In this project we aim at bringing together multiparametric DBS data for clinical support i.e. to go from “mental imagination” to “intuitive visualization” in the surgical planning and follow up of DBS. The work proceeds in parallel but interactive work packages with partners from an international multidisciplinary team with abroad expertise in both technical and clinical DBS-research.
Professor Simone Hemm-Ode
Institute for Medical Engineering and Medical Informatics, University of Applied Sciences and Art Northwestern Switzerland (FHNW), CH and Guest Researcher at Linköping University.
Professor Marwan Hariz
Past chair of Functional Neurosurgery, Institute of Neurology, University College London, UK, Adjunct Prof. DBS Unit, Norrland Univ. Hospital, Umeå
Dr. Peter Zsigmond
Consultant Neurosurgeon, Dept. of Neurosurgery, Linköping University Hospital, Sweden
Dr. Anders Fytagoridis, Consultant Neurosurgeon, Department of Neurosurgery, Karolinska University Hospital, Stockholm
Deep brain stimulation
Deep brain stimulation (DBS) is an important therapy for movement disorders such as Parkinson’s disease and essential tremor, and DBS is expanding towards psychiatric illness e.g. Tourette syndrome (Hariz et al., 2013). Four contacts DBS leads are the most commonly implanted, but DBS leads which can steer the field are other options recently introduced.
Stereotactic DBS implantation and imaging
Stereotactic MRI is used for pre-operative target identification and planning of trajectories. During surgery the DBS electrode is introduced to the target point and the operation is fulfilled. Intraoperative measurements of neuronal activity with microelectrode recording (MER), microvascular blood flow with laser Doppler flowmetry (LDF), or movement with wrist accelerometers may be done in relation to surgery. Post-operative verification of the DBS lead position is accomplished using MRI or CT (Hemm and Wårdell, 2010).
Patient-specific electric field simulations
Finite element method (FEM) simulation of the electric field surrounding the DBS lead is done in COMSOL Multiphysics. Individual DBS settings together with the pre- and postoperative images makes it patient-specific. Brain models are built in MatLab. Preprogrammed COMSOL-Apps for DBS lead configurations and stimulations modes will be designed. Results are visualized with the patient own preoperative images (Åström et al., 2009, Alonso et al., 2016).
By using diffusion MRI (dMRI) different white matter tracts connecting brain regions involved in DBS will be anatomically visualized and combined with the patient-specific electric field simulations. The dentato-rubro-thalamo-cortical circuit is important for DBS in the Vim and Zi (Pujol et al., 2017). Other white fiber tract of interest are the pallidothalamic tracts and the hyper direct cortico-subthalamic tracts.