Résumé
Almost a century ago, neurosurgeons performed the first surgical disconnections of the frontal lobe (leucotomies) in psychiatric diseases, and then frontal lobectomies (FL), mainly in epilepsy. Since these initial resections, which induced a high rate of neurologic consequences, FL were conceptually associated to a combination of cognitive, emotional and behavioral symptoms known under the term of “frontal syndrome”. However, because of a recent paradigmatic shift from a localizationist to a connectomal theory of neural processing, and thanks to advances in brain mapping techniques, the traditional concept of irrevocable frontal syndrome generated by FL has been called into question [1]. Indeed, in the more recent field of neurooncological surgery, massive FL have been achieved up to individual eloquent networks identified by intraoperative direct electrical stimulation both at cortical and subcortical levels [2]. Using this philosophy of functional mapping-based resection, the existence of a huge potential of cortical plasticity has been evidenced, allowing a preservation of neurologic and neurocognitive status, including executive functions, mentalizing and metacognition, following unilateral or even bilateral FL [3]. Such a functional compensation is possible owing to the preservation of the white matter tracts that represent the limitation of neuroplasticity [4]. In fact, to prevent the occurrence of a “frontal syndrome”, which is most of the time the consequence of a dysconnectionism syndrome, the goal of FL is to surgically spare the intra-lobar connectivity (e.g. the frontal aslant tract), the inter-lobar long-range association fibers (e.g. the superior longitudinal fasciculus, arcuate fasciculus and inferior fronto-occipital fasciculus) as well as the projection fibers (e.g. the fronto-striatal tract) [5]. This improved knowledge of the functional connectome enables to significantly increase the overall survival while preserving the quality of life of brain tumor patients [6]. In addition, these new insights into cerebral processing can be applied to other fields of neurosurgery, such as brain-computer interface, to neurology and neurorehabilitation, by elaborating specific programs of cognitive remediation, and to basic neurosciences by proposing new behavioral models challenging the classical localist dogma.