Background and PurposeThe absence of acute ischemic lesions in diffusion-weighted imaging (DWI) in transient ischemic attack (TIA) patients makes it difficult to diagnose the true vascular etiologies. Among patients with DWI-negative TIA, we investigated whether the presence of a perfusion-weighted imaging (PWI) abnormality implied a true vascular event by identifying new acute ischemic lesions in follow-up magnetic resonance imaging (MRI) in areas corresponding to the initial PWI abnormality.MethodsThe included patients underwent DWI and PWI within 72 hours of TIA and also follow-up DWI at 3 days after the initial MRI. These patients had visited the emergency room between July 2009 and May 2015. Patients who demonstrated initial DWI lesions were excluded. The initial PWI abnormalities in the corresponding vascular territory were visually classified into three patterns: no abnormality, focal abnormality, and territorial abnormality.ResultsNo DWI lesions were evident in initial MRI in 345 of the 443 TIA patients. Follow-up DWI was applied to 87 of these 345 DWI-negative TIA patients. Initial PWI abnormalities were significantly associated with follow-up DWI abnormalities: 8 of 43 patients with no PWI abnormalities (18.6%) had new ischemic lesions, whereas 13 of 16 patients with focal perfusion abnormalities (81.2%) had new ischemic lesions in the areas of initial PWI abnormalities [odds ratio (OR)=15.1, 95% confidence interval (CI)=3.6–62.9], and 14 of 28 patients with territorial perfusion abnormalities (50%) had new lesions (OR=3.7, 95% CI=1.2–11.5).ConclusionsPWI is useful in defining whether or not the transient neurological symptoms in DWI-negative TIA are true vascular events, and will help to improve the understanding of the pathomechanism of TIA.

Background: Lateral medullary infarction (LMI) is not an uncommon disease. Although lesions are usually restricted to the lateral medullary area, some patients have additional infarcts in other parts of the brain. The clinical features and prognosis of isolated LMI (pure LMI, LMIpr) have been investigated. However, it remains unclear whether clinical characteristics, prognosis and factors associated with prognosis differ between patients with LMIpr and those with additional lesions (LMI plus, LMIpl). Methods: Patients with LMI identified by MRI were enrolled. The demographic and clinical characteristics, in-hospital outcome (intensive care unit [ICU] admission, pneumonia and modified Rankin scale [mRS] at discharge), and long-term residual symptoms (vertigo/dizziness, sensory disturbances, dysphagia) and outcomes (occurrence of stroke, acute coronary syndrome [ACS], death, and mRS at follow-up) were compared between LMIpr and LMIpl patients. Factors associated with poor functional outcome (mRS 2–6) at the follow-up were analyzed. Results: Among 248 LMI patients, 161 (64.9%) had LMIpr and 87 (35.1%) had LMIpl. During admission, patients with LMIpl more frequently experienced ICU care, pneumonia and had a higher discharge mRS (3 vs. 2; p < 0.001) than LMIpr patients. The occurrence of stroke, ACS, frequency of death and functional outcome was not different during follow-up. However, residual neurologic symptoms such as dizziness (p = 0.002), dysphagia (p = 0.04) and sensory symptoms (p < 0.001) were more frequent in LMIpr than in LMIpl patients. In LMIpr patients, the rostral location of LMI was associated with poor functional outcome (p = 0.041), whereas in LMIpl patients, the presence of medial posterior-inferior cerebellar artery lesion was associated with good functional outcome (p = 0.030). Conclusion: Although the short-term outcome is poorer in LMIpl than LMIpr patients, long-term residual symptoms are more common in LMIpr patients. The location of the LMI and extra-medullary lesion affects the long-term functional outcome of LMIpr and LMIpl patients respectively.

The new PSMS grading system for patients with VCM correlated well with the previously used systems and included pain evaluation. This new grading system is an easy tool for the evaluation and comparison of outcomes before and after endovascular treatment.

Identification of a symptomatic aneurysm should be associated with clinical presentation pattern. Targeted obliteration of the aneurysm by embolization and/or surgery resulted in improvement of symptoms and stabilization of SAVM.

Background: Intracranial artery dissection (IAD) is gaining recognition as an important cause of stroke, but limited information is available about the morphology of the dissection. This study aimed to investigate the relationship between acute cerebral infarctions and the shape of hematoma in patients with IADs using high-resolution magnetic resonance imaging (HRMRI). Methods: We enrolled consecutive patients who presented with vascular headaches, transient ischemic attacks, or ischemic strokes with acute IAD confirmed by HRMRI using key pathognomonic radiological findings of IAD, including intimal flap, intramural hematoma (IMH), and double lumen. All patients were enrolled and HRMRI was performed, both within 7 days of symptom onset. All patients with acute ischemic infarction within 7 days were enrolled. Patients were divided into 2 groups: those with a proximal dominant intramural hematoma (PIMH) and those with a distal dominant intramural

Background: The stroke mechanism for anterolateral pontine infarction (ALPI) is poorly understood. We aimed to investigate the perforator arteries relevant to ALPI using high-resolution MRI (HR-MRI). Methods: Of 62 patients with ALPI who were admitted to the Asan Medical Center, 13 patients agreed to participate in this study. We used HR-MRI with a 3-Tesla scanner and assessed the perforating branches directly connected with the infarcted area. Results: Perforating arteries penetrating ALPI were identified in all 13 patients. Perforators arising from the basilar artery (BA) were involved in the stroke mechanism in 9 patients, the superior cerebellar artery (SCA) perforator in 1 patient, and the anterior inferior cerebellar artery perforator in 1 patient. In 2 patients, both BA and SCA perforators were involved. Conclusions: Using 3-Tesla HR-MRI may allow visualization of the perforating branches presumably related to ALPI. Identification of the relevant cerebral perforating arteries may help us to understand the stroke mechanism in patients with posterior circulation territory infarction.

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