The Importance of Middle Cerebral Artery Stenosis In Patients With A Lacunar Infarction In The Carotid Artery Territory

ABSTRACT

BACKGROUND: It is well known that a lacunar infarction may develop by an atherosclerosis of the large intracranial arteries at the site of the perforating arteries. However, their frequency, clinical, and radiological findings have rarely been described. METHODS: Carotid angiograpies were carried out in 26 Korean patients with lacunar infarctions in the carotid arterial territory. They all had classical lacunar symptoms with a computed tomogram (CT) or a magnetic resonance image (MRI) evidence of a small infarction. A transesophageal echocardiography (TEE) was carried out in fifteen patients when either an angiography result was normal, the potential source of cardioembolism was suggested, or no other atherothrom-botic causes of stroke were found. Tc-99m single positron emission computed tomograms (SPECT) were performed in nine patients. We divided patients into two groups; one for patients with MCA occlusive lesion, and another for those without it. The clinical and radiological features were compared between the two groups. RESULTS: Twenty patients (77%) demonstrated abnormal angiographic findings. Fourteen of them showed atherosclerotic changes in the proximal MCA at the site of the orifice of the lenticulostriatal arteries, while another three showed stenosis in the intracranial portion of the internal cerebral artery (ICA), and the other three in the extracranial ICA. Among six patients with normal angiograms, a TEE demonstrated embolic sources of embolism in two patients. The temporal profile and findings of MRI and SPECT in patients with MCA stenosis differed from those with ICA stenosis or normal angiograms. Unstable temporal profiles exclusively occurred in patients with MCA stenosis. The most patients with conglomatory aggregations of the lacune in a MRI showed MCA lesions. The SPECT findings were even more characteristic in that patients with MCA lesions showed relatively large areas of decreased perfusion. CONCLUSIONS: The atherosclerotic diseases at the orifice of the lenticulostri-atal arteries were the most common causes of lacunar infarctions in the carotid artery territory. They were clearly different from those without MCA occlusive lesions in terms of preceding transient ishemic attacks, unstable temporal profiles, uni-lateral multiple lacunes with conglomatory MRI findings, and widespread perfusion defects SPECT.