Mr Of The Pathogenesis Of Posterior Cerebral Artery Territory Infarction

Background and Purpose:Although cardiac embolism has been shown to be the leading stroke mechanism of posterior cerebral artery (PCA) territory infarction, intrinsic PCA atherosclerotic disease may play a more important role in regions where intracranial diseases are prevalent. We aimed to assess the etiologies and stroke pattern of PCA territory infarction in a Chinese population.Method:We reviewed consecutive patients with acute PCA territory infarction who underwent magnetic resonance imaging(MRI) and magnetic resonance angiography (MRA) within 7 days after onset.Results:A total of 82 patients (male 57.3%, mean age 64±13.7 years) were recruited. 'Superficial','deep'and'superficial plus deep'infarcts accounted for 25.6%,50% and 24.4% of infarcts, respectively. There were 50 patients who had infarcts limited to the PCA territory, whereas 32 patients had concomitant infarcts in other territories. Large artery atherosclerosis (LAA,43.9%) was the most frequent etiology, followed by cardiogenic embolism (19.5%), small-vessel occlusion(18.3%), undetermined (17.1%) and other determined (1.2%)etiology. Among the 36 patients with LAA,15 had intrinsic PCA disease without atherosclerosis in the proximal vessels.In these patients, stroke mechanisms included atheromatous branch occlusion (n=8), in situ thrombotic occlusion(n=4) and artery-to-artery embolism (n=3). While the occipital area was the most frequently involved in general, the ventrolateral thalamic area was more frequently involved than the occipital area in patients with intrinsic PCA atherosclerotic disease.Conclusion:The patterns of PCA territory infarction are different according to underlying etiologies. In our population, intrinsic atherosclerotic disease is a relatively important cause of PCA territory infarction that produces strokes through a variety of mechanisms.