How accurately are subthalamic nucleus electrodes implanted relative to the ideal stimulation location for Parkinson's disease?

INTRODUCTION: The efficacy of subthalamic nucleus (STN) deep brain stimulation (DBS) in Parkinson's disease (PD) depends on how closely electrodes are implanted relative to an individual's ideal stimulation location. Yet, previous studies have assessed how closely electrodes are implanted relative to the planned location, after homogenizing data to a reference. Thus here, we measured how accurately electrodes are implanted relative to an ideal, dorsal STN stimulation location, assessed on each individual's native imaging. This measure captures not only the technical error of stereotactic implantation but also constraints imposed by planning a suitable trajectory. METHODS: This cross-sectional study assessed 226 electrodes in 113 consecutive PD patients implanted with bilateral STN-DBS by experienced clinicians utilizing awake, microelectrode guided, surgery. The error (Euclidean distance) between the actual electrode trajectory versus a nominated ideal, dorsal STN stimulation location was determined in each hemisphere on native imaging and predictive factors sought. RESULTS: The median electrode location error was 1.62 mm (IQR = 1.23 mm). This error exceeded 3 mm in 28/226 electrodes (12.4%). Location error did not differ between hemispheres implanted first or second, suggesting brain shift was minimised. Location error did not differ between electrodes positioned with (48/226), or without, a preceding microelectrode trajectory shift (suggesting such shifts were beneficial). There was no relationship between location error and case order, arguing against a learning effect. DISCUSSION/CONCLUSION: The proximity of STN-DBS electrodes to a nominated ideal, dorsal STN, stimulation location is highly variable, even when implanted by experienced clinicians with brain shift minimized, and without evidence of a learning effect. Using this measure, we found that assessments on awake patients (microelectrode recordings and clinical examination) likely yielded beneficial intraoperative decisions to improve positioning. In many patients the error is likely to have reduced therapeutic efficacy. More accurate methods to implant STN-DBS electrodes relative to the ideal stimulation location are needed.

The relationship between dual practice, intention to work abroad and job satisfaction: A population-based study in the Serbian public healthcare sector.

Increasing dual practice and emigration of health workers threatens the effectiveness of the healthcare system. Insufficient information exists about these phenomena in the transitional countries of South-East Europe. Serbia, a European Union candidate, permits dual practice and there is a high intention to work abroad among its prospective healthcare professionals. A population-based, cross-sectional study was conducted to determine the prevalence and predictors of job satisfaction, dual practice, and intention to work abroad of all workers in the Serbian public healthcare sector (73,940 employees, a response rate of 83.8%). This study observed that 22.6% of the respondents were dissatisfied with their jobs, 11.7% reported dual practice, and 14.3% had an intention to work abroad. Physicians and nurses younger than 55 years of age employed in a tertiary healthcare institution, and males were more likely to be dissatisfied than other workers. Poor management and working conditions increased job dissatisfaction, with a subsequent increased odds for dual practice and intention to work abroad by 1.5 and 3.6 times, respectively. The national and institutional framework for health workforce policy and management must be powerful and efficient when taking advantage of the positive effects and managing the negative aspects of dual practice and the intention to work abroad.