Christophe Tzourio

Vascular Contributions to Cognitive Impairment and Dementia A Statement for Healthcare Professionals From the American Heart Association/American Stroke Association

Background and Purpose— This scientific statement provides an overview of the evidence on vascular contributions to cognitive impairment and dementia. Vascular contributions to cognitive impairment and dementia of later life are common. Definitions of vascular cognitive impairment (VCI), neuropathology, basic science and pathophysiological aspects, role of neuroimaging and vascular and other associated risk factors, and potential opportunities for prevention and treatment are reviewed. This statement serves as an overall guide for practitioners to gain a better understanding of VCI and dementia, prevention, and treatment. Methods— Writing group members were nominated by the writing group co-chairs on the basis of their previous work in relevant topic areas and were approved by the American Heart Association Stroke Council Scientific Statement Oversight Committee, the Council on Epidemiology and Prevention, and the Manuscript Oversight Committee. The writing group used systematic literature reviews (primarily covering publications from 1990 to May 1, 2010), previously published guidelines, personal files, and expert opinion to summarize existing evidence, indicate gaps in current knowledge, and, when appropriate, formulate recommendations using standard American Heart Association criteria. All members of the writing group had the opportunity to comment on the recommendations and approved the final version of this document. After peer review by the American Heart Association, as well as review by the Stroke Council leadership, Council on Epidemiology and Prevention Council, and Scientific Statements Oversight Committee, the statement was approved by the American Heart Association Science Advisory and Coordinating Committee. Results— The construct of VCI has been introduced to capture the entire spectrum of cognitive disorders associated with all forms of cerebral vascular brain injury—not solely stroke—ranging from mild cognitive impairment through fully developed dementia. Dysfunction of the neurovascular unit and mechanisms regulating cerebral blood flow are likely to be important components of the pathophysiological processes underlying VCI. Cerebral amyloid angiopathy is emerging as an important marker of risk for Alzheimer disease, microinfarction, microhemorrhage and macrohemorrhage of the brain, and VCI. The neuropathology of cognitive impairment in later life is often a mixture of Alzheimer disease and microvascular brain damage, which may overlap and synergize to heighten the risk of cognitive impairment. In this regard, magnetic resonance imaging and other neuroimaging techniques play an important role in the definition and detection of VCI and provide evidence that subcortical forms of VCI with white matter hyperintensities and small deep infarcts are common. In many cases, risk markers for VCI are the same as traditional risk factors for stroke. These risks may include but are not limited to atrial fibrillation, hypertension, diabetes mellitus, and hypercholesterolemia. Furthermore, these same vascular risk factors may be risk markers for Alzheimer disease. Carotid intimal-medial thickness and arterial stiffness are emerging as markers of arterial aging and may serve as risk markers for VCI. Currently, no specific treatments for VCI have been approved by the US Food and Drug Administration. However, detection and control of the traditional risk factors for stroke and cardiovascular disease may be effective in the prevention of VCI, even in older people. Conclusions— Vascular contributions to cognitive impairment and dementia are important. Understanding of VCI has evolved substantially in recent years, based on preclinical, neuropathologic, neuroimaging, physiological, and epidemiological studies. Transdisciplinary, translational, and transactional approaches are recommended to further our understanding of this entity and to better characterize its neuropsychological profile. There is a need for prospective, quantitative, clinical-pathological-neuroimaging studies to improve knowledge of the pathological basis of neuroimaging change and the complex interplay between vascular and Alzheimer disease pathologies in the evolution of clinical VCI and Alzheimer disease. Long-term vascular risk marker interventional studies beginning as early as midlife may be required to prevent or postpone the onset of VCI and Alzheimer disease. Studies of intensive reduction of vascular risk factors in high-risk groups are another important avenue of research.

Atherosclerotic Disease of the Aortic Arch and the Risk of Ischemic Stroke

BACKGROUND Atherosclerotic disease of the aortic arch has been suspected to be a potential source of cerebral emboli. We conducted a study to quantify the risk of ischemic stroke associated with atherosclerotic disease of the aortic arch. METHODS Using transesophageal echocardiography, we performed a prospective case-control study of the frequency and thickness of atherosclerotic plaques in the ascending aorta and proximal arch in 250 consecutive patients admitted to the hospital with ischemic stroke and 250 consecutive controls, all over the age of 60 years. RESULTS Atherosclerotic plaques > or = mm in thickness were found in 14.4 percent of the patients but in only 2 percent of the controls. After adjustment for atherosclerotic risk factors, the odds ratio for ischemic stroke among patients with such plaques was 9.1 (95 percent confidence interval, 3.3 to 25.2; P < 0.001). Among the 78 patients who had brain infarcts with no obvious cause, 28.2 percent had plaques > or = 4 mm in thickness, as compared with 8.1 percent of the 172 patients who had infarcts whose possible or likely causes were known (odds ratio, 4.7; 95 percent confidence interval, 2.2 to 10.1; P < 0.001). Plaques of > or = 4 mm in the aortic arch were not associated with the presence of atrial fibrillation or stenosis of the extracranial internal carotid artery. In contrast, plaques that were 1 to 3.9 mm thick were frequently associated with carotid stenosis of > or = 70 percent. CONCLUSIONS These results indicate a strong, independent association between atherosclerotic disease of the aortic arch and the risk of ischemic stroke. The association was particularly strong with thick plaques. Atherosclerotic disease of the aortic arch should be regarded as a risk factor for ischemic stroke and as a possible source of cerebral emboli.

Genome-wide Analysis of Genetic Loci Associated With Alzheimer Disease

CONTEXT Genome-wide association studies (GWAS) have recently identified CLU, PICALM, and CR1 as novel genes for late-onset Alzheimer disease (AD). OBJECTIVES To identify and strengthen additional loci associated with AD and confirm these in an independent sample and to examine the contribution of recently identified genes to AD risk prediction in a 3-stage analysis of new and previously published GWAS on more than 35,000 persons (8371 AD cases). DESIGN, SETTING, AND PARTICIPANTS In stage 1, we identified strong genetic associations (P < 10(-3)) in a sample of 3006 AD cases and 14,642 controls by combining new data from the population-based Cohorts for Heart and Aging Research in Genomic Epidemiology consortium (1367 AD cases [973 incident]) with previously reported results from the Translational Genomics Research Institute and the Mayo AD GWAS. We identified 2708 single-nucleotide polymorphisms (SNPs) with P < 10(-3). In stage 2, we pooled results for these SNPs with the European AD Initiative (2032 cases and 5328 controls) to identify 38 SNPs (10 loci) with P < 10(-5). In stage 3, we combined data for these 10 loci with data from the Genetic and Environmental Risk in AD consortium (3333 cases and 6995 controls) to identify 4 SNPs with P < 1.7x10(-8). These 4 SNPs were replicated in an independent Spanish sample (1140 AD cases and 1209 controls). Genome-wide association analyses were completed in 2007-2008 and the meta-analyses and replication in 2009. MAIN OUTCOME MEASURE Presence of Alzheimer disease. RESULTS Two loci were identified to have genome-wide significance for the first time: rs744373 near BIN1 (odds ratio [OR],1.13; 95% confidence interval [CI],1.06-1.21 per copy of the minor allele; P = 1.59x10(-11)) and rs597668 near EXOC3L2/BLOC1S3/MARK4 (OR, 1.18; 95% CI, 1.07-1.29; P = 6.45x10(-9)). Associations of these 2 loci plus the previously identified loci CLU and PICALM with AD were confirmed in the Spanish sample (P < .05). However, although CLU and PICALM were confirmed to be associated with AD in this independent sample, they did not improve the ability of a model that included age, sex, and APOE to predict incident AD (improvement in area under the receiver operating characteristic curve from 0.847 to 0.849 in the Rotterdam Study and 0.702 to 0.705 in the Cardiovascular Health Study). CONCLUSIONS Two genetic loci for AD were found for the first time to reach genome-wide statistical significance. These findings were replicated in an independent population. Two recently reported associations were also confirmed. These loci did not improve AD risk prediction. While not clinically useful, they may implicate biological pathways useful for future research.

Prevalence of parkinsonism and Parkinson's disease in Europe: the EUROPARKINSON Collaborative Study. European Community Concerted Action on the Epidemiology of Parkinson's disease.

OBJECTIVES: To assess and compare the prevalence of parkinsonism and Parkinsons disease in five European populations that were surveyed with similar methodology and diagnostic criteria. METHODS: Joint analysis of five community surveys--Gironde (France), eight centres in Italy, Rotterdam (The Netherlands), Girona (Spain), and Pamplona (Spain)--in which subjects were screened in person for parkinsonism. Overall, these surveys comprised 14,636 participants aged 65 years or older. RESULTS: The overall prevalence (per 100 population), age adjusted to the 1991 European standard population, was 2.3 for parkinsonism and 1.6 for Parkinsons disease. The overall prevalence of parkinsonism for the age groups 65 to 69, 70 to 74, 75 to 79, 80 to 84, and 85 to 89 years was respectively, 0.9, 1.5, 3.7, 5.0, and 5.1. The corresponding age specific figures for Parkinsons disease were 0.6, 1.0, 2.7, 3.6, and 3.5. After adjusting for age and sex, the prevalence figures did not differ significantly across studies, except for the French study in which prevalence was lower. Prevalence was similar in men and women. Overall, 24% of the subjects with Parkinsons disease were newly detected through the surveys. CONCLUSIONS: Prevalence of both parkinsonism and Parkinsons disease increased with age, without significant differences between men and women. There was no convincing evidence for differences in prevalence across European countries. A substantial proportion of patients with Parkinsons disease went undetected in the general population.

The prevalence of ulcerated plaques in the aortic arch in patients with stroke.

BACKGROUND AND METHODS The cause of cerebral infarction is obscure in up to 40 percent of patients with this disorder who are studied prospectively. In this investigation, we determined the frequency of ulcerated plaques in the aortic arch and explored the part they may play in the formation of cerebral emboli. Using an autopsy data bank, we studied the prevalence of ulcerated plaques in the aortic arch in 500 consecutive patients with cerebrovascular and other neurologic diseases who were studied at autopsy. RESULTS Ulcerated plaques were present in 26 percent of the 239 patients with cerebrovascular disease but in only 5 percent of the 261 patients with other neurologic diseases (P less than 0.001). After we controlled for age and heart weight, the adjusted rates were 16.9 percent and 5.1 percent, respectively (adjusted odds ratio, 4.0; 95 percent confidence interval, 2.1 to 7.8; P less than 0.001). Among the patients with cerebrovascular disease, the prevalence of ulcerated plaques in the aortic arch was 28 percent in the 183 patients with cerebral infarcts and 20 percent in the 56 patients with brain hemorrhage. The prevalence of ulcerated plaques was 61 percent among the 28 patients with no known cause of cerebral infarction, as compared with 22 percent among the 155 patients with a known cause of cerebral infarction (P less than 0.001). After adjustment for covariates, the prevalence was 57.8 percent among patients with no known cause of cerebral infarction and 20.2 percent among those with a known cause (adjusted odds ratio, 5.7; 95 percent confidence interval, 2.4 to 13.6; P less than 0.001). The presence of ulcerated plaques in the aortic arch was not correlated with the presence of extracranial internal-carotid artery stenosis, suggesting that these were two independent risk factors for stroke. CONCLUSIONS Ulcerated plaques in the aortic arch may play a part in causing cerebral infarction, especially in patients in whom cerebral infarction has no known cause.

Dietary patterns and risk of dementia The Three-City cohort study

Background: Dietary fatty acids and antioxidants may contribute to decrease dementia risk, but epidemiologic data remain controversial. The aim of our study was to analyze the relationship between dietary patterns and risk of dementia or Alzheimer disease (AD), adjusting for sociodemographic and vascular risk factors, and taking into account the ApoE genotype. Methods: A total of 8,085 nondemented participants aged 65 and over were included in the Three-City cohort study in Bordeaux, Dijon, and Montpellier (France) in 1999–2000 and had at least one re-examination over 4 years (rate of follow-up 89.1%). An independent committee of neurologists validated 281 incident cases of dementia (including 183 AD). Results: Daily consumption of fruits and vegetables was associated with a decreased risk of all cause dementia (hazard ratio [HR] 0.72, 95% CI 0.53 to 0.97) in fully adjusted models. Weekly consumption of fish was associated with a reduced risk of AD (HR 0.65, 95% CI 0.43 to 0.994) and all cause dementia but only among ApoE ε4 noncarriers (HR 0.60, 95% CI 0.40 to 0.90). Regular use of omega-3 rich oils was associated with a decreased risk of borderline significance for all cause dementia (HR 0.46, 95% CI 0.19 to 1.11). Regular consumption of omega-6 rich oils not compensated by consumption of omega-3 rich oils or fish was associated with an increased risk of dementia (HR 2.12, 95% CI 1.30 to 3.46) among ApoE ε4 noncarriers. Conclusion: Frequent consumption of fruits and vegetables, fish, and omega-3 rich oils may decrease the risk of dementia and Alzheimer disease, especially among ApoE ε4 noncarriers. GLOSSARY: AD = Alzheimer disease; BMI = body mass index; CCPPRB = Consultative Committee for the Protection of Persons participating in Biomedical Research; DHA = docosahexaenoic acid; EI = energy intake; HR = hazard ratio; PUFA = polyunsaturated fatty acids.

Case-control study of migraine and risk of ischaemic stroke in young women

Abstract Objective: To determine whether migraine is a risk factor for ischaemic stroke in young women. Design: A case-control study. Setting: Five hospitals in Paris and suburbs. Subjects: 72 women aged under 45 with ischaemic stroke and 173 controls randomly selected from women hospitalised in the same centres. Main outcome measures: Ischaemic stroke confirmed by cerebral computerised tomography or magnetic resonance imaging; history of headache recorded with structured interview, and diagnosis of migraine assessed by reproducibility study. Results: Ischaemic stroke was strongly associated with migraine, both migraine without aura (odds ratio 3.0 (95% confidence interval 1.5 to 5.8)) and migraine with aura (odds ratio 6.2 (2.1 to 18.0)). The risk of ischaemic stroke was substantially increased for migrainous women who were using oral contraceptives (odds ratio 13.9) or who were heavy smokers (>/=20 cigarettes/day) (odds ratio 10.2). Conclusions: These results indicate an independent association between migraine and the risk of ischaemic stroke in young women. Although the absolute risk of ischaemic stroke in young women with migraine is low, the reduction of known risk factors for stroke, in particular smoking and use of oral contraceptives, should be considered in this group.

Effects of Blood Pressure Lowering on Cerebral White Matter Hyperintensities in Patients With Stroke The PROGRESS (Perindopril Protection Against Recurrent Stroke Study) Magnetic Resonance Imaging Substudy

Background—The prevalence of white matter hyperintensities (WMHs) detected on cerebral MRI is associated with hypertension, but it is not known whether blood pressure lowering can arrest their progression. We report here the results of an MRI substudy of PROGRESS (Perindopril Protection Against Recurrent Stroke Study), a randomized trial of blood pressure lowering in subjects with cerebrovascular disease. Methods and Results—The substudy comprised 192 participants who had a cerebral MRI both at baseline and after a mean follow-up time of 36 months (SD=6.0 months). At the first MRI, WMHs were graded with a visual rating scale from A (no WMH) to D (severe WMH). Participants were assigned to a combination of perindopril plus indapamide (or their placebos; 58%) or to single therapy with perindopril (or placebo). At the time of the second MRI, the blood pressure reduction in the active arm compared with the placebo arm was 11.2 mm Hg for systolic blood pressure and 4.3 mm Hg for diastolic blood pressure. Twenty-four subjects (12.5%) developed new WMHs at follow-up. The risk of new WMH was reduced by 43% (95% CI −7% to 89%) in the active treatment group compared with the placebo group (P=0.17). The mean total volume of new WMHs was significantly reduced in the active treatment group (0.4 mm3 [SE=0.8]) compared with the placebo group (2.0 mm3 [SE=0.7]; P=0.012). This difference was greatest for patients with severe WMH at entry, 0.0 mm3 (SE=0) in the active treatment group versus 7.6 mm3 (SE=1.0) in the placebo group (P<0.0001). Conclusions—These results indicate that an active blood pressure–lowering regimen stopped or delayed the progression of WMHs in patients with cerebrovascular disease.

Cognitive decline in individuals with high blood pressure A longitudinal study in the elderly

Objective: To examine whether baseline high blood pressure and antihypertensive treatment predicts cognitive decline in elderly individuals. Methods: A longitudinal population-based study of elderly individuals (n = 1,373) in Nantes (western France) was undertaken. Individuals 59 to 71 years of age were selected from electoral rolls. High blood pressure at baseline was defined as systolic blood pressure ≥ 160 mm Hg or diastolic blood pressure ≥ 95 mm Hg. Cognitive decline was defined as a drop of 4 points or more on the Mini-Mental State Examination between baseline and the 4-year assessment. Results: There is an association between high blood pressure at baseline and cognitive decline at the 4-year assessment (odds ratio, 2.8; 95% CI, 1.6 to 5.0). In participants with high blood pressure, the risk of cognitive decline was 4.3 (95% CI, 2.1 to 8.8) in those without antihypertensive therapy and 1.9 (95% CI, 0.8 to 4.4) in those being treated. In participants with high blood pressure both at baseline and at the 2-year assessment, the risk for untreated participants was 6.0 (95% CI, 2.4 to 15.0) compared with 1.3 (95% CI, 0.3 to 4.9) in treated participants. Conclusions: High blood pressure was associated with cognitive decline. In individuals with high blood pressure, cognitive decline occurred in a relatively short time period and the risk was highest in untreated hypertensive patients.

Long-term Prognosis in Cerebral Venous Thrombosis: Follow-up of 77 Patients

BACKGROUND AND PURPOSE Very little is known about the long-term outcome of patients with cerebral venous thrombosis (CVT), particularly regarding the risk of residual epilepsy and further thrombotic events. We retrospectively studied 77 patients with CVT diagnosed by angiography and/or MRI. METHODS A cohort of 77 patients aged 18 to 77 (mean, 38.5) years with CVT, evaluated from 1975 through 1990, was followed up for a mean of 77.8 months (range, 14 to 204 months; median, 63 months). Information on death, neurological status, seizures, recurrent CVT, other thrombotic events, and subsequent pregnancies was obtained from direct observation, mail questionnaire, or telephone interviews. RESULTS Sixty-six of 77 patients (85.7%) had no neurological sequelae during follow-up. Eleven patients (14.3%) remained neurologically impaired. Two who initially presented with isolated intracranial hypertension had blindness due to optic atrophy. The other 9 had focal signs at the time of CVT and were left with various cognitive or focal deficits. Four of 28 (14.3%) patients who had seizures at the acute stage had recurrent seizures. One of the 51 patients with lateral sinus thrombosis developed a dural arteriovenous fistula. Nine of the 77 patients (11.7%) suffered a second CVT, all but one in the first year. Noncerebral thrombotic events occurred in 11 patients (14.3%). No recurrence of CVT occurred during later pregnancies, but 1 patient had a postpartum deep vein thrombosis. CONCLUSIONS In the present series, CVT has an essentially good long-term prognosis. The frequency of long-standing epilepsy was low, suggesting that long-term anticonvulsant treatment is not necessary in the majority of cases. A second CVT or another thrombotic episode occurred in 20% of patients, stressing the need in a minority of cases for long-term anticoagulation.