CADASIL is an arteriopathy that is due to NOTCH3 mutation that is mainly underestimated and misdiagnosed. We will report a case of a 59-year-old female that was admitted to the ICU due to rapid evolution of the neurological symptoms, which is unusual for this particular pathology within tachycardia thats not usually found The exact mechanism of the rapid evolution, still a mystery and could be related to either a new mutation that led to a quicker evolution or another mutation that emphasized the NOTCH3 mutation Category: Neurology, emergency medicine. Genetic pathology.