The presence and type of symptomatology attributable to the Trephined Syndrome, its duration, severity and its modification after cranioplasty will be recorded. The delay for cranioplasty and any complications (such as hematoma or infectious complications) of the latter will be noted. The study aims to provide valuable information on how to to better plan the care for patients who undergoes decompressive craniectomy and to determine the optimal delay for the cranioplasty.