Localization of DBS-Electrodes in a 3D Atlas of the Basal Ganglia

Introduction:

Deep Brain Stimulation (DBS) has been established as an invasive therapy of treatment of severve forms of movement disorders such as Parkinson’s Disease (PD). Most patients with PD are treated by DBS in the area of the subthalamic nucleus (STN). However, the exact location of the best target site is still under debate.

Methods:

In a consecutive patient series (Zurich University Hospital, 2009–2011) we compared preoperative MRI planning, intraoperative target adjustment and postoperative CT reconstruction. The localizations of the DBS electrodes were documented in a 3-dimensional atlas of the basal ganglia and the thalamus (Morel-Atlas).

Results:

The series includes 21 patients (6 female/15 male; 42 implantations). For the implantations in 47.6% of cases the central trajectory was chosen, in 38.1% the medial trajectory. Posterior, anterior and lateral trajectories were rarely chosen (each 4.8%). There was a significant difference between the planning coordinates and the coordinates of the definitive stimulation site. The definitive stimulation site was more anterior and more superior on average. Of 24 implanted electrodes, 21 (87.5%) were within the averaged STN volume provided by the atlas. Mean penetration depth amounted to 4.00±1.96mm.

Conclusions:

The deviation between preoperative planning and postoperative CT reconstruction demonstrate the importance of intraoperative recording of neuronal activity and clinical testing of stimulation efficiency. The documentation of the DBS electrodes in a three-dimensional atlas was used to investigate the anatomical structures, which are stimulated by the DBS. The variability between the individual anatomical STN-configurations is sufficiently small to permit the application of the averaged atlas.

Literatur: Morel A. Stereotactic atlas of the human thalamus and basal ganglia. New York: Informa Healthcare; 2007. Krauth A, Blanc R, Poveda A, Jeanmonod D, Morel A, Székely G. A mean three-dimensional atlas of the human thalamus: Generation from multiple histological data. NeuroImage 2010; 49: 2053–2062.