Brain deformations associated with burr hole and dura opening during Deep Brain Stimulation (DBS) surgeries can significantly affect electrodes' placement, directly impacting optimal treatment response. Enhanced interpretation of clinical outcomes and, in addition, study the effects of shifting electrode leads on neural pathways can be accomplished by coupling patient-specific finite element biomechanical/bioelectric tissue and conventional neurophysiological models. A dataset of six patients who had undergone intraoperative Magnetic Resonance (iMR)-guided DBS procedure is considered in this study. To realistically predict soft tissue deformation during DBS surgery, biomechanical models were constructed based on patient-specific imaging data and driven with iMR data. In addition, bioelectric finite element models for both undeformed (no shift) and deformed states were used to estimate the effect of electric fields using two conventional neuromodulation prediction approaches. In the first approach, successful neuron pathway recruitment was established using a neurophysiological simulation estimating the likelihood that a given field would influence action potential dynamics. In the second approach, recruitment was based on the direct use of an electric-field norm threshold to establish an activation volume. Results showed about 49% difference in recruited neuronal pathways when comparing neurophysiological models and electric-field norm threshold neural activation model.
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