A 65-year-old woman came to a doctor with complaints of weakness in her left limbs. The weakness appeared in the morning and was gradually increasing throughout the day. Objectively, her consciousness is clear, her blood pressure is 190/100 mm Hg, her heart rate is 80 / min., rhythmic, a systolic murmur can be detected on the neck in the projection of the bifurcation of the right common carotid artery. Examination of the neurological status detects a smoothed-out nasolabial fold on the left, deviation of the tongue to the left, a decrease in the muscle strength of the left limbs to 3 points, tendon reflexes are S > D, the Babinski sign is positive on the left, left-sided hemihypersthesia is observed. What is the most likely diagnosis in this case?