Diffuse low-grade gliomas (DLGG) are cerebral tumors occurring in young adults, with an inescapable progression to higher grade of malignancy, resulting in functional impairment and death. DLGG evolve in several phases: an asymptomatic period despite a slow radiological growth; a period in which inaugural symptoms occur, usually epilepsy with possible mild cognitive disorders; then a phase with malignant transformation generating disabling neurological deficits; and ultimately the terminal stage. Early maximal surgical resection significantly increases overall survival while preserving quality of life. Surgeries are conducted under local anesthesia in order to map neural networks crucial for brain functions, and with the goal to use neuroplasticity mechanisms by sparing cerebral connectivity. Adjuvant oncological treatments such as chemotherapy and/or radiotherapy are kept for partial resection or non-operable recurrences. Because of an increase of incidentally discovered DLGG, explained by a facilitated access to brain imaging, awake surgery has been proposed in asymptomatic patients, with the aim of maximizing the rate of total or even "supratotal" resection in smaller tumors. Outcomes have been optimized, both regarding oncological results thanks to minimization of malignant transformation, as well as regarding functional results, with neither neurological deficit nor epilepsy in this sub-group of incidental DLGG. Thus, it seems legitimate to set up a screening by cerebral MRI in the population from 20 to 40years, to propose adapted therapeutic strategies based upon an upfront radical surgery, and so to create the foundations of a prophylactic and personalized functional neuro-oncologie.