Clinical analysis of cerebral infarction types in patients with arteriosclerotic middle cerebral artery stenosis

Objective To observe the cerebral infarction types and distributions under MRI in patients with arteriosclerotic middle cerebral artery (MCA) stenosis,and investigate the pathophysiological mechanism of cerebral infarction induced by arteriosclerotic MCA stenosis.Methods We retrospectively analyzed the infarction characteristics under MRI diffusion weighted imaging (DWI) of 71 patients with ≥50％ MCA stenosis (not associating with ipsilateral internal carotid artery stenosis or occlusion,and having at least one atherosclerosis risk factors),diagnosed by digital subtraction angiography (DSA) of the whole brain in our hospital from January 2009 to December 2010;and the cerebral infarction types were also analyzed.Results MCA stenosis was noted in 65 cases and MCA occlusion in 6 cases by DSA; MRI-DWI showed that subcortical infarctions were the most common,followed by external border-zone infarctions (n=26,36.6％) and shallow perforator infarctions (n=14,19.7％); subcortical infarctions included deep perforator infarctions (n=31,43.7％) and internal border-zone infarctions (n=30,42.3％); external border-zone infarctions included anterior border-zone infarctions (n=9) and posterior ones (n=17); shallow perforator infarctions included cortical spotty lesions (n=10,14.1％) and territorial infarctions (n=2,2.8％).The same patient had multiple infarction types.Conclusion Patients with arteriosclerotic MCA stenosis might appear various types of cerebral infarction,suggesting that MCA stenosis can lead to different pathophysiological mechanisms of cerebral infarction; therefore,different treatments should be adopted accordingly. Key words: Middle cerebral artery;  Stenosis;  Cerebral infarction;  Magnetic resonance diffusion weighted imaging