Paroxysmal exercise-induced dystonia: eight new sporadic cases and a review of the literature.

We report eight new sporadic cases of paroxysmal dystonia induced by prolonged or sustained exercise and review an additional seven previously reported cases. The attacks in our patients lasted from a few minutes to up to 2 h, and patient age at onset ranged from 2 to 30 years. Four of the eight patients had hemidystonic attacks, both legs were involved in two other cases, and the remaining two patients had involvement of the right foot only. We propose that such cases should be classified as paroxysmal exercise-induced dystonia.