Instruct: Given a scientific claim, retrieve relevant passages that support or refute the claim.
Query: Migraine with aura is associated with ischemic stroke.
OBJECTIVE To evaluate the association between migraine and cardiovascular disease, including stroke, myocardial infarction, and death due to cardiovascular disease. DESIGN Systematic review and meta-analysis. DATA SOURCES Electronic databases (PubMed, Embase, Cochrane Library) and reference lists of included studies and reviews published until January 2009. Selection criteria Case-control and cohort studies investigating the association between any migraine or specific migraine subtypes and cardiovascular disease. Review methods Two investigators independently assessed eligibility of identified studies in a two step approach. Disagreements were resolved by consensus. Studies were grouped according to a priori categories on migraine and cardiovascular disease. DATA EXTRACTION Two investigators extracted data. Pooled relative risks and 95% confidence intervals were calculated. RESULTS Studies were heterogeneous for participant characteristics and definition of cardiovascular disease. Nine studies investigated the association between any migraine and ischaemic stroke (pooled relative risk 1.73, 95% confidence interval 1.31 to 2.29). Additional analyses indicated a significantly higher risk among people who had migraine with aura (2.16, 1.53 to 3.03) compared with people who had migraine without aura (1.23, 0.90 to 1.69; meta-regression for aura status P=0.02). Furthermore, results suggested a greater risk among women (2.08, 1.13 to 3.84) compared with men (1.37, 0.89 to 2.11). Age less than 45 years, smoking, and oral contraceptive use further increased the risk. Eight studies investigated the association between migraine and myocardial infarction (1.12, 0.95 to 1.32) and five between migraine and death due to cardiovascular disease (1.03, 0.79 to 1.34). Only one study investigated the association between women who had migraine with aura and myocardial infarction and death due to cardiovascular disease, showing a twofold increased risk. CONCLUSION Migraine is associated with a twofold increased risk of ischaemic stroke, which is only apparent among people who have migraine with aura. Our results also suggest a higher risk among women and risk was further magnified for people with migraine who were aged less than 45, smokers, and women who used oral contraceptives. We did not find an overall association between any migraine and myocardial infarction or death due to cardiovascular disease. Too few studies are available to reliably evaluate the impact of modifying factors, such as migraine aura, on these associations.
Stroke is a heterogeneous syndrome caused by multiple disease mechanisms, but all result in a disruption of cerebral blood flow with subsequent tissue damage. This review covers the mechanisms responsible for regulation of the normal cerebral circulation, and how they are disrupted in disease states. A central concept in treating patients with acute ischaemic stroke is the existence of an ischaemic penumbra of potentially salvageable tissue, and the evidence for its existence in humans is reviewed.
OBJECTIVE The aim of this study was to investigate the possible microstructural abnormalities of the corpus callosum (CC) in adult patients with migraine without aura complicated with depressive/anxious disorder. BACKGROUND Emotional disorders, especially depression and anxiety, are with relatively higher incidence in migraine population. However, the mechanism of migraine complicated with depressive/anxious disorder remains unclear. METHODS Diffusion tensor magnetic resonance imaging was carried out in 12 adult patients with simple migraine (without aura and without depressive/anxious disorder) (S-M group), 12 adult patients with complicated migraine (without aura but complicated with depressive/anxious disorder) (Co-M group), and 12 age- and sex-matched healthy subjects (Control group). Fractional anisotropy (FA) and apparent diffusion coefficient were measured at genu, body, and splenium of the CC, respectively. RESULTS There were significant differences in FA values at all locations of the CC among the 3 groups. The FA values from both the SM and Co-M groups were significantly lower than the control (P < .05 and P < .01, respectively). The FA values from Co-M group were significantly lower than the SM group (P < .01). The apparent diffusion coefficient values of the above regions had no significant differences among these groups (P > .05). There were negative correlations between FA value of genu of the CC and disease course as well as FA value of genu and body of the CC and headache frequency (P < .05). Negative correlations were also found between FA values at all locations of the CC and Hamilton anxiety and Hamilton depression scores (both P < .05). CONCLUSIONS There might be an integrity change of neurofibrotic microstructures existing as a possible neuroanatomical basis in the CC of migraine patients complicated with depressive/anxious disorder.
BACKGROUND Metformin, a widely used hypoglycemic drug, reduces stroke incidence and alleviates chronic inflammation in clinical trials. However, the effect of metformin in ischemic stroke is unclear. Here, we investigated the effect of metformin on ischemic stroke in mice and further explored the possible underlying mechanisms. METHODS Ninety-eight adult male CD-1 mice underwent 90-minute transient middle cerebral artery occlusion (tMCAO). Metformin (200 mg/kg) was administrated for up to 14 days. Neurobehavioral outcomes, brain infarct volume, inflammatory factors, blood-brain barrier (BBB) permeability and AMPK signaling pathways were evaluated following tMCAO. Oxygen glucose deprivation was performed on bEND.3 cells to explore the mechanisms of metformin in inhibiting inflammatory signaling pathways. RESULTS Infarct volume was reduced in metformin-treated mice compared to the control group following tMCAO (P < 0.05). Neurobehavioral outcomes were greatly improved in metformin-treated mice (P < 0.05). MPO+ cells, Gr1+ cells, MPO activity and BBB permeability were decreased after metformin administration (P < 0.05). In addition, metformin activated AMPK phosphorylation, inhibited NF-κB activation, down-regulated cytokine (IL-1β, IL-6, TNF-α) and ICAM-1 expression following tMCAO (P < 0.05). Furthermore, metformin activated AMPK signaling pathway and alleviated oxygen-glucose deprivation-induced ICAM-1 expression in bEND.3 cells (P < 0.05). Compound C, a selective AMPK inhibitor, eliminated this promotional effect. CONCLUSIONS Metformin down-regulated ICAM-1 in an AMPK-dependent manner, which could effectively prevent ischemia-induced brain injury by alleviating neutrophil infiltration, suggesting that metformin is a promising therapeutic agent in stroke therapy.
The locations of cerebral infarctions were studied in 14 patients with tuberculous meningitis (TBM) and 173 patients with noninflammatory ischemic stroke (IS). In patients with TBM, 75% of infarctions occurred in the “TB zone” supplied by medial striate and thalamoperforating arteries; only 11% occurred in the “IS zone” supplied by lateral striate, anterior choroidal and thalamogeniculate arteries. In patients with IS 29% of infarctions occurred in the IS zone, 29% in the subcortical white matter, and 24% in (or involving) the cerebral cortex. Only 11% occurred in the TB zone. Bilaterally symmetrical infarctions of the TB zone were common with TMB (71%) but rare with IS (5%).
OBJECTIVE To measure in vivo, using diffusion tensor magnetic resonance imaging (DT-MRI) the extent of pathological damage of normal appearing brain tissue (NABT) from patients with migraine. METHODS Dual echo and DT-MRI scans of the brain were acquired from 34 patients with migraine and 17 sex and age matched healthy volunteers. Mean diffusivity (MD) and fractional anisotropy (FA) histograms of the NABT were obtained from all subjects and the histograms' peak heights and average NABT MD and FA measured. When present, average MD and FA values of T2 visible lesions were also measured. RESULTS In comparison with healthy volunteers, patients with migraine had lower MD histogram peak height (p=0.02) of the NABT. No differences were found in FA histogram derived metrics between migraine patients and healthy subjects. No difference was found for any MD and FA histogram derived metrics between migraine patients with and without brain MRI lesions, and between patients with and without aura. CONCLUSIONS This study shows that, although brain damage may extend beyond T2 weighted abnormalities in patients with migraine, the severity of these "occult" changes is mild compared with that found in other diseases associated with white matter abnormality.
BACKGROUND AND PURPOSE Soluble corin was decreased in coronary heart disease. Given the connections between cardiac dysfunction and stroke, circulating corin might be a candidate marker of stroke risk. However, the association between circulating corin and stroke has not yet been studied in humans. Here, we aimed to examine the association in patients wtith stroke and community-based healthy controls. METHODS Four hundred eighty-one patients with ischemic stroke, 116 patients with hemorrhagic stroke, and 2498 healthy controls were studied. Serum soluble corin and some conventional risk factors of stroke were examined. Because circulating corin was reported to be varied between men and women, the association between serum soluble corin and stroke was evaluated in men and women, respectively. RESULTS Patients with ischemic and hemorrhagic stroke had a significantly lower level of serum soluble corin than healthy controls in men and women (all P values, <0.05). In multivariate analysis, men in the lowest quartile of serum soluble corin were more likely to have ischemic (odds ratio [OR], 4.90; 95% confidence interval, 2.99-8.03) and hemorrhagic (OR, 17.57; 95% confidence interval, 4.85-63.71) stroke than men in the highest quartile. Women in the lowest quartile of serum soluble corin were also more likely to have ischemic (OR, 3.10; 95% confidence interval, 1.76-5.44) and hemorrhagic (OR, 8.54; 95% confidence interval, 2.35-31.02) stroke than women in the highest quartile. ORs of ischemic and hemorrhagic stroke were significantly increased with the decreasing levels of serum soluble corin in men and women (all P values for trend, <0.001). CONCLUSIONS Serum soluble corin was decreased in patients with stroke compared with healthy controls. Our findings raise the possibility that serum soluble corin may have a pathogenic role in stroke.
The frontal lobe is the largest lobe of the brain, and it is thus commonly involved in stroke. Moreover, almost one in five strokes is limited to the prerolandic areas. This high frequency of anatomical involvement is in sharp contrast with the apparent rarity of clinical frontal dysfunction in stroke. It is remarkable that frontal behavioral syndromes have been rather uncommonly reported in patients with stroke as compared to patients with other diseases, such as brain tumor. This fact is paradoxical, because an acute process (stroke) is expected to yield more clinical dysfunction than a more chronic disease (tumor). A volume effect may be the main factor leading to this phenomenon. Another interesting aspect of frontal strokes is the contribution of so-called 'silent' strokes, the recurrence of which may nevertheless lead to intellectual decline and compromise recovery from another stroke with more specific neurologic dysfunction. The contribution of stroke to understanding of frontal lobe dysfunction is important, because of the focal nature of this disease, and great opportunity for clinical-topographic classification correlations. One of the first modern attempts to develop a clinical-topographic classification of frontal lobe lesions came from the school of Luria, who tried to delineate three main types of frontal lobe syndromes (premotor syndrome, prefrontal syndrome, medial-frontal syndrome). Recent anatomic correlates using MRI make it possible to improve this classification. We suggest considering six main clinical-anatomic frontal stroke syndromes: (1) prefrontal; (2) premotor; (3) superior medial; (4) orbital-medial; (5) basal forebrain; (6) white matter. Finally, another fascinating topic relates to frontal lobe symptomatology due to stroke sparing the frontal cortex or white matter. This occurs mainly in three instances: lenticulo-capsular stroke, caudate stroke, and thalamic stroke. Studies using blood flow or metabolism measurements suggest that diaschisis (frontal lobe dysfunction from a remote lesion) may play a role. We believe that this is more likely to be related to dynamic interruption of complex circuitry than to static frontal lobe deactivation.
The availability of valid migraine-specific questionnaires is important when large numbers of migraine patients have to be analysed. The Finnish Migraine-Specific Questionnaire has been validated in two stages. In the first, a clinical diagnosis of migraine was reached, using International Headache Society criteria, in 100 consecutive patients. Migraine was then diagnosed independently on the basis of responses to the Finnish Migraine-Specific Questionnaire. In the second stage, responses to 100 questionnaires returned consecutively in a family study in progress were analysed, and respondents were contacted by telephone for interview and diagnosis of migraine. Contact proved impossible in six cases. The sensitivity of the questionnaire for migraine was 0.99 (167 out of 168; validation stages 1 and 2 combined) and specificity was 0.96 (25 out of 26 cases; validation stage 2). It also proved possible to differentiate between migraine with and without aura on the basis of responses to the Finnish Migraine-Specific Questionnaire: chance-corrected agreement (Cohen's kappa) was 0.804 in relation to diagnoses reached on the basis of responses to the Finnish Migraine-Specific Questionnaire and clinically was 0.858 in relation to diagnoses reached on the basis of responses to the Finnish Migraine-Specific Questionnaire combined with the results of the telephone interviews. A value for Cohen's kappa > 0.75 indicates good agreement. Therefore, use of the Finnish Migraine-Specific Questionnaire in research into migraine genetics is justified.
Stroke ranks as the third leading cause of death in the United States. It is now estimated that there are more than 700 000 incident strokes annually and 4.4 million stroke survivors.1 2 The economic burden of stroke was estimated by the American Heart Association to be $51 billion (direct and indirect costs) in 1999.3 Despite the advent of treatment of selected patients with acute ischemic stroke with tissue plasminogen activator and the promise of other experimental therapies, the best approach to reducing the burden of stroke remains prevention.4 5 High-risk or stroke-prone individuals can be identified and targeted for specific interventions.6 This is important because epidemiological data suggest a substantial leveling off of prior declines in stroke-related mortality and a possible increase in stroke incidence.7 8   The Stroke Council of the American Heart Association formed an ad hoc writing group to provide a clear and concise overview of the evidence regarding various established and potential stroke risk factors. The writing group was chosen based on expertise in specific subject areas, and it used literature review, reference to previously published guidelines, and expert opinion to summarize existing evidence and formulate recommendations (Table 1⇓). View this table:   Table 1. Levels of Evidence and Grading of Recommendations    As given in Tables 2 through 4⇓⇓⇓, risk factors or risk markers for a first stroke were classified according to potential for modification (nonmodifiable, modifiable, or potentially modifiable) and strength of evidence (well documented, less well documented).5 The tables give the estimated prevalence, population attributable risk, relative risk, and risk reduction with treatment for each factor when known. Population attributable risk reflects the proportion of ischemic strokes in the population that can be attributed to a particular risk factor and is given by the formula 100×[prevalence(relative risk−1)/prevalence(relative risk−1)+1]). …
Young patients with an ischaemic stroke or transient ischaemic attack (TIA) often have no vascular risk factors. Hyperhomocysteinaemia is an established risk factor for stroke in elderly patients but it is uncertain whether it is also important for the prognosis of young ischaemic stroke and TIA patients. We examined the possible effect of the plasma homocysteine level on the risk of recurrent vascular events in patients between 18 and 45 years of age. The study population consisted of 161 consecutive patients with a recent cerebral infarction or TIA. Data on the primary event and the homocysteine level were collected retrospectively from hospital records. General practitioners and patients were contacted by telephone to record vascular events and the type of medication used during the follow–up period. Vascular events included cerebral infarction, TIA, pulmonary embolism, venous thrombosis, myocardial infarction and peripheral arterial disease. A Kaplan- Meier curve showed a dose effect relationship between event-free survival time and tertiles of the homocysteine level (Log rank statistic 5.91; p = 0.05). The Cox hazard ratio, after adjustment for homocysteine lowering treatment, was 1.7 (95 % CI, 1.1 to 2.8) for any vascular outcome event, 1.9 (95% CI, 1.1 to 3.0) for arterial outcome events and 1.8 (95 % CI, 1.1 to 2.9) for cerebral outcome events. In spite of our small number of outcome events we found a significant association at the 95% confidence level between homocysteine level and the risk of recurrent vascular events in young patients with an ischaemic stroke or TIA. The association is of the same magnitude as in elderly people.
BACKGROUND AND PURPOSE The level of total homocysteine (tHcy) that confers a risk of ischemic stroke is unsettled, and no prospective cohort studies have included sufficient elderly minority subjects. We investigated the association between mild to moderate fasting tHcy level and the incidence of ischemic stroke, myocardial infarction, and vascular death in a multiethnic prospective study. METHODS A population-based cohort was followed for vascular events (stroke, myocardial infarction, and vascular death). Baseline values of tHcy and methylmalonic acid were measured among 2939 subjects (mean age, 69+/-10; 61% women, 53% Hispanics, 24% blacks, and 20% whites). Cox proportional models were used to calculate hazard ratios (HRs) and 95% CIs in tHcy categories after adjusting for age, race, education, renal insufficiency, B12 deficiency, and other risk factors. RESULTS The adjusted HR for a tHcy level > or =15 micromol/L compared with <10 micromol/L was greatest for vascular death (HR=6.04; 95% CI, 3.44 to 10.60), followed by combined vascular events (HR=2.27; 95% CI, 1.51 to 3.43), ischemic stroke (HR=2.01; 95% CI, 1.00 to 4.05), and nonvascular death (HR=2.02; 95% CI, 1.31 to 3.14). Mild to moderate elevations of tHcy of 10 to 15 micromol/L were not significantly predictive of ischemic stroke, but increased the risk of vascular death (2.27; 95% CI, 1.44 to 3.60) and combined vascular events (1.42; 95% CI, 1.06 to 1.88). The effect of tHcy was stronger among whites and Hispanics, but not a significant risk factor for blacks. CONCLUSIONS Total Hcy elevations above 15 micromol/L are an independent risk factor for ischemic stroke, whereas mild elevations of tHcy of 10 to 15 micromol/L are less predictive. The vascular effects of tHcy are greatest among whites and Hispanics, and less among blacks.
BACKGROUND Intracranial aneurysm (IA) is significantly more prevalent in patients with coarctation of the aorta or bicuspid aortic valve than in the general population, suggesting a common pathophysiology connecting IA and aortopathy. Here, we analyzed echocardiographic aortic root dimension (ARD) in patients with IA to confirm this possibility. METHODS From January 2008 to December 2010, 260 consecutive patients with IA who were admitted to our institution for coil embolization or for acute stroke management and who also underwent echocardiography were enrolled. We hypothesized that patients with large, ruptured, or multiple IAs are more likely to harbor co-prevalent aortopathy as measured by ARD compared to patients with small, isolated, unruptured IAs. Eccentric group was defined as patients aged <55 years with at least one ruptured aneurysm, an aneurysm ≥7 mm in size, or multiple aneurysms; the remainder was classified into a non-eccentric group. Clinical, angiographic, and echocardiographic findings of the two groups were compared. RESULTS ARD was significantly larger in the eccentric group than in the non-eccentric group (P = 0.049), and the difference was confirmed by multivariable analysis (P = 0.02). Subgroup analysis of patients aged <55 years showed similar result for ARD (P = 0.03), whereas hypertension was more associated with the non-eccentric group (P = 0.01). In addition, height was inversely related to aneurysm size after adjustment for age, sex, weight, ARD, smoking status, and number of aneurysms (P = 0.004). CONCLUSIONS A certain group of IA patients share a common intrinsic wall defect with aortopathy. Shared neural crest cell origin may give rise to this phenomenon.
OBJECTIVE Serum soluble corin has been associated with stroke. However, whether it is associated with stroke prognosis has not yet been studied. Therefore, we aimed to study the association of serum soluble corin with risk of poor outcomes within 3 months after stroke. METHODS We followed 522 stroke patients for 3 months to identify major disability, death and vascular events. Serum soluble corin was measured at baseline for all participants. Logistic regression was used to examine the associations of baseline serum soluble corin with outcomes of stroke, adjusting for age, sex, baseline NIHSS score, hours from onset to hospitalization, smoking, drinking, hypertension, diabetes, coronary heart disease, atrial fibrillation, family history of stroke, and stroke subtype. RESULTS Patients with high corin had a significantly lower crude risk for the composite outcome of major disability or death (OR = 0.64, 95%CI: 0.43-0.96) than patients with low corin (the lowest tertile). After adjustment for age and baseline NIHSS score, patients with high corin still had a significantly lower risk for the composite outcome of major disability or death (OR = 0.60, 95%CI: 0.36-0.99). This association became bottom line significant after additionally adjusting for other conventional factors (OR = 0.61, P = 0.058). No association was found between serum soluble corin and other composite outcomes. CONCLUSION Serum soluble corin deficiency predicted risk for major disability within 3 months after stroke, independent of baseline neurological deficient. Our results may indicate a probable role of corin in stroke prognosis.
PURPOSE Mutations in the leucine rich, glioma inactivated gene (LGI1) were recently described in a small number of families with autosomal dominant lateral temporal epilepsy (ADLTE). ADLTE is characterized by partial seizures with symptoms suggestive of a lateral temporal onset, including frequent auditory aura. Here we report the results of clinical and genetic analyses of two newly identified families with ADTLE. METHODS We identified two families whose seizure semiology was suggestive of ADLTE. Evaluation included a detailed history and neurologic examination, as well as collection of DNA. The coding sequence of the LGI1 gene from affected subjects from both families was analyzed for evidence of mutation. RESULTS Each patient had a history of partial seizures, often with secondary generalization earlier in the course. Auditory aura was reported by approximately two thirds of affected patients in each pedigree. Novel mutations in LGI1 were detected in both families. A heterozygous single-nucleotide deletion at position 329 (del 329C) was detected in affected individuals from one family, whereas patients from the second family had a nonsynonymous variation, corresponding to C435G. CONCLUSIONS We identified two novel mutations in the LGI1 gene. The phenotype of these two families was similar to that of other kindreds with ADLTE, as auditory aura was absent in one third of affected individuals. Our results further support that LGI1 mutations should be considered in patients with a history of partial seizures if the semiology of seizures is consistent with the onset in the lateral temporal lobe.
Coronary heart disease (CHD) patients often show atherosclerotic vascular disease in other vascular territories. We evaluated how often whole-body MR imaging detects concomitant arterial pathologies in CHD patients, and how often these pathologies were not known to the patients previously. Of 4,814 participants in the population-based Heinz Nixdorf Recall Study, 327 reported CHD (i.e., previous coronary bypass surgery, angioplasty); of those, 160 patients (mean age 66.4 years) were examined using MR of the brain, the heart (excluding the coronary arteries), and whole-body MR angiography. The prevalence of each vascular pathology was assessed, correlated to the others and compared to patients’ histories. Of the 160 CHD patients, 16 (10%) showed MR signs of stroke, and 77 (48.1%) had a stenosis >50% in at least one extracerebral peripheral artery (other than the coronaries), including 28 (17.5%) with relevant renal artery stenoses, and 20 (12.5%) with relevant extracerebral internal carotid artery stenoses. False negative histories were reported in 12 of 81 cases with myocardial infarctions, and in 11 of 16 cases with cerebrovascular infarctions. This whole-body atherosclerosis MR screening program allows previously unknown concomitant vascular disease to be detected in coronary heart disease patients. Its prospective value should be assessed in further studies.
OBJECTIVES We sought to determine which ICD-9-CM codes in Medicare Part A data identify cardiovascular and stroke risk factors. DESIGN AND PARTICIPANTS This was a cross-sectional study comparing ICD-9-CM data to structured medical record review from 23,657 Medicare beneficiaries aged 20 to 105 years who had atrial fibrillation. MEASUREMENTS Quality improvement organizations used standardized abstraction instruments to determine the presence of 9 cardiovascular and stroke risk factors. Using the chart abstractions as the gold standard, we assessed the accuracy of ICD-9-CM codes to identify these risk factors. MAIN RESULTS ICD-9-CM codes for all risk factors had high specificity (>0.95) and low sensitivity (< or =0.76). The positive predictive values were greater than 0.95 for 5 common, chronic risk factors-coronary artery disease, stroke/transient ischemic attack, heart failure, diabetes, and hypertension. The sixth common risk factor, valvular heart disease, had a positive predictive value of 0.93. For all 6 common risk factors, negative predictive values ranged from 0.52 to 0.91. The rare risk factors-arterial peripheral embolus, intracranial hemorrhage, and deep venous thrombosis-had high negative predictive value (> or =0.98) but moderate positive predictive values (range, 0.54-0.77) in this population. CONCLUSIONS Using ICD-9-CM codes alone, heart failure, coronary artery disease, diabetes, hypertension, and stroke can be ruled in but not necessarily ruled out. Where feasible, review of additional data (eg, physician notes or imaging studies) should be used to confirm the diagnosis of valvular disease, arterial peripheral embolus, intracranial hemorrhage, and deep venous thrombosis.
BACKGROUND AND PURPOSE There are only few small studies assessing potential risk factors, comorbidity, and prognostic factors in adult spontaneous cervicocerebral artery dissection (CAD). METHODS We conducted a retrospective, hospital-based analysis on the prognostic factors and association of CAD with vascular risk factors in 301 consecutive Finnish patients, diagnosed from 1994 to 2007. RESULTS Two thirds of the patients were men (68%). Women were younger than men. Migraine (36% of all patients), especially with visual aura (63% of all migraineurs), and smoking were more common in patients with CAD compared with the general Finnish population. At 3 months, 247 (83%) patients reached a favorable outcome. Occlusion of the dissected artery, internal carotid artery dissection (ICAD), and recent infection in infarction patients were associated with a poorer outcome. ICAD patients had less often brain infarction, but the strokes they had were more severe. Seven (2.3%) patients died during the follow-up (mean 4.0 years, 1186 patient years). Six (2%) patients had verified CAD recurrence. CONCLUSIONS This study provides evidence for the association of CAD with male sex, and possible association with smoking and migraine. Occlusion of the dissected artery, ICAD, and infection appear to be associated with poorer outcome.
In the adult brain, new neurons are continuously generated in the subventricular zone and dentate gyrus, but it is unknown whether these neurons can replace those lost following damage or disease. Here we show that stroke, caused by transient middle cerebral artery occlusion in adult rats, leads to a marked increase of cell proliferation in the subventricular zone. Stroke-generated new neurons, as well as neuroblasts probably already formed before the insult, migrate into the severely damaged area of the striatum, where they express markers of developing and mature, striatal medium-sized spiny neurons. Thus, stroke induces differentiation of new neurons into the phenotype of most of the neurons destroyed by the ischemic lesion. Here we show that the adult brain has the capacity for self-repair after insults causing extensive neuronal death. If the new neurons are functional and their formation can be stimulated, a novel therapeutic strategy might be developed for stroke in humans.
CONTEXT Clinicians and trialists have difficulty with identifying which patients are highest risk for cardiovascular events. Prior ischemic events, polyvascular disease, and diabetes mellitus have all been identified as predictors of ischemic events, but their comparative contributions to future risk remain unclear. OBJECTIVE To categorize the risk of cardiovascular events in stable outpatients with various initial manifestations of atherothrombosis using simple clinical descriptors. DESIGN, SETTING, AND PATIENTS Outpatients with coronary artery disease, cerebrovascular disease, or peripheral arterial disease or with multiple risk factors for atherothrombosis were enrolled in the global Reduction of Atherothrombosis for Continued Health (REACH) Registry and were followed up for as long as 4 years. Patients from 3647 centers in 29 countries were enrolled between 2003 and 2004 and followed up until 2008. Final database lock was in April 2009. MAIN OUTCOME MEASURES Rates of cardiovascular death, myocardial infarction, and stroke. RESULTS A total of 45,227 patients with baseline data were included in this 4-year analysis. During the follow-up period, a total of 5481 patients experienced at least 1 event, including 2315 with cardiovascular death, 1228 with myocardial infarction, 1898 with stroke, and 40 with both a myocardial infarction and stroke on the same day. Among patients with atherothrombosis, those with a prior history of ischemic events at baseline (n = 21,890) had the highest rate of subsequent ischemic events (18.3%; 95% confidence interval [CI], 17.4%-19.1%); patients with stable coronary, cerebrovascular, or peripheral artery disease (n = 15,264) had a lower risk (12.2%; 95% CI, 11.4%-12.9%); and patients without established atherothrombosis but with risk factors only (n = 8073) had the lowest risk (9.1%; 95% CI, 8.3%-9.9%) (P < .001 for all comparisons). In addition, in multivariable modeling, the presence of diabetes (hazard ratio [HR], 1.44; 95% CI, 1.36-1.53; P < .001), an ischemic event in the previous year (HR, 1.71; 95% CI, 1.57-1.85; P < .001), and polyvascular disease (HR, 1.99; 95% CI, 1.78-2.24; P < .001) each were associated with a significantly higher risk of the primary end point. CONCLUSION Clinical descriptors can assist clinicians in identifying high-risk patients within the broad range of risk for outpatients with atherothrombosis.
Seizures in focal epilepsies are sustained by a highly synchronous neuronal discharge that arises at restricted brain sites and subsequently spreads to large portions of the brain. Despite intense experimental research in this field, the earlier cellular events that initiate and sustain a focal seizure are still not well defined. Their identification is central to understand the pathophysiology of focal epilepsies and to develop new pharmacological therapies for drug-resistant forms of epilepsy. The prominent involvement of astrocytes in ictogenesis was recently proposed. We test here whether a cooperation between astrocytes and neurons is a prerequisite to support ictal (seizure-like) and interictal epileptiform events. Simultaneous patch-clamp recording and Ca2+ imaging techniques were performed in a new in vitro model of focal seizures induced by local applications of N-methyl-D-aspartic acid (NMDA) in rat entorhinal cortex slices. We found that a Ca2+ elevation in astrocytes correlates with both the initial development and the maintenance of a focal, seizure-like discharge. A delayed astrocyte activation during ictal discharges was also observed in other models (including the whole in vitro isolated guinea pig brain) in which the site of generation of seizure activity cannot be precisely monitored. In contrast, interictal discharges were not associated with Ca2+ changes in astrocytes. Selective inhibition or stimulation of astrocyte Ca2+ signalling blocked or enhanced, respectively, ictal discharges, but did not affect interictal discharge generation. Our data reveal that neurons engage astrocytes in a recurrent excitatory loop (possibly involving gliotransmission) that promotes seizure ignition and sustains the ictal discharge. This neuron-astrocyte interaction may represent a novel target to develop effective therapeutic strategies to control seizures.
Coarctation of the aorta (CofA) has been associated with an increased risk of intracranial aneurysm (IA). This magnetic resonance angiography (MRA) study investigates the prevalence of IAs in 80 children treated in early life for CofA. MRA was performed at mean age of 15.7 ± 7.1 years, and surgical or endovascular treatment for CofA occurred at a mean age of 2.6 ± 4.4 years. No IA was found. In contrast with earlier findings in adult patients with late treatment for CofA, this first systematic study of very early treated patients for CofA failed to confirm the association between CofA and IAs. Our results call the abnormal developmental relation between CofA and IAs into question and suggest that modifiable risk factors like hypertension may be responsible for IA development in patients with CofA with adult diagnosis and treatment. In conclusion, our data suggest that early treatment of CofA can reduce the formation of IAs in children so as to make MRA screening less valuable in this young population.
Observational clinical and ex vivo studies have established a strong association between atrial fibrillation and inflammation. However, whether inflammation is the cause or the consequence of atrial fibrillation and which specific inflammatory mediators may increase the atria's susceptibility to fibrillation remain elusive. Here we provide experimental and clinical evidence for the mechanistic involvement of myeloperoxidase (MPO), a heme enzyme abundantly expressed by neutrophils, in the pathophysiology of atrial fibrillation. MPO-deficient mice pretreated with angiotensin II (AngII) to provoke leukocyte activation showed lower atrial tissue abundance of the MPO product 3-chlorotyrosine, reduced activity of matrix metalloproteinases and blunted atrial fibrosis as compared to wild-type mice. Upon right atrial electrophysiological stimulation, MPO-deficient mice were protected from atrial fibrillation, which was reversed when MPO was restored. Humans with atrial fibrillation had higher plasma concentrations of MPO and a larger MPO burden in right atrial tissue as compared to individuals devoid of atrial fibrillation. In the atria, MPO colocalized with markedly increased formation of 3-chlorotyrosine. Our data demonstrate that MPO is a crucial prerequisite for structural remodeling of the myocardium, leading to an increased vulnerability to atrial fibrillation.
BACKGROUND Common carotid intima media thickness (CIMT) and ankle brachial pressure index (ABPI) are used as surrogate marker of atherosclerosis, and have been shown to correlate with arterial stiffness, however their correlation with global atherosclerotic burden has not been previously assessed. We compare CIMT and ABPI with atheroma burden as measured by whole body magnetic resonance angiography (WB-MRA). METHODS 50 patients with symptomatic peripheral arterial disease were recruited. CIMT was measured using ultrasound while rest and exercise ABPI were performed. WB-MRA was performed in a 1.5T MRI scanner using 4 volume acquisitions with a divided dose of intravenous gadolinium gadoterate meglumine (Dotarem, Guerbet, FR). The WB-MRA data was divided into 31 anatomical arterial segments with each scored according to degree of luminal narrowing: 0 = normal, 1 = <50%, 2 = 50-70%, 3 = 70-99%, 4 = vessel occlusion. The segment scores were summed and from this a standardized atheroma score was calculated. RESULTS The atherosclerotic burden was high with a standardised atheroma score of 39.5±11. Common CIMT showed a positive correlation with the whole body atheroma score (β 0.32, p = 0.045), however this was due to its strong correlation with the neck and thoracic segments (β 0.42 p = 0.01) with no correlation with the rest of the body. ABPI correlated with the whole body atheroma score (β -0.39, p = 0.012), which was due to a strong correlation with the ilio-femoral vessels with no correlation with the thoracic or neck vessels. On multiple linear regression, no correlation between CIMT and global atheroma burden was present (β 0.13 p = 0.45), while the correlation between ABPI and atheroma burden persisted (β -0.45 p = 0.005). CONCLUSION ABPI but not CIMT correlates with global atheroma burden as measured by whole body contrast enhanced magnetic resonance angiography in a population with symptomatic peripheral arterial disease. However this is primarily due to a strong correlation with ilio-femoral atheroma burden.
BACKGROUND The MTHFR 677C→T polymorphism has been associated with raised homocysteine concentration and increased risk of stroke. A previous overview showed that the effects were greatest in regions with low dietary folate consumption, but differentiation between the effect of folate and small-study bias was difficult. A meta-analysis of randomised trials of homocysteine-lowering interventions showed no reduction in coronary heart disease events or stroke, but the trials were generally set in populations with high folate consumption. We aimed to reduce the effect of small-study bias and investigate whether folate status modifies the association between MTHFR 677C→T and stroke in a genetic analysis and meta-analysis of randomised controlled trials. METHODS We established a collaboration of genetic studies consisting of 237 datasets including 59,995 individuals with data for homocysteine and 20,885 stroke events. We compared the genetic findings with a meta-analysis of 13 randomised trials of homocysteine-lowering treatments and stroke risk (45,549 individuals, 2314 stroke events, 269 transient ischaemic attacks). FINDINGS The effect of the MTHFR 677C→T variant on homocysteine concentration was larger in low folate regions (Asia; difference between individuals with TT versus CC genotype, 3·12 μmol/L, 95% CI 2·23 to 4·01) than in areas with folate fortification (America, Australia, and New Zealand, high; 0·13 μmol/L, -0·85 to 1·11). The odds ratio (OR) for stroke was also higher in Asia (1·68, 95% CI 1·44 to 1·97) than in America, Australia, and New Zealand, high (1·03, 0·84 to 1·25). Most randomised trials took place in regions with high or increasing population folate concentrations. The summary relative risk (RR) of stroke in trials of homocysteine-lowering interventions (0·94, 95% CI 0·85 to 1·04) was similar to that predicted for the same extent of homocysteine reduction in large genetic studies in populations with similar folate status (predicted RR 1·00, 95% CI 0·90 to 1·11). Although the predicted effect of homocysteine reduction from large genetic studies in low folate regions (Asia) was larger (RR 0·78, 95% CI 0·68 to 0·90), no trial has evaluated the effect of lowering of homocysteine on stroke risk exclusively in a low folate region. INTERPRETATION In regions with increasing levels or established policies of population folate supplementation, evidence from genetic studies and randomised trials is concordant in suggesting an absence of benefit from lowering of homocysteine for prevention of stroke. Further large-scale genetic studies of the association between MTHFR 677C→T and stroke in low folate settings are needed to distinguish effect modification by folate from small-study bias. If future randomised trials of homocysteine-lowering interventions for stroke prevention are undertaken, they should take place in regions with low folate consumption. FUNDING Full funding sources listed at end of paper (see Acknowledgments).