Essential tremor and buccolinguofacial dyskinesias.

Essential tremor (ET) has been described in association with major dyskinesias, such as dystonia musculorum deformans, torticollis, and dystonic writer's cramp. In a series of 104 patients affected by ET, the incidence of buccolinguofacial dyskinesias (BLFD) has been investigated, including a comparison with another dyskinesia involving the facial muscles--mimic muscle tremor. The association of ET and BLFD may be casual; however, on the other hand, it might suggest the existence of a subgroup of patients suffering from a non-specific sign of motor control impairment, such as ET, in which other non-specific disorders of voluntary movement, such as BLFD, can gradually develop, particularly late in life.