Abstract
**Ischemic stroke** is the most common type of stroke, accounting for 80 to 85% of all stroke cases. Identifying the cause of stroke plays a crucial role in guiding treatment and preventing recurrence. In addition to the three major etiological categories—large-artery atherosclerosis, cardioembolism, and small-vessel disease—there are several other identifiable causes that, although accounting for a small proportion of cases, are of great importance in terms of accurate identification and appropriate treatment. Some of these causes include infective endocarditis, aortic dissection, and aortic arch atherosclerosis. **Stroke due to infective endocarditis** is a severe condition, and its management differs substantially from that of other stroke etiologies. Septic embolism originating from endocarditic vegetations can cause cerebral infarction, which may progress to brain abscess, and can also give rise to infectious (mycotic) aneurysms, with complications such as intracerebral hemorrhage or subarachnoid hemorrhage. The most essential component of treatment is potent antibiotic therapy, along with management of cardiac complications if present, and treatment of neurological complications—which may include prolonged antibiotic therapy in cases of brain abscess, and endovascular intervention if the mycotic aneurysm is clinically significant. **Aortic dissection** is a cardiovascular emergency that may require emergency surgery. In some cases, stroke may be the first or most prominent manifestation of aortic dissection, resulting either from embolism originating from thrombus at the dissection site or from occlusion of the cerebral-supplying arteries due to extension of the dissection. In stroke caused by aortic dissection, thrombolytic therapy is contraindicated, and endovascular thrombectomy, although technically feasible, is very challenging and depends on the classification and extent of the aortic dissection. Early recognition of aortic dissection is a prerequisite for making appropriate treatment decisions, particularly in coordinating multidisciplinary care to achieve the best possible outcome for the patient. **Aortic arch atherosclerosis** is one of the rare causes of stroke. Solid evidence and clear treatment guidelines are still lacking. Evaluation for aortic arch atherosclerosis should be included in the diagnostic workup for embolic stroke of undetermined source. Currently feasible diagnostic modalities include transesophageal echocardiography and CT angiography. At present, treatment primarily consists of antiplatelet therapy and statins, along with control of risk factors. The role of anticoagulation remains undetermined, and further data are needed in the future.
