The Effect of Pulsatility Index on Infarct Volume in Acute Lacunar Stroke

PURPOSE: Lacunar stroke, in the context of small vessel disease, is a type of cerebral infarction caused by occlusion of a penetrating artery. Pulsatility index (PI) is an easily measurable parameter in Transcranial Doppler ultrasound (TCD) study. PI reflects distal cerebral vascular resistance and has been interpreted as a surrogate marker of small vessel disease. We hypothesized that an increased PI, a marker of small vessel disease, might be associated with a larger infarct volume in acute lacunar stroke. MATERIALS AND METHODS: This study included 64 patients with acute lacunar stroke who underwent TCD and brain MRI. We evaluated the association between the mean PI value of bilateral middle cerebral arteries and infarct volume on diffusion-weighted MRI using univariate and multivariate linear regression. RESULTS: The mean infarct volume and PI were 482.18±406.40 mm3 and 0.86±0.18, respectively. On univariate linear regression, there was a significant positive association between PI and infarct volume (p=0.001). In the multivariate model, a single standard deviation increase of PI (per 0.18) was associated with an increase of 139.05 mm3 in infarct volume (95% confidence interval, 21.25 to 256.85; p=0.022). CONCLUSION: We demonstrated that PI was an independent determinant of infarct volume in acute lacunar stroke. The PI value measured in acute stroke may be a surrogate marker of the extent of ischemic injury.

Plasma Total Homocysteine Level Is Associated with the Pulsatility Index of Cerebral Arteries in Lacunar Infarction

PURPOSE: The pulsatility index (PI), measured by transcranial Doppler (TCD), is a surrogate marker for distal vascular resistance in cerebral arteries, and elevated plasma total homocysteine (tHcyt) is regarded as a cause of ischemic stroke, including lacunar infarction. We investigated the relationship between the PI of cerebral arteries and plasma tHcyt in patients with lacunar infarction. MATERIALS AND METHODS: Plasma tHcyt level and TCD examination were performed in 94 patients with lacunar infarction. Mean flow velocity (MFV) and PI were assessed at the ipsilateral middle cerebral artery (MCA) and contralateral MCA, relative to the infarction, and the basilar artery (BA). Multivariate regression analysis was conducted between log-transformed tHcyt levels (logHcyt) and the PI of individual arteries. RESULTS: There was a significant correlation between logHcyt and the PI in all tested arteries (ipsilateral MCA: r=0.21, p=0.03; contralateral MCA: r=0.21, p=0.04; BA: r=0.35, p=0.01). In multivariate regression analysis, this significance remained unchanged after adjusting for vascular risk factors, creatinine, hematocrit and platelet count (ipsilateral MCA: beta=0.26, p=0.01; contralateral MCA: beta=0.21, p=0.04; BA: beta=0.39, p=0.001). There was no significant association between logHcyt and MFV of individual arteries. CONCLUSION: A significant association between plasma tHcyt and the PI of cerebral arteries indicates that homocysteine plays a role in the increase of distal arterial resistance in lacunar infarction.

Analysis of an Association between Single Nucleotide Polymorphisms of Vascular Endothelial Growth Factor Gene and Risk of Cerebral White Matter Lesion

BACKGROUND: Endothelial dysfunction is suggested to be one of the pathogenesis of cerebral white matter lesion (cWML). Vascular endothelial growth factor (VEGF) plays a crucial role in angiogenesis and integrity of vascular endothelial cell, and altered expression of VEGF gene induces vascular diseases including cerebrovascular diseases. The objective of this study is to investigate whether single nucleotide polymorphism (SNP) of VEGF gene confers an increased risk of cWML. METHODS: Total 337 study subjects without history of stroke were included. The presence and severity of cWML were measured on fluid-attenuated inversion recovery image. Genotypes of VEGF -2578G>A, -1154G>A, -634G>C and +936C>T were analyzed. RESULTS: Among 337 study subjects, cWML was found in 208 patients (62%), and fifty-eight cases (17%) of them had overt cWML. In univariate analysis, age, female sex and plasma total homocysteine level (tHcyt) were higher in the mild and overt cWML group than no cWML group (p<0.05). The percentage of previous history of hypertension and the value of systolic blood pressure were higher in overt cWML group than no cWML group. In univariate and logistic regression analysis, none of four tested VEGF SNPs was significantly different between control group, mild and overt cWML groups. There was no difference between plasma tHcyt levels and each VEGF SNPs in control group and cWML groups. CONCLUSIONS: In this study, old age, female sex, hypertension and plasma tHcyt were associated with cWML. However, we failed to find an association between cWML and VEGF gene polymorphism, which may indicate that genetic polymorphism of VEGF does not play a direct role in the pathogenesis of cWML.

Association between Single Nucleotide Polymorphisms of alpha2A-, alpha2B-, and alpha2C-Adrenergic Receptor Genes and Risk of Cerebral White Matter Lesion / 대한뇌졸중학회지

BACKGROUND: An alpha2-adrenergic receptor (alpha2-AR, ADRA2) mediates induction of hypotension and inhibition of lipolysis and insulin secretion. We evaluated whether single nucleotide polymorphisms (SNPs) of alpha2A (ADRA2A), alpha2B (ADRA2B), and alpha2C (ADRA2C) adrenergic receptors are associated with cerebral white matter lesion (cWML). METHODS: Total 336 study subjects who had no stroke were enrolled in this study. The Indices of cWML include total WML (TWML), periventricular WML (PVWML), and subcortical WML (SCWML) on brain fluid-attenuated inversion recovery (FLAIR) image. Common genetic variants of ADRA2A (1780G>A), ADRA2B (Ins/Del301-303), and ADRA2C (Ins/Del322-325) were examined. RESULTS: Among 336 study subjects, cWML was found in 66 patients (20%). In multivariate analysis, there were no significant effects of all tested ADRA2 polymorphisms on TWML. Significant association of ADRA2A 1780 AA genotype was found in PVWML (OR: 3.368, 95% CIs: 1.280-8.865, adjusted p-value after false discovery rate (FDR) correction=0.014) but not SCWML. CONCLUSION: Although SNPs of three ADRA2 subtypes failed to reach a significance in overall risk for cWML, the ADRA2A 1780G>A polymorphism may be associated with development of PVWML.

Chronic Inflammatory Demyelinating Polyradiculoneuropathy in a Patient with Chronic Hepatitis C after Alpha-Interferon Treatment

No abstract available.

Orbital Myositis of the Lateral Rectus Muscle Presenting With Adduction Impairment

No abstract available.