Role of electrode design on the volume of tissue activated during deep brain stimulation

Deep brain stimulation (DBS) is an established clinical treatment for a range of neurological disorders. Depending on the disease state of the patient, different anatomical structures such as the ventral intermediate nucleus of the thalamus (VIM), the subthalamic nucleus or the globus pallidus are targeted for stimulation. However, the same electrode design is currently used in nearly all DBS applications, even though substantial morphological and anatomical differences exist between the various target nuclei. The fundamental goal of this study was to develop a theoretical understanding of the impact of changes in the DBS electrode contact geometry on the volume of tissue activated (VTA) during stimulation. Finite element models of the electrodes and surrounding medium were coupled to cable models of myelinated axons to predict the VTA as a function of stimulation parameter settings and electrode design. Clinical DBS electrodes have cylindrical contacts 1.27 mm in diameter (d) and 1.5 mm in height (h). Our results show that changes in contact height and diameter can substantially modulate the size and shape of the VTA, even when contact surface area is preserved. Electrode designs with a low aspect ratio (d/h) maximize the VTA by providing greater spread of the stimulation parallel to the electrode shaft without sacrificing lateral spread. The results of this study provide the foundation necessary to customize electrode design and VTA shape for specific anatomical targets, and an example is presented for the VIM. A range of opportunities exist to engineer DBS systems to maximize stimulation of the target area while minimizing stimulation of non-target areas. Therefore, it may be possible to improve therapeutic benefit and minimize side effects from DBS with the design of target-specific electrodes.

[1]  J. B. Ranck,et al.  Which elements are excited in electrical stimulation of mammalian central nervous system: A review , 1975, Brain Research.

[2]  D. Mcneal Analysis of a Model for Excitation of Myelinated Nerve , 1976, IEEE Transactions on Biomedical Engineering.

[3]  F. Rattay Analysis of Models for External Stimulation of Axons , 1986, IEEE Transactions on Biomedical Engineering.

[4]  D. Durand,et al.  Modeling the effects of electric fields on nerve fibers: Determination of excitation thresholds , 1992, IEEE Transactions on Biomedical Engineering.

[5]  Robert Plonsey,et al.  Bioelectromagnetism: Principles and Applications of Bioelectric and Biomagnetic Fields , 1995 .

[6]  A. Benabid,et al.  Chronic electrical stimulation of the ventralis intermedius nucleus of the thalamus as a treatment of movement disorders. , 1996, Journal of neurosurgery.

[7]  E. Behnke,et al.  Correlation between MRI-Based Stereotactic Thalamic Deep Brain Stimulation Electrode Placement, Macroelectrode Stimulation and Clinical Response to Tremor Control , 2000, Stereotactic and Functional Neurosurgery.

[8]  A. Benabid,et al.  Improvement of levodopa induced dyskinesias by thalamic deep brain stimulation is related to slight variation in electrode placement: possible involvement of the centre median and parafascicularis complex , 1999, Journal of neurology, neurosurgery, and psychiatry.

[9]  Patricia Limousin,et al.  Chronic Electrical Stimulation of the Ventralis Intermedius Nucleus of the Thalamus and of Other Nuclei as a Treatment for Parkinson's Disease , 1999 .

[10]  B. Erwin,et al.  Mechanisms of deep brain stimulation and future technical developments , 2000, Neurological research.

[11]  P. Krack,et al.  Deep-brain stimulation of the subthalamic nucleus or the pars interna of the globus pallidus in Parkinson's disease. , 2001, The New England journal of medicine.

[12]  Clemens M. Zierhofer Analysis of a linear model for electrical stimulation of axons-critical remarks on the "activating function concept" , 2001, IEEE Transactions on Biomedical Engineering.

[13]  C. McIntyre,et al.  Modeling the excitability of mammalian nerve fibers: influence of afterpotentials on the recovery cycle. , 2002, Journal of neurophysiology.

[14]  J. Dostrovsky,et al.  Surgery of the motor thalamus: Problems with the present nomenclatures , 2002, Movement disorders : official journal of the Movement Disorder Society.

[15]  J. Volkmann,et al.  Introduction to the programming of deep brain stimulators , 2002, Movement disorders : official journal of the Movement Disorder Society.

[16]  Mojgan Hodaie,et al.  Chronic Anterior Thalamus Stimulation for Intractable Epilepsy , 2002, Epilepsia.

[17]  P. Dowsey-Limousin Postoperative management of Vim DBS for tremor , 2002, Movement disorders : official journal of the Movement Disorder Society.

[18]  F. Lenz,et al.  Intraoperative microelectrode and semi‐microelectrode recording during the physiological localization of the thalamic nucleus ventral intermediate , 2002, Movement disorders : official journal of the Movement Disorder Society.

[19]  J. Gybels,et al.  Deep brain stimulation for treatment‐refractory obsessive‐compulsive disorder: psychopathological and neuropsychological outcome in three cases , 2003, Acta psychiatrica Scandinavica.

[20]  J. Vitek,et al.  Stimulation of the Subthalamic Nucleus Changes the Firing Pattern of Pallidal Neurons , 2003, The Journal of Neuroscience.

[21]  Warren M. Grill,et al.  Prediction of myelinated nerve fiber stimulation thresholds: limitations of linear models , 2004, IEEE Transactions on Biomedical Engineering.

[22]  C. McIntyre,et al.  Electric field and stimulating influence generated by deep brain stimulation of the subthalamic nucleus , 2004, Clinical Neurophysiology.

[23]  C. McIntyre,et al.  Cellular effects of deep brain stimulation: model-based analysis of activation and inhibition. , 2004, Journal of neurophysiology.

[24]  W. Grill,et al.  Deep brain stimulation creates an informational lesion of the stimulated nucleus , 2004, Neuroreport.

[25]  J. Dostrovsky,et al.  Histological analysis of the location of effective thalamic stimulation for tremor. Case report. , 2004, Journal of neurosurgery.

[26]  C. McIntyre,et al.  Uncovering the mechanism(s) of action of deep brain stimulation: activation, inhibition, or both , 2004, Clinical Neurophysiology.

[27]  Warren M. Grill,et al.  Selective Microstimulation of Central Nervous System Neurons , 2000, Annals of Biomedical Engineering.

[28]  C. McIntyre,et al.  Tissue and electrode capacitance reduce neural activation volumes during deep brain stimulation , 2005, Clinical Neurophysiology.

[29]  A. Lozano,et al.  Deep Brain Stimulation for Treatment-Resistant Depression , 2005, Neuron.

[30]  A. Destée,et al.  Bilateral deep-brain stimulation of the globus pallidus in primary generalized dystonia. , 2005, The New England journal of medicine.

[31]  C. McIntyre,et al.  Sources and effects of electrode impedance during deep brain stimulation , 2006, Clinical Neurophysiology.

[32]  Nicholas T. Carnevale,et al.  The Neuron Simulation Environment in Epilepsy Research , 2008 .