Anatomo-functional approach to multimodal motor mapping in diffuse glioma surgery: hierarchical networks.

Onco-functional balance during motor-eloquent diffuse glioma resection is challenging. This balance is personal according to individual background, treatment expectations and surgical experience. Nevertheless, preservation of muscle contraction in isolation is no longer an accepted outcome. Motor planning and accurate purposeful execution are essential for useful motor function after surgery. Multiple brain networks work together to achieve this result: local networks focused on motor output, modular networks dedicated to sensorimotor integration and integrative networks responsible for the incorporation of motor function within the overall brain cognition. Intraoperatively, local networks are better probed by asleep techniques whereas integrative networks can only be assessed with awake techniques (modular networks is a crossroad for both techniques). Here, we propose a schematic hierarchical model to address these networks according to an orthogonal plane organization. Local networks are always pivotal given the common final output of motor function. Modular sensorimotor networks achieve their higher specialization within the central lobe given the subcortical connection via specialized U-fiber system underneath central sulcus. Integrative networks are fundamental anterior and posterior to the central lobe within the corona radiata and capsules where the main association fibers that subserve the large brain networks and cognitive hubs are located.