Chapter 49 Paroxysmal choreic, athetotic, or dystonic attacks

We have grouped attacks showing choreic, athetotic, and dystonic movements together in this section. Sometimes it is difficult to determine whether the movement disturbance in a particular type of paroxysm is choreic or dystonic. This can be due to the brief duration of the bout, the presence of both elements, or inadequate descriptions in the literature. Thus, it has been believed that the movements in paroxysmal kinesigenic dyskinesia tend to be choreic, while those in paroxysmal dystonic dyskinesia and paroxysmal exercise-induced dyskinesia are dystonic. However, this may not necessarily be the case and a range of dyskinesias can occur in these disorders (Demirkirin and Jankovic 1995, Bhatia 1997, Houser et al. 1999). Similarly, there are a variety of choreic, myoclonic, and dystonic actions in the disorder we have chosen to call ‘paroxysmal hypnic dystonia’ but sustained posturing seems to be the most prominent.