3D Functional Database of Subcortical Structures for Surgical Guidance in Image Guided Stereotactic Neurosurgery

Current techniques for deep brain stereotactic neurosurgery require identification of targets by preoperative imaging localization. Many critical structures targeted in this way (the thalamic nuclei) are functionally distinct but not discernable on magnetic resonance images. These structures are also surrounded by critical brain areas which must not be damaged by the surgical procedure. These factors make accurate localization of lesion targets crucial. Digitized anatomical atlases derived from histochemically stained brain specimens registered to patient MRI datasets aid in delineating targets but accuracy of registration withinhomogeneous anatomy remains questionable. To address this problem, we have designed a searchable and expandable database of functional organization for the sensorimotor thalamus, internal capsule, and internal pallidum from a population of patients (n=40). Data were obtained through microcellular recording, microstimulation, and macrostimulation mapping performed during stereotactic thalamotomies and pallidotomies. After registration of the database into standard stereotactic space, clustering of like physiological responses was noted in the internal capsule and sensorimotor thalamus and an articulated joint-based organization was observed in the internal pallidum. Furthermore, a clear delineation of the kinesthetic-paresthetic functional border was observed within the thalamus. When registered to a patient MRI within our image guided visualization platform, the database provides a visual representation of deep brain functional organization facilitating physiological exploration and preoperative planning.