Tardive dystonia is an iatrogenic complication of dopamine receptor antagonist medication such as first-generation antipsychotics. It occurs in up to 2% of patients and only 10% recover after stopping medication. Deep brain stimulation for primary dystonia has proven to be effective and its application for secondary dystonias is gaining acceptance. We report our experience in treating three ethnic Chinese schizophrenia patients with severe medically refractory tardive dystonia by globus pallidus internus deep brain stimulation. Preoperatively, all required assistance with essential activities of daily living and two were bed-bound. The mean Burke-Fahn-Marsden Dystonia Rating Scale score was 61 (range, 44-80) and mean Global Dystonia Rating Scale score was 47 (range, 40-52). No procedure-related complications were encountered. By 3 months all could return to unassisted living and walk with support with a mean of 77% and 66% improvement in the Burke-Fahn-Marsden Dystonia Rating Scale and Global Dystonia Rating Scale scores, respectively. Quality-of-life assessment performed for two patients using the EuroQol-5 dimensions visual analogue scale showed a mean improvement of 86% at 3 months. On clinical follow-up, the effect was well maintained for a period of 3 to 10 years. Pallidal deep brain stimulation is a safe and highly effective form of symptomatic treatment for patients with medically refractory tardive dystonia.
Keywords: Deep brain stimulation; Dystonia; Treatment outcome.