Deep brain stimulation for hemidystonia: A meta-analysis with individual patient data.

BACKGROUND: Deep brain stimulation (DBS) is now well established for the treatment of dystonic movement disorders. There is limited data, however, on the efficacy of DBS in hemidystonia. This meta-analysis aims to summarize the published reports on DBS for hemidystonia of different etiologies, to compare different stimulation targets, and to evaluate clinical outcome. METHODS: A systematic literature review was performed on PubMed, Embase and Web of Science to identify appropriate reports. The primary outcome variables were the improvement in the Burke-Fahn-Marsden Dystonia Rating Scale movement (BFMDRS-M) and disability (BFMDRS-D) scores for dystonia. RESULTS: Twenty-two reports (39 patients; 22 with pallidal stimulation, 4 with subthalamic stimulation, 3 with thalamic stimulation, and 10 with combined target stimulation) were included. Mean age at surgery was 26.8 years. Mean follow-up time was 31.72 months. An overall mean improvement of 40% in the BFMDRS-M score was achieved (range 0%-94%), which was paralleled by a mean improvement of 41% in the BFMDRS-D score. When considering a 20% cut-off for improvement, 23/39 patients (59%) would qualify as responders. Hemidystonia due to anoxia did not significantly improve with DBS. Several limitations of the results must be considered, most importantly the low level of evidence and the small number of reported cases. CONCLUSION: Based on the results of the current analysis, DBS can be considered as a treatment option for hemidystonia. The posteroventral lateral GPi is the target used most often. More research is needed to understand the variability in outcome and to identify prognostic factors.

Absent epiglottic inversion as seen on flexible endoscopic evaluations of swallowing (FEES) is associated with a gestalt reduction in swallowing mechanics.

PURPOSE: Epiglottic inversion, which provides one layer of the requisite protection of the airway during swallowing, is dependent on a number of biomechanical forces. The aim of this study was to examine the association between swallowing mechanics, as visualized during a Modified Barium Swallow (MBS) exam, and the rating of epiglottic inversion as seen on Flexible Endoscopic Evaluation of Swallowing (FEES). METHODS: This study analyzed twenty-five adult outpatients referred for a simultaneous FEES/MBS exams. Each participant swallowed a 5 mL thin liquid bolus, which was the bolus size analyzed for this study's question. Epiglottic inversion, as seen on FEES, was rated by three independent raters. Additionally, twelve swallowing landmarks tracked the shape change of each participant's swallow on the MBS video using a MatLab-specific tracking tool. Analyses were run to determine mean differences in swallowing shape change between the swallows across 3 groups: complete, reduced, and absent epiglottic inversion, as seen on FEES. Using a Computerized Analysis of Swallowing Mechanics (CASM), canonical variate analyses and discriminant function testing were carried out. Other swallowing mechanics were also analyzed for kinematic movements to isolate the function of the hyoid and larynx. A two-sample t-test was conducted to compare mean hyolaryngeal movement between complete and incomplete epiglottic inversion groups. RESULTS: Overall swallowing shape changes were statistically significantly different between the absent, reduced, and complete epiglottic inversion groups on FEES. Canonical variate analyses revealed a significant overall effect of shape change between the groups (eigenvalue = 2.46, p < 0.0001). However, no statistically significant differences were found on hyoid excursion (p = 0.37) and laryngeal elevation (p = 0.06) kinematic measurements between patients with complete and incomplete epiglottic inversion on FEES. CONCLUSION: Epiglottic inversion on FEES is a valuable rating that infers reduced range of motion of structures that cannot be seen on FEES. This small sample of patients suggests that FEES ratings of absent epiglottic inversion may represent gestalt reduction in swallowing mechanics.