Predictive factors for long-term clinical outcomes of deep brain stimulation in the treatment of primary Meige syndrome

OBJECTIVE Primary Meige syndrome is characterized by blepharospasm and orofacial-cervical dystonia. Deep brain stimulation (DBS) is recognized as an effective therapy for patients with this condition, but previous studies have focused on clinical effects. This study explored the predictors of clinical outcome in patients with Meige syndrome who underwent DBS. METHODS Twenty patients who underwent DBS targeting the bilateral subthalamic nucleus (STN) or globus pallidus internus (GPi) at the Chinese People's Liberation Army General Hospital from August 2013 to February 2018 were enrolled in the study. Their clinical outcomes were evaluated using the Burke-Fahn-Marsden Dystonia Rating Scale at baseline and at the follow-up visits; patients were accordingly divided into a good-outcome group and a poor-outcome group. Putative influential factors, such as age and course of disease, were examined separately, and the factors that reached statistical significance were subjected to logistic regression analysis to identify predictors of clinical outcomes. RESULTS Four factors showed significant differences between the good- and poor-outcome groups: 1) the DBS target (STN vs GPi); 2) whether symptoms first appeared at multiple sites or at a single site; 3) the sub-item scores of the mouth at baseline; and 4) the follow-up period (p < 0.05). Binary logistic regression analysis revealed that initial involvement of multiple sites and the mouth score were the only significant predictors of clinical outcome. CONCLUSIONS The severity of the disease in the initial stage and presurgical period was the only independent predictive factor of the clinical outcomes of DBS for the treatment of patients with Meige syndrome.