Paroxysmal dyskinesias as a paradigm of paroxysmal movement disorders.

Paroxysmal dyskinesias are genetically and clinically heterogeneous. Paroxysmal kinesigenic choreoathetosis is frequently familial, with autosomal-dominant transmission. Benign infantile convulsions can be observed in these families and both diseases as linked to the pericentromeric region of chromosome 16. Two different forms of paroxysmal dystonic choreoathetosis are distinguished on clinical grounds, by the presence or absence of spasticity, and genetically, as they are linked with loci on different chromosomes. Among the paroxysmal disorders, these diseases may belong to the group of channelopathies.