There are three main forms of dystonia, the causes of which are different for each:
> The focal forms (a muscular area concerned) are the most frequent forms. These are prolonged contractures that affect a particular muscle group. This can be a torticollis that turns the head, forward, backward or on one side. This can be an embarrassment to writing, so called cramp of the writer or musician. This can reach the eyelids: it is called blepharospasm. The eyes close and blink involuntarily. But be careful: it's not because you have an eyelid that "jumps" from time to time, that you suffer from dystonia.
This can reach the muscles of the face that start to grin and contract. The cause of this local form dystonia is still unknown.
> Secondary forms: the symptoms are the same. Involuntary contractions of certain muscle groups. But in secondary forms, the cause is identified. As the name suggests, the secondary form comes as a result of a pathology or brain injury (stroke or tumor ...). These secondary forms may be the consequence of taking certain drugs, including neuroleptics.
> Genetic forms: they appear most often in childhood or at the time of adolescence. These are generalized forms that tend, most often, to affect all muscles.