Subthalamic deep brain stimulation in patients with primary dystonia: A ten-year follow-up study

Background: Subthalamic deep brain stimulation (STN-DBS) is a promising intervention for primary dystonia; however, evidence regarding its efficacy is lacking. Thus, a long-term follow-up is indispensable. Objective: This trial was designed to examine the efficacy and consistency of subthalamic deep brain stimulation in patients with primary dystonia over the long term. Method: This was a retrospective study involving 14 patients with primary dystonia who underwent STN-DBS and consented to a follow-up of at least 10 years. The Burke-Fahn-Marsden Dystonia Rating Scale (BFMDRS) and 36-item Short-Form General Health Survey were employed, at five time points (pre-operation [baseline], 1 month post-operation, 1 year post-operation, 5 years post-operation, and last follow-up), to assess improvement of dystonic symptoms and changes in quality of life. Outcomes: All patients gained extensive clinical benefits from STN-DBS therapy, without experiencing serious adverse effects. Improvements of 59.0% at 1 month, 85.0% at 1 year, and 90.8% at 5 years after the operation, and up to 91.4% at the last follow-up, were demonstrated by movement evaluation with the BFMDRS. All patients achieved a substantial improvement in quality of life. Conclusion: Subthalamic deep brain stimulation is an effective and persisting alternative to pallidal deep brain stimulation, and importantly, it is very safe even with extremely long-term chronic stimulation.