A 60-year-old female patient was admitted due to sudden onset of impaired movement in the right limb. Past medical history includes diabetes mellitus (DM) and atrial fibrillation. Examination: The patient cannot express herself but can understand others; normal blood pressure (BP), no abnormalities on cardiopulmonary exam, conscious, cooperative, but unable to speak. Right nasolabial fold is shallow, forehead wrinkles are symmetrical, tongue deviates to the right, right limb muscle strength is grade 3, and right pathological signs are positive. The most likely diagnosis is: