Can You Still Ride a Bike? Tool to Diagnose Parkinson’s Disease
The ability to ride a bike can be a reliable way to diagnose Parkinson’s disease and distinguish it from atypical parkinsonism, according to a new study. Differentiating between these two disorders, which have similar symptoms, is important because they respond differently to treatment.
Riding a bike is a test for Parkinson's disease
Parkinson’s disease is a progressive, chronic movement disorder that affects nerve cells (neurons) in the brain and causes them to malfunction and die. Some of the dying cells produce dopamine, a chemical necessary for controlling coordination and movement. As the amount of dopamine declines, a person is unable to control his or her movements. Symptoms of Parkinson’s disease include tremors at rest, slowness of movement, stiffness, unsteady gait, and freezing while walking.
People with atypical parkinsonism have some of the same symptoms of Parkinson’s disease, but theirs are caused by a loss of neurons plus degeneration of cells in other areas of the nervous system. People with atypical parkinsonism may also have abnormal eye movements, unstable blood pressure, and impaired bowel, bladder, and sexual function along with the symptoms characteristic of Parkinson's disease.
To help clinicians differentiate between the two conditions, Japanese researchers used the “bicycle sign.” People who have atypical parkinsonism lose their ability to ride a bike during the early stage of their illness, while people with Parkinson’s disease can still ride well.
The investigators from Wakayama Medical University in Wakayama, Japan, found that 88.9% of patients with atypical parkinsonism had stopped bicycling during the time their illness began, as compared with only 9.8% of patients who had Parkinson’s disease. Since bike riding is a very common activity in Japan, using the “bicycle sign” can be a reliable diagnostic tool in that country.
Treatment of Parkinson’s disease typically involves dopamine replacement in the form of levodopa, which is converted into dopamine by the brain. However, people with atypical parkinsonism do not respond to levodopa treatment.
According to Hideto Miwa of the Department of Neurology at Wakayama Medical University, “although bicycling cultures may differ between countries, it is possible that the ‘bicycle sign’ could contribute to earlier and better differential diagnosis of parkinsonism during the diagnostic interview.” A simple question--Can you still ride a bike?—may provide doctors with important information when diagnosing Parkinson’s disease.