Affected twins in the familial intracranial aneurysm study.

BACKGROUND AND PURPOSE: Very few cases of intracranial aneurysms (IAs) in twins have been reported. Previous work has suggested that vulnerability to IA formation is heritable. Twin studies provide an opportunity to evaluate the impact of genetics on IA characteristics, including IA location. We therefore sought to examine IA location concordance, multiplicity, and rupture status within affected twin-pairs. METHODS: The Familial Intracranial Aneurysm study was a multicenter study whose goal was to identify genetic and other risk factors for formation and rupture of IAs. The study required at least three affected family members or an affected sibling pair for inclusion. Subjects with fusiform aneurysms, an IA associated with an AVM, or a family history of conditions known to predispose to IA formation, such as polycystic kidney disease, Ehlers-Danlos syndrome, Marfan syndrome, fibromuscular dysplasia, or moyamoya syndrome were excluded. Twin-pairs were identified by birth date and were classified as monozygotic (MZ) or dizygotic (DZ) through DNA marker genotypes. In addition to zygosity, we evaluated twin-pairs by smoking status, major arterial territory of IAs, and rupture status. Location concordance was defined as the presence of an IA in the same arterial distribution (ICA, MCA, ACA, and vertebrobasilar), irrespective of laterality, in both members of a twin-pair. The Fisher exact test was used for comparisons between MZ and DZ twin-pairs. RESULTS: A total of 16 affected twin-pairs were identified. Location concordance was observed in 8 of 11 MZ twin-pairs but in only 1 of 5 DZ twin-pairs (p = 0.08). Three MZ subjects had unknown IA locations and comprised the three instances of MZ discordance. Six of the 11 MZ twin-pairs and none of the 5 DZ twin-pairs had IAs in the ICA distribution (p = 0.03). Multiple IAs were observed in 11 of 22 MZ and 5 of 10 DZ twin-pairs. Thirteen (13) of the 32 subjects had an IA rupture, including 10 of 22 MZ twins. CONCLUSIONS: We found that arterial location concordance was greater in MZ than DZ twins, which suggests a genetic influence upon aneurysm location. The 16 twin-pairs in the present study are nearly the total of affected twin-pairs that have been reported in the literature to date. Further studies are needed to determine the impact of genetics in the formation and rupture of IAs.

Genome-wide association study of intracranial aneurysm identifies a new association on chromosome 7.

BACKGROUND AND PURPOSE: Common variants have been identified using genome-wide association studies which contribute to intracranial aneurysms (IA) susceptibility. However, it is clear that the variants identified to date do not account for the estimated genetic contribution to disease risk. METHODS: Initial analysis was performed in a discovery sample of 2617 IA cases and 2548 controls of white ancestry. Novel chromosomal regions meeting genome-wide significance were further tested for association in 2 independent replication samples: Dutch (717 cases; 3004 controls) and Finnish (799 cases; 2317 controls). A meta-analysis was performed to combine the results from the 3 studies for key chromosomal regions of interest. RESULTS: Genome-wide evidence of association was detected in the discovery sample on chromosome 9 (CDKN2BAS; rs10733376: P<1.0×10(-11)), in a gene previously associated with IA. A novel region on chromosome 7, near HDAC9, was associated with IA (rs10230207; P=4.14×10(-8)). This association replicated in the Dutch sample (P=0.01) but failed to show association in the Finnish sample (P=0.25). Meta-analysis results of the 3 cohorts reached statistical significant (P=9.91×10(-10)). CONCLUSIONS: We detected a novel region associated with IA susceptibility that was replicated in an independent Dutch sample. This region on chromosome 7 has been previously associated with ischemic stroke and the large vessel stroke occlusive subtype (including HDAC9), suggesting a possible genetic link between this stroke subtype and IA.

Familial intracranial aneurysms: is anatomic vulnerability heritable?

BACKGROUND AND PURPOSE: Previous studies have suggested that family members with intracranial aneurysms (IAs) often harbor IAs in similar anatomic locations. IA location is important because of its association with rupture. We tested the hypothesis that anatomic susceptibility to IA location exists using a family-based IA study. METHODS: We identified all affected probands and first-degree relatives (FDRs) with a definite or probable phenotype in each family. We stratified each IA of the probands by major arterial territory and calculated each family's proband-FDR territory concordance and overall contribution to the concordance analysis. We then matched each family unit to an unrelated family unit selected randomly with replacement and performed 1001 simulations. The median concordance proportions, odds ratios (ORs), and P values from the 1001 logistic regression analyses were used to represent the final results of the analysis. RESULTS: There were 323 family units available for analysis, including 323 probands and 448 FDRs, with a total of 1176 IAs. IA territorial concordance was higher in the internal carotid artery (55.4% versus 45.6%; OR, 1.54 [1.04-2.27]; P=0.032), middle cerebral artery (45.8% versus 30.5%; OR, 1.99 [1.22-3.22]; P=0.006), and vertebrobasilar system (26.6% versus 11.3%; OR, 2.90 [1.05-8.24], P=0.04) distributions in the true family compared with the comparison family. Concordance was also higher when any location was considered (53.0% versus 40.7%; OR, 1.82 [1.34-2.46]; P<0.001). CONCLUSIONS: In a highly enriched sample with familial predisposition to IA development, we found that IA territorial concordance was higher when probands were compared with their own affected FDRs than with comparison FDRs, which suggests that anatomic vulnerability to IA formation exists. Future studies of IA genetics should consider stratifying cases by IA location.

Apolipoprotein E, statins, and risk of intracerebral hemorrhage.

BACKGROUND AND PURPOSE: Apolipoprotein E (ApoE) genotypes have been associated with lobar intracerebral hemorrhage (ICH). Although statins have been associated with an increased risk of ICH, meta-analyses have not consistently shown a statin-induced risk of ICH. Here, we test whether hypercholesterolemia (HC) and ApoE polymorphisms affect the risk of ICH by statin use. METHODS: The Genetic and Environmental Risk Factors for Hemorrhagic Stroke (GERFHS) study is a prospective, demographically matched case-control study of ICH. A similar study of ICH, Genetic Risks for Medication-Related Hemorrhagic Stroke (GOCHA), was used as a replication cohort. Subjects were classified as normocholesterolemia, HC without statin use, and HC with statin use. Statistical comparisons were performed using Fisher exact test, χ2 tests, and the Breslow-Day test. RESULTS: The discovery cohort consisted of 558 ICH cases and 1444 controls, and the replication cohort consisted of 1020 ICH cases and 382 controls. The association of lower risk for HC was not attenuated by statin use. Statin use was observed to confer a higher risk for lobar ICH in those carrying ApoE4/E4 and ApoE2/E4 genotypes in both discovery and replication cohorts, and a test for interaction showed a trend towards significance (P=0.11 for statin and ApoE4/E4). CONCLUSIONS: Statin use does not seem to attenuate the association of HC with decreased risk for nonlobar ICH. Our data support a gene-by-drug effect for lobar ICH, but larger sample sizes are needed to confirm the association before any clinical change is warranted. CLINICAL TRIAL REGISTRATION URL: http://clinicaltrials.gov. Unique identifier: NCT00930280.

Genome-wide association study of intracranial aneurysms confirms role of Anril and SOX17 in disease risk.

BACKGROUND: Genomewide association studies have identified novel genetic factors that contribute to intracranial aneurysm (IA) susceptibility. We sought to confirm previously reported loci, to identify novel risk factors, and to evaluate the contribution of these factors to familial and sporadic IA. METHOD: We utilized 2 complementary samples, one recruited on the basis of a dense family history of IA (discovery sample 1: 388 IA cases and 397 controls) and the other without regard to family history (discovery sample 2: 1095 IA cases and 1286 controls). Imputation was used to generate a common set of single nucleotide polymorphisms (SNP) across samples, and a logistic regression model was used to test for association in each sample. Results from each sample were then combined in a metaanalysis. RESULTS: There was only modest overlap in the association results obtained in the 2 samples. In neither sample did results reach genomewide significance. However, the metaanalysis yielded genomewide significance for SNP on chromosome 9p (CDKN2BAS; rs6475606; P=3.6×10(-8)) and provided further evidence to support the previously reported association of IA with SNP in SOX17 on chromosome 8q (rs1072737; P=8.7×10(-5)). Analyses suggest that the effect of smoking acts multiplicatively with the SNP genotype, and smoking has a greater effect on risk than SNP genotype. CONCLUSIONS: In addition to replicating several previously reported loci, we provide further evidence that the association on chromosome 9p is attributable to variants in CDKN2BAS (also known as ANRIL, an antisense noncoding RNA).

The relationship between smoking and replicated sequence variants on chromosomes 8 and 9 with familial intracranial aneurysm.

BACKGROUND AND PURPOSE: The purpose of this study was to replicate the previous association of single nucleotide polymorphisms (SNPs) with risk of intracranial aneurysm (IA) and to examine the relationship of smoking with these variants and the risk of IA. METHODS: White probands with an IA from families with multiple affected members were identified by 26 clinical centers located throughout North America, New Zealand, and Australia. White control subjects free of stroke and IA were selected by random digit dialing from the Greater Cincinnati population. SNPs previously associated with IA on chromosomes 2, 8, and 9 were genotyped using a TaqMan assay or were included in the Affymetrix 6.0 array that was part of a genomewide association study of 406 IA cases and 392 control subjects. Logistic regression modeling tested whether the association of replicated SNPs with IA was modulated by smoking. RESULTS: The strongest evidence of association with IA was found with the 8q SNP rs10958409 (genotypic P=9.2x10(-5); allelic P=1.3x10(-5); OR=1.86, 95% CI: 1.40 to 2.47). We also replicated the association with both SNPs on chromosome 9p, rs1333040 and rs10757278, but were not able to replicate the previously reported association of the 2 SNPs on chromosome 2q. Statistical testing showed a multiplicative relationship between the risk alleles and smoking with regard to the risk of IA. CONCLUSIONS: Our data provide complementary evidence that the variants on chromosomes 8q and 9p are associated with IA and that the risk of IA in patients with these variants is greatly increased with cigarette smoking.

Genome screen to detect linkage to common susceptibility genes for intracranial and aortic aneurysms.

BACKGROUND AND PURPOSE: Risk for both intracranial aneurysms (IAs) and aortic aneurysms (AAs) is thought to be heritable with mounting evidence for genetic predisposition. The concept of shared risk for these conditions is challenged by differences in age of diagnosis and demographic characteristics. We performed a genomewide linkage analysis in multiplex families with both IA and AA from the Familial Intracranial Aneurysm study. METHODS: Available medical records of subjects who reported IA or abdominal/thoracic AA were reviewed with adjudication as definite/probable, possible, or not a case. To identify genes contributing to the susceptibility for IA and AA, genomewide linkage analysis was performed in the 26 multiplex IA families who had members who also had thoracic or abdominal AA. Individuals (n=91) were defined as affected if they had an IA (definite/probable) or an aortic or thoracic AA (definite/probable). RESULTS: Maximum logarithm of odds (LOD) scores were found on chromosomes 11 (144 cM; LOD=3.0) and 6 (33 cM; LOD=2.3). In both chromosomal regions, analyses of these same 26 families considering only IA as the disease phenotype produced LOD scores of 1.8 and 1.6, respectively. CONCLUSIONS: Our linkage analysis in these 26 families using the broadest disease phenotype, including IA, abdominal AA, and thoracic AA, supports the concept of shared genetic risk. The chromosome 11 locus appears to confirm earlier independent associations in IA and AA. The chromosome 6 finding is novel. Both warrant further investigation.

Greater rupture risk for familial as compared to sporadic unruptured intracranial aneurysms.

BACKGROUND AND PURPOSE: The risk of intracranial aneurysm (IA) rupture in asymptomatic members of families who have multiple affected individuals is not known. METHODS: First-degree unaffected relatives of those with a familial history of IA who had a history of smoking or hypertension but no known IA were offered cerebral MR angiography (MRA) and followed yearly as part of a National Institute of Neurological Diseases and Stroke-funded study of familial IA (Familial Intracranial Aneurysm [FIA] Study). RESULTS: A total of 2874 subjects from 542 FIA Study families were enrolled. After study enrollment, MRAs were performed in 548 FIA Study family members with no known history of IA. Of these 548 subjects, 113 subjects (20.6%) had 148 IAs by MRA of whom 5 subjects had IA >or=7 mm. Two subjects with an unruptured IA by MRA/CT angiography (3-mm and 4-mm anterior communicating artery) subsequently had rupture of their IA. This represents an annual rate of 1.2 ruptures per 100 subjects (1.2% per year; 95% CI, 0.14% to 4.3% per year). None of the 435 subjects with a negative MRA have had a ruptured IA. Survival curves between the MRA-positive and -negative cohorts were significantly different (P=0.004). This rupture rate of unruptured IA in the FIA Study cohort of 1.2% per year is approximately 17 times higher than the rupture rate for subjects with an unruptured IA in the International Study of Unruptured Aneurysm Study with a matched distribution of IA size and location 0.069% per year. CONCLUSIONS: Small unruptured IAs in patients from FIA Study families may have a higher risk of rupture than sporadic unruptured IAs of similar size, which should be considered in the management of these patients.

Genome screen in familial intracranial aneurysm.

BACKGROUND: Individuals with 1st degree relatives harboring an intracranial aneurysm (IA) are at an increased risk of IA, suggesting genetic variation is an important risk factor. METHODS: Families with multiple members having ruptured or unruptured IA were recruited and all available medical records and imaging data were reviewed to classify possible IA subjects as definite, probable or possible IA or not a case. A 6 K SNP genome screen was performed in 333 families, representing the largest linkage study of IA reported to date. A 'narrow' (n = 705 definite IA cases) and 'broad' (n = 866 definite or probable IA) disease definition were used in multipoint model-free linkage analysis and parametric linkage analysis, maximizing disease parameters. Ordered subset analysis (OSA) was used to detect gene x smoking interaction. RESULTS: Model-free linkage analyses detected modest evidence of possible linkage (all LOD < 1.5). Parametric analyses yielded an unadjusted LOD score of 2.6 on chromosome 4q (162 cM) and 3.1 on chromosome 12p (50 cM). Significant evidence for a gene x smoking interaction was detected using both disease models on chromosome 7p (60 cM; p

Genome screen to detect linkage to intracranial aneurysm susceptibility genes: the Familial Intracranial Aneurysm (FIA) study.

BACKGROUND AND PURPOSE: Evidence supports a substantial genetic contribution to the risk of intracranial aneurysm (IA). The purpose of this study was to identify chromosomal regions likely to harbor genes that contribute to the risk of IA. METHODS: Multiplex families having at least 2 individuals with "definite" or "probable" IA were ascertained through an international consortium. First-degree relatives of individuals with IA who were at increased risk of an IA because of a history of hypertension or present smoking were offered cerebral magnetic resonance angiography. A genome screen was completed using the Illumina 6K SNP system, and the resulting data from 192 families, containing 1155 genotyped individuals, were analyzed. Narrow and broad disease definitions were used when testing for linkage using multipoint model-independent methods. Ordered subset analysis was performed to test for a gene x smoking (pack-years) interaction. RESULTS: The greatest evidence of linkage was found on chromosomes 4 (LOD=2.5; 156 cM), 7 (LOD=1.7; 183 cM), 8 (LOD=1.9; 70 cM), and 12 (LOD=1.6; 102 cM) using the broad disease definition. Using the average pack-years for the affected individuals in each family, the genes on chromosomes 4 (LOD=3.5; P=0.03), 7 (LOD=4.1; P=0.01) and 12 (LOD=3.6; P=0.02) all appear to be modulated by the degree of smoking in the affected members of the family. On chromosome 8, inclusion of smoking as a covariate did not significantly strengthen the linkage evidence, suggesting no interaction between the loci in this region and smoking. CONCLUSIONS: We have detected possible evidence of linkage to 4 chromosomal regions. There is potential evidence for a gene x smoking interaction with 3 of the loci.

Screening for brain aneurysm in the Familial Intracranial Aneurysm study: frequency and predictors of lesion detection.

OBJECT: Approximately 20% of patients with an intracranial saccular aneurysm report a family history of intracranial aneurysm (IA) or subarachnoid hemorrhage. A better understanding of predictors of aneurysm detection in familial IA may allow more targeted aneurysm screening strategies. METHODS: The Familial Intracranial Aneurysm (FIA) study is a multicenter study, in which the primary objective is to define the susceptibility genes related to the formation of IA. First-degree relatives (FDRs) of those affected with IA are offered screening with magnetic resonance (MR) angiography if they were previously unaffected, are > or = 30 years of age, and have a history of smoking and/or hypertension. Independent predictors of aneurysm detection on MR angiography were determined using the generalized estimating equation version of logistic regression. RESULTS: Among the first 303 patients screened with MR angiography, 58 (19.1%) had at least 1 IA, including 24% of women and 11.7% of men. Ten (17.2%) of 58 affected patients had multiple aneurysms. Independent predictors of aneurysm detection included female sex (odds ratio [OR] 2.46, p = 0.001), pack-years of cigarette smoking (OR 3.24 for 20 pack-years of cigarette smoking compared with never having smoked, p < 0.001), and duration of hypertension (OR 1.26 comparing those with 10 years of hypertension to those with no hypertension, p = 0.006). CONCLUSIONS: In the FIA study, among the affected patients' FDRs who are > 30 years of age, those who are women or who have a history of smoking or hypertension are at increased risk of suffering an IA and should be strongly considered for screening.

The effects of study participation in the Familial Intracranial Aneurysm Study on cigarette smoking.

BACKGROUND: Cigarette smoking is the most modifiable risk factor for the formation and rupture of intracranial aneurysm (IA). This study examined the impact of participation in the Familial IA study on smoking behavior. METHODS: On entry into the study, a baseline smoking history was obtained. At follow-up visits, subjects were surveyed concerning their current smoking status. Risk reduction education was site specific and the study did not include a standard approach. RESULTS: Of participants, 66% had a history of cigarette smoking, with 33.1% being current smokers. There was a significant reduction in the proportion of current smokers by the third yearly follow-up visit (26.7%, P < .001). There was a significant reduction in the daily amount of cigarettes smoked (17.7-11.5, P < .001), with the most significant reduction at the first follow-up visit. Current smokers given the diagnosis of an IA before entry or during the course of the study were more likely to decrease their smoking (19.4-9.8 cigarettes/day, P < .001) than those not given a diagnosis of an IA (16.0-13.3, P = .002). Individuals older then 51 years had a greater reduction in the amount of cigarettes smoked per day compared with those younger than 51 years (2.3 cigarettes/day reduction v 1.5, P = .002). CONCLUSION: Subjects who entered into the Familial IA study had a significant decrease in their smoking by the end of 3 years. Factors associated with decreased smoking were diagnosis of IA and older age.

Subarachnoid hemorrhage: tests of association with apolipoprotein E and elastin genes.

BACKGROUND: Apolipoprotein E (APOE) and elastin (ELN) are plausible candidate genes involved in the pathogenesis of stroke. We tested for association of variants in APOE and ELN with subarachnoid hemorrhage (SAH) in a population-based study. We genotyped 12 single nucleotide polymorphisms (SNPs) on APOE and 10 SNPs on ELN in a sample of 309 Caucasian individuals, of whom 107 are SAH cases and 202 are age-, race-, and gender-matched controls from the Greater Cincinnati/Northern Kentucky region. Associations were tested at genotype, allele, and haplotype levels. A genomic control analysis was performed to check for spurious associations resulting from population substructure. RESULTS: At the APOE locus, no individual SNP was associated with SAH after correction for multiple comparisons. Haplotype analysis revealed significant association of the major haplotype (Hap1) in APOE with SAH (p = 0.001). The association stemmed from both the 5' promoter and the 3' region of the APOE gene. APOE epsilon2 and epsilon 4 were not significantly associated with SAH. No association was observed for ELN at genotype, allele, or haplotype level and our study failed to confirm previous reports of ELN association with aneurysmal SAH. CONCLUSION: This study suggests a role of the APOE gene in the etiology of aneurysmal SAH.

Gene expression in blood changes rapidly in neutrophils and monocytes after ischemic stroke in humans: a microarray study.

Ischemic brain and peripheral white blood cells release cytokines, chemokines and other molecules that activate the peripheral white blood cells after stroke. To assess gene expression in these peripheral white blood cells, whole blood was examined using oligonucleotide microarrays in 15 patients at 2.4+/-0.5, 5 and 24 h after onset of ischemic stroke and compared with control blood samples. The 2.4-h blood samples were drawn before patients were treated either with tissue-type plasminogen activator (tPA) alone or with tPA plus Eptifibatide (the Combination approach to Lysis utilizing Eptifibatide And Recombinant tPA trial). Most genes induced in whole blood at 2 to 3 h were also induced at 5 and 24 h. Separate studies showed that the genes induced at 2 to 24 h after stroke were expressed mainly by polymorphonuclear leukocytes and to a lesser degree by monocytes. These genes included: matrix metalloproteinase 9; S100 calcium-binding proteins P, A12 and A9; coagulation factor V; arginase I; carbonic anhydrase IV; lymphocyte antigen 96 (cluster of differentiation (CD)96); monocarboxylic acid transporter (6); ets-2 (erythroblastosis virus E26 oncogene homolog 2); homeobox gene Hox 1.11; cytoskeleton-associated protein 4; N-formylpeptide receptor; ribonuclease-2; N-acetylneuraminate pyruvate lyase; BCL6; glycogen phosphorylase. The fold change of these genes varied from 1.6 to 6.8 and these 18 genes correctly classified 10/15 patients at 2.4 h, 13/15 patients at 5 h and 15/15 patients at 24 h after stroke. These data provide insights into the inflammatory responses after stroke in humans, and should be helpful in diagnosis, understanding etiology and pathogenesis, and guiding acute treatment and development of new treatments for stroke.

Primary stroke prevention.

The best way to prevent a first-time stroke is to identify at-risk patients and control as many risk factors as possible. Some risk factors, such as smoking, can be eliminated; others, such as hypertension and carotid artery stenosis, can be controlled or treated to reduce the risk of stroke. Nurses are encouraged to work with patients to identify all risk factors in order to reduce the prevalence of this medical condition that costs billions of dollars annually and results in significant disability.

Potential applicability of recombinant factor VIIa for intracerebral hemorrhage.

BACKGROUND AND PURPOSE: To date, there are no proven, effective treatments for intracerebral hemorrhage (ICH) beyond supportive medical care. A recent randomized, blinded, placebo-controlled trial of recombinant factor VIIa (rFVIIa) administered intravenously within 4 hours of ICH onset reported a reduction in morbidity and mortality compared with placebo. We sought to determine the potential applicability of rFVIIa in a large, population-based cohort of ICH patients. METHODS: All of the patients age > or =18 years hospitalized with nontraumatic ICH in the Greater Cincinnati region were identified from May 1998 to July 2001 and August 2002 to April 2003. Patient demographics were compared with the inclusion and exclusion criteria from the rFVIIa trial to determine eligibility for treatment and reasons for exclusion. Mortality in the eligible patient group was compared with the placebo group in the rFVIIa trial. RESULTS: Over 4 calendar years, 1018 ICH patients were identified; of these, 133 (13.1%) had no exclusions and presented within the prescribed time window. An additional 45 patients (4.4%) may have been eligible but had uncertain onset or computed tomography scan times. The most common reasons for exclusion (not mutually exclusive) were late presentation (n=398), vaso-occlusive disease (n=369), deep coma (n=219), and prolonged international normalized ratio or partial thromboplastin time (n=200). Mortality at 90 days among potentially eligible patients was the same as for the placebo group in the rFVIIa trial (29% versus 29%; P=0.99). CONCLUSIONS: In this large, population-based ICH cohort, 13.1% to 17.5% of patients would have qualified for treatment with rFVIIa by trial criteria.

Racial variations in location and risk of intracerebral hemorrhage.

BACKGROUND AND PURPOSE: Risk factors for intracerebral hemorrhage (ICH) vary by location. Incidence rates of ICH are known to be higher in American blacks than whites, but how rates may differ by hemorrhage location is unknown. We sought to define incidence rates for different ICH locations in a biracial population. METHODS: All hospitalized patients age > or =20 years with spontaneous ICH were identified in the Greater Cincinnati/Northern Kentucky metropolitan area from May 1998 to July 2001 and August 2002 to April 2003. Incidence rates per 100,000 persons were age, sex, and race adjusted as appropriate to the 2000 US population. Risk ratios (RRs) with 95% CIs were calculated from unadjusted incidence rates. RESULTS: There were 1038 qualifying ICHs. Annual incidence rates per 100,000 persons > or =20 years of age were 48.9 for blacks and 26.6 for whites. Annual incidence rates per 100,000 blacks in lobar, deep cerebral, brain stem, and cerebellar locations were 15.2, 25.7, 5.1, and 2.9, respectively. Annual incidence rates per 100,000 whites in the same locations were 9.4, 13.0, 1.3, and 2.9. The greatest excess risk of ICH in blacks compared with whites was found among young to middle-aged (35 to 54 years) persons with brain stem (RR, 9.8; 95% CI, 4.2 to 23.0) and deep cerebral (RR, 4.5; 3.0 to 6.8) hemorrhage. CONCLUSIONS: The excess risk of ICH in American blacks is largely attributable to higher hemorrhage rates in young and middle-aged persons, particularly for deep cerebral and brain stem locations. Hypertension is the predominant risk factor for hemorrhages in these locations.

Association of apolipoprotein E4 and haplotypes of the apolipoprotein E gene with lobar intracerebral hemorrhage.

BACKGROUND AND PURPOSE: Conflicting reports in the literature exist with regard to the association of apolipoprotein E (apo E) alleles and lobar intracerebral hemorrhage (ICH). We genotyped 12 single-nucleotide polymorphisms in the 5' upstream regulatory, exonic, and intronic regions of the apo E gene and performed genotype and haplotype association analyses. METHODS: We prospectively enrolled subjects with hemorrhagic stroke and matched them with 2 controls based on age, race, and sex. Each case was reviewed by a physician to determine case status and location of the ICH. Multivariate logistic-regression modeling with backward elimination was used to determine significant risk factors for lobar ICH. Associations at the genotype and haplotype levels and linkage disequilibrium were conducted according to standard statistical methods. RESULTS: Between May 1997 and December 2002, 315 cases of ICH were recruited, of whom 107 were lobar ICH cases matched to 205 controls. No association was found for apo E2, E3, or E4 with nonlobar ICH. Independent, significant risk factors for lobar ICH included apo E4, untreated hypertension, anticoagulant use, a first-degree relative with ICH, and < or =high school education (compared with >high school education). Treated hypercholesterolemia compared with "no history of hypercholesterolemia" was associated with a decreased risk of lobar ICH. Haplotype association analysis demonstrated a significant association of the apo E gene with lobar ICH among whites (P<0.0001) and blacks (P=0.0024). CONCLUSIONS: Apo E4 is independently associated with lobar ICH but not nonlobar ICH. Haplotypes of the apo E gene are associated with lobar ICH. Untreated hypertension is a risk factor for lobar ICH.

The Familial Intracranial Aneurysm (FIA) study protocol.

BACKGROUND: Subarachnoid hemorrhage (SAH) due to ruptured intracranial aneurysms (IAs) occurs in about 20,000 people per year in the U.S. annually and nearly half of the affected persons are dead within the first 30 days. Survivors of ruptured IAs are often left with substantial disability. Thus, primary prevention of aneurysm formation and rupture is of paramount importance. Prior studies indicate that genetic factors are important in the formation and rupture of IAs. The long-term goal of the Familial Intracranial Aneurysm (FIA) Study is to identify genes that underlie the development and rupture of intracranial aneurysms (IA). METHODS/DESIGN: The FIA Study includes 26 clinical centers which have extensive experience in the clinical management and imaging of intracerebral aneurysms. 475 families with affected sib pairs or with multiple affected relatives will be enrolled through retrospective and prospective screening of potential subjects with an IA. After giving informed consent, the proband or their spokesperson invites other family members to participate. Each participant is interviewed using a standardized questionnaire which covers medical history, social history and demographic information. In addition blood is drawn from each participant for DNA isolation and immortalization of lymphocytes. High- risk family members without a previously diagnosed IA undergo magnetic resonance angiography (MRA) to identify asymptomatic unruptured aneurysms. A 10 cM genome screen will be performed to identify FIA susceptibility loci. Due to the significant mortality of affected individuals, novel approaches are employed to reconstruct the genotype of critical deceased individuals. These include the intensive recruitment of the spouse and children of deceased, affected individuals. DISCUSSION: A successful, adequately-powered genetic linkage study of IA is challenging given the very high, early mortality of ruptured IA. Design features in the FIA Study that address this challenge include recruitment at a large number of highly active clinical centers, comprehensive screening and recruitment techniques, non-invasive vascular imaging of high-risk subjects, genome reconstruction of dead affected individuals using marker data from closely related family members, and inclusion of environmental covariates in the statistical analysis.

Perimesencephalic subarachnoid hemorrhage: incidence, risk factors, and outcome.

BACKGROUND: Nonaneurysmal perimesencephalic subarachnoid hemorrhage (PMSAH) appears to have an etiology and natural history distinct from aneurysm rupture. Referral-based studies suggest that 15% of SAH patients have no discernable cause of bleeding, but the incidence of PMSAH is unknown. We describe the first population-based study of PMSAH and place it in the context of all non-traumatic SAH, with presentation of incidence rates, patient demographics, and clinical outcomes. METHODS: All patients age >/= 18 hospitalized with first-ever, non-traumatic SAH in the Greater Cincinnati area were identified from 5/98-7/01 and 8/02-4/04. PMSAH was defined as hemorrhage restricted to the cisterns surrounding the brainstem and suprasellar cistern and a negative cerebral angiogram. Incidence rates were age, race, and sex adjusted to the 2000 US population. RESULTS: There were 431 SAHs identified. Cases in Asian-Americans (2) were excluded, leaving 429 SAHs for analysis. Of these patients, 77 did not have angiograms. Among remaining cases, 285 had aneurysm rupture, 43 had nonaneurysmal hemorrhage not of the PMSAH pattern, and 24 had PMSAH. The overall annual incidence rates for SAH and PMSAH were 8.7 (95% CI 7.9-9.5) and 0.5 (95% CI 0.3-0.7) per 100,000 persons age >/= 18. Patients with PMSAH were younger (p = 0.018) and less likely to be female (p = 0.020) or hypertensive (p = 0.005) than other SAH patients. There was one death among PMSAH patients during 14 months mean follow-up. CONCLUSIONS: PMSAH represents approximately 5% of all SAH. Its risk factors and outcome differ from other forms of SAH.