Hodotopy, neuroplasticity and diffuse gliomas

The historical approach in neurooncology is used to mainly investigate the tumor, with very few considerations regarding the brain itself. Nonetheless, to select the best personalized therapeutic management for each patient with a diffuse glioma, i.e. to optimize the "onco-functional balance", the brain reaction induced by glioma growth and migration should be studied. Indeed, due to strong interactions between the glioma and the brain, cerebral adaptive phenomena often occur in order to maintain neurological and cognitive functions, as well as to compensate glioma spreading. Here, the goal is to detail mechanisms underlying neuroplasticity and its implications for surgical neurooncology.

Data issues from cerebral mapping and functional outcomes in patients who underwent awake surgery for gliomas were discussed.

Massive resections of the brain, including so-called "eloquent areas", are possible without generating permanent neurological deficits in adult patients harbouring a diffuse glioma.

From a fundamental point of view, these findings open the door to a hodotopical anatomo-functional organization of the brain, i.e. organized in dynamic and interactive parallel large-scale distributed networks, able to compensate for each other. Furthermore, cognitive neurosciences represent valuable help to neuro-oncology, by leading to the elaboration of new treatment strategies, such as multistage surgical approach, made possible thanks to cerebral remapping over years. In other words, understanding neuroplasticity in a connectomal account of brain processing permitted a dramatic improvement of both quality of life as well as overall survival in glioma patients, and resulted in the proposal of an "individualized functional neurooncology".