[Paroxysmal dyskinesias]

Paroxysmal dyskinesias are uncommon movements disorders that consist on recurrent brief episodes characterized by attacks with any combination of dystonia, chorea, athetosis or ballismus.

The pathophysiology of paroxysmal dyskinesias is unclear at the present time. An epileptic mechanism and basal ganglia disorders have been proposed although channelopathy due to ion channel mutations have been recently suggested. These disorders were classified by Demirkiran and Jankovic into two main groups: paroxysmal kinesigenic dyskinesia if the attacks were induced by sudden movement and paroxysmal nonkinesigenic dyskinesia if they were not. In addition to these groups, two more types have been known, namely paroxysmal exercise-induced dyskinesia and hypnogenic paroxysmal dyskinesia. As well association between benign infantile familial convulsions and paroxysmal choreoathetosis, or rolandic epilepsy, episodes of exercise induced dystonia, and writers' cramp have been described. Also others paroxysmal movements disorders have been known, we mention below. Paroxysmal dyskinesias can further be divided into idiopathic (familiar in most of the cases) or secondary cases depending on underlying cause.