Modelling and simulation of the therapeutic effect of deep brain stimulation in a rat brain model

The objective of this project is to obtain a better understanding of the mechanisms of action of deep brain stimulation (DBS). DBS is a clinically efficient neurosurgical therapy for the treatment of motor dysfunctions of Parkinson’s disease (PD). Based on a Hemiparkinson model of DBS for the long term therapy of freely moving rats a computational model is developed. The long-term animal experiments have been conducted by K. Badstübner of the research training group within the project “Electrical Interaction between Implant and Bio-Systems”. The computational model will include an anatomical volume conductor model of the rat brain including the bipolar and unipolar stimulation electrodes, respectively, used in the experimental setup, the encapsulation layer surrounding the stimulation electrode and the dielectric properties of the brain tissues in the target region. The main target regions in human DBS are the subthalamic nucleus (STN) and the globus pallidus internus (GPi). In the rat brain, the entopeduncular nucleus (EPN) is the equivalent of the GPi. The STN and EPN are nuclei of the basal ganglia. DBS of the STN can exert the therapeutic effect of pathological oscillations in the basal ganglia and cortex. Therefore, the STN and EPN as well as the surrounding brain structures are chosen as a target region for the modelling of DBS. Based on the Waxholm Space atlas with anatomical delineations for the Sprague Dawley rat brain, a 3D-model of the rat brain is developed.

• Development of an anatomical CAD model of the DBS target region in the rat brain.
• Implementation of the anisotropic material properties of the brain tissues using diffusion tensor imaging (DTI) data derived from the digital rat brain atlas.
• Simulation and detailed consideration of the stimulation field of DBS in the target region in a volume conductor model.
• Simulation and detailed consideration of the neuronal activation due to DBS in the STN, the EBN and the surrounding brain structures.
• Optimization and further development of the stimulation protocol and electrode for DBS in the rat on the basis of the simulations.
• Validation of the possibility to link up the simulation studies with the conducted behavioral tests in the Hemiparkinsonian model

Reviewed paper important congresses

• BÖHME, A., SCHMIDT, C. and VAN RIENEN, U. 2015. Numerical Simulation of the Electric Field Distribution of Deep Brain Stimulation in a Realistic Rat Brain Model. 5th International Symposium Interface Biology of Implants, Rostock.
• BÖHME, A., SCHMIDT, C. and VAN RIENEN, U. 2015. Partial Anisotropy in an Anatomically Realistic Volume Conductor Model of Deep Brain Stimulation in the Hemiparkinsonian Rat. 37th Annual International Conference of the IEEE Engineering in Medicine and Biology Society, Milano, Italy.

• Prof. Dr. Ursula van Rienen
• Dr. Christian Schmidt
• Prof. Dr. med. Rüdiger Köhling