Deep brain stimulation for Parkinson’s disease: meta-analysis of results of randomized trials at varying lengths of follow-up

Abstract

OBJECTIVE Deep brain stimulation (DBS) is effective in the management of patients with advanced Parkinson's disease (PD). While both the globus pallidus pars interna (GPi) and the subthalamic nucleus (STN) are accepted targets, their relative efficacy in randomized controlled trials (RCTs) has not been established beyond 12 months. The objective of this study was to conduct a meta-analysis of RCTs to compare outcomes among adults with PD undergoing DBS of GPi or STN at various time points, including 36 months of follow-up. METHODS The MEDLINE, Embase, CENTRAL, Web of Science, and CINAHL databases were searched. Registries for clinical trials, selected conference proceedings, and the table of contents for selected journals were also searched. Screens were conducted independently and in duplicate. Among the 623 studies initially identified (615 through database search, 7 through manual review of bibliographies, and 1 through a repeat screen of literature prior to submission), 19 underwent full-text review; 13 of these were included in the quantitative meta-analysis. Data were extracted independently and in duplicate. The Cochrane Collaboration tool was used to assess the risk of bias. The GRADE evidence profile tool was used to assess the quality of the evidence. Motor scores, medication dosage reduction, activities of daily living, depression, dyskinesias, and adverse events were compared. The influence of disease duration (a priori) and the proportion of male patients within a study (post hoc) were explored as potential subgroups. RESULTS Thirteen studies (6 original cohorts) were identified. No difference in motor scores or activities of daily living was identified at 36 months. Medications were significantly reduced with STN stimulation (5 studies, weighted mean difference [WMD] -365.46, 95% CI -599.48 to -131.44, p = 0.002). Beck Depression Inventory scores were significantly better with GPi stimulation (3 studies; WMD 2.53, 95% CI 0.99-4.06 p = 0.001). The motor benefits of GPi and STN DBS for PD are similar. CONCLUSIONS The motor benefits achieved with GPi and STN DBS for PD are similar. DBS of STN allows for a greater reduction of medication, but not as significant an advantage as DBS of GPi with respect to mood. This difference is sustained at 36 months. Further long-term studies are necessary.

Acute effects of Adaptive Deep Brain Stimulation in Parkinson’s disease

“…Findings have been reported in [17]. 2 This patient was operated in the GPi, and therefore the results were reported separately in [39] 3,4 These randomisation orders belong to the same patient (PD01). As this patient had to be measured unilaterally in both hemispheres, due to a defect in one of the aDBS box channels, each hemisphere was assigned to a different randomisation order.…”

“…These include incomplete symptom suppression and side effects, such as stimulation-induced dysarthria (SID), and dyskinesias. In addition to this, most of the studies have documented the benefits of DBS only up to three years after implantation [2]. A handful of studies that have followed DBS patients in the long term (5-10 years after implantation) have suggested that the efficacy of DBS may reduce over time, especially in bradykinesia items [3,4].…”

Invasive and Noninvasive Brain Stimulation in Parkinson's Disease: Clinical Effects and Future Perspectives

“…Based on long‐term follow‐up, patients treated with STN DBS still have significant improvement in PD cardinal features and reduced motor fluctuation and levodopa‐induced dyskinesia (LID) at 10 years after surgery . Although bilateral GPi DBS may have more variable long‐term results, significant improvement was maintained for up to 5 years …”

“…7 Although bilateral GPi DBS may have more variable long-term results, significant improvement was maintained for up to 5 years. 8 GPi DBS is usually considered as effective as STN DBS for treatment of PD cardinal symptoms. 5 A recent meta-analysis concluded that GPi and STN DBS provide equivalent tremor suppression.…”

Comparing Current Steering Technologies for Directional Deep Brain Stimulation Using a Computational Model That Incorporates Heterogeneous Tissue Properties

“…Deep brain stimulation (DBS) has been established as an effective therapy for movement disorders such as essential tremor (ET) and Parkinson's disease (PD) over the past decades . Traditionally, DBS uses 120–185 Hz pulses via a lead implanted in a target brain structure, such as the subthalamic nucleus (STN).…”