Hoo Won Kim

Interaction between Sleep-Disordered Breathing and Acute Ischemic Stroke

Background and Purpose Sleep-disordered breathing (SDB) is suggested to be strongly associated with ischemic strokes. Risk factors, stroke subtypes, stroke lesion distribution, and the outcome of SDB in stroke patients remain unclear in Korea. Methods We prospectively studied 293 patients (159 men, 134 women; age 68.4±10.5) with acute ischemic stroke. Cardiovascular risk factors, stroke severity, sleep-related stroke onset, distribution of stroke lesions, and 3-month score on the modified Rankin Scale (mRS) were assessed. Stroke severity was assessed by the US National Institutes of Health Stroke Scale (NIHSS) and the mRS. The apnea-hypopnea index (AHI) was determined 6.3±2.2 days after stroke onset with the Apnea Link portable sleep apnea monitoring device. Results The prevalence of SDB (defined as an AHI of ≥10) was 63.1% (111 men, 74 women). Those in the SDB group were older, had higher NIHSS and mRS scores, greater bulbar weakness, and a higher incidence of sleep-associated stroke onset. Among risk-factor profiles, alcohol consumption and atrial fibrillation were significantly related to SDB. The stroke outcome was worse in patients with SDB than in those without SDB. The lesion location and specific stroke syndrome were not correlated with SDB. Conclusions SDB is very common in acute cerebral infarction. Different risk-factor profiles and sleep-related stroke onsets suggest SDB as a cause of ischemic stroke. The higher NIHSS score and greater bulbar involvement in the SDB group seem to show the influence of ischemic stroke on the increased SDB prevalence.

Histologic features of acute thrombi retrieved from stroke patients during mechanical reperfusion therapy

Background The histologic features of thrombus may differ according to the stroke subtypes. However, in acute reperfusion therapy, fibrin-specific thrombolytics are used based on the assumption that all thrombi are alike. Aims The histologic characteristics of thrombi were compared between patients with different stroke etiologies. Methods Between April 2010 and March 2012, we analyzed thrombi retrieved from acute stroke patients during mechanical thrombectomy. All thrombi were analyzed using component-specific stains such as Martius scarlet blue for fibrins and immunostaining with CD42b antibody for platelets. The stroke subtypes were determined based on the Trial of ORG 10172 in Acute Stroke Treatment classification. Results Among 36 patients, 22 were diagnosed with cardioembolism, 8 with atherothrombosis, and 6 with undetermined etiology. In arteriogenic thrombi, red blood cells were most abundant (56.9 ± 12.2%), and the platelets covered the fibrin layers or were localized at the edge or periphery of the thrombus. In cardiogenic thrombi, fibrin was most abundant (39.5 ± 13.5%), and platelets were clustered within the rich fibrin. Red blood cells proportion was greater in arteriogenic thrombi than in cardiogenic thrombi (p < 0.001), whereas fibrin proportion was greater in cardiogenic thrombi than in arteriogenic thrombi (p = 0.003). Of six patients with undetermined etiology, the thrombi in five showed histologic features and composition similar to that of cardiogenic thrombi. Conclusions Acute thrombi showed different histologic features according to the stroke etiology. The distribution of platelets and proportion of red blood cells and fibrin were major distinguishing factors between stroke subtypes.

Arteriovenous Malformation with an Occlusive Feeding Artery Coexisting with Unilateral Moyamoya Disease

Background Arteriovenous malformations (AVMs) with vascular abnormalities, including aneurysms, have been reported frequently. However, the coexistence of AVM and unilateral moyamoya disease is rare. We report herein an AVM patient who presented with acute ischemic stroke with unilateral moyamoya disease and occlusion of the feeding artery. Case Report A-41-year old man was admitted with sudden dysarthria and facial palsy. Brain computed tomography and magnetic resonance imaging revealed an acute infarction adjacent to a large AVM in the right frontal lobe. Cerebral angiography revealed occlusions of the proximal right middle cerebral and proximal anterior cerebral arteries, which were the main feeders of the AVM. Innumerable telangiectatic moyamoya-type vessels between branches of the anterior cerebral artery and dilated lenticulostriate arteries on the occluded middle cerebral artery were detected. However, a nidus of the AVM was still opacified through the distal right callosomarginal artery, which was supplied by the remaining anterior cerebral artery and leptomeningeal collaterals from the posterior cerebral artery. Conclusions While AVM accompanied by unilateral moyamoya disease is rare, our case suggests an association between these two dissimilar vascular diseases.

Increased microbleeds after infective endocarditis in a patient with valvular replacement

A 35-year-old women with mechanical mitral valve replacement presented with fever followed by loss of consciousness. Brain magnetic resonance imaging showed left middle cerebral artery infarction with multiple microbleeds (Fig. 1a). Transesophageal echocardiography showed vegetation and blood culture was positive for Staphylococcus capitis. A parenteral antibiotic therapy was immediately started, and appropriate anticoagulation with warfarin was carried out (time in therapeutic range 68.9%). One year later, she experienced left hemiparesis, and the follow-up magnetic resonance imaging showed another right middle cerebral artery infarction with increased microbleeds during a relatively short period (Fig. 1b, arrows). In the case of a cerebral infarction as a result of septic emboli, there is a chance of septic erosion of the arterial wall caused by the embolus to increase microbleeds. As long-term anticoagulation increases the risk of intracerebral hemorrhage in patients with multiple microbleeds, it might be necessary to follow up magnetic resonance imaging including gradient echo imaging within short periods, especially in