The 37-year-old Canadian actor Michael J. Fox has Parkinson disease, a progressive degenerative disease of the part of the brain called the substantia nigra that controls movement. Although Parkinson disease occurs mostly in older people, it sometimes does strike people in their forties or, as with Mr. Fox, even younger people.
Mr. Fox was first diagnosed when he noticed a “twitch” in his left little finger while he was working on the set of the 1991 film Doc Hollywood, he told People magazine. Parkinson disease has several classic signs and symptoms including tremors, stiffness of the limbs, a mask-like face, gait disturbance (difficulty walking), depression and, late in the disease, dementia.
The tremor is characteristically a resting tremor that especially involves the hands and fingers. It is described as a “pill rolling” tremor, a name that harks back to the similarity between the tremor’s movement and that required to “roll a pill” in pharmacies past. In the early stages of Parkinson disease, the tremor stops when the person does something active, such as walking. Mr. Fox said that he paced during an interview to quell his tremor.
