Comparison of Pallidal Deep Brain Stimulation and Bilateral Pallidotomy for Medically Refractory Status Dystonicus: A Systematic Review and Meta-Analysis

Introduction: Status dystonicus (SD) is a medical emergency that results from a primary or secondary dystonia condition and is life-threatening if untreated. Also known as dystonic storm, SD is characterized by an acute onset of prolonged and unrelenting generalized dystonia and sometimes chorea. Surgical intervention is indicated for swift resolution of medically refractory SD. This study looks to compare bilateral pallidotomy against deep brain stimulation (DBS) for SD treatment. Objective: to determine the efficacy of bilateral pallidotomy for treatment of SD compared to DBS Methodology: A meta-analysis was conducted according to PRISMA guidelines. The terms pallidotomy, deep brain stimulation and status dystonicus were used on January 2nd, 2024 to search PubMed, EMBASE, Scopus and Web of Science. All article data was uploaded to the systematic review software Rayyan where duplicates were removed with three independent reviewers screening the remaining articles. Data was manually collected after quality assessment and analyzed in R version 4.3.3. Results: Forty-three total patients (32 DBS and 11 pallidotomy; 27 male and 16 female) were included. Average age of SD onset was 12.49 plus/minus 8.55 years (11.95 plus/minus 9.69 for DBS and 13.71 plus/minus 5.30 for pallidotomy with a p-value of 0.15) Change in movement disorder score was 48 plus/minus 34% overall (54 plus/minus 33% for DBS and 34 plus/minus 33% for pallidotomy; p=0.09). A subgroup meta-analysis showed a standardized mean difference of changes in movement disorder score of -1.55 [-2.97, -0.13] for DBS and -1.35 [-2.40, -0.30] with a chi-square test for subgroup difference p-value of 0.83. A meta-analysis of proportions showed a 40% complication rate for DBS and 16% complication rate for pallidotomy with a chi-square test for subgroup difference p-value of 0.14. Conclusion: Based on the patients in our review, there was no difference between pallidotomy or DBS for SD treatment, but there was a difference in complication rates that trended towards significance. This suggests that pallidotomy may be a valid alternative in resource-limited settings or when DBS is contraindicated, although further comparative studies are needed.