What artery is most often affected by stroke? The Middle Cerebral Artery (MCA). This is the one of the largest arteries supplying blood to the cerebrum (or the two hemispheres of the brain). Because it’s so large, this is why it’s most commonly affected by Stroke. While symptoms of an MCA stroke will be different depending on which branch and side is affected, some of the most common symptoms include: - one sided weakness or numbness - facial droop - speech issues - neglect #stroke #strokerecove