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Hyung-Min Kwon

Publications and source records attributed to Hyung-Min Kwon.

9 recordsLinked to original sources
PubMed2006

Retinopathy as an indicator of silent brain infarction in asymptomatic hypertensive subjects.

BACKGROUND AND PURPOSE: Silent brain infarction (SBI), which is cerebral target organ damage of hypertensive microangiopathies, is frequently seen in hypertensive patients. The purpose of this study is to investigate the relation between hypertensive retinopathy (HTR) and SBI in subjects without a history of stroke or transient ischemic attack. METHODS: Five hundred-fifty hypertensive subjects without history of stroke or transient ischemic attack had brain MRI and retinal photographs taken. The presence of SBI was assessed from the MRI scans, which was defined as a lesion of at least 3 mm in diameter with typical imaging characteristics. The presence HTR was defined from digitized retinal photographs. RESULTS: Seventy-seven subjects (14%) showed HTR (grade 1 in 46, grade 2 in 31 persons). A multivariate analysis showed that age (OR, 1.07; 95% CI, 1.03 to 1.10) and HTR (OR, 2.01 for grade 1; OR, 3.03 for grade 2) were the independent indicators for the presence of SBI. The higher the grade of HTR, the more prevalent SBI than persons with normal retina (by linear by linear association test, p=0.001). CONCLUSION: HTR is associated with the presence of SBI. This finding suggests that retinal photography may be useful for identifying hypertensive subjects at increased risk of having SBI regardless of current blood pressure status.

Aged↗
PubMed2006

Mild left ventricular dysfunction is associated with thrombogenicity in cardioembolic stroke.

BACKGROUND: Transesophageal echocardiography (TEE) has been recognized as a valuable tool for identifying the left cardiac thrombus (LCT) or spontaneous echocardiographic contrast (SEC). We aimed to identify risk groups where TEE should be performed in patients with suspected cardioembolic stroke according to magnetic resonance imaging analysis. METHODS: One hundred and forty-six patients (mean age 64.7 +/- 11.8 years, 101 males) with suspected cardioembolic stroke were analyzed. We used TEE for the presence of LCT and/or SEC as indication of thrombogenicity. We evaluated the association between thrombogenicity and demographic features, stroke risk factors and echocardiographic variables. RESULTS: The study included 40 patients (27.3%) who showed thrombogenicity (10 LCT and 30 SEC). The independent echocardiographic variables of thrombogenicity were atrial fibrillation (OR 7.14; 95% CI 2.62-19.48; p < 0.001) and left ventricular ejection fraction </=50% (OR 4.01; 95% CI 1.40-11.49; p = 0.01). CONCLUSION: We recommend that TEE should be considered in patients with mildly reduced left ventricular dysfunction (ejection fraction </=50%) after suspected cardioembolic stroke.

Atrial Fibrillation↗
PubMed2006

A case of Bickerstaff's brainstem encephalitis; the evidence of cerebellum involvement by SPM analysis using PET.

Although the clinical manifestations such as drowsiness, brisk reflexes, extensor plantar responses and hemisensory disturbance usually are considered to suggest Bickerstaff's brainstem encephalitis (BBE) rather than Miller Fisher syndrome (MFS), the nosological relationship between BBE and MFS has yet to be established. Herein, we report upon a 58-year-old man who showed ophthalmoplegia, ataxia and consciousness disturbance. In the absence of any abnormality on brain MRI, electrophysiological studies and SPM analysis using (18)F-FDG PET showed evidence of brainstem and cerebellum involvements.

Ataxia↗
PubMed2005

Metabolic syndrome as an independent risk factor of silent brain infarction in healthy people.

BACKGROUND AND PURPOSE: Metabolic syndrome (MetS) is associated with an increased risk of the subsequent development of cardiovascular disease or stroke. Moreover, a silent brain infarction (SBI) can predict clinical overt stroke or dementia. We examined the associations between SBI and MetS in apparently healthy individuals. METHODS: We evaluated 1588 neurologically healthy subjects (927 males and 661 females) who underwent brain MRI at Seoul National University Hospital Healthcare System Gangnam Center. MetS was defined using the criteria of the National Cholesterol Education Program Adult Treatment Panel III. We examined associations between full syndrome (> or =3 of the 5 conditions) as well as its components and SBI by controlling possible confounders. RESULTS: Eighty-eight (5.5%) were found to have > or =1 SBI on MRI. Age was found to be significantly related to SBI prevalence (odds ratio [OR], 1.06; 95% CI, 1.04 to 1.09). A history of coronary artery disease was associated with an elevated odds ratio of SBI (OR, 2.83; 95% CI, 1.38 to 5.82), and MetS was significantly associated with SBI (OR, 2.18; 95% CI, 1.38 to 3.44). The components model of MetS showed a strong significance between an elevated blood pressure (OR, 3.75; 95% CI, 2.05 to 6.85) and an impaired fasting glucose (OR, 1.74; 95% CI, 1.08 to 2.80) and the risk of SBI. CONCLUSIONS: MetS was found to be significantly associated with SBI. This finding has clinical utility in terms of identifying healthy people at increased risk of developing SBI.

Adult↗
PubMed2005

Transcranial Doppler sonography evaluation of anterior cerebral artery hypoplasia or aplasia.

BACKGROUND AND PURPOSE: Transcranial Doppler (TCD) sonography is useful to evaluate intracranial arteries, however, interpretation of the TCD results in anterior cerebral artery (ACA) is difficult because of hypoplasia or aplasia. We try to define useful TCD indices and cut-off values to determine the variations of ACA. METHODS: Consecutive patients who underwent TCD and magnetic resonance angiography (MRA) were included. Patients with cerebrovascular abnormality or inadequate temporal windows were excluded. ACA status was classified as normal (NL), hypoplasia (HP), and aplasia (AP) according to MRA. TCD indices of mean flow velocity (MFV), pulsatility index (PI), ACA/middle cerebral artery (MCA) flow velocity ratio (ACA/MCA FVR), and asymmetry index (AI) of ACA were blindly compared with MRA between three groups. RESULTS: Two hundred and forty-one patients were included, and 193 patients (80%) were classified as NL, 34 (14%) as HP and 14 (6%) as AP. MFV was significantly lower in HP and AP (p<0.001), however, PI and ACA/MCA FVR were not different. AI was significantly different between NL and HP (21.5% vs. 50.4%), NL and AP (21.5% vs. 105.2%) (p<0.001). CONCLUSIONS: MFV of ACA should be interpreted with caution for its frequent anatomical variations. AI is useful to differentiate hypoplasia and aplasia from normal ACA with optimal criteria.

Adult↗
PubMed2004

Effects of hsp70.1 gene knockout on the mitochondrial apoptotic pathway after focal cerebral ischemia.

BACKGROUND AND PURPOSE: Murine heat-shock protein 70 (HSP70) protein, which is produced from 2 genes, hsp70.1 and hsp70.3, is known to protect the brain against ischemic injury. However, little information is available on the antiapoptotic mechanism of HSP70.1 protein after cerebral ischemia. To evaluate the role of HSP70.1 protein in ischemia, we analyzed the mitochondrial apoptotic pathway using hsp70.1 knockout (KO) mice and their wild-type (WT) mice. METHODS: hsp70.1 KO and WT mice underwent focal ischemia for 120 minutes. DNA fragmentation was evaluated by TUNEL staining. Cytochrome c release and the activation of caspase-3 were analyzed by Western blotting and immunohistochemistry. RESULTS: hsp70.1 mRNA was not detected in hsp70.1 KO mice after ischemia, and HSP70 protein expression was markedly suppressed versus WT mice. KO mice showed a significantly greater infarction volume and DNA fragmentation in the cortex than WT mice at 24 hours after ischemia. At 8 hours, cytochrome c release into the cytoplasm was markedly higher in KO mice than in WT mice. Caspase-3 activation was also significantly enhanced in KO mice versus WT mice, as evidenced by higher levels of activated caspase-3 and cleaved gelsolin. CONCLUSIONS: These findings suggest that the deletion of the hsp70.1 gene increases cytochrome c release into the cytoplasm and subsequent caspase-3 activation, thereby exacerbating apoptosis after focal cerebral ischemia.

Animals↗
PubMed2003

A case of multiple brain infarctions associated with Erysipelothrix rhusiopathiae endocarditis.

A 63-year-old woman was admitted to our hospital because of fever and altered mentality. Brain magnetic resonance imaging showed multiple infarctions at the basal ganglia, cerebellum, and subcortical white matter with petechial hemorrhage, which was more easily seen on gradient echo images. Erysipelothrix rhusiopathiae was cultured from her blood, and echocardiography showed septic vegetations in the mitral valve. She recovered fully after 6 weeks of appropriate antibiotic treatment.

Brain Infarction↗