Long-term outcomes of pallidal deep brain stimulation in X-linked dystonia parkinsonism (XDP): Up to 84 months follow-up and review of literature

Abstract

IntroductionX-linked dystonia-parkinsonism (XDP/DYT3/Lubag) patients had improved dystonia and parkinsonism with bilateral pallidal deep brain stimulation (DBS) in the literature. MethodWe reviewed eleven XDP patients who underwent bilateral pallidal DBS from October 2009 to September 2018. The Burke-Fahn-Marsden Dystonia Rating Scale (BFMDRS) and Unified Parkinson's Disease Rating Scale (UPDRS)-III scores were reviewed from baseline up to the longest follow-up together with the demographic and clinical data. The published case reports on DBS in XDP were also reviewed. ResultsThe mean age was 39 ± 9.2 years with a mean disease duration of 3 years (range 1–9 years). An immediate response for dystonia post-DBS (1 month) was seen in all cases, with a mean BFMDRS score of 23.3 ± 12.12 [from a mean baseline of 36.3 ± 12.1] and a small change in the mean UPDRS-III score of 20 ± 10.39 [from a mean baseline of 24.04 ± 8.74]. At 12 months (n = 10), the mean BFMDRS score was 13.7 ± 10.63 and the mean UPDRS-III score was 19 ± 13.19. There was improvement in the clinical and functional stage of the patients, with majority in Stage 1 (n = 3) and Stage 2 (n = 5) at their last follow-up. ConclusionBilateral pallidal DBS should be considered as a treatment option for XDP. It is effective in the first 12 months in controlling dystonia with variable response in controlling parkinsonism. It may be effective in up to 72–84 months, as seen in three patients.