Ability To Ride a Bike Helps in Parkinson's Diagnosis
The expression “as easy as falling off a bike” may apply to the findings of a new study about Parkinson’s disease. A report from three doctors in The Netherlands notes that the ability to ride a bike can help in the diagnosis of Parkinson’s.
“Can you still ride a bicycle?”
Parkinson’s disease is the most common form of parkinsonism, a group of motor system disorders that are the result of the loss of dopamine-producing cells in the brain. The cause is unknown.
In other forms of parkinsonism, the cause is known or suspected or it occurs as a secondary effect of another neurological cause. These disorders are known as atypical Parkinson’s. Atypical Parkinson’s may be related to a brain tumor, head trauma, drug use (e.g., phenothiazines, reserpine), toxins, or neurological conditions such as Alzheimer’s disease or Wilson’s disease, among others.
No test can confirm whether a person has Parkinson’s disease, thus it is a clinical diagnosis based on medical history, medication use, a neurological examination, and response to medications that imitate or stimulate the production of dopamine. Brain scans or laboratory tests are used to rule out other diseases.
Now scientists have noted that the ability or inability to ride a bike may be a way to help diagnose atypical Parkinson’s disease. Differentiating Parkinson’s disease from atypical parkinsonism is important for treatment and to select patients for clinical trials, yet making the distinction has been difficult. The answer to the question, “Can you still ride a bicycle?” may offer a significant clue.
The researchers conducted a prospective observational study of 156 patients with parkinsonism without a definitive diagnosis. In addition to standard clinical diagnostics, the individuals were asked about their bicycling activities—whether, when, and why cycling had become impossible.
The four main symptoms of Parkinson’s are tremor in the hands, arms, legs, jaw, and face; rigidity or stiffness of the limbs and trunk; slowness of movement (bradykinesia); and impaired balance and coordination. Before the study patients’ symptoms first appeared, 111 rode a bicycle. Of these, 45 eventually developed Parkinson’s disease and 64 had a type of atypical parkinsonism.
After having symptoms of the disease for an average of 30 months, 34 of the 64 patients with atypical parkinsonism had stopped cycling, regardless of the reason for their disease, compared with only two of the 45 patients with Parkinson’s disease.
The authors suggest that the loss of the ability to ride a bike after onset of disease symptoms may be a good diagnostic sign of atypical parkinsonism. Physicians could ask patients about their bike riding ability as part of the differential diagnosis of parkinsonism.
Aerts MB et al. Lancet 2011 Jan 8; 377(9760): 125-26
National Institute of Neurological Disorders and Stroke