Insulotakia: Nawigacja przez wyspę mózgową z użyciem nowego systemu stereotaktycznego

Introduction: The insula represents a critical target for functional neurosurgery due to its involvement in diverse neurological disorders including epilepsy and chronic pain. As this practice evolves, optimal targeting will require standardized outcome measures that compare electrode lead or laser source with postprocedural changes in outcome measures. Traditional neuroimaging registration approaches fail to address the significant person-to-person variability in insular gyral configuration and the relative internal rotations of insular gyri compared to the standard direction of stereotactic spaces. Objective: The authors propose and present a novel stereotactic coordinate system based on anatomical landmarks to facilitate the planning and delineation of outcomes based on extent of ablation or region of stimulation within the insular cortex. Methods: Our approach begins with transforming brain MRIs into standard AC-PC space, followed by an insular-specific transformation based on five anatomical landmarks: four points defining the central sulcus of the insula and one inferior point at the middle cerebral artery (MCA) bifurcation (at the limen insulae). This system calculates two angles: theta for rotation in the axial plane and phi for rotation in the sagittal plane between the AC-PC line and the insular axis. The brain volume undergoes sequential rotations through these angles, followed by translation to position the coordinate system origin along the insular axis. Results: The angle between the AC-PC line and the insular axis was found to range between -12 to 17 degrees when viewed axially (theta) and 24 to 57 degrees when viewed sagittally (phi). In the insular coordinate system, the insular axis is where z=0 and the MCA turning point is where y=0. Using this coordinate system, a custom open-access MATLAB graphical user interface was developed to allow for intuitive standardization of targeting and interpretation in clinical practice. Implanted electrodes can be identified from CT in this space, and laser tip position and burn geometry can be calculated based on the intraoperative and postoperative MRI. This approach enables the pooling of outcome data across patients by aligning interventions or electrophysiology/imaging data according to insular-specific anatomy rather than external reference frames or distant proxy landmarks. Conclusion: With the advent of stereotactic surgery for insular targets, an insular-specific coordinate system is introduced that may facilitate operative planning, functional mapping, improve surgical outcomes, and standardize outcome assessment.