Focal task-specific tremors.

Focal task-specific tremors besides primary writing tremor have rarely been reported in the literature. We describe nine cases of focal tremors induced by different specific tasks, involving a repetitive and frequently performed movement. Only one of these patients had a family history of any similar disorders. There was no overt dystonia in any of the cases, but these tremors may be forms of focal dystonia, rather than a manifestation of essential tremor.