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Background/Aims: The aims of this study were to determine the differences in clinical characteristics and the risk of ischemic stroke between patients with transient ischemic attack (TIA) attributable to extracranial carotid and intracranial artery occlusive lesions. Methods: Among 445 patients admitted to our stroke care unit within 48 h of TIA onset between April 2008 and December 2013, 85 patients (63 men, mean age 69.4 years) with large artery occlusive lesions relevant to symptoms were included in this study. The primary endpoints were ischemic stroke at 2 and 90 days after TIA onset. Results: Twenty-eight patients had carotid artery occlusive lesions (extracranial group), and 57 patients had intracranial artery occlusive lesions (intracranial group). Patients in the intracranial group were significantly younger, had lower levels of fibrinogen, and were less likely to have occlusion when compared with those in the extracranial group. Eleven patients in the extracranial group and none in the intracranial group underwent revascularization procedures within 90 days of TIA onset. The 2-day risk (14.2 vs. 0%, p = 0.044) and the 90-day risk (17.1 vs. 0%, p = 0.020) of ischemic stroke after TIA onset were significantly higher in the intracranial group than in the extracranial group. Conclusions: Among our patients with TIA caused by large artery disease, patients with intracranial artery occlusive lesions were more frequent and were at higher risk of early ischemic stroke than those with extracranial carotid artery occlusive lesions. These data highlight the importance of prompt assessment of intracranial artery lesions in patients with TIA.

Background: Atrial fibrillation (AF) is an important risk factor for transient ischemic attack (TIA). However, little is known about the characteristics of TIA patients with AF. This study investigated the characteristics of such patients, using data from a retrospective, observational, multicenter study. Methods: TIA patients admitted to 13 stroke centers in Japan within 7 days of onset between January 2008 and December 2009 were included. The present analyses compared baseline characteristics, clinical symptoms, findings from diffusion-weighted imaging (DWI), and clinical outcomes between patients with and without AF (AF and non-AF groups). Results: A total of 464 patients (292 men; mean age 68.5 ± 13.2 years) were registered. Of these, 79 patients (17%) had AF. Patients in the AF group were older (73.9 ± 9.1 vs. 67.4 ± 13.6 years, p < 0.001) and more likely to show disturbance of consciousness (13 vs. 6%, p = 0.046) and aphasia (9 vs. 3%, p = 0.007) than patients in the non-AF group. Although no difference in the overall DWI-positive rate was seen between the groups (28 vs. 20%, p = 0.102), a single lesion (23 vs. 10%, p < 0.001), a lesion ≥15 mm (11 vs. 4%, p = 0.006), and a single lesion ≥15 mm (11 vs. 2%, p < 0.001) on DWI were more frequent in the AF group. Multivariate logistic regression analysis identified increased age [odds ratio (OR) 1.04; 95% confidence interval (CI) 1.02-1.07] and DWI single lesion ≥15 mm (OR 5.67; 95% CI 1.92-16.7) as independently associated with the presence of AF. Conclusions: In this study, 17% of our TIA patients had AF. We found an association between the acute ischemic lesion pattern on DWI of a single lesion ≥15 mm and AF in TIA patients. These results might lead to a better diagnosis of TIA patients with AF.

Background: We conducted a survey by questionnaire to identify the essential components of stroke centers in Japan and compared our results with the European Expert Survey. Methods: In 2007, a questionnaire was mailed to the directors of 740 facilities certified by the Japan Stroke Society to ask their opinion on the essential components of comprehensive stroke centers (CSC), primary stroke centers (PSC) and any hospital ward (AHW) admitting acute stroke patients. The directors were asked to provide 1 of the following 6 possible answers regarding 112 components: ‘irrelevant'; ‘useful but not necessary'; ‘desirable'; ‘important but not absolutely necessary'; ‘absolutely necessary', or ‘question unclear or ambiguous'. The components considered ‘absolutely necessary' by more than 75% of the respondents were compared between our survey and the European Expert Survey. In addition, we compared the rates of neurosurgeons and neurologists who answered ‘absolutely necessary' with regard to each component. Results: Responses were obtained from 428 directors (57.8% response rate). Among these respondents, 298 (69.6%) were neurosurgeons. There was no component considered ‘absolutely necessary' for AHW by more than 75% of the respondents, and this was similar to the results of the European Expert Survey. The following components were considered ‘absolutely necessary' for PSC in our survey: brain CT scanning 24 h a day, 7 days a week (24/7); automated monitoring of the ECG, pulse oximetry, blood pressure and breathing, and respiratory support. In both our survey and the European Expert Survey, the essential components for CSC were as follows: physiotherapist; brain CT scanning 24/7; monitoring of the ECG, pulse oximetry and blood pressure; carotid surgery; angioplasty and stenting, and intravenous recombinant tissue plasminogen activator protocols. The components multidisciplinary stroke team, stroke-trained nurse, ultrasonography, collaboration with an outside rehabilitation center, stroke pathway and clinical research were deemed essential only in the European Expert Survey. However, MRI 24/7, MR angiography 24/7, conventional angiography 24/7, respiratory support as well as most neuroendovascular and neurosurgical treatments were considered necessary for CSC by more than 75% of the respondents in our survey. Analyzing the responses from only neurologists reduced the differences between our survey and the European Expert Survey. Conclusions: The present study indicated the essential components expected for stroke centers in Japan. Our survey demonstrated that more emphasis was likely to be placed on installations than on a dedicated stroke team and the use of stroke care maps. In addition, the results of this study may reflect some characteristics of the stroke care environment in Japan, such as the predominance of neurosurgeons and widespread use of MRI.

Background: Atheromatous plaques of the aortic arch that extend to the origin of its branches may cause stroke. The frequency and clinical implications of plaque at the origin of the left subclavian artery (LSCA) in patients with recent ischemic stroke were investigated. Methods: We studied 347 consecutive patients (223 men, 69 ± 12 years) who developed symptomatic ischemic stroke and underwent transesophageal echocardiography (TEE). Results: The origin of the LSCA was identified in 303 of 347 patients (87.3%). Plaque ≧1.0 mm was detected in 108 of the 303 patients (35.6%), ranging between 1.0 and 6.1 mm (median, 2.5 mm). Patients having thicker plaque (≧2.5 mm) were older (p = 0.012) and more commonly took antiplatelets prior to stroke (p = 0.038) than patients with no plaque and those with thinner plaque (Conclusions: Atheromatous plaque at the origin of the LSCA was present in approximately one third of patients with a recent ischemic stroke. High IMT at the aortic arch was independently related to the presence of thick plaque at the LSCA origin. The present study does not support the concept that plaque at the LSCA origin may be associated with posterior circulation infarction.

Objective: To elucidate the frequency and clinical profiles of patients with medial medullary infarction (MMI) identified by diffusion-weighted MRI (DWI). Methods: We assessed the frequency, radiological findings, etiology and clinical features of MMI detected by DWI from our single-center registry of acute ischemic patients. Results: Thirty patients (1.5% of 2,014 with ischemic stroke) had MMI, including isolated unilateral MMI in 26 patients. Lesions were located by DWI in the rostral medulla of 25 patients (83%). Culprit infarcts that were undetectable by DWI in 6 (38%) of 16 patients who were assessed within 24 h after onset were later confirmed as MMI. The major etiological mechanism was small artery occlusion (SAO; 19 patients) and the median initial National Institutes of Health Stroke Scale score was 4 (interquartile range: 3–4.75). The most frequent symptom was contralateral hemiparesis (27 patients). None of the patients fulfilled the classical Dejerine Triad. Twenty-two patients (73%) had a modified Rankin Scale score of ≤2 at 3 months. A patient developed transient ischemic attack within 3 months; none developed recurrent stroke. Conclusions: Rostral medullary infarction with mild neurological deficits resulting from SAO is relatively frequent. Because emergency DWI within 24 h could not detect MMI in one third of the patients, this type of infarction could be misdiagnosed as capsular/pontine lacunae or other neurological disorders.

Background: Intracranial arterial lesions are important causes of ischemic stroke, particularly in the Asian population. Of the intracranial lesions, the etiology of isolated anterior cerebral artery (ACA) territory infarction is not fully elucidated. The purpose of this study was to determine the etiological and clinical characteristics of patients with isolated ACA territory infarction, especially those with ACA dissection. Methods: Of 3,115 consecutive patients with acute ischemic stroke, 42 patients (1.3%, 30 men, 38–88 years old) having an isolated ACA territory infarction were studied. Infarcts were principally verified by diffusion-weighted MRI, and vascular lesions were identified by MRA, CTA, or digital subtraction angiography. Three-dimensional rotational angiography was performed if needed. Results: Eighteen patients (43%) were diagnosed as having ACA dissection. The stroke subtypes of the other 24 patients included cardioembolism for 6 patients and large-artery atherosclerosis for 8. Patients with dissection were younger (p < 0.001) and heavier (p = 0.026), less commonly had heart disease (p = 0.002) and previous stroke (p = 0.002), and had lower initial systolic blood pressure (p = 0.029) and lower levels of D-dimer (p = 0.041) than patients without dissection. Stroke onset more commonly followed physical exertion (p = 0.013) and headache (p = 0.041) in patients with dissection than in patients without dissection. At hospital discharge, the modified Rankin scale score was lower in patients with dissection than in patients without dissection (p = 0.005). Conclusions: Arterial dissection was the most common vascular lesion underlying an isolated ACA territory infarction in our Japanese cohort. Patients with ACA dissection had unique baseline characteristics and unique conditions at stroke onset.

To determine the frequency and clinical correlates of intra- and extracranial arterial occlusive lesions in a stroke-free population, we studied cerebral arteries in 156 subjects with no evidence of stroke who presented at a neurologic clinic with concerns about a possible stroke (104 males ranging in age from 37 to 83 years, with a mean age of 63.0) by using MR angiographies (MRAs). According to a validated rating scheme of MRAs for occlusive lesions, the degree of stenoses in the cervical portion of the carotid artery and of the intracranial arteries including the intracranial portion of the internal carotid artery, the middle cerebral artery stem, and the basilar artery were evaluated. Stenoses (>25% narrowing in diameter) were found in 18 patients (11.5%) in the cervical carotid artery, and in 23 patients (14.7%) in the intracranial arteries. Multiple logistic regression analysis showed that age and hyperlipidemia were significant and independent predictors for cervical carotid artery stenoses, and that age and hypertension were predictors for intracranial artery stenoses. Our data based on this special cohort of stroke-free patients suggested that the risk factors for extra- and intracranial artery lesions were different, and that MRA is possibly efficient in those patients in whom cerebral artery occlusive lesions may be suspected, e.g. in hyperlipidemic or hypertensive elderly. Larger population-based studies are needed to confirm these results.

A transient ischemic attack (TIA) is a medical emergency that is associated with a high risk of early ischemic stroke and other vascular events. Several evidence-based guidelines have been published to provide recommendations for the evaluation and treatment of patients with TIA. These guidelines underline the need for the urgent referral of patients with TIA so that they can access expert evaluation and immediate treatment. The distinction between TIA and ischemic stroke has recently become less important because these two conditions share pathophysiological mechanisms and many of the preventive approaches are applicable to both. Therefore, current guidelines are often described without a distinction between TIA and ischemic stroke. However, the applicability of recommendations for applying treatment for ischemic stroke to TIA has not been proven. Further studies are required to determine the effects of urgent intervention or treatment early after TIA.

We evaluated the usefulness of three-dimensional time-of-flight magnetic resonance angiography (3-D TOF MRA) in the estimation of carotid artery bifurcation stenosis by comparing it with conventional

To evaluate the accuracy of 3-dimensional time-of-flight magnetic resonance angiography (3D TOF MRA) for detecting intracranial arterial occlusive disease, this technique was compared with conventiona