1. Clinically, it is common for professionals who have been engaged in fine manual operation for a long time, such as teachers, editors, secretaries, writers, painters, calligraphers, transcribers, draftsmen, typists, telegraphists, pianists, etc.
2. Fingers are mainly inflexible and uncoordinated; Spastic contraction of hand muscles or tremors of both hands or even tremors of the whole arm muscles hinder the function of both hands and prevent them from doing fine work; It is typical and intuitive to see that it is difficult to write, and the writing is crooked. In serious cases, it is impossible to write. Symptoms are gradual. At first, only the fingers and forearms were stiff and easy to get tired. Later, with the aggravation of symptoms, local muscles contracted spasmodically when writing. In severe cases, due to the strong spasmodic contraction of the flexor muscles of the fingers, the patient cannot hold the pen. At the same time, there are some pains.
3. The disease is often induced by physical fatigue (especially hand fatigue) or nervousness. And the more nervous, the more afraid of bad handwriting, the more obvious the spasm. If you do other things that don't need careful operation with your hands, you will feel calm, easy to operate, and the degree of convulsions is very light, even without convulsions.
4. Middle-aged and elderly people are prone to nervous system diseases such as Parkinson's disease or cerebellar ataxia, and symptoms such as finger spasm or tremor may occur after illness.