Paroxysmal Dyskinesias in Children.

Paroxysmal dyskinesias are rare movement disorders. The onset of paroxysmal dyskinesias in childhood are typically idiopathic (sporadic or familial), whereas those in adulthood are usually secondary to an identifiable cause. Paroxysmal dyskinesias are classified according to precipitating factors, and these include paroxysmal kinesigenic dyskinesia, paroxysmal nonkinesigenic dyskinesia, paroxysmal exertion-induced dyskinesia, and paroxysmal hypnogenic dyskinesia. The pathophysiology remains unknown; however, there is increasing evidence that channelopathies may play a role, which explains the response to anticonvulsant medications in certain kindreds. Pharmacologic treatment with anticonvulsant medications, clonazepam, tetrabenazine, trihexyphenidyl, or levodopa is reviewed herewith. Paroxysmal dyskinesias go by many names, but a rational classification does exist. Of those that respond to medications, the majority of paroxysmal dyskenesias respond to anticonvulsant medications. Channelopathies have been implemented as a cause in paroxysmal dyskinesias.