Thrombosis of the Azygos Anterior Cerebral Artery

Abstract

The azygos anterior cerebral artery is a rare variant, characterized by the absence of the anterior communicating artery and the union of two proximal segments of the anterior cerebral artery, forming a single trunk and ascending through the interhemispheric fissure. The incidence in the population varies from 0.3 to 2%. The presence of occlusion for this vessel causes bifrontal infarcts, with potentially devastating functional consequences, hence the importance of recognizing this anatomical variation in imaging exams.

Mechanical Thrombectomy for Azygos Anterior Cerebral Artery Occlusion: A Case Report and Literature Review

“…The patient's aphasia and quadriparesis improved gradually after the procedure, and GCS score also improved to 15 (E4V5M6) and NIHSS score decreased lower limb, total aphasia, and left conjugate deviation of the eyes were present, suggesting that the ischemic state was more dominant in the left ACA territory than the right hemisphere because of difference in collateral blood flow from the middle cerebral artery (MCA) or posterior cerebral artery. In four of the previous cases, [4][5][6][7] the patients were diagnosed as ischemic stroke in the late phase and head CT revealed low intensity lesions suggestive of a large ischemic core, and hence, MTs were not indicated. The clinical outcomes of these four cases were poor, with no improvement of weakness in bilateral lower limbs.…”

“…13) Stroke should be suspected with sudden onset neurological symptoms and neuroimaging such as MRI/MRA or CT angiogram is useful to distinct between AIS and stroke mimics. 14) Five case reports of azygos ACA occlusion were previously published [4][5][6][7][8] (Table 1). Since the azygos ACA supplies both hemispheres, complete occlusion might result in large bilateral frontal infarctions and severe symptoms, such as quadriparesis, disturbance of consciousness and aphasia.…”

Tetraparesis following an Anterior Circulation Stroke: A Case Report

“…De Sousa et al [1] reported a 63-year-old male patient with sudden lowering of his level of consciousness. The patient had a history of hypertension and diabetes.…”

“…The azygos anterior cerebral artery (AACA), an anomaly of the circle of Willis, is a large single anterior cerebral artery (ACA) that supplies both medial territories of the anterior cerebral hemispheres. It has an incidence rate of 0.3–2.0% in adults [1, 2]. The AACA results from two vessels that instead of forming two ACA, fuse to one midline artery [3].…”

“…The AACA can be associated with other anomalies such as saccular aneurysm or arteriovenous malformation [4]. As the AACA is responsible for the perfusion of both anterior cerebral hemispheres, occlusion of the AACA results in bifrontal infarction [1, 5]. We describe a patient who suffered from a tetraparesis following a bilateral ACA territory infarction due to an occluded AACA.…”