Lacunar Infarction in Caudate Nucleus: Case Study of a 56-Year-Old Male with Carotid Artery Stenosis

A 56-year-old man was admitted to the hospital with a headache and abnormal behavior, including forgetting to turn off the faucet and confusing zebra crossings. Physical examination revealed weakness in his left hand with occasional numbness. An MRI scan indicated acute lacunar infarction in the right caudate nucleus. Routine ultrasound examination showed a slightly hypoechoic plaque located at the bifurcation of the right common carotid artery and the beginning of the internal carotid artery, resulting in stenosis of the initial segment of the internal carotid artery. The maximum flow velocity at the stenosis was approximately 272 cm/s, and the flow velocity near the proximal end of the stenosis was around 81 cm/s. The ICA/CCA PSV ratio was 3.36, and the diameter stenosis rate was approximately 58.4% according to the NASCET standard.