I hope the following information on my page about PD could be of help to you. Because it is not contagious and does not have to be reported by physicians, the incidence of the disease is often underestimated. PD may appear at any age, but it is uncommon in people younger than 30, and the risk of developing it increases with age. It occurs in all parts of the world, and men are affected slightly more often than women. Following is a list of the primary symptoms of Parkinson's disease.
Rigidity is an increased tone or stiffness in the muscles.
Unless it is temporarily eased by anti-Parkinson's medications, rigidity is always present. However, it increases during movement. It is often responsible for a mask-like expression of the face. In some patients, rigidity leads to sensations of pain, especially in the arms and shoulders. When it is present, the tremor may be worse on one side of the body.