Indeed, when dealing with brain lesions located in functional areas, such as sensorimotor, language or vision, neurosurgeons aim at removing the maximum amount of lesion minimizing the risk of producing neurological deficits so as to avoid impairing patient’s quality of life. As a matter of fact, in the span of a few millimetres around the margin of the resection, as well as within the lesion to be removed, one can find eloquent sites whose function is better explored on an awake individual. In fact the collaboration of an awake patient is crucial to guide the surgeon in sparing the function while being as most radical as possible in removing the tumour.