Chapter 34 - Paroxysmal Dyskinesias

Abstract

This chapter deals with the paroxysmal dyskinesias. Some disorders, like familial autosomal dominant paroxysmal nonkinesigenic dyskinesia, seem fairly distinct both clinically and genetically, while there is possibly an overlap between paroxysmal kinesigenic dyskinesia and paroxysmal exercise-induced dyskinesia. Although the genes for these have not yet been located, the similarities between these paroxysmal dyskinesias and other intermittent neurological disorders like periodic paralysis and episodic ataxias are an indication that these are also likely to be caused by defective ion channel genes. Finding the genes results in a better understanding of the pathophysiology, classification, and treatment of these curious disorders. The discovery of the genes also leads to the possibility of developing animal models and to do functional studies at a cellular level particularly if the gene disorders are ion channel mutations.