Branch occlusive disease Clinical and magnetic resonance angiography findings

Background: We evaluated the clinicoradiologic characteristics of patients with branch occlusive disease (BOD)–type intracranial atherosclerotic stroke (ICAS) compared with those of patients with non-BOD–type ICAS or with small artery disease (SAD). Methods: We analyzed 201 consecutive patients with acute infarcts within the middle cerebral artery (MCA) distribution but no demonstrable carotid or cardiac embolism sources. According to the diffusion-weighted imaging (DWI) distribution and the presence of ipsilateral MCA stenosis, of any degree, on magnetic resonance angiography (3-T MRI), we divided patients into 3 groups: 1) BOD: subcortical infarcts with MCA stenosis (n = 46); 2) non-BOD: infarcts beyond the subcortical area with MCA stenosis (n = 52); and 3) SAD (n = 103). We compared risk factors, degree of stenoses and distribution, and radiologic features of microangiopathy (leukoaraiosis and cerebral microbleeds) among the groups. Results: Risk factor profiles were similar among the groups, except that hypertension and current smoking were more prevalent in the non-BOD than in the BOD group ( p = 0.032 and 0.045). The relevant MCA had more severe and focal stenosis in the non-BOD than in the BOD group (stenosis of ≥70%; 76.9% vs 28.3%; p p Conclusions: BOD is prevalent (47% of ICAS) and shares common characteristics with non-BOD–type ICAS, although its clinicoradiologic features may resemble those of SAD. The morphologic characteristics of stenosis and risk factors may associate with a stroke phenotype in patients with ICAS.