Browsing by Author "O'Maley, Karen"

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    Alternate subthalamic nucleus deep brain stimulation parameters to manage motor symptoms of Parkinson’s disease: Systematic review and meta-analysis
    (John Wiley & Sons, 2018-09) Conway, Zachary; Silburn, Peter; Thevathasan, Wesley; O'Maley, Karen; Naughton, Geraldine; Cole, Michael
    ABSTRACT Background The use of alternate frequencies, amplitudes and pulse widths to manage motor symptoms in Parkinson's disease (PD) patients with subthalamic nucleus deep brain stimulation (STN-DBS) is of clinical interest, but currently lacks systematic evidence. Objective/Hypothesis Systematically review whether alternate STN-DBS settings influence the therapy's efficacy for managing PD motor symptoms. Methods Systematic searches identified studies that; involved bilateral STN-DBS PD patients; manipulated ≥1 STN-DBS parameter (e.g. amplitude); assessed ≥1 motor symptom (e.g. tremor); and contrasted the experimental and chronic stimulation settings. A Mantel-Haenszel random-effects meta-analysis compared the UPDRS-III sub-scores at low (60-Hz) and high frequencies (≥130 Hz). Inter-study heterogeneity was assessed with the Cohen's χ2 and I2 index, while the standard GRADE evidence assessment examined strength of evidence. Results The meta-analysis indicated a very low quality for the pooled evidence due to risks of bias, significant heterogeneity and imprecision. Separate analyses involving studies that attempted to maintain the total electrical energy derived by increasing amplitude at 60-Hz frequencies suggested that low-frequency STN-DBS reduced UPDRS-III sub-scores by 5.8 points (95% CI=1.5-10.2; Z=2.6; P=0.009) compared to frequencies ≥130 Hz. This alternate stimulation strategy may be beneficial for those with severe axial symptoms post STN-DBS, however, benefits may only be short-term. Conclusion(s) The meta-analysis reported a very low quality of evidence for the efficacy of low-frequency STN-DBS for managing PD motor symptoms. Furthermore, it highlighted that lower amplitudes lead to the re-emergence of motor symptoms and further research is needed to understand the potential benefits of alternate STN-DBS parameters for PD patients. This article is protected by copyright. All rights reserved.