Globus pallidus vs subthalamic nucleus deep brain stimulation for parkinson's disease: A meta-analysis

OBJECTIVE: To systematically compare the efficacy and safety of STN versus GPi DBS in advanced Parkinson disease (PD) patients.BACKGROUND: Deep brain stimulation (DBS), targeting the globus pallidus interna (GPi) or subthalamic nucleus (STN), is a safe and effective treatment of PD. It is a matter of controversy whether one target provides superior or safer outcomes than the other.METHODS: MEDLINE, Web of Science, CENTRAL and Scopus databases were undertaken to identify randomized and non-randomized controlled trials published before 30 August 2013 including PD patients undergoing DBS. Efficacy outcomes included motor function, motor complications, disability, quality-of-life and levodopa-equivalent dosage (LED). Safety outcomes included surgical, hardware-related and stimulation-related complications.RESULTS: From 1882 screened references, 93 were assessed for eligibility and 8 were included for a total of 698 subjects. GPi DBS significantly improved disability ON-medications (ADL mean change score MD 1.38, 95% CI 0.57 to 2.18, N=592, p=0.0008, I2=47%; ADL score at follow up MD 1.04 , 95% CI 0.01 to 2.08, N=592, p=0.05, I2=0%), while LED was significantly lower in the STN DBS group (mean change MD mg/day -218.45, 95% CI -390.89 to -46.00, I2=60%, N=541, p=0.01; at follow-up: MD mg/day -250.37, 95% CI -342.99 to -157.75, I2=0%, N=541, p<0.00001). There was no significantly difference between groups for motor function, motor complications, quality-of-life, surgical and stimulation-related complications.CONCLUSIONS: The efficacy and the safety of DBS is comparable by target and stable over time. GPi DBS appears to significantly improve disability ON medications, although STN stimulation allows for significant LED reduction.