Electrode recording of field potentials along an axial trajectory: An approach for target localization improvement in deep brain stimulation implant surgery

A thesis presented on a method to enhance the subcortical target localization in stereotactic neurosurgery for the placement of chronic implant stimulation electrode for deep brain stimulation therapy.; Electrical stimulation of subcortical cerebral nuclei is an FDA approved treatment for movement disorder symptoms associated with Parkinson's and Essential Tremor diseases that afflict millions of people worldwide. A chronically implanted stimulation electrode used for deep brain stimulation (DBS) must be placed at the subcortical nucleic target site millimetric precision in order to convey the best efficacy of treatment. A novel electrode configuration is demonstrated in a simulated physiologically relevant environment. The additional electrodes are integrated into the present stereotactically positioned microelectrode recording apparatus. The electrodes are optimized for detection of subcortical electroencephalograph (EEG) signals. Subcortical low-frequency EEG signals result from ensembles of neurons firing action potentials concomitantly. An analysis of the neuronal architecture in the subthalamic nucleus is investigated to elucidate the parameters relevant to the formation of dipolar field potential emissive sites. Experimental results from an emulated electrode assembly in a homogenous medium are reported.; The analysis and results show that novel electrode configuration increases the localization information content extracted from each insertion track. These signals could be further processed and used as an aid in converging on the nucleic target in subsequent track insertions.