.5
Deep brain stimulation (DBS) is a surgery that can treat PD. It can be highly effective when PD symptoms are difficult to control. However, studies have shown that women do not receive this treatment as often as men. Researchers are looking to understand why this happens.5
Other considerations
Researchers do not know why women are less likely to develop PD than men. They also do not know why their symptoms are different. Researchers think it might be because women’s bodies may respond differently to PD and PD drugs.5
Another theory focuses on environmental factors. Some possible causes of PD are exposure to pesticides and head injuries. Lower rates of PD in women may be because they experience these less often than men.5
Finally, estrogen is known to be protective against osteoporosis and heart disease. Estrogen’s role in PD is not understood. However, some scientists believe it may also protect women from PD. Researchers are currently studying this.5