Unilateral pallidal deep brain stimulation in a patient with dystonia secondary to episodic ataxia type 2.

Background/aims: This paper describes the use of deep brain stimulation (DBS) of the globus pallidus internus (GPi) in the treatment of secondary dystonia caused by expisodic ataxia type 2 (EA2).

Methods: We present the case of a patient with EA2, an autosomal dominant condition, who developed late-onset cervical and right upper limb segmental dystonia. The patient underwent left GPi DBS.

Results: Within 4 months of commencing stimulation of the left GPi, the patient had resolution of his neck pain and was able to keep the head straighter for longer time intervals. There was also improvement in right arm segmental dystonia. There was an improvement in the Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS 21.5) of 55% at 4 months and of 51% at 22 months.

Conclusion: The treatment of secondary dystonia is difficult and the results with GPi DBS are less favourable compared with primary dystonia. This case illustrates the successful treatment of secondary dystonia caused by EA2.