Search

The lenticulostriate arteries (LSA) supply the lateral half of the head of the caudate nucleus, entire putamen, anterior limb, genu and the superior part of the internal capsule (IC) and a part of the corona radiata. The LSA consists with medial, intermediate and lateral branches. The medial branches perfuse the lateral segment of the globus pallidus, the head of the caudate nucleus and the anterior limb of the IC. The intermediate branches supply the anterior half of the LSA territory, while the lateral branches supply the posterior half. The anterior cerebral artery (ACA) perforators, predominantly Heubner's artery, perfuse the inferomedial part of the caudate head, the anteromedial part of putamen, the anterior part of the lateral segment of the globus pallidus and anterior limb of the internal capsule. Such territories can be represented by the anterior and ventral basal ganglions. The anterior choroidal artery (AChA) gives off three main groups of branches including the lateral branches that supply the medial temporal lobe, the medial branches that supply the cerebral peduncle and the superior branches that supply the internal capsule and the basal ganglia. The superior branches are further discriminated into proximal branches that supply the anterior one third of the posterior limb of internal capsule (PLIC) and the medial segment of the globus pallidus and distal branches that supply the posterior two-third of PLIC, retro-lenticular part of the internal capsule and the lateral thalamic nuclei. The superficial penetrating arteries, i.e. medullary arteries, arise from the cortical branches of the middle cerebral artery (MCA) and supply the deep white matter. Infarcts caused by the medullary artery occlusion are located in the centrum-semiovale and half of them were caused by embolic mechanism. The centrum-semiovale corresponds to cortical border-zone (BZ) while the corona radiate corresponds to internal BZ.

We present two patients (case 1: a 78-year-old right-handed woman, case 2: a 66-year-old right-handed woman) with suspected transient global amnesia. Both patients showed sudden onset amnesia that appeared to resolve within 24 hours, and they showed no abnormal findings on electroencephalography or single photon emission tomography. However, the results of the Wechsler Memory Scale-Revised (WMS-R) on the ninth (case2) or tenth day (case1) after the onset indicated memory impairment. And diffusion-weighted magnetic resonance imaging (DWI) revealed a unilateral high-intensity area in the hippocampus, leading to the diagnosis of hippocampal infarction in both patients. Case 1 had a left hippocampal lesion and exhibited impairment of predominantly verbal memory, while case 2 had a right hippocampal lesion and demonstrated impairment of predominantly visual memory. When evaluating a patient with suspected transient global amnesia, imaging of the hippocampus and tests on memory function after an appropriate interval from the onset are often helpful in establishing a correct diagnosis.