Infarct patterns in atherosclerotic middle cerebral artery versus internal carotid artery disease

Objective: To compare clinical and radiologic characteristics of atherosclerotic middle cerebral artery (MCA) vs internal carotid artery (ICA) disease. Methods: The authors defined atherosclerotic MCA and ICA disease as > 50% symptomatic stenosis or occlusion without significant ICA and MCA stenosis on MR angiography. Patients with potential cardiac sources of embolism were excluded. The authors analyzed clinical, laboratory, and neuroradiologic data of the two groups. Results: Among the 920 consecutive patients with acute ischemic strokes, 112 met the criteria for atherosclerotic MCA and 71 met the criteria for ICA disease. Clinically, the MCA group more frequently presented with lacunar syndrome ( p = 0.001), whereas the ICA group more often presented with total anterior circulation infarct and had higher initial NIH Stroke Scale scores than the MCA group ( all p < 0.001). Whereas deep perforator and internal border-zone infarcts were associated with MCA disease ( p < 0.001 and 0.012), territorial infarcts and superficial perforator infarcts were associated with ICA disease ( p < 0.001 and p = 0.009). The topographic patterns with respect to the degree of stenosis were also significantly different between the two groups. Conclusions: The clinical and radiologic stroke patterns were distinctively different between atherosclerotic MCA and ICA disease, suggesting different underlying pathogeneses.