Determining the rotational orientation of directional deep brain stimulation electrodes using magnetoencephalography

Abstract

Objective. The aim of the present study was to evaluate the effect of different electrode configurations on the accuracy of determining the rotational orientation of the directional deep brain stimulation (DBS) electrode with our previously published magnetoencephalography (MEG)-based method. Approach. A directional DBS electrode, along with its implantable pulse generator, was integrated into a head phantom and placed within the MEG sensor array. Predefined bipolar electrode configurations, based on activation of different directional and omnidirectional contacts of the electrode, were set to generate a defined magnetic field during stimulation. This magnetic field was then measured with MEG. Finite element modeling and model fitting approach were used to calculate electrode orientation. Main results. The accuracy of electrode orientation detection depended on the electrode configuration: the vertical configuration (activation of two directional contacts arranged one above the other) achieved an average accuracy of only about 41 ∘. The diagonal configuration (activation of the electrode tip and a single directional contact at the next higher level of the electrode) achieved an accuracy of 13∘, while the horizontal electrode configuration (activation of two adjacent directional contacts at the same electrode level) achieved the best accuracy of 6∘. The accuracy of orientation detection of the DBS electrode depends on the change in spatial distribution of the magnetic field with the rotation of the electrode along its own axis. In the vertical configuration, rotation of the electrode has a small effect on the magnetic field distribution, while in the diagonal or horizontal configuration, electrode rotation has a significant effect on the magnetic field distribution. Significance. Our work suggests that in order to determine rotational orientation of a DBS electrode using MEG, horizontal configuration should be used as it provides the most accurate results compared to other possible configurations.

MaDoPO: Magnetic Detection of Positions and Orientations of Segmented Deep Brain Stimulation Electrodes: A Radiation-Free Method Based on Magnetoencephalography

“…In this study, we presented a radiation-free method for determining the position and orientation of a directional DBS electrode using a series of short SQUID-MEG measurements with different predefined electrode configurations. The potential of MEG recordings for such an application has already been demonstrated in our previous work [ 20 , 22 ]. The aim of this study was to develop a simple, realistic, and patient-friendly measurement method that can be used for clinical practice.…”

“…The feasibility of DBS electrode localization based on scalp EEG has already been demonstrated, but localization errors of more than 10 mm have been reported [ 17 ]. The potential of MEG recordings to detect electrode position and orientation has been demonstrated in our previous research [ 18 , 19 , 20 , 21 , 22 ]. In this study, we present an improved and patient-oriented method for the radiation-free detection of electrode positions and orientations using a series of measurements with a conventional SQUID-based MEG.…”

Individualized brain mapping for navigated neuromodulation

“…[ 98 ] In addition to the above three types of MRI-guided DBS electrode localization, positron emission tomography (PET), [ 99 ] single photon emission computed tomography (SPECT), [ 100 ] and magnetoencephalography (MEG) [ 101 ] are also adopted for searching the optimal stimulation target. Yalaz et al [ 102 ] used MEG to non-invasively detect the position and orientation of DBS electrodes. Although the average detection accuracy of the electrode location was 2.2 mm due to the insufficient measurement accuracy of the MEG system, future magnetometry systems with higher measurement accuracy may serve to more precisely detect the position and orientation of DBS electrodes.…”