Kyoungsub Kim

Mechanism of Medullary Infarction Based on Arterial Territory Involvement

Background and Purpose The blood supply to the medulla oblongata is distinct from that of other areas of the brainstem, and thus the mechanism underlying medullary infarctions may be distinct. However, few studies have investigated this. Methods Of 3833 stroke patients who were on the stroke registry between February 1999 and April 2008, those with medullary infarctions demonstrated on diffusion-weighted magnetic resonance imaging were enrolled. We analyzed the topography, the involved arterial territories, and the etiologic mechanisms of the lesions. Results In total, 142 patients were enrolled in the study. Bilateral medullary infarctions were rare (2.2%). Lesions involving the anteromedial or lateral territories were common in the upper medulla oblongata, whereas lateral territorial involvements were common in the middle and lower regions of the medulla oblongata. Significant stenosis (>50%) or occlusion of the vertebral artery was common (52.2%). Among stroke subtypes, large-artery atherosclerosis was most common (34.5%), while lacunae and cardioembolism were rare (3.5% and 4.2%, respectively). Vertebral artery dissection was frequent. The stroke mechanisms differed with the involved vascular territories. Large-artery atherosclerosis produced lesions in the lateral, anteromedial, and posterior territories. None of the cardioembolisms or other etiologies involved anteromedial or anterolateral territories, but all involved the lateral and/or posterior territories. Lacunar infarction was found only in the anteromedial and anterolateral territories. Conclusions The topography and mechanisms of infarctions involving the medulla oblongata are different with the involved arterial territories. These findings may be associated with the distinct pattern of arterial supply to the medulla oblongata.

Prevalence and patterns of anti‐nuclear antibodies in Korean children with juvenile idiopathic arthritis according to ILAR criteria

Objectives: To investigate the prevalence and patterns of anti‐nuclear antibodies (ANA) in different subtypes of juvenile idiopathic arthritis (JIA) according to the International League of Associations for Rheumatology (ILAR) criteria. Methods: One hundred and fifty‐three Korean patients (M:F 83:70) with JIA were followed between 1990 and 2006 and were tested for ANA by an indirect immunofluorescence method using HEp‐2 cells as the substrate. ANA tests were repeated in 37 patients during the course of the disease. The median age at onset was 7.5 years (range 0.8–15.9 years). Results: ANA were positive in 50 (33%) of the 153 patients at a dilution of 1:40 or higher (>1:40 in 70%, >1:80 in 2%, >1:160 in 16%, >1:320 in 2%, and >1:640 in 10%). The patterns of immunofluorescence staining were homogeneous in 50%, speckled in 38%, nucleolar in 8%, and centromere in 4%. ANA titres were decreased in 25 (68%) of the 37 patients, and the nuclear fluorescence patterns changed in 14 (38%) during follow‐up. ANA seropositivity was associated with female sex (p<0.0001), negative HLA‐B27 (p = 0.01), and a persistently elevated erythrocyte sedimentation rate (ESR) at follow‐up (p = 0.014). Furthermore, a high ANA titre (>1:160) was associated with a poor clinical outcome (active patients at follow‐up) (p = 0.005). Conclusions: ANA may be an important marker of disease activity in patients with JIA. ANA titres tend to decrease during disease remission but the fluorescence patterns do not appear to be related to disease activity or clinical outcome.

Histopathological findings of intracranial thrombi in nonbacterial thrombotic endocarditis

Kyoungsub Kim, Jayoung Kim, Seong Hwan Ahn, Woo Seok Ha, Yu Jin Koo, Dong Joon Kim, Hyo Suk Nam, Ji Hoe Heo Department of Neurology, Yonsei University College of Medicine, Seoul, Korea Department of Neurology, Mediplex Sejong Hospital, Incheon, Korea Severance Integrative Research Institute for Cerebral & Cardiovascular Disease, Yonsei University Health System, Seoul, Korea Department of Neurology, Chosun University School of Medicine, Gwangju, Korea Department of Radiology, Yonsei University College of Medicine, Seoul, Korea

Impact of white matter hyperintensities on the prognosis of cryptogenic stroke patients

Background To our knowledge, little is known regarding whether white matter hyperintensities (WMH) affect the prognosis of cryptogenic stroke (CS) patients. Understanding this association may be helpful with expecting the prognosis of CS patients. Methods This retrospective observational study enrolled consecutive CS patients who underwent brain MRI and comprehensive cardiac evaluation. Severe WMH was defined as Fazekas’ score ≥3. We defined poor functional outcome as modified Rankin Scale score ≥3 at 3 months. Long-term mortality and causes of death were identified using national death certificates and assessed by Kaplan-Meier method and regression analysis model. Results Among 2732 patients with first-ever ischemic stroke, 599 (21.9%) patients were classified as having CS. After exclusions, 235 patients were enrolled and followed up for a median of 7.7 years (IQR, 6.7–9.0). Severe WMH were found in 81 (34.5%) patients. After adjustments, severe WMH were an independent predictor for poor functional outcomes at 3 months (OR 5.25, 95% CI, 2.07–13.31). Subgroup analysis showed that severe WMH were an independent predictor for long-term mortality only in younger patients (age < 65) (HR 3.11, 95% CI, 1.29–7.50), but not in older patients (HR 1.19, 95% CI, 0.63–2.23). Conclusions Severe WMH were independently associated with short-term functional outcomes in CS patients and independently associated with long-term mortality in younger CS patients. Grading WMH is of value in predicting prognosis of CS patients with young age.

Delayed Intravenous Thrombolysis in Patients with Minor Stroke

Background: The actions and responses of the hospital personnel during acute stroke care in the emergency department (ED) may differ according to the severity of a patient’s stroke symptoms. We investigated whether the time from arrival at ED to various care steps differed between patients with minor and non-minor stroke who were treated with intravenous tissue plasminogen activator (IV tPA). Methods: We included consecutive patients who received IV tPA during a 1.5 year-period in 5 hospitals. Minor stroke was defined as a National Institutes of Health Stroke Scale (NIHSS) score < 5. We compared various intervals from arrival at the ED to treatment between patients with minor stroke and those with non-minor stroke (NIHSS score ≥5). Delayed treatment was defined as a door-to-needle time > 40 min. Results: During the study period, 356 patients received IV tPA treatment. The median door-to-needle time was significantly longer in the minor stroke group than it was in the non-minor stroke group (43 min [interquartile range [IQR] 35.5–55.5] vs. 37 min [IQR 30–46], p < 0.001). The minor stroke group had a significantly longer door-to-notification time (7 min [IQR 4.5–12] vs. 5 min [IQR 3–8], p < 0.001) and door-to-imaging time (20 min [IQR 15–26.5] vs. 16 min [IQR 11–21], p < 0.001) than did the non-minor stroke group. However, the imaging-to-needle time was not different between the groups. Multivariable analyses revealed that minor stroke was associated with delayed treatment (OR 2.54 [95% CI 1.52–4.30], p = 0.001). Conclusions: Our findings show that the door-to-needle time was longer in patients with minor stroke than it was in those with non-minor stroke, mainly owing to delayed action in the initial steps of neurology notification and imaging. Our findings suggest that some quality improvement initiatives are necessary for patients with suspected stroke with minor symptoms.

Differential impact of white matter hyperintensities on long-term outcomes in ischemic stroke patients with large artery atherosclerosis

Background The presence of white matter hyperintensity (WMH) is related to poor long-term outcomes in stroke patients. However, the long-term outcome is unknown in patients with both large artery atherosclerosis (LAA) and WMH. Methods We investigated the impact of WMH on long-term outcome in patients with LAA. Consecutive patients in a prospective stroke registry were included. Patients were followed for a median of 7.7 years (interquartile range, 5.6–9.7). The degree of WMH was assessed by Fazekas grade on fluid-attenuated inversion recovery images. Total WMH burden was calculated by summation of Fazekas scores in periventricular and deep white matter. Severe WMH was defined as total burden score ≥ 3. Results Among 2529 patients, 639 patients (25.3%) were classified with the LAA subtype. After applying exclusion criteria, the data from 538 patients were analyzed. The mean patient age was 65.7 ± 10.3 years. Severe WMHs were found in 243 patients (45.2%). During follow-up, 200 patients (37.2%) died. Cox regression analysis showed that LAA patients with severe WMH had a 1.50-fold (95% CI, 1.12–2.00, p = 0.007) higher death rate compared to those without. In the older age group (≥65 years), Cox regression revealed that patients with severe WMH had a 1.75-fold (95% CI, 1.15–2.65, p = 0.008) higher 5-year death rate, whereas the younger age group did not have this association. Conclusion The degree of WMH might be a surrogate marker for long-term outcome in patients with LAA. Atherosclerotic burdens in both small and large arteries might impact long-term prognosis in ischemic stroke patients.

Poor long-term outcomes in stroke patients with asymptomatic coronary artery disease in heart CT

BACKGROUND AND AIMS Although stroke patients have a high risk of ischemic heart disease, little information is available on the risk of coronary events in stroke patients with asymptomatic coronary artery disease (CAD). We investigated the long-term vascular outcomes in stroke patients with asymptomatic CAD diagnosed with multi-detector coronary computed tomography (MDCT). METHODS This study was a retrospective analysis using a prospective cohort of ischemic stroke patients. We included consecutive stroke patients without history or symptoms of CAD who underwent MDCT. We investigated the long-term risk of major adverse cardiovascular events (MACE: cardiovascular mortality, ischemic stroke, myocardial infarction, unstable angina, and urgent coronary revascularization) and composite of MACE/all-cause mortality/elective coronary revascularization. We further investigated the value of MDCT for MACE prediction. RESULTS Among the 1893 included patients, 1349 (71.3%) patients had some degree of CAD and 654 patients (34.5%) had significant (≥50%) CAD. At follow-up (median, 4.4 years), MACE occurred in 230 patients (12.2%). Event rates of MACE increased with the increasing extent of CAD. After adjustment for age, sex, and risk factors, the hazard ratios for MACE in mild CAD, 1-VD, 2-VD, and 3-VD or left main coronary disease were 1.28 (95% confidence interval [CI]: 0.88-1.87), 1.39 (95% CI: 0.90-2.16), 2.22 (95% CI: 1.39-3.55), and 2.91 (95% CI: 1.82-4.65), respectively (no CAD as a reference). Diagnosis of asymptomatic CAD significantly improved the prediction of MACE. CONCLUSIONS Asymptomatic CAD detected on MDCT was associated with increased risks of vascular events or deaths in acute stroke patients.