"Y appearance" infarction: caused by essential thrombocythemia.

Essential thrombocythemia (ET) is a myeloproliferative malignancy caused by the excessive proliferation of megakaryocytes in the bone marrow, resulting in the overproduction of peripheral platelets. ET can lead to thrombotic events, such as ischemic stroke (IS), though it is a rare cause of IS. Bilateral medial medullary infarction (BMMI), also known as "Y appearance" infarction due to its distinctive imaging morphology, is a rare clinical subtype of IS which typically has a poor prognosis and a high mortality rate. Herein, we report the case of a 43-year-old male with a history of ET. The patient's platelet count was poorly controlled, and he did not receive regular treatment. After developing symptoms such as dizziness, dysphagia, choking on water, slurred speech, blurred vision, and bilateral limb numbness. Head magnetic resonance imaging revealed a "Y appearance" infarction in the bilateral medial medulla. After admission, the patient was administered intravenous antiplatelet therapy with tirofiban. However, when he was switched to oral aspirin after three days, he experienced decreased muscle strength and worsening symptoms. Therefore, tirofiban was continued for 14 days. Upon discharge, the patient experienced residual limb numbness. His National Institutes of Health Stroke Scale score was 1, Modified Rankin Scale score was 0, and platelet count had decreased to the normal range. During the 9-month follow-up period after discharge, the patient still had only mild limb numbness. Our report presents a special case of "Y appearance" infarction due to ET. Owing to fluctuations in the patient's condition, he received long-term high-dose tirofiban, which ultimately led to a significant improvement in his symptoms.