Medical Student, Class of 2025 Carle Illinois College of Medicine, University of Illinois Urbana-Champaign
Introduction: Minimally invasive access to the sensory-motor cortex is increasingly important with the development of emerging neurotechnologies. Canines are potentially useful for preclinical testing of cranial access devices when other large-animal models are not suitable, but literature on their characterization for this purpose is limited. In particular, the volume and configuration of the frontal sinus and skull thickness may contribute to the utility of canines in preclinical testing of advanced neurotechnologies. This study utilizes a veterinary radiology database to characterize the suitability of the canis lupis familiaris as a model for devices requiring cranial access to the sensory-motor cortex.
Methods: The computed tomography scans of twelve neurologically normal canines were analyzed using 3D Slicer. They were classified by their cranial index (CI) using established methods. Access to the central sulcus was simulated by creating a 4 mm cranial access point perpendicular to the skull on coronal view. Position of the cranial access point relative to bregma, thickness of skull at access point, and the shortest distance between the frontal sinus and the determined trajectory were measured and validated by independent researchers.
Results: Access to the central sulcus was successful in all twelve simulated attempts. Small canines (CI>60) had access points 6.92±3.47 mm posterior and 10.92±0.53 mm lateral to bregma and determined trajectories 17.15±2.7 mm from the frontal sinus. Large canines (CI < 60) had access points 8.54±3.28 mm posterior and 22.1±2.36 mm lateral to bregma and determined trajectories 5.87±3.61mm from the frontal sinus. The skull thicknesses were 4.41±1.58mm and 8.66±0.26 mm for small and large dogs respectively.
Conclusion : Smaller dog breeds (CI>60) pose the advantage of shorter frontal sinus length and thinner cortical bone, making them potentially suitable for preclinical testing of devices requiring cranial access to the sensory-motor cortex. Intra-breed variability is significant, and may require expanded radiographic study using similar methods.
