Patterns of Posterior Circulatory Stroke in Magnetic Resonance Imaging: A Case Series

Abstract

The present study aimed to document the patterns of posterior circulatory stroke in magnetic resonance imaging. The four cases in this series highlight the diverse MRI findings in posterior circulatory stroke. A 53-year-old male (Case 1) exhibited an acute infarct in the right medulla, characterized by a focal FLAIR hyperintense area with restricted diffusion, alongside bilateral fronto-temporo-parietal white matter hyperintensities and prominent ventricles and basal cisterns. Hypoplastic left transverse and sigmoid sinuses were noted, with absent flow in the distal right vertebral artery. In Case 2, a 47-year-old male showed a large infarct in the left thalamus, parietal, medial temporal, and occipital lobes with perilesional oedema and mass effect. T2/FLAIR hyperintensities were seen in the bilateral periventricular regions and right frontal deep white matter, and MR angiogram revealed a hypoplastic right vertebral artery and narrowed basilar and posterior cerebellar arteries. Case 3 involved a 75-year-old male with extensive T2/FLAIR hyperintensities and diffusion restriction in the bilateral parieto-occipital, posterior temporal, high parietal, and cerebellar hemispheres, suggesting posterior reversible encephalopathy syndrome, with a small T1 hyperintensity in the left cerebellar hemisphere and absent flow in the left posterior communicating artery. Lastly, Case 4 presented with acute infarcts in the left thalamus, left cerebral peduncle, and left medial temporal lobe, punctate FLAIR hyperintensities in the right midbrain and left occipital lobes, gliosis and hemosiderin deposition in the left occipital region, and bilateral papilledema.