Electrode Location in a Microelectrode Recording-Based Model of the Subthalamic Nucleus Can Predict Motor Improvement After Deep Brain Stimulation for Parkinson's Disease.

Rens Verhagen,Rob De Bie,Vincent Odekerken,Lo Bour,P Schuurman,Pepijn Van Den Munckhof

doi:10.3390/brainsci9030051

Rens Verhagen, Rob De Bie + Show 4 more

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https://doi.org/10.3390/brainsci9030051

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Abstract

Motor improvement after deep brain stimulation (DBS) in the subthalamic nucleus (STN) may vary substantially between Parkinson’s disease (PD) patients. Research into the relation between improvement and active contact location requires a correction for anatomical variation. We studied the relation between active contact location relative to the neurophysiological STN, estimated by the intraoperative microelectrode recordings (MER-based STN), and contralateral motor improvement after one year. A generic STN shape was transformed to fit onto the stereotactically defined MER sites. The location of 43 electrodes (26 patients), derived from MRI-fused CT images, was expressed relative to this patient-specific MER-based STN. Using regression analyses, the relation between contact location and motor improvement was studied. The regression model that predicts motor improvement based on levodopa effect alone was significantly improved by adding the one-year active contact coordinates (R2 change = 0.176, p = 0.014). In the combined prediction model (adjusted R2 = 0.389, p < 0.001), the largest contribution was made by the mediolateral location of the active contact (standardized beta = 0.490, p = 0.002). With the MER-based STN as a reference, we were able to find a significant relation between active contact location and motor improvement. MER-based STN modeling can be used to complement imaging-based STN models in the application of DBS.

Highlights

Deep brain stimulation (DBS) of the subthalamic nucleus (STN) is a widely used and effective surgical treatment for advanced Parkinson’s disease (PD), when treatment with dopaminergic medication is no longer satisfactory [1,2,3]
Of the 45 implanted electrodes from the Netherlands SubThalamic And Pallidal Stimulation (NSTAPS) trial that matched our inclusion criteria, one was excluded because the microelectrode recordings (MER) classifications of different trajectories were conflicting, and we were unable to produce a reliable MER-based STN estimation
Using the neurophysiological borders based on MER to create individual STN models as prediction model in which the mediolateral location has the largest a reference for active contact location, we found a significant relation between active contact location unique contribution

Summary

Introduction

Deep brain stimulation (DBS) of the subthalamic nucleus (STN) is a widely used and effective surgical treatment for advanced Parkinson’s disease (PD), when treatment with dopaminergic medication is no longer satisfactory [1,2,3]. Determining the active contact location solely in relation to the midcommissural point (MCP) as the anatomical reference ignores a large part of the anatomical variation in STN size and location. This may be the reason that a clear relation between active contact location and motor improvement was not demonstrated with these methods [23,24,25]. The transformation of brain atlases, based on anatomical landmarks, only partially corrects for anatomical variations [13,16,26]

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