New Blood Test Detects Parkinson's Before Symptoms Appear
A substance present in the blood of people who have Parkinson’s disease can now be detected using a new blood test developed by scientists from the United Kingdom. The breakthrough test can identify Parkinson’s disease in individuals before symptoms appear, which opens the door to early treatment and planning.
Early detection of Parkinson’s disease may be possible
An estimated 50,000 to 60,000 people are diagnosed each year in the United States with Parkinson’s disease, a neurodegenerative brain disorder that slowly robs individuals of their ability to control muscle movements and other non-motor activities. Although there is not yet a cure, treatments are available to help individuals manage their symptoms.
Parkinson’s disease develops when the brain cells (neurons) that produce dopamine—a chemical that transmits messages between parts of the brain to control body movements—are damaged. Once 60 to 80 percent of a person’s dopamine-producing cells are damaged, the motor symptoms of Parkinson’s appear.
The new blood test detects a substance called phosphorylated alpha-synuclein, which is commonly found in people who have Parkinson’s disease. Use of this test “would mean you could find out if a person was in danger of getting the disease, before the symptoms started,” explained one of the researchers, David Allsop, PhD, who works from the Division of Biomedical and Life Sciences and the School of Health and Medicine at the University of Lancaster, UK.
Allsop and his colleagues developed the test by studying a group of 32 Parkinson’s disease patients and a control group of 30 healthy adults. Analysis of blood samples collected from all the participants showed elevated levels of phosphorylated alpha-synuclein in the Parkinson’s patients, which prompted the scientists to develop a test to detect it when the disease is in its early stages.
The four typical symptoms associated with Parkinson’s disease include
- Tremor or shaking at rest
- Rigidity or stiffness of the arms, legs, or trunk
- Slow movements (bradykinesia)
- Difficulty with balance (postural instability; usually appears later in the disease)
Gerald Weissmann, MD, editor-in-chief of the FASEB Journal, which published the study’s findings, noted that aside from the commonly recognized symptoms of Parkinson’s, many people with the disease also have other neurological difficulties that can be more difficult to identify early on. However, “having a blood test not only helps doctors rule out other possible causes of the outward symptoms, but it also allows for early detection which can help patients and their caregivers prepare for the possibility of the mental, emotional, and behavioral problems that the disease can cause.”
Secondary symptoms of Parkinson’s disease may include loss of facial expression due to rigidity of facial muscles, reduced ability to blink and swallow, reduced arm swing and/or slight foot drag on the affected side, loss of sense of smell, and a tendency to fall backwards, as well as depression, constipation, sleep disturbances, hallucinations, pain, and skin problems.
While the new blood test for Parkinson’s disease is not a cure or treatment, it may serve as an important tool in the fight against the disease. Because it can identify the disease before symptoms begin, it “would help the development of medicines that could protect the brain,” noted Allsop, “which would be better for the quality of life and future health of older people.”
Foulds PG et al. Phosphorylated α-synuclein can be detected in blood plasma and is potentially a useful biomarker for Parkinson’s disease. The FASEB Journal 2011; 25(12): 4127
National Parkinson Foundation
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