Gene expression profiling in whole blood stimulated ex vivo with lipopolysaccharide as a tool to predict post-stroke depressive symptoms: Proof-of-concept study.

Prediction of post-stroke depressive symptoms (DSs) is challenging in patients without a history of depression. Gene expression profiling in blood cells may facilitate the search for biomarkers. The use of an ex vivo stimulus to the blood helps to reveal differences in gene profiles by reducing variation in gene expression. We conducted a proof-of-concept study to determine the usefulness of gene expression profiling in lipopolysaccharide (LPS)-stimulated blood for predicting post-stroke DS. Out of 262 enrolled patients with ischemic stroke, we included 96 patients without a pre-stroke history of depression and not taking any anti-depressive medication before or during the first 3 months after stroke. We assessed DS at 3 months after stroke using the Patient Health Questionnaire-9. We used RNA sequencing to determine the gene expression profile in LPS-stimulated blood samples taken on day 3 after stroke. We constructed a risk prediction model using a principal component analysis combined with logistic regression. We diagnosed post-stroke DS in 17.7% of patients. Expression of 510 genes differed between patients with and without DS. A model containing 6 genes (PKM, PRRC2C, NUP188, CHMP3, H2AC8, NOP10) displayed very good discriminatory properties (area under the curve: 0.95) with the sensitivity of 0.94 and specificity of 0.85. Our results suggest the potential utility of gene expression profiling in whole blood stimulated with LPS for predicting post-stroke DS. This method could be useful for searching biomarkers of post-stroke depression.

Multi-ancestry GWAS reveals excitotoxicity associated with outcome after ischaemic stroke.

During the first hours after stroke onset, neurological deficits can be highly unstable: some patients rapidly improve, while others deteriorate. This early neurological instability has a major impact on long-term outcome. Here, we aimed to determine the genetic architecture of early neurological instability measured by the difference between the National Institutes of Health Stroke Scale (NIHSS) within 6 h of stroke onset and NIHSS at 24 h. A total of 5876 individuals from seven countries (Spain, Finland, Poland, USA, Costa Rica, Mexico and Korea) were studied using a multi-ancestry meta-analyses. We found that 8.7% of NIHSS at 24 h of variance was explained by common genetic variations, and also that early neurological instability has a different genetic architecture from that of stroke risk. Eight loci (1p21.1, 1q42.2, 2p25.1, 2q31.2, 2q33.3, 5q33.2, 7p21.2 and 13q31.1) were genome-wide significant and explained 1.8% of the variability suggesting that additional variants influence early change in neurological deficits. We used functional genomics and bioinformatic annotation to identify the genes driving the association from each locus. Expression quantitative trait loci mapping and summary data-based Mendelian randomization indicate that ADAM23 (log Bayes factor = 5.41) was driving the association for 2q33.3. Gene-based analyses suggested that GRIA1 (log Bayes factor = 5.19), which is predominantly expressed in the brain, is the gene driving the association for the 5q33.2 locus. These analyses also nominated GNPAT (log Bayes factor = 7.64) ABCB5 (log Bayes factor = 5.97) for the 1p21.1 and 7p21.1 loci. Human brain single-nuclei RNA-sequencing indicates that the gene expression of ADAM23 and GRIA1 is enriched in neurons. ADAM23, a presynaptic protein and GRIA1, a protein subunit of the AMPA receptor, are part of a synaptic protein complex that modulates neuronal excitability. These data provide the first genetic evidence in humans that excitotoxicity may contribute to early neurological instability after acute ischaemic stroke.

Identification of optimal reference genes for gene expression studies in a focal cerebral ischaemia model-Spatiotemporal effects.

A proper reference gene (RG) is required to reliably measure mRNA levels in biological samples via quantitative reverse transcription PCR (RT-qPCR). Various experimental paradigms require specific and stable RGs. In studies using rodent models of brain ischaemia, a variety of genes, such as ß-actin (Actb), hypoxanthine phosphoribosyltransferase 1 (Hprt1), peptidyl-propyl isomerase A (Ppia) and glyceraldehyde-3-phosphate dehydrogenase (Gapdh), are used as RGs. However, most of these genes have not been validated in specific experimental settings. The aim of this study was to evaluate the time- and brain region-dependent expression of RG candidates in a rat model of transient middle cerebral artery occlusion (tMCAO). The following genes were selected: Actb, Hprt1, Ppia, Gapdh, tyrosine 3-monooxygenase/tryptophan 5-monooxygenase activation protein, zeta (Ywhaz) and beta-2 microglobulin (B2m). Focal cerebral ischaemia was induced by 90 min of tMCAO in male Sprague-Dawley rats. Expression was investigated at four time points (12 and 24 h; 3 and 7 days) and in three brain areas (the frontal cortex, hippocampus and dorsal striatum) within the ischaemic brain hemisphere. The RT-qPCR results were analysed using variance analysis and the ΔCt, GeNorm, NormFinder and BestKeeper methods. Data from these algorithms were ranked using the geometric mean of ranks of each analysis. Ppia, Hprt1 and Ywhaz were the most stable genes across the analysed brain areas and time points. B2m and Actb exhibited the greatest fluctuations, and the results for Gapdh were ambiguous.

Subtypes of delirium after ischaemic stroke-predisposing factors and outcomes: a prospective observational study (PROPOLIS).

BACKGROUND AND PURPOSE: Delirium is a serious complication after stroke. It remains unclear whether different motor subtypes of delirium are associated with diverse risk factors and outcomes. The aim was to investigate if delirium subtypes differ in predisposing factors, clinical characteristics and outcomes. METHODS: In all, 698 patients with ischaemic stroke or transient ischaemic attack (median age 73 years; 53.7% female) were prospectively included. Core features of delirium during the first 7 days after admission were examined. The Diagnostic and Statistical Manual of Mental Disorders (DSM-5) criteria for delirium were used. Pre-stroke characteristics were compared between different delirium subtypes and logistic regression and Cox proportional hazard models were used to explore the association between delirium, functional outcome and death. RESULTS: Hyperactive, hypoactive and mixed delirium were diagnosed in 28, 75 and 66 patients, respectively. Patients with hyperactive delirium had less severe neurological deficit on admission and more often had transient ischaemic attack compared with patients with hypoactive and mixed delirium. Compared with patients with hypoactive delirium, those with hyperactive delirium more often suffered from irritability/lability prior to stroke. Hyperactive and hypoactive delirium did not differ in age, sex, comorbidities, pre-stroke dependency, cognitive decline and severity of delirium. Hyperactive, hypoactive and mixed delirium were associated with an increased risk of poor 3- and 12-month functional outcome compared with patients without delirium. Moreover, patients with hypoactive and mixed delirium had an elevated risk of death. CONCLUSIONS: Hyperactive delirium is associated with less severe stroke and higher scores of pre-existing irritability/lability. All three motor subtypes of delirium are associated with poor outcome, although hyperactive delirium seems to have a less unfavourable prognosis.

Early Neurological Change After Ischemic Stroke Is Associated With 90-Day Outcome.

BACKGROUND AND PURPOSE: Large-scale observational studies of acute ischemic stroke (AIS) promise to reveal mechanisms underlying cerebral ischemia. However, meaningful quantitative phenotypes attainable in large patient populations are needed. We characterize a dynamic metric of AIS instability, defined by change in National Institutes of Health Stroke Scale score (NIHSS) from baseline to 24 hours baseline to 24 hours (NIHSSbaseline - NIHSS24hours = ΔNIHSS6-24h), to examine its relevance to AIS mechanisms and long-term outcomes. METHODS: Patients with NIHSS prospectively recorded within 6 hours after onset and then 24 hours later were enrolled in the GENISIS study (Genetics of Early Neurological Instability After Ischemic Stroke). Stepwise linear regression determined variables that independently influenced ΔNIHSS6-24h. In a subcohort of tPA (alteplase)-treated patients with large vessel occlusion, the influence of early sustained recanalization and hemorrhagic transformation on ΔNIHSS6-24h was examined. Finally, the association of ΔNIHSS6-24h with 90-day favorable outcomes (modified Rankin Scale score 0-2) was assessed. Independent analysis was performed using data from the 2 NINDS-tPA stroke trials (National Institute of Neurological Disorders and Stroke rt-PA). RESULTS: For 2555 patients with AIS, median baseline NIHSS was 9 (interquartile range, 4-16), and median ΔNIHSS6-24h was 2 (interquartile range, 0-5). In a multivariable model, baseline NIHSS, tPA-treatment, age, glucose, site, and systolic blood pressure independently predicted ΔNIHSS6-24h (R2=0.15). In the large vessel occlusion subcohort, early sustained recanalization and hemorrhagic transformation increased the explained variance (R2=0.27), but much of the variance remained unexplained. ΔNIHSS6-24h had a significant and independent association with 90-day favorable outcome. For the subjects in the 2 NINDS-tPA trials, ΔNIHSS3-24h was similarly associated with 90-day outcomes. CONCLUSIONS: The dynamic phenotype, ΔNIHSS6-24h, captures both explained and unexplained mechanisms involved in AIS and is significantly and independently associated with long-term outcomes. Thus, ΔNIHSS6-24h promises to be an easily obtainable and meaningful quantitative phenotype for large-scale genomic studies of AIS.

Association of early and later depressive symptoms with functional outcome after ischemic stroke.

BACKGROUND: Post-stroke depressive symptoms (DS) can be chronic or transient, occurring shortly or long after stroke and lasting only few months. It remains unclear if the prognosis differs between patients with DS in the acute phase of stroke and those who develop DS several months later. We aimed to determine whether outcomes vary among patients with different trajectories of post-stroke depressive symptoms. METHODS: Of 698 enrolled patients with ischemic stroke, we included 335 participants (median age: 68, 48% female) who were assessed for DS both 8 days and 3 months post-stroke. We divided patients into 4 groups: without greater DS (Group 1), only earlier DS (Group 2), only later DS (Group 3), and persistent DS (Group 4). Logistic regression was used to determine the association between DS and 3- and 12-month functional outcome. RESULTS: Group 2 was predominantly female and had the highest rate of previous stroke or transient ischemic attack. Group 3 was more likely to suffer from delirium and more severe stroke. Group 4 had the highest frequency of vascular risk factors, pre-morbid psychiatric symptoms, and cognitive decline. In multivariate analysis, Group 3, but not Groups 2 and 4, had an increased risk of poor 3- and 12-month functional outcome (adjusted OR 2.59, 95% CI 1.64-4.07, P < 0.01 and OR 3.97, 95% CI 2.32-6.76, P < 0.01, respectively) compared with Group 1. CONCLUSIONS: Different trajectories of post-stroke DS are related to different outcomes. Patients who only have later DS also have the worst prognosis.

Early apathetic, but not depressive, symptoms are associated with poor outcome after stroke.

BACKGROUND AND PURPOSE: Depression and apathy are frequent neuropsychiatric disturbances after stroke and may appear together. Despite the overlap in symptoms between poststroke depression and apathy, these two syndromes might be associated with different prognoses and benefit from different treatments. We aimed to disentangle the relationship between early depressive and apathetic symptoms and outcome after stroke. METHODS: Of 698 enrolled patients with ischemic stroke, we included 443 participants (median age = 69 years, 51% female) who underwent depressive and apathetic symptom assessment on Day 8 after stroke. We divided patients into four groups: without greater depressive and apathetic symptoms (Group 1), with only apathetic symptoms (Group 2), with only depressive symptoms (Group 3), and with both depressive and apathetic symptoms (Group 4). RESULTS: After adjusting for age and stroke severity, Group 2 and Group 4 had an increased risk of poor 3-month outcome (odds ratio [OR] = 1.98, 95% confidence interval [CI] = 1.16-3.38, p = 0.01 and OR = 1.58, 95% CI = 1.24-2.01, p < 0.01, respectively). Group 2 and Group 4 also had an increased risk of poor 12-month outcome (OR = 3.85, 95% CI = 2.19-6.78, p < 0.01 and OR = 1.54, 95% CI = 1.22-1.96, p < 0.01, respectively) and mortality (hazard ratio [HR] = 2.76, 95% CI = 1.19-6.41, p = 0.02 and HR = 1.77, 95% CI = 1.32-2.38, p < 0.01, respectively). Compared with Group 1, Group 3 did not have an increased risk of unfavorable outcomes. CONCLUSIONS: Early apathetic, but not depressive, symptoms are related to worse outcomes after stroke. Our study underscores the importance of recognizing apathetic symptoms independently from depressive symptoms.

The Slow-Releasing and Mitochondria-Targeted Hydrogen Sulfide (H2S) Delivery Molecule AP39 Induces Brain Tolerance to Ischemia.

Ischemic stroke is the third leading cause of death in the world, which accounts for almost 12% of the total deaths worldwide. Despite decades of research, the available and effective pharmacotherapy is limited. Some evidence underlines the beneficial properties of hydrogen sulfide (H2S) donors, such as NaSH, in an animal model of brain ischemia and in in vitro research; however, these data are ambiguous. This study was undertaken to verify the neuroprotective activity of AP39, a slow-releasing mitochondria-targeted H2S delivery molecule. We administered AP39 for 7 days prior to ischemia onset, and the potential to induce brain tolerance to ischemia was verified. To do this, we used the rat model of 90-min middle cerebral artery occlusion (MCAO) and used LC-MS/MS, RT-PCR, LuminexTM assays, Western blot and immunofluorescent double-staining to determine the absolute H2S levels, inflammatory markers, neurotrophic factor signaling pathways and apoptosis marker in the ipsilateral frontal cortex, hippocampus and in the dorsal striatum 24 h after ischemia onset. AP39 (50 nmol/kg) reduced the infarct volume, neurological deficit and reduced the microglia marker (Iba1) expression. AP39 also exerted prominent anti-inflammatory activity in reducing the release of Il-1ß, Il-6 and TNFα in brain areas particularly affected by ischemia. Furthermore, AP39 enhanced the pro-survival pathways of neurotrophic factors BDNF-TrkB and NGF-TrkA and reduced the proapoptotic proNGF-p75NTR-sortilin pathway activity. These changes corresponded with reduced levels of cleaved caspase 3. Altogether, AP39 treatment induced adaptative changes within the brain and, by that, developed brain tolerance to ischemia.

The specific ex vivo released cytokine profile is associated with ischemic stroke outcome and improves its prediction.

BACKGROUND: Inflammation is associated with poor outcome after stroke. A relationship between ex vivo cytokine synthesis and stroke outcome remains unclear. We explored an association between ex vivo cytokine release, circulating interleukin (IL)-6 as a marker of systemic inflammation, and stroke prognosis. We assessed the utility of ex vivo synthesized cytokines for predicting stroke outcome. METHODS: We collected blood from 248 ischemic stroke patients and stimulated it ex vivo with lipopolysaccharide. We measured concentration of synthesized cytokines (TNFα, IP-10, IL-1ß, IL-6, IL-8, IL-10, and IL-12) and plasma IL-6. We assessed functional outcome 3 months after stroke using the modified Rankin Scale. To assess the prognostic ability of cytokines, we applied multivariate logistic regression, cluster analysis, and construction of multimarker score. RESULTS: Decreased release of IP-10, TNFα, IL-1ß, and IL-12; increased release of IL-10 and IL-8; and higher plasma IL-6 level were associated with poor outcome. Cluster analysis identified three groups of patients with distinct cytokine profiles. The group with the worst outcome demonstrated high synthesis of IL-10, IL-8, IL-1ß, and IL-6 and low synthesis of IL-12, IP-10, and TNFα accompanied by high circulating IL-6 level. The group with the best prognosis showed high synthesis of TNFα, IP-10, IL-12, IL-1ß, and IL-6; low synthesis of IL-10 and IL-8; and low plasma IL-6. Patients with intermediate outcome had low synthesis of all cytokines accompanied by low circulating IL-6. We constructed a multimarker score composed of ex vivo released IL-12, IL-10, TNFα, and plasma IL-6. Addition of this score to clinical variables led to significant increase in c-statistic (0.81 vs 0.73, p = 0.02) and net reclassification improvement. CONCLUSION: The decreased ex vivo release of pro-inflammatory cytokines and increased release of IL-10 and IL-8 are related to poor outcome after stroke. Cytokine-based multimarker score adds prognostic value to clinical model for predicting stroke outcome.

Glucocorticoid Resistance is Associated with Poor Functional Outcome After Stroke.

Systemic inflammation is associated with poor outcome after stroke. Glucocorticoids (GCs) play a fundamental role in limiting inflammation. The aim of this study was to explore the associations between GC sensitivity, systemic inflammation, and outcome after ischemic stroke. The study population compised 246 ischemic stroke patients (median age: 69.0 years; 41.1% female). To assess GC sensitivity, we incubated venous blood samples that were obtained at day 3 after stroke with lipopolysaccharide (10 ng/mL) and dexamethasone (10-6 mol/L). We defined the GC sensitivity index as the ratio of tumor necrosis factor α (TNFα) released after blood stimulation with lipopolysaccharide and dexamethasone to the amount of TNFα released after blood stimulation with lipopolysaccharide alone. A higher index indicates higher GC resistance. The patients with poor functional outcome had a higher GC sensitivity index than those with good outcome (median: 16.1% vs. 13.5%, P < 0.01). In a logistic regression analysis adjusted for age, stroke severity, pneumonia, leukocyte count, plasma interleukin-6, and TNFα release ex vivo, a higher GC sensitivity index was associated with a higher risk of poor outcome after stroke (OR 2.32, 95% CI 1.21-4.45, P = 0.01). In conclusion, GC resistance is associated with poor functional outcome after stroke.

Genome-wide association study of cerebral small vessel disease reveals established and novel loci.

Intracerebral haemorrhage and small vessel ischaemic stroke (SVS) are the most acute manifestations of cerebral small vessel disease, with no established preventive approaches beyond hypertension management. Combined genome-wide association study (GWAS) of these two correlated diseases may improve statistical power to detect novel genetic factors for cerebral small vessel disease, elucidating underlying disease mechanisms that may form the basis for future treatments. Because intracerebral haemorrhage location is an adequate surrogate for distinct histopathological variants of cerebral small vessel disease (lobar for cerebral amyloid angiopathy and non-lobar for arteriolosclerosis), we performed GWAS of intracerebral haemorrhage by location in 1813 subjects (755 lobar and 1005 non-lobar) and 1711 stroke-free control subjects. Intracerebral haemorrhage GWAS results by location were meta-analysed with GWAS results for SVS from MEGASTROKE, using 'Multi-Trait Analysis of GWAS' (MTAG) to integrate summary data across traits and generate combined effect estimates. After combining intracerebral haemorrhage and SVS datasets, our sample size included 241 024 participants (6255 intracerebral haemorrhage or SVS cases and 233 058 control subjects). Genome-wide significant associations were observed for non-lobar intracerebral haemorrhage enhanced by SVS with rs2758605 [MTAG P-value (P) = 2.6 × 10-8] at 1q22; rs72932727 (P = 1.7 × 10-8) at 2q33; and rs9515201 (P = 5.3 × 10-10) at 13q34. In the GTEx gene expression library, rs2758605 (1q22), rs72932727 (2q33) and rs9515201 (13q34) are significant cis-eQTLs for PMF1 (P = 1 × 10-4 in tibial nerve), NBEAL1, FAM117B and CARF (P < 2.1 × 10-7 in arteries) and COL4A2 and COL4A1 (P < 0.01 in brain putamen), respectively. Leveraging S-PrediXcan for gene-based association testing with the predicted expression models in tissues related with nerve, artery, and non-lobar brain, we found that experiment-wide significant (P < 8.5 × 10-7) associations at three genes at 2q33 including NBEAL1, FAM117B and WDR12 and genome-wide significant associations at two genes including ICA1L at 2q33 and ZCCHC14 at 16q24. Brain cell-type specific expression profiling libraries reveal that SEMA4A, SLC25A44 and PMF1 at 1q22 and COL4A1 and COL4A2 at 13q34 were mainly expressed in endothelial cells, while the genes at 2q33 (FAM117B, CARF and NBEAL1) were expressed in various cell types including astrocytes, oligodendrocytes and neurons. Our cross-phenotype genetic study of intracerebral haemorrhage and SVS demonstrates novel genome-wide associations for non-lobar intracerebral haemorrhage at 2q33 and 13q34. Our replication of the 1q22 locus previous seen in traditional GWAS of intracerebral haemorrhage, as well as the rediscovery of 13q34, which had previously been reported in candidate gene studies with other cerebral small vessel disease-related traits strengthens the credibility of applying this novel genome-wide approach across intracerebral haemorrhage and SVS.

Clinical Relevance of Changes in Peripheral Blood Cells After Intracranial Aneurysm Rupture.

BACKGROUND: The rupture of an intracranial aneurysm (IA) causes a systemic response that involves an immune/inflammatory reaction. We sought to characterize the systemic response to IA rupture. METHODS: We included 19 patients in the acute phase of IA rupture and 20 control subjects. Flow cytometry was used to analyze alterations in the level of mononuclear leukocytes. Cell-related parameters, including the neutrophil-to-lymphocyte ratio (NL-R), lymphocyte-to-monocyte ratio (LM-R), platelet-to-lymphocyte ratio (PL-R), and systemic immune-inflammation index (SII), were calculated, and the relationship between the analyzed hematological parameters and clinical status was investigated. RESULTS: Patients with ruptured IAs presented with significantly higher white blood cells (WBC) and neutrophil counts but lower lymphocyte counts than control subjects. NL-R and SII values were higher and the LM-R was lower in the acute phase after IA rupture. Analyzing the severity of clinical status and the outcome of patients with subarachnoid hemorrhage, we found that patients with poor clinical status, as measured by the Glasgow Coma Scale (GCS) and the Hunt and Hess scale, had significantly lower lymphocyte counts and higher NL-R, PL-R and SII values than those with good clinical status. Additionally, patients with lower GCS scores presented a lower proportion of CD3+CD4-CD8- cells. Worse outcomes assessed at discharge were associated with lower lymphocyte counts but higher PL-R values. CONCLUSIONS: The current study pointed to the significance of systemic immune and inflammatory responses after IA rupture and the potential clinical utility of hematological parameters, which can be easily calculated. In particular, the role of DN T cells and the significance of the SII as a marker related to clinical status should be further investigated.

Systemic response to rupture of intracranial aneurysms involves expression of specific gene isoforms.

BACKGROUND: Rupture of an intracranial aneurysm (IA) causes a systemic response that involves an immune/inflammatory reaction. Our previous study revealed a downregulation of genes related to T lymphocytes and an upregulation of genes related to monocytes and neutrophils after IA rupture. It remains unknown whether that resulted from alterations in transcription or cell count. We sought to characterize the systemic response to IA rupture through analysis of transcript expression profiles in peripheral blood cells. We also investigated effects of IA rupture on the composition of mononuclear cells in peripheral blood. METHODS: We included 19 patients in the acute phase of IA rupture (RAA, first 72 h), 20 patients in the chronic phase (RAC, 3-15 months), and 20 controls. Using deep transcriptome sequencing, we analyzed the expression of protein-coding and noncoding RNAs. Expression levels, transcript biotypes, alternative splicing and other features of the regulated transcripts were studied. A functional analysis was performed to determine overrepresented ontological groups among gene expression profiles. Flow cytometry was used to analyze alterations in the level of mononuclear leukocyte subpopulations. RESULTS: Comparing RAA and controls, we identified 491 differentially expressed transcripts (303 were downregulated, and 188 were upregulated in RAA). The results indicate that the molecular changes in response to IA rupture occur at the level of individual transcripts. Functional analysis revealed that the most impacted biological processes are related to regulation of lymphocyte activation and toll-like receptor signaling pathway. Differences between RAC and controls were less prominent. Analysis of leukocyte subsets revealed a significantly decreased number of CD4+ lymphocytes and increase of classical and intermediate monocytes in RAA patients compared to controls. CONCLUSIONS: IA rupture in the acute phase strongly influences the transcription profiles of peripheral blood cells as well as the composition of mononuclear cells. A specific pattern of gene expression alteration was found, suggesting a depression of lymphocyte response and enhancement of monocyte activity.

Posterior Subthalamic Area Deep Brain Stimulation for Treatment of Refractory Holmes Tremor.

Three right-handed patients diagnosed with Holmes tremor (HT), who suffered from pharmacotherapy-refractory tremor, were eligible for unilateral posterior subthalamic area deep brain stimulation (PSA-DBS). All patients were evaluated with the Fahn-Tolosa-Marin Tremor Rating Scale (FTMTRS) and Clinical Global Impression scale (CGI) before DBS, 6, and 12 months after the PSA-DBS as well as at the last follow-up. In all patients, we observed a significant improvement of tremor control as demonstrated by changes in the FTMTRS and the CGI scales. Mean improvement of tremor in all patients was 56% for the FTMRTS with a corresponding change in the CGI scale. Our study demonstrates that PSA-DBS is efficacious in the treatment of HT. Indeed, PSA is a promising target for DBS for intractable proximal and distal tremor, even in cases of previous, suboptimal functional neurosurgery. The beneficial effect lasts over a long-term follow-up. PSA-DBS may be considered as an alternative target of DBS in tremor treatment.

Reduced ex vivo release of pro-inflammatory cytokines and elevated plasma interleukin-6 are inflammatory signatures of post-stroke delirium.

BACKGROUND: Experimental studies suggest that systemic inflammation contributes to the pathophysiology of delirium. The aim of our study was to determine blood-derived inflammatory signatures of post-stroke delirium. METHODS: We included 144 ischemic stroke patients. We assessed delirium on a daily basis during the first 7 days of hospitalization. Venous blood was collected at day 3 after the onset of stroke and stimulated ex vivo with lipopolysaccharide (LPS). We measured LPS-induced cytokine concentration (TNFα, IP-10, IL-1ß, IL-6, IL-8, IL-10, and IL-12p70) as well as plasma levels of IL-6 and TNFα. RESULTS: Delirium was diagnosed in 21.5% of patients. After correction for monocyte count, patients with delirium had reduced LPS-induced TNFα, IP-10, IL-1ß, IL-6, and IL-12 release. The plasma IL-6 level was higher in delirious patients compared to patients without delirium. After adjusting for stroke severity and infections, higher ex vivo TNFα (OR 0.29, 95%CI 0.11-0.72, P = 0.01), IP-10 (OR 0.25, 95%CI 0.08-0.73, P = 0.01), IL-1ß (OR 0.42, 95%CI 0.20-0.89, P = 0.02), and IL-12 (OR 0.07, 95%CI 0.01-0.70, P = 0.02) release was associated with the reduced risk of delirium. In multivariate analysis, the higher plasma IL-6 was associated with the increased risk of delirium (OR 1.61, 95%CI 1.00-2.58, P = 0.04). CONCLUSIONS: Reduced ex vivo release of pro-inflammatory cytokines after LPS stimulation and the elevated plasma IL-6 are signatures of post-stroke delirium.

Reduced release of TNFα and IP-10 after ex vivo blood stimulation with endotoxin is associated with poor outcome after stroke.

BACKGROUND AND AIMS: The immune response to acute cerebral ischemia plays an important role in the pathophysiology of stroke and could be a therapeutic target. Toll-like receptor 4 (TLR4) is a master regulator of innate immunity. The aim of our study was to determine the association between selected cytokine release after TLR4 activation in blood cells and the outcome after ischemic stroke. METHODS: We included 156 ischemic stroke patients (median age: 69; 40.4% female). Venous blood was collected at day 3 after the onset of stroke and stimulated ex vivo with lipopolysaccharide (LPS). The LPS-induced level of tumor necrosis factor alpha (TNFα) was used as a proxy of the MyD88-dependent pathway, and interferon-gamma-inducible protein 10 (IP-10) was used as a proxy of the MyD88-independent pathway. The functional outcome was assessed at 3 months after stroke onset. RESULTS: TNFα (median: 2.2 vs. 3.5 pg/103 monocytes, p < .01) and IP-10 release (median: 0.3 vs. 0. 6 pg/103 monocytes, p < .01) was reduced in patients with a poor outcome. In a multivariate logistic regression analysis adjusted for age, stroke severity, and pneumonia, low TNFα release was associated with a poor outcome (OR: 4.23, 95%CI: 1.64-10.90, p = .03). Similarly, low IP-10 release was related to an unfavorable prognosis (adjusted OR: 3.42, 95%CI: 1.49-8.21, p < .01). CONCLUSIONS: The reduced release of TNFα and IP-10 after ex vivo blood stimulation with endotoxin is independently associated with poor outcome after stroke. Our results suggest that the inhibition of both the MyD88-dependent pathway and MyD88-independent pathway of TLR4 signaling in blood cells correlates with an unfavorable prognosis in stroke patients.

Meta-analysis of genome-wide association studies identifies 1q22 as a susceptibility locus for intracerebral hemorrhage.

Intracerebral hemorrhage (ICH) is the stroke subtype with the worst prognosis and has no established acute treatment. ICH is classified as lobar or nonlobar based on the location of ruptured blood vessels within the brain. These different locations also signal different underlying vascular pathologies. Heritability estimates indicate a substantial genetic contribution to risk of ICH in both locations. We report a genome-wide association study of this condition that meta-analyzed data from six studies that enrolled individuals of European ancestry. Case subjects were ascertained by neurologists blinded to genotype data and classified as lobar or nonlobar based on brain computed tomography. ICH-free control subjects were sampled from ambulatory clinics or random digit dialing. Replication of signals identified in the discovery cohort with p < 1 × 10(-6) was pursued in an independent multiethnic sample utilizing both direct and genome-wide genotyping. The discovery phase included a case cohort of 1,545 individuals (664 lobar and 881 nonlobar cases) and a control cohort of 1,481 individuals and identified two susceptibility loci: for lobar ICH, chromosomal region 12q21.1 (rs11179580, odds ratio [OR] = 1.56, p = 7.0 × 10(-8)); and for nonlobar ICH, chromosomal region 1q22 (rs2984613, OR = 1.44, p = 1.6 × 10(-8)). The replication included a case cohort of 1,681 individuals (484 lobar and 1,194 nonlobar cases) and a control cohort of 2,261 individuals and corroborated the association for 1q22 (p = 6.5 × 10(-4); meta-analysis p = 2.2 × 10(-10)) but not for 12q21.1 (p = 0.55; meta-analysis p = 2.6 × 10(-5)). These results demonstrate biological heterogeneity across ICH subtypes and highlight the importance of ascertaining ICH cases accordingly.

Genetic variants in CETP increase risk of intracerebral hemorrhage.

OBJECTIVE: In observational epidemiologic studies, higher plasma high-density lipoprotein cholesterol (HDL-C) has been associated with increased risk of intracerebral hemorrhage (ICH). DNA sequence variants that decrease cholesteryl ester transfer protein (CETP) gene activity increase plasma HDL-C; as such, medicines that inhibit CETP and raise HDL-C are in clinical development. Here, we test the hypothesis that CETP DNA sequence variants associated with higher HDL-C also increase risk for ICH. METHODS: We performed 2 candidate-gene analyses of CETP. First, we tested individual CETP variants in a discovery cohort of 1,149 ICH cases and 1,238 controls from 3 studies, followed by replication in 1,625 cases and 1,845 controls from 5 studies. Second, we constructed a genetic risk score comprised of 7 independent variants at the CETP locus and tested this score for association with HDL-C as well as ICH risk. RESULTS: Twelve variants within CETP demonstrated nominal association with ICH, with the strongest association at the rs173539 locus (odds ratio [OR] = 1.25, standard error [SE] = 0.06, p = 6.0 × 10-4 ) with no heterogeneity across studies (I2 = 0%). This association was replicated in patients of European ancestry (p = 0.03). A genetic score of CETP variants found to increase HDL-C by ∼2.85mg/dl in the Global Lipids Genetics Consortium was strongly associated with ICH risk (OR = 1.86, SE = 0.13, p = 1.39 × 10-6 ). INTERPRETATION: Genetic variants in CETP associated with increased HDL-C raise the risk of ICH. Given ongoing therapeutic development in CETP inhibition and other HDL-raising strategies, further exploration of potential adverse cerebrovascular outcomes may be warranted. Ann Neurol 2016;80:730-740.

Association between C677T polymorphism of MTHFR gene and risk of amyotrophic lateral sclerosis: Polish population study and a meta-analysis.

OBJECTIVE: Genetic factors play a role in pathogenesis of amyotrophic lateral sclerosis (ALS). A few studies demonstrated that the TT genotype of C677T polymorphism of the 5,10-methylenetetrahydrofolate reductase (MTHFR) gene can increase the risk of sporadic ALS. The aim of our study was to determine the relationship between C677T polymorphism of MTHFR gene and the risk of sporadic ALS in Polish population and to perform the meta-analysis assessing the significance this polymorphism for the risk of ALS in Caucasian population. METHODS: We included 251 patients with ALS and 500 control subjects recruited from Polish population and performed the meta-analysis of published data from Caucasian population. MTHFR C677T polymorphism was genotyped using a TaqMan assay and 7900HT Fast real Time PCR System. RESULTS: The frequency of genotypes did not differ significantly between Polish ALS patients and control subjects (CC: 45.0 vs 45.8%, CT: 48.2 vs 45.0%, TT: 6.8 vs 9.2%, P=0.46). The meta-analysis including 863 ALS patients and 1362 controls revealed that TT genotype increases the risk of sporadic ALS in Caucasian population. CONCLUSION: Although we did not find the association between C677T polymorphism of MTHRF gene and risk of ALS in Polish population, the results of meta-analysis suggest that the TT genotype can be a genetic risk factor for ALS in Caucasian population.