Migraine-Associated Common Genetic Variants Confer Greater Risk of Posterior vs. Anterior Circulation Ischemic Stroke☆

OBJECTIVE

To examine potential genetic relationships between migraine and the two distinct phenotypes posterior circulation ischemic stroke (PCiS) and anterior circulation ischemic stroke (ACiS), we generated migraine polygenic risk scores (PRSs) and compared these between PCiS and ACiS, and separately vs. non-stroke control subjects.

METHODS

Acute ischemic stroke cases were classified as PCiS or ACiS based on lesion location on diffusion-weighted MRI. Exclusion criteria were lesions in both vascular territories or uncertain territory; supratentorial PCiS with ipsilateral fetal posterior cerebral artery; and cases with atrial fibrillation. We generated migraine PRS for three migraine phenotypes (any migraine; migraine without aura; migraine with aura) using publicly available GWAS data and compared mean PRSs separately for PCiS and ACiS vs. non-stroke control subjects, and between each stroke phenotype.

RESULTS

Our primary analyses included 464 PCiS and 1079 ACiS patients with genetic European ancestry. Compared to non-stroke control subjects (n=15396), PRSs of any migraine were associated with increased risk of PCiS (p=0.01-0.03) and decreased risk of ACiS (p=0.010-0.039). Migraine without aura PRSs were significantly associated with PCiS (p=0.008-0.028), but not with ACiS. When comparing PCiS vs. ACiS directly, migraine PRSs were higher in PCiS vs. ACiS for any migraine (p=0.001-0.010) and migraine without aura (p=0.032-0.048). Migraine with aura PRS did not show a differential association in our analyses.

CONCLUSIONS

Our results suggest a stronger genetic overlap between unspecified migraine and migraine without aura with PCiS compared to ACiS. Possible shared mechanisms include dysregulation of cerebral vessel endothelial function.

Detailed phenotyping of posterior vs. anterior circulation ischemic stroke: a multi-center MRI study

OBJECTIVE

Posterior circulation ischemic stroke (PCiS) constitutes 20-30% of ischemic stroke cases. Detailed information about differences between PCiS and anterior circulation ischemic stroke (ACiS) remains scarce. Such information might guide clinical decision making and prevention strategies. We studied risk factors and ischemic stroke subtypes in PCiS vs. ACiS and lesion location on magnetic resonance imaging (MRI) in PCiS.

METHODS

Out of 3,301 MRIs from 12 sites in the National Institute of Neurological Disorders and Stroke (NINDS) Stroke Genetics Network (SiGN), we included 2,381 cases with acute DWI lesions. The definition of ACiS or PCiS was based on lesion location. We compared the groups using Chi-squared and logistic regression.

RESULTS

PCiS occurred in 718 (30%) patients and ACiS in 1663 (70%). Diabetes and male sex were more common in PCiS vs. ACiS (diabetes 27% vs. 23%, p < 0.05; male sex 68% vs. 58%, p < 0.001). Both were independently associated with PCiS (diabetes, OR = 1.29; 95% CI 1.04-1.61; male sex, OR = 1.46; 95% CI 1.21-1.78). ACiS more commonly had large artery atherosclerosis (25% vs. 20%, p < 0.01) and cardioembolic mechanisms (17% vs. 11%, p < 0.001) compared to PCiS. Small artery occlusion was more common in PCiS vs. ACiS (20% vs. 14%, p < 0.001). Small artery occlusion accounted for 47% of solitary brainstem infarctions.

CONCLUSION

Ischemic stroke subtypes differ between the two phenotypes. Diabetes and male sex have a stronger association with PCiS than ACiS. Definitive MRI-based PCiS diagnosis aids etiological investigation and contributes additional insights into specific risk factors and mechanisms of injury in PCiS.

Subsyndromal delirium is associated with poor functional outcome after ischaemic stroke

BACKGROUND AND PURPOSE

Subsyndromal delirium (SSD) refers to patients with delirious symptoms who do not meet the criteria for delirium. The aim was to determine the prognostic significance of SSD in stroke patients.

METHODS

In all, 564 patients with ischaemic stroke (median age 71 years, 50.5% female) were included. The Confusion Assessment Method was used to assess symptoms of delirium and the Diagnostic and Statistical Manual of Mental Disorders, 5th edn, criteria were used to diagnose delirium. SSD was defined as one or more core features of delirium without fulfilling diagnostic criteria. Functional outcome was assessed using the modified Rankin Scale at 3 and 12 months after stroke.

RESULTS

Delirium was diagnosed in 23.4% of patients and SSD in 10.3% of patients. SSD was associated with increased risk of poor functional outcome. The adjusted odds ratios (ORs) for unfavourable outcome at 3 and 12 months were 2.88 [95% confidence interval (CI) 1.43-5.79, P < 0.01] and 2.93 (95% CI 1.39-6.22, P < 0.01), respectively. In multivariate analysis, delirium was an independent predictor of poor functional outcome at 3 months (OR 6.41, 95% CI 3.36-12.21, P < 0.01) and 12 months (OR 6.11, 95% CI 3.05-12.27, P < 0.01) after stroke. Delirium was also independently associated with increased risk of death within 3 months (hazard ratio 3.68, 95% CI 1.69-8.02, P < 0.01) and 12 months (hazard ratio 3.76, 95% CI 2.05-6.90, P < 0.01). SSD was not associated with increased risk of death.

CONCLUSIONS

In SSD patients the risk of poor functional outcome after stroke is increased and intermediate between patients with and patients without delirium.

Brain inflammasomes in stroke and depressive disorders: Regulation by oestrogen

Neuroinflammation is a devastating pathophysiological process that results in brain damage and neuronal death. Pathogens, cell fragments and cellular dysfunction trigger inflammatory responses. Irrespective of the cause, inflammasomes are key intracellular multiprotein signalling platforms that sense neuropathological conditions. The activation of inflammasomes leads to the auto-proteolytic cleavage of caspase-1, resulting in the proteolysis of the pro-inflammatory cytokines interleukin (IL)1β and IL18 into their bioactive forms. It also initiates pyroptosis, a type of cell death. The two cytokines contribute to the pathogenesis in acute and chronic brain diseases and also play a central role in human aging and psychiatric disorders. Sex steroids, in particular oestrogens, are well-described neuroprotective agents in the central nervous system. Oestrogens improve the functional outcome after ischaemia and traumatic brain injury, reduce neuronal death in Parkinson's and Alzheimer's disease, as well as in amyotrophic lateral sclerosis, attenuate glutamate excitotoxicity and the formation of radical oxygen species, and lessen the spread of oedema after damage. Moreover, oestrogens alleviate menopause-related depressive symptoms and have a positive influence on depressive disorders probably by influencing growth factor production and serotonergic brain circuits. Recent evidence also suggests that inflammasome signalling affects anxiety- and depressive-like behaviour and that oestrogen ameliorates depression-like behaviour through the suppression of inflammasomes. In the present review, we highlight the most recent findings demonstrating that oestrogens selectively suppress the activation of the neuroinflammatory cascade in the brain in acute and chronic brain disease models. Furthermore, we aim to describe putative regulatory signalling pathways involved in the control of inflammasomes. Finally, we consider that psychiatric disorders such as depression also contain an inflammatory component that could be modulated by oestrogen.

Thrombolysis and thrombectomy in patients treated with dabigatran with acute ischemic stroke: Expert opinion

Systemic thrombolysis with rt-PA is contraindicated in patients with acute ischemic stroke anticoagulated with dabigatran. This expert opinion provides guidance on the use of the specific reversal agent idarucizumab followed by rt-PA and/or thrombectomy in patients with ischemic stroke pre-treated with dabigatran. The use of idarucizumab followed by rt-PA is covered by the label of both drugs.

The sphingosine 1-phosphate receptor agonist FTY720 is neuroprotective after cuprizone-induced CNS demyelination

BACKGROUND AND PURPOSE

Modulation of the sphingosine 1-phosphate receptor is an approved treatment for relapsing multiple sclerosis because of its anti-inflammatory effect of retaining lymphocytes within the lymph nodes. Here, we evaluated the potential of an agonist at this receptor, FTY720 (fingolimod), to activate the promyelinating pathways within the brain to encourage remyelination and neuroprotection.

EXPERIMENTAL APPROACH

In this study, we used the cuprizone model in male C57BL/6 mice and tested the promyelinating and neuroprotective effects of FTY720 after acute and chronic toxin-induced experimental demyelination. We used histological, immunohistochemical and gene expression methods.

KEY RESULTS

The midline of the corpus callosum was severely demyelinated after acute and chronic cuprizone-induced demyelination. Robust endogenous remyelination was evident after acute, but impaired after chronic, demyelination. FTY720 treatment modestly accelerated myelin recovery after acute but not chronic cuprizone exposure. Markers of gliosis (astrocyte and microglia activation) were not affected by FTY720 treatment. Remarkably, the accumulation of amyloid precursor protein-positive spheroids in axons was less distinct in FTY720-treated animals, indicating that this compound alleviated ongoing axonal damage.

CONCLUSIONS AND IMPLICATIONS

We show that even during endogenous remyelination, axonal degeneration continued at a low level, accumulating over time. This continuous neurodegenerative process was ameliorated by FTY720 treatment. FTY720 preserved CNS integrity by direct interaction with brain resident cells, the actions of which are still to be defined.

Clinical presentation of early-onset Alzheimer's disease as a result of mutation in exon 12 of the PSEN-1 gene

INTRODUCTION

Mutations in the gene for presenilin 1 (PSEN-1) cause familial, early-onset Alzheimer's disease (EOAD). Diagnosis of EOAD is often a challenge because of the high frequency of atypical presentations. Clinical manifestation of EOAD may vary depending on underlying mutation; specific genetic mutations influence development of specific clinical phenotypes; however, intrafamilial phenotypic heterogeneity has also been noted in some pedigrees.

CASE PRESENTATION

We report a case of a 36-year-old woman presenting with progressive behavioral disturbances, dementia, involuntary movements, pyramidal signs, epilepsy, and a family history of early-onset dementia accompanied by involuntary movements. On genetic testing, the mutation at codon 424 (Leu→Arg) in PSEN-1 gene was identified.

CONCLUSION

Our case describes a new phenotype of a known mutation of PSEN-1 at codon 424.

Electrophysiological correlates of attentional processes in patients with liver cirrhosis without minimal or clinically-overt hepatic encephalopathy

Liver cirrhosis is often accompanied by a spectrum of cognitive deficits, labelled hepatic encephalopathy (HE). The precise specification of cognitive impairment associated with HE has not been yet elucidated. The aim of this study was an attempt to examine cortical function in cirrhotic patients using EEG event-related potentials during a demanding task involving selective attention. We compared group of 30 patients with liver cirrhosis without minimal or overt HE with education-, age- and sex-matched 29 non-cirrhotic controls. Both groups performed an attentional blink (AB) task, which requires detecting and identifying two target characters in a longer series of rapidly and sequentially presented characters. EEG signals from 32 electrodes were measured and then analyzed in the paradigm of event-related potentials (ERP). Though the groups did not differ in the detection rate of the target stimuli, ERP waveforms revealed two group differences of component amplitudes. The first difference was related to the waveform amplitude within the 200-400 ms after first target in the right frontal region (frontocentral N2 component). Moreover, in patient group this amplitude positively correlated with the blood plasma level of alkaline phosphatase and gamma-glutamyl transpeptidase. The second amplitude difference was observed in the midline parieto-occipital regions within the 400-600 ms after the first target (P3b component). The AB task and ERP analysis allowed to find differences in cortical functioning in cirrhotic patients even without overt cognitive deficits. Our finding demonstrates that liver dysfunction can influence cortical processing associated with detecting and categorizing stimulus change.

Cognitive evoked response potentials in patients with liver cirrhosis without diagnosis of minimal or overt hepatic encephalopathy. A pilot study

Liver cirrhosis is often accompanied by cognitive deficits called minimal hepatic encephalopathy (MHE) when it is observed to a moderate extent. In the present study, brain activity and cognitive functioning were examined in patients with liver cirrhosis without MHE or overt clinical hepatic encephalopathy. A battery of neuropsychological tests and event related potentials (ERPs) were used. Moreover, an additional n-back task was administered with two difficulty levels (1- and 2-back). This task was designed to engage cognitive processes of storage and manipulation of information in working memory. The participants have to decide whether the letter shown was the same as a target (congruence condition). No significant differences were found in the performance of either the neuropsychological tests or the n-back task. However, the expected effects of decreased performance as well as a decrease in P3 amplitude with difficulty level were identified. The interaction of group x congruence condition was also observed in the P2 component time window. These results may indicate group differences manifesting in early stages of information processing in working memory. It confirms that the patients whose neuropsychological performance is within the normal range can still reveal subtle changes in CNS functioning visible in ERP research. The study confirms the usability of the ERP method in diagnosis of neurocognitive functions in patients with liver cirrhosis, which seems to be more sensitive than neuropsychological tests.

Interleukin 6-174G>C polymorphism and risk of aneurysmal subarachnoid hemorrhage: case-control study and meta-analysis

OBJECTIVES

Vascular inflammation contributes to the pathogenesis of aneurysmal subarachnoid hemorrhage (aSAH). Interleukin 6 (IL6) is a proinflammatory cytokine involved in many vascular pathologies. Two studies analyzing an association of the functional IL6 gene -174G>C promoter polymorphism with aSAH provided inconsistent results. The aim of this study was to investigate whether this IL6 polymorphism is associated with aSAH in a Polish population.

MATERIAL AND METHODS

We genotyped 276 aSAH patients and 581 unrelated control subjects. All were of Caucasian origin. In addition, a meta-analysis combining results of the current and previously published studies was conducted.

RESULTS

The distribution of IL6 genotypes and alleles did not differ significantly between aSAH (GG - 29.7%, GC - 50.0%, CC - 20.2%, G - 54.7%) and control subjects (GG - 32.0%, GC - 47.3%, CC - 20.7%, G - 44.3%). In the meta-analysis, the IL6-174G>C polymorphism was not associated with aSAH risk either.

CONCLUSIONS

We failed to find an association between the IL6 -174G>C polymorphism and aSAH in analyzed European populations.

Genetic variation at CR1 increases risk of cerebral amyloid angiopathy

OBJECTIVE

Accumulated evidence suggests that a variant within the CR1 gene (single nucleotide polymorphism rs6656401), known to increase risk for Alzheimer disease (AD), influences β-amyloid (Aβ) deposition in brain tissue. Given the biologic overlap between AD and cerebral amyloid angiopathy (CAA), a leading cause of intracerebral hemorrhage (ICH) in elderly individuals, we investigated whether rs6656401 increases the risk of CAA-related ICH and influences vascular Aβ deposition.

METHODS

We performed a case-control genetic association study of 89 individuals with CAA-related ICH and 280 individuals with ICH unrelated to CAA and compared them with 324 ICH-free control subjects. We also investigated the effect of rs6656401 on risk of recurrent CAA-ICH in a prospective longitudinal cohort of ICH survivors. Finally, association with severity of histopathologic CAA was investigated in 544 autopsy specimens from 2 longitudinal studies of aging.

RESULTS

rs6656401 was associated with CAA-ICH (odds ratio [OR] = 1.61, 95% confidence interval [CI] 1.19-2.17, p = 8.0 × 10(-4)) as well as with risk of recurrent CAA-ICH (hazard ratio = 1.35, 95% CI 1.04-1.76, p = 0.024). Genotype at rs6656401 was also associated with severity of CAA pathology at autopsy (OR = 1.34, 95% CI 1.05-1.71, p = 0.009). Adjustment for parenchymal amyloid burden did not cancel this effect, suggesting that, despite the correlation between parenchymal and vascular amyloid pathology, CR1 acts independently on both processes, thus increasing risk of both AD and CAA.

CONCLUSION

The CR1 variant rs6656401 influences risk and recurrence of CAA-ICH, as well as the severity of vascular amyloid deposition.

Paraoxonase 1 gene polymorphisms do not influence the response to treatment in Alzheimer's disease

BACKGROUND

Acetylcholinesterase inhibitors (AChEIs) are the treatment of choice for patients with Alzheimer's disease (AD). However, their efficacy is moderate and differs from patient to patient. Recent studies suggest that the Q192R variant of the paraoxonase 1 gene (PON1) might affect individual susceptibility to these drugs.

METHODS

We investigated the influence of 3 single nucleotide polymorphisms (SNPs) in PON1 (rs 662, rs 854560, rs 705381) and the APOE common polymorphism in 101 Polish patients with late-onset AD in response to treatment with AChEIs.

RESULTS

No significant differences were observed between carriers and non-carriers of the PON1 SNPs or the APOE common polymorphism in terms of treatment response. These results did not change after stratification of APOE status.

CONCLUSION

Our results suggest that both the investigated PON1 and APOE common SNPs do not influence treatment response to AChEIs in patients with AD.

Paraoxonase gene polymorphism and the risk for Alzheimer's disease in the polish population

BACKGROUND

The relationship between different paraoxonase (PON) gene polymorphisms and the risk of Alzheimer's disease (AD) was studied several times and the results were controversial.

METHODS

We investigated the association of 4 single-nucleotide polymorphisms (SNPs) of the PON1 (M55L; Q192R; -161C/T) and the PON2 (C311S) genes that were shown to affect the risk of sporadic AD. We studied 360 Caucasian cases with late-onset AD and 354 nondemented controls.

RESULTS

No significant differences were observed between the studied PON SNPs and AD risk. The results did not change after stratification of the apolipoprotein E status. Meta-analyses of studies in Caucasians assessing the associations between the PON1 M55L, -161C/T and Q192R SNPs and the risk of AD were performed, and no associations were found.

CONCLUSION

Our results suggest that the studied PON1 and PON2 polymorphisms are not associated with late-onset AD.

Tau levels do not influence human ALS or motor neuron degeneration in the SOD1G93A mouse

BACKGROUND

The microtubule-associated protein tau is thought to play a pivotal role in neurodegeneration. Mutations in the tau coding gene MAPT are a cause of frontotemporal dementia, and the H1/H1 genotype of MAPT, giving rise to higher tau expression levels, is associated with progressive supranuclear palsy, corticobasal degeneration, and Parkinson disease (PD). Furthermore, tau hyperphosphorylation and aggregation is a hallmark of Alzheimer disease (AD), and reducing endogenous tau has been reported to ameliorate cognitive impairment in a mouse model for AD. Tau hyperphosphorylation and aggregation have also been described in amyotrophic lateral sclerosis (ALS), both in human patients and in the mutant SOD1 mouse model for this disease. However, the precise role of tau in motor neuron degeneration remains uncertain.

METHODS

The possible association between ALS and the MAPT H1/H2 polymorphism was studied in 3,540 patients with ALS and 8,753 controls. Furthermore, the role of tau in the SOD1(G93A) mouse model for ALS was studied by deleting Mapt in this model.

RESULTS

The MAPT genotype of the H1/H2 polymorphism did not influence ALS susceptibility (odds ratio = 1.08 [95% confidence interval 0.99-1.18], p = 0.08) and did not affect the clinical phenotype. Lowering tau levels in the SOD1(G93A) mouse failed to delay disease onset (p = 0.302) or to increase survival (p = 0.557).

CONCLUSION

These findings suggest that the H1/H2 polymorphism in MAPT is not associated with human amyotrophic lateral sclerosis, and that lowering tau levels in the mutant SOD1 mouse does not affect the motor neuron degeneration in these animals.

Interleukin-1 gene -511 CT polymorphism and the risk of Alzheimer's disease in a Polish population

Interleukin-1 is a potent proinflammatory cytokine involved in the pathophysiology of Alzheimer's disease (AD). We genotyped IL-1beta (-511 C/T) and the apolipoprotein E (APOE) common polymorphisms in a large case-controlled study in a Polish population. We included 332 patients with late-onset AD and 220 controls without any neurological deficit, cognitive complaints and history of neurological diseases, aged > or = 65 years. The distribution of the IL-1beta (-511 C/T) genotypes was similar to that in the controls (AD: C/C = 45.8%, C/T = 44.6%, T/T = 9.6% vs. controls: C/C = 53.9%, C/T = 38.3%, T/T = 7.3%, p > 0.05). Our study confirms previous reports that APOE epsilon4 is strongly related to the risk of AD (odds ratio = 6.60, 95% confidence interval 4.19-10.41). APOE status did not affect the distribution of the studied IL-1beta polymorphism. The IL-1beta (-511 C/T) polymorphism is not a risk factor for late-onset AD in a Polish population.

A-G-4G haplotype of PAI-1 gene polymorphisms -844 G/A, HindIII G/C, and -675 4G/5G is associated with increased risk of ischemic stroke caused by small vessel disease

BACKGROUND

Plasminogen activator inhibitor type 1 (PAI-1) is the major inhibitor of fibrinolysis. It was reported that PAI-1 gene polymorphisms affected PAI-1 level and might therefore influence the risk of vascular diseases, including stroke. We studied the association of three common polymorphisms in PAI-1 gene (-844 G/A, -675 4G/5G, and HindIII G/C) with the odds of different causes of ischemic stroke.

METHODS

We studied 390 patients with ischemic stroke due to large vessel disease (n = 117), small vessel disease (n = 121), and cardioembolism (n = 152) as well as 291 controls. The etiology of ischemic stroke was established using TOAST criteria. PAI-1 polymorphisms were genotyped with restriction fragment length polymorphism and single strand conformation polymorphism method.

RESULTS

A-G-4G haplotype of PAI-1 gene was found more frequently in stroke patients with small vessel disease than in control subjects (44.9% vs 35.7%; P = 0.02). No association was found between investigated genotype or allele frequencies and distinct causes of ischemic stroke.

CONCLUSIONS

Our results demonstrate that A-G-4G PAI-1 gene haplotype is associated with increased risk of small vessel disease stroke, but this study does not support an association of -844 G/A, -675 4G/5G, and HindIII G/C PAI-1 gene polymorphisms with particular etiology of ischemic stroke.

A large-scale international meta-analysis of paraoxonase gene polymorphisms in sporadic ALS

BACKGROUND

Six candidate gene studies report a genetic association of DNA variants within the paraoxonase locus with sporadic amyotrophic lateral sclerosis (ALS). However, several other large studies, including five genome-wide association studies, have not duplicated this finding.

METHODS

We conducted a meta-analysis of 10 published studies and one unpublished study of the paraoxonase locus, encompassing 4,037 ALS cases and 4,609 controls, including genome-wide association data from 2,018 ALS cases and 2,425 controls.

RESULTS

The combined fixed effects odds ratio (OR) for rs662 (PON1 Q192R) was 1.09 (95% confidence interval [CI], 1.02-1.16, p = 0.01); the genotypic OR for RR homozygotes at Q192R was 1.25 (95% CI, 1.07-1.45, p = 0.0004); the combined OR for rs854560 (PON1 L55M) was 0.97 (95% CI, 0.86-1.10, p = 0.62); the OR for rs10487132 (PON2) was 1.08 (95% CI, 0.92-1.27, p = 0.35). Although the rs662 polymorphism reached a nominal level of significance, no polymorphism was significant after multiple testing correction. In the subanalysis of samples with genome-wide data from which population outliers were removed, rs662 had an OR of 1.06 (95% CI, 0.97-1.16, p = 0.22).

CONCLUSIONS

In contrast to previous positive smaller studies, our genetic meta-analysis showed no significant association of amyotrophic lateral sclerosis (ALS) with the PON locus. This is the largest meta-analysis of a candidate gene in ALS to date and the first ALS meta-analysis to include data from whole genome association studies. The findings reinforce the need for much larger and more collaborative investigations of the genetic determinants of ALS.

Prefrontal N-acetylaspartate and poststroke recovery: a longitudinal proton spectroscopy study

BACKGROUND AND PURPOSE

Functional imaging studies suggest that poststroke recovery is related to the reorganization in both contralesional and ipsilesional prefrontal cortex. Little is known, however, about how longitudinal metabolic changes in prefrontal regions relate to the improvement after stroke. We sought to determine whether poststroke recovery is associated with changes in N-acetylaspartate/creatine (NAA/Cr) ratio within contralesional prefrontal regions.

MATERIALS AND METHODS

Twenty-seven patients with a first ischemic stroke located outside the frontal lobes were included. Proton MR spectroscopy ((1)H-MRS) was performed on a 1.5T scanner. Point-resolved spectroscopy sequence (PRESS) was used. NAA/Cr was measured both in ipsilesional and contralesional prefrontal regions in early (14 +/- 6 days after stroke) and chronic phases of the disease (110 +/- 30 days after). Patients' neurologic status was assessed using Scandinavian Stroke Scale (SSS) at discharge from the stroke unit and during second (1)H-MRS examination.

RESULTS

Subjects showing increased contralesional NAA/Cr from first to follow-up examination improved significantly more on the SSS than patients not showing this increase. Analysis was performed while correcting for change in NAA/Cr levels in the ipsilesional hemisphere. For the whole group, the change in contralesional NAA/Cr was significantly correlated to the change in SSS scores (r = 0.40, P = .03). Change in the ipsilesional NAA/Cr measures did not correlate with the change in SSS scores.

CONCLUSION

Poststroke recovery was related to the increase in contralesional prefrontal NAA/Cr. This association may reflect recovery mechanisms involving the nonaffected hemisphere. Further assessment of these regions may provide information about mechanisms contributing to neurologic improvement.

Hypoalbuminemia in acute ischemic stroke patients: frequency and correlates

OBJECTIVE

Hypoalbuminemia in acute stroke patients is associated with increased mortality and morbidity. The aim of our study was to determine the frequency and correlates of hypoalbuminemia in unselected cohort of patients with acute cerebral infarction.

DESIGN

Prospective study.

SETTING

University hospital.

SUBJECTS

Seven hundred and five consecutive ischemic stroke patients.

METHODS

Albumin and other serum protein fractions were measured within 36 h after stroke using electrophoresis.

RESULTS

Hypoalbuminemia defined as serum albumin level <35 g/l was found in 45.5% of patients. Serum albumin level correlates significantly with age (r=-0.13, P<0.01), Scandinavian Stroke Scale score (r=0.14, P<0.01), body temperature on admission (r=0.14, P<0.01), leukocyte count (r=-0.17, P<0.01), fasting glucose (r=-0.16, P<0.01), total cholesterol (r=0.14, P<0.01), alpha1-globulin (r=-0.48, P<0.01), alpha2-globulin (r=-0.49, P<0.01), beta-globulin (r=-0.26, P<0.01) and gamma-globulin (r=-0.35, P<0.01).

CONCLUSIONS

Hypoalbuminemia is a frequent finding in acute stroke patients and it is associated with more severe stroke and pro-inflammatory pattern of serum protein electrophoresis.

ACE I/D polymorphism in different etiologies of ischemic stroke

OBJECTIVES

Data concerning an association between angiotensin-converting enzyme (ACE) gene insertion/deletion (I/D) polymorphism and ischemic stroke (IS) remain inconsistent. Results of some studies suggest that DD genotype may be a risk factor for small vessel disease (SVD) stroke. Here, we investigated whether this polymorphism is associated with IS of different etiologies in a Polish population.

SUBJECTS AND METHODS

Ischemic stroke etiology was established according to the TOAST criteria. We studied 92 stroke patients with large vessel disease and their 184 matched controls; 96 stroke patients with SVD and 192 controls; 180 patients with cardioembolic stroke (CE) and 180 controls. ACE I/D polymorphism was determined using the polymerase chain reaction method.

RESULTS

The distribution of ACE genotypes and alleles was essentially the same in all analyzed IS subtypes and their matched controls.

CONCLUSIONS

We failed to find an association between ACE polymorphism and etiological subtypes of IS in a Polish population.

Paraoxonase gene polymorphisms and sporadic ALS

BACKGROUND

The human paraoxonase (PON) gene family consists of three members, PON1, PON2, and PON3, located adjacent to each other on chromosome 7. PON catalytic activity may be influenced by frequent amino acid variants. Chronic exposure to certain chemicals or to environmental factors causing enhanced lipid peroxidation metabolized by paraoxonases may be a risk factor for sporadic ALS (sALS).

OBJECTIVE

The aim of this study was to examine the association between PON1 Q192R, PON1 L55M, and PON2 C311S functional polymorphisms and the risk of sALS in a Polish population.

METHODS

The authors included 185 patients with a definite or probable diagnosis of sALS (El Escorial Criteria) and 437 healthy controls of similar age and gender. The paraoxonase polymorphisms were studied by PCR and restriction enzyme digestion.

RESULTS

Using logistic regression analyses, the C allele of the C311S polymorphism was associated with sALS in dominant and additive models, whereas the R allele of the Q192R polymorphism was associated with sALS in recessive, additive, and dominant models. The authors compared the distribution of haplotypes between cases and controls. The R-C haplotype was overrepresented among cases (odds ratio 3.44, 95% CI: 1.55 to 7.62, p = 0.002).

CONCLUSIONS

Frequent amino acid variants in the paraoxonase 1 and paraoxonase 2 genes are associated with sporadic ALS in a Polish population.

Serum albumin level and nosocomial pneumonia in stroke patients

Hypoalbuminemia is associated with increased risk of infections. The aim of this study was to determine if serum albumin level is an independent predictor of nosocomial pneumonia in stroke patients. Data of 705 consecutive ischemic stroke patients admitted within 24 h after stroke onset were analyzed retrospectively. Serum albumin level was measured within 36 h after stroke onset. Nosocomial pneumonia was found in 10.5% of stroke patients. Patients with pneumonia had significantly lower serum albumin level than those without pneumonia (31.9 +/- 7.5 g/l vs. 35.5 +/- 6.9 g/l) and serum albumin level was associated with risk of pneumonia on multivariate analysis (OR: 0.95, 95% CI: 0.91-0.98). Our results show that serum albumin level is an independent predictor of nosocomial pneumonia in stroke patients.

DD genotype of ACE gene is a risk factor for intracerebral hemorrhage

Genetic factors may play a role in susceptibility to stroke. The angiotensin converting enzyme (ACE) gene is a candidate gene for two phenotypically different types of stroke affecting small perforating arteries: spontaneous intracerebral hemorrhage (SIH) and ischemic stroke due to small vessel disease (SVD). The authors report evidence that ACE gene DD homozygosity of the I/D polymorphism in intron 16 is an independent risk factor for SIH, and not for SVD stroke, in a Polish population.

Serum interleukin-6 predicts cortisol release in acute stroke patients

Altered hypothalamo-pituitary-adrenal axis was reported in stroke patients; however, mechanisms responsible for this phenomenon are barely understood. Acute cerebral ischemia triggers interleukin-6 (IL-6) release into blood. Circulating IL-6 can stimulate hypothalamo-pituitary-adrenal axis. The goal of our study was to assess a relationship between serum IL-6 and cortisol in acute ischemic stroke. Twenty two patients with ischemic stroke and 17 controls were included. Serum samples were collected on the 2nd day of stroke at 6:00, 10:00 18:00, 22:00 h and at the same time points in control group. Cytokines and cortisol levels were measured using ELISA method. Serum IL-6 and cortisol levels were higher in stroke patients than in controls. Cortisol displayed diurnal variations in both stroke patients and controls. In contrast with control subjects, serum IL-6 levels did not display diurnal variations in stroke patients. In stroke patients, but not in controls, IL-6 level correlated significantly with cortisol level and morning serum IL-6 level independently predicted evening/night cortisol level. In conclusion, brain ischemia could stimulate IL-6 release in blood and in this way modulate hypothalamo-pituitary-adrenal axis.

Transient hyperglycemia in ischemic stroke patients

The aim of the study was to investigate glucose derangement and its short- and long-term prognostic significance in nondiabetic ischemic stroke patients. The study involved 262 consecutive patients, mean age: 70.1+/-12.4 years, with a supratentorial ischemic stroke. The following data were collected: patients characteristics, risk factors, comorbidities, and stroke severity assessed by the Scandinavian Stroke Scale (SSS). Serum glucose levels were measured on admission, on the next, 2nd, 3rd, 5th, 7th and 14th day after stroke onset. The outcome measures on day 30 were mortality and capacity to perform daily activities: the Barthel Index and Rankin Scale. The 1-year survival was estimated by the Kaplan-Meier method. Cox proportional hazards regression was used to assess predictors of 1-year mortality in nondiabetics. Diabetes mellitus was found in 24.8% of patients and transient hyperglycemia in 36.3% of patients. Patients with transient hyperglycemia scored lower on SSS in the subsequent days of assessment than patients with either diabetes mellitus or normoglycemia. They had larger ischemic lesions on computer tomography (CT) than diabetics and had higher 30-day mortality than normoglycemics (p<0.05). One-year mortality was similar in transient hyperglycemics and diabetics, and both were significantly higher than in normoglycemics (p<0.05). A proportional hazards model analysis showed that transient hyperglycemia is not an independent predictor of death within a year after stroke.

Activation of MAP kinase (ERK-1/ERK-2), tyrosine kinase and VEGF in the human brain following acute ischaemic stroke

We examined expression of vascular endothelial growth factor (VEGF), phosphorylation of mitogen activated protein kinase (MAP) kinase (ERK1 and ERK2) and tyrosine phosphorylation in 19 patients (aged 58-90 years; mean 75) who died 1-44 days after acute ischaemic stroke. In the grey matter penumbra, 13 of 19 patients showed an increase in MAP kinase tyrosine phosphorylation (ERK1; 2.0- to 8-fold, ERK2; 2.2- to 11-fold) compared with normal contralateral tissue. In almost all cases, ERK-2 phosphorylation was higher than ERK1. Of these 13 patients, 11 also showed a general increase in tyrosine kinase phosphorylation, and eight expressed increased levels of VEGF protein (2.5- to 5-fold). In tissue examined directly from the infarct core, activation of the above proteins was not observed in the, majority of patients. In the white matter, seven of 19 patients (penumbra), and nine of 19 patients (stroke) had an increase in MAP kinase tyrosine phosphorylation (ERK1; 2.0- to 4.6-fold and ERK-2; 2.3- to 5.4-fold respectively) compared with normal contralateral tissue. There was no relationship between activation of MAP kinase and expression of VEGF. Examination of phosphorylated MAP kinase by immunohistochemistry revealed an increase in immunoreactivity in neurones, astroglial cells, reactive microglia and endothelial cells in areas surrounding infarcts, especially in areas with the highest density of microvessels. In conclusion, chronic activation of tyrosine phosphorylated events, in particular redistribution and phosphorylation of MAP kinase (ERK1/ERK2) occurs consistently in the grey matter penumbra of brain tissue following ischaemic stroke, and may be associated with increase in expression of VEGF. These signal transduction events could be important determinants of the extent of neuronal survival and/or angiogenic activity in the recovering brain tissue.

Serial measurement of vascular endothelial growth factor and transforming growth factor-beta1 in serum of patients with acute ischemic stroke

BACKGROUND AND PURPOSE

Both vascular endothelial growth factor (VEGF) and transforming growth factor-beta1 (TGF-beta1) are expressed in higher than normal concentrations in the penumbra of patients after ischemic stroke. Because both cytokines are central to the processes of angiogenesis, tissue inflammation, and fibrosis, we performed serial measurements of these cytokines in patients with cerebral infarction and determined their relationship to stroke etiology and volume.

METHODS

We serially (at days 0, 1, 3, 7, and 14) measured the serum levels of VEGF and active TGF-beta1 in 29 patients with acute ischemic stroke. Age-matched healthy subjects (n=26) were used as controls.

RESULTS

Expression of VEGF was significantly increased in the majority of patients after acute stroke at each of the time points compared with normal controls. Highest expression occurred at day 7 (588+/-121 pg/mL; P=0.005), and it remained significantly elevated at 14 days after stroke. Expression of VEGF correlated with infarct volume, clinical disability (Scandinavian Stroke Scale), and peripheral leukocytosis and was significantly higher in patients with atherothrombotic large-vessel disease and ischemic heart disease (P<0.05 in all cases). In contrast, expression of active TGF-beta1 was not significantly different from control patients at any of the measured time points. When the mean concentration of TGF-beta1 from each patient (pooled time points) was compared with the control mean, a significant increase was found in only 2 patients, whereas levels decreased in 12 patients (P<0.05). There was no correlation between circulating active TGF-beta1 and VEGF expression, leukocytosis, stroke subtype, or patient disability as assessed by Scandinavian Stroke Scale score.

CONCLUSIONS

VEGF but not TGF-beta1 showed a dramatic increase in serum of stroke patients. Correlation between stroke severity and VEGF concentration suggests it could be involved in the subsequent repair processes resulting in partial recovery after stroke. Correlation between VEGF expression and peripheral leukocytosis suggests that these changes may also reflect the immunologic status of the patient. VEGF may play an important role in the pathophysiology of acute ischemic stroke and could be of value in future treatment strategies.

Inducible nitric oxide production and expression of transforming growth factor-beta1 in serum and CSF after cerebral ischaemic stroke in man

A residual blood supply to the ischaemic brain is a crucial determinant for tissue survival. Early changes in the vascular network and subsequent angiogenesis may be mediated by short-lived molecules like nitric oxide (NO) or growth factors such as transforming growth factor-beta1 (TGF-beta1). Although TGF-beta1 can inhibit NO production, this interaction has not been studied after ischaemia in humans. Serum samples were taken from patients at 24 h and 6 months and cerebrospinal fluid (CSF) samples at 24 h and 1 week later for possible correlation between the two factors. Tissue expression of TGF-beta1 and of the inducible isoform of NO synthase (NOS2) was assessed by immunohistochemistry. CSF levels of NO2-/NO3- as well as total (active + latent) TGF-beta1 were higher in stroke patients as compared to controls 24 h after the stroke. Both NO2-/NO3- and TGF-beta1 were lower 6 months after the stroke compared to 24 h. Levels of NO2-/NO3- correlated with levels of TGF-beta1 within the time points (P = 0.041, Kendall correlation coefficient). There was a strong staining for NOS2 in brain tissue sections in neurones, reactive astrocytes, infiltrating white blood cells, and endothelial cells of larger microvessels. TGF-beta1 expression was mainly limited to neurones and reactive astrocytes. These findings suggest that the interaction between TGF-beta1 and NOS2 might be important for angiogenesis after cerebral ischaemia and may indicate that TGF-beta1 is upregulated as a negative feedback response to elevated levels of NO.