Clinical outcome of deep brain stimulation for dystonia: constant-current or constant-voltage stimulation? A non-randomized study.

Background and purpose Bilateral globus pallidus deep brain stimulation (GPi-DBS) represents an effective and relatively safe therapy for different forms of refractory dystonia. The aim of this study was to assess, retrospectively, the effect of two different stimulation settings during GPi-DBS in 22 patients affected by primary generalized or multi-segmental dystonia. Methods Thirteen patients were stimulated using a voltage-controlled setting whilst in the other nine patients a current-controlled setting was used. Clinical features were evaluated for each patient at baseline, 6 months and 12 months after surgery by means of the Burke−Fahn−Marsden Dystonia Rating Scale. Results Globus pallidus deep brain stimulation was effective in all patients. However, comparing constant-current and constant-voltage stimulation, a better outcome was found in the current-controlled group during the last 6 months of follow-up. Conclusions Current-controlled stimulation is effective during GPi-DBS for primary dystonia and it could be a better choice than voltage-controlled stimulation over long-term follow-up.