The intron 4c allele of the NOS3 gene is associated with ischemic stroke in African Americans.

BACKGROUND: Ischemic stroke is the most common cause of disability in North America and in addition to the generally accepted risk factors, there is increasing evidence for the potential pathophysiological role of genes. One of these genes, the endothelial nitric oxide synthase gene (NOS3) has been reported as a genetic risk factor for ischemic stroke. To independently confirm and extend the results of these previous reports, we investigated this gene as a risk factor for stroke in an ethnically diverse study population. METHODS: Using the TOAST classification, we characterized and studied 377 patients with ischemic stroke. We genotyped two common variants in the NOS3 gene, the intron 4 insertion/deletion and an exonic single nucleotide polymorphism (SNP), G894T, in these patients and compared them with 502 controls. Chi-square or Fisher's exact tests were used to examine allele effects on stroke and stroke subtypes. Logistic regression analysis was used to adjust for confounding covariate effects. RESULTS: All genotypes are in Hardy-Weinberg equilibrium except for intron 4c, which is overrepresented in ischemic stroke patients. In pooled analysis of all patients, intron 4c, but not intron 4a, intron 4b or G894T alleles are associated with stroke (p < 0.01). In subgroup analysis by race, the intron 4c allele is most strongly associated with large artery ischemic stroke in African Americans (p < 0.01). CONCLUSION: We are unable to confirm previous reports of an association of the intron 4a or the G894T alleles with ischemic stroke. However, although limited by a relatively small sample size, our study suggests a potentially important role of the intron 4c allele as a genetic marker of ischemic stroke in African Americans.

Cerebrovascular disease among patients from the Indian subcontinent.

In this study, the authors document the characteristics of South Asian (SA) cerebrovascular patients. A retrospective medical record review comparing SA (n = 99) and European-American (n = 106) patients was performed. SA patients were younger and had a greater prevalence of diabetes, but lower prevalences of hyperlipidemia and tobacco use. SA patients experienced a 75% lower risk of cardiogenic infarctions, but a threefold increased risk of intracranial atherothrombosis. Risk factor modifications and secondary prevention strategies may differ for SA patients.

MRI-guided, open trial of abciximab for ischemic stroke within a 3- to 24-hour window.

The authors assessed the effect of IV abciximab on early neurologic improvement and ischemic lesion growth in 29 patients with supratentorial stroke and NIH stroke scale score (NIHSSS) > or = 4 (11.1 +/- 5.9), treated within 3 to 24 (13.6 +/- 5.5) hours of onset. The 48 to 72-hour NIHSSS improvement was 4.4 +/- 3.2 and the 24-hour lesion growth on DWI was +23% (-50%, +103%); 7/26 (27%) patients experienced lesion size decrease. Treatment of sub-24-hour stroke with abciximab improves early post-treatment neurologic status and often attenuates ischemic lesion growth.

Plaque morphology correlates with cerebrovascular symptoms in patients with complex aortic arch plaque.

BACKGROUND: Studies of aortic arch plaques with transesophageal echocardiography have demonstrated that complex aortic arch plaques (CAPs) greater than or equal to 4 mm in thickness are associated with ischemic stroke. Recent studies have demonstrated that the morphological features of plaques may aid in the identification of aortic plaques that are more likely to be associated with embolic stroke. OBJECTIVE: To identify aortic plaques that are more likely to be associated with embolic stroke by means of their morphological features. METHODS: Transcutaneous B-mode ultrasonography was used to image aortic arch plaques in 500 consecutive patients. The criteria used to identify the morphological features of carotid artery plaques that are more likely to be associated with ischemic stroke (heterogeneous rather than homogeneous) were applied to aortic arch plaques. Statistical comparisons were made using the Fisher exact test. RESULTS: Ischemic symptoms (eg, stroke, transient ischemic attack, and amaurosis fugax) were present in 38% of 104 patients with CAP and in 34% of 391 patients without CAP. Nineteen (51%) of 37 patients with heterogeneous CAP were symptomatic. Twenty-one (31%) of 67 patients with homogeneous CAP were symptomatic (P = .04). CONCLUSION: Transcutaneous B-mode ultrasonography of the aortic arch can help to identify heterogeneous plaques that are more likely to be associated with ischemic stroke using morphological criteria derived from studies of carotid artery plaque.

Benign angioedema after thrombolysis for acute stroke.

We present a case of acute angioedema after administration of recombinant tissue plasminogen activator (t-PA) for acute ischemic stroke. Our patient was treated with t-PA in accordance with the National Institute of Neurological Disorders and Stroke (NINDS) protocol, and subsequently developed angioedema of the lower lip that subsided within 2 hours. Five patients who required upper airway control after the use of t-PA for ischemic stroke have been reported in the literature. Although the outcome in our case was excellent, development of angioedema after t-PA administration is a potential complication of which treating physicians need to be aware.