Parkinson's disease is a common degenerative disease of the nervous system, and one of its main symptoms is tremor. This tremor has several distinctive features:
At first, it usually starts on one limb and gradually affects other parts. This means that tremors may occur initially in only one hand or foot, but over time, the tremors may spread to the other limb and even affect the head, lips or jaw.
Second, the tremor of Parkinson's disease is most pronounced at rest and may lessen or disappear during activity or sleep. As a result, the tremor may be most intense when sitting or lying down.
In addition, the frequency of this tremor is usually between 4-6 Hz, giving people a "pill-rubbing" feeling. In other words, it looks like the patient's hands or feet are constantly making small, rapid back-and-forth, or side-to-side movements.
Finally, unlike many other types of tremors, tremors in Parkinson's disease tend to be persistent rather than paroxysmal. This means that it is likely to be there forever, although its intensity may vary.
As mentioned above, the tremor of Parkinson's disease is characterized by gradual, pronounced at rest, specific frequency, and persistent. These features help doctors accurately diagnose Parkinson's disease.