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Background and Purpose The location of cerebral microbleeds (CMBs) may differ according to ischemic stroke subtype, and the underlying pathomechanism may differ by their location. Here, we investigated the characteristics of CMBs according to various ischemic stroke subtypes to verify this issue. Methods Patients with acute ischemic stroke were consecutively included. The presence of CMBs was determined by gradient echo image sequence. The distribution of CMBs was classified as deep, lobar, or diffuse (both deep and lobar). The prevalence, risk factors, and distribution of CMBs were compared among patients with different stroke subtypes. Factors associated with the distribution of CMBs were investigated. Results Among the 1033 patients included in this study, ischemic stroke subtypes were classified as large artery atherosclerosis (LAA; n=432), small vessel occlusion (SVO; n=304), and cardioembolism (CE; n=297). The prevalence of CMBs was highest in patients with SVO (40.5%), followed by CE (33.0%) and LAA (24.8%; P

Background The location of plaque may be associated with the vascular geometry. Aim We aimed to examine the relationship between the geometry of middle cerebral artery and the plaque location detected by high-resolution magnetic resonance imaging. Methods Among patients with a single subcortical infarction without a significant middle cerebral artery stenosis on magnetic resonance angiography, those with a plaque detected from high-resolution magnetic resonance imaging were prospectively enrolled. The shape of middle cerebral artery was measured from the coronal view, and was classified as straight, U-shaped, inverted U-shaped, and S-shaped. The location of the plaque was divided into superior and inferior, and analyzed according to the shape of middle cerebral artery. Results Among the 40 patients, the shape of middle cerebral artery was straight in 7 (17·5%), U-shaped in 10 (15·0%), inverted U-shaped in 11 (27·5%), and S-shaped in 12 patients (30·0%). The superior plaque was more closely associated with straight (85·7%) or U-shaped middle cerebral arteries (90·0%), whereas inverted U-shaped (81·8%) and S-shaped middle cerebral arteries (75·0%) were more often associated with inferior plaque. The prevalence of symptomatic plaque was higher in superior than inferior plaques (70·0% vs. 25·0%, P = 0·004). Multivariate analysis showed that straight and U-shaped middle cerebral artery was the only significant factor associated with the superior plaque. Conclusion The shape of middle cerebral artery may be a factor determining the location of early atherosclerotic plaque.

Background Traditionally, single subcortical infarction has been considered to be caused by lipohyalinosis of small perforating arteries. However, atherosclerosis in the parental artery produces similar single subcortical infarction by blocking the orifice of branching arteries. The purpose of this paper is to review the evolving concepts, clinical characteristics, and classification issues of single subcortical infarction associated with parental artery disease. Summary of review Single subcortical infarction associated with parental artery disease is an important cause of subcortical infarction, more so in the posterior than in anterior circulation stroke. It is one of the major causes of brainstem infarction. Single subcortical infarction associated with parental artery disease seems to be common in Asian population where intracranial atherosclerosis is prevalent. Although the clinical characteristics of single subcortical infarction associated with parental artery disease are similar to single subcortical infarction caused by small artery disease, single subcortical infarction associated with parental artery disease is more often associated with characteristics of atherosclerosis, and fluctuating and poorer outcomes. With advanced imaging techniques such as high-resolution cross-sectional magnetic resonance imaging, single subcortical infarction associated with parental artery disease emerges as an even more important stroke sub-type. Nevertheless, it has been neglected in previous stroke sub-type classifications, being erroneously classified as small artery disease or cryptogenic stroke. Prevention and treatment trials focusing on single subcortical infarction associated with parental artery disease are not available. Conclusion Single subcortical infarction associated with parental artery disease is an important stroke sub-type, distinct from small artery disease, illustrating that greater efforts should be made in its accurate diagnosis. Studies are needed to investigate the prevalence of single subcortical infarction associated with parental artery disease in various parts of the world and to design a stroke classification system that includes single subcortical infarction associated with parental artery disease. Prevention and treatment trials should consider this important sub-group of stroke, so that tailored strategies can be applied in clinical practice.

Background and Purpose— Single subcortical infarction (SSI) may be classified as proximal SSI (pSSI) or distal SSI (dSSI) according to its extension to the middle cerebral artery (MCA). We investigated the differences between pSSI and dSSI in terms of their clinical features, lesion size, and the frequency of MCA plaques detected by high-resolution MRI. Methods— Thirty-nine patients with SSI (20 pSSI and 19 dSSI) were prospectively enrolled who did not show relevant MCA disease on MR angiography. Lesion size, neurological status (initial National Institutes of Health Stroke Scale score and modified Rankin Scale at 3 months), and the presence and location (superior versus inferior) of high-resolution MRI–identified plaques were evaluated. Results— The frequencies of MCA plaques did not differ between patients with pSSI and those with dSSI (8 [40%] versus 12 [63.2%]; P =0.205); however, superiorly located plaques were significantly more common in patients with pSSI than in those with dSSI (6 [75%] versus 2 [16.7%]; P =0.019). Initial lesion volumes were larger (1.96±1.18 versus 1.11±1.11 mm 3 ; P =0.025), National Institutes of Health Stroke Scale scores were higher (5 [3–6.75] versus 3 [1–3] points; P =0.017), and microbleeds were fewer (1 [5%] versus 10 [52.6%]; P =0.001) in patients with pSSI than in those with dSSI. Three-month modified Rankin Scale scores were higher in patients with superior plaques than in those with inferior plaques. Conclusions— Compared with dSSI, pSSI is closely associated with large lesions, severe clinical symptoms, and superiorly located MCA plaques, suggesting that the location, rather than simple presence of plaques, determines the SSI location.

Limb shaking is a well-known symptom of TIA associated with the steno-occlusion of the internal carotid artery (ICA).1 It has been shown that the symptom is closely associated with hemodynamic impairment in the anterior circulation.2 However, the pathogenic nature of the limb-shaking symptom remains unclear. We describe a patient presenting with limb-shaking TIA caused by severe distal ICA stenosis, which turned out to be an asterixis electrophysiologically using surface EMG.