Association of candidate genetic variants and circulating levels of ApoE/ApoJ with common neuroimaging features of cerebral amyloid angiopathy.

Introduction: Cerebral amyloid angiopathy (CAA) is characterized by the accumulation of amyloid-ß (Aß) in brain vessels and is a main cause of lobar intracerebral hemorrhage (ICH) in the elderly. CAA is associated with magnetic resonance imaging (MRI) markers of small vessel disease (SVD). Since Aß is also accumulated in Alzheimer's disease (AD) in the brain parenchyma, we aimed to study if several single nucleotide polymorphisms (SNPs) previously associated with AD were also associated with CAA pathology. Furthermore, we also studied the influence of APOE and CLU genetic variants in apolipoprotein E (ApoE) and clusterin/apolipoprotein J (ApoJ) circulating levels and their distribution among lipoproteins. Methods: The study was carried out in a multicentric cohort of 126 patients with lobar ICH and clinical suspicion of CAA. Results: We observed several SNPs associated with CAA neuroimaging MRI markers [cortical superficial siderosis (cSS), enlarged perivascular spaces in the centrum semiovale (CSO-EPVS), lobar cerebral microbleeds (CMB), white matter hyperintensities (WMH), corticosubcortical atrophy and CAA-SVD burden score]. Concretely, ABCA7 (rs3764650), CLU (rs9331896 and rs933188), EPHA1 (rs11767557), and TREML2 (rs3747742) were significantly associated with a CAA-SVD burden score. Regarding circulating levels of apolipoproteins, protective AD SNPs of CLU [rs11136000 (T) and rs9331896 (C)] were significantly associated with higher HDL ApoJ content in the lobar ICH cohort. APOEε2 carriers presented higher plasma and LDL-associated ApoE levels whereas APOEε4 carriers presented lower plasma ApoE levels. Additionally, we observed that lower circulating ApoJ and ApoE levels were significantly associated with CAA-related MRI markers. More specifically, lower LDL-associated ApoJ and plasma and HDL-associated ApoE levels were significantly associated with CSO-EPVS, lower ApoJ content in HDL with brain atrophy and lower ApoE content in LDL with the extent of cSS. Discussion: This study reinforces the relevance of lipid metabolism in CAA and cerebrovascular functionality. We propose that ApoJ and ApoE distribution among lipoproteins may be associated with pathological features related to CAA with higher ApoE and ApoJ levels in HDL possibly enhancing atheroprotective, antioxidative, and anti-inflammatory responses in cerebral ß-amyloidosis.

Impact on functional outcome of an adaptive Stroke Unit based system of care for patients undergoing endovascular treatment during pandemic times.

Introduction: The COVID19 pandemic collapsed intensive care units (ICUs) all around the world, conditioning systems of care (SOC) for other critical conditions such as severe ischemic stroke requiring endovascular treatment (EVT). Our aim was to evaluate the impact of an adaptive Stroke Unit (SU) based SOC on functional outcomes, with the goal of avoiding both general anesthesia (GA) and ICU admission in stroke patients treated with EVT. Material and methods: We performed an observational study comparing data from our traditional ICU-GA based SOC and the adaptive SU-Conscious Sedation (CS) based SOC (consecutive patients undergoing EVT 1 year prior and after onset of the pandemic). Primary outcome was 90-days modified Rankin Scale (mRS), and secondary outcomes included, among others, in-hospital complications, and hospital length of stay (LOS). Results: A total of 210 EVT were performed during the study period (107 under the traditional-SOC and 103 under the adaptive-SOC). A significantly greater proportion of patient was treated under CS (15.9% vs 57.3%; p < 0.001) and admitted for post-procedural care at SU (15% vs 66%; p < 0.001) in the adaptive SOC. Rates of in-hospital complications were similar in both periods, with reduced hospital LOS in the adaptive SOC (10 (7-15) vs 8 (6-12); p = 0.005). The adaptive SOC was associated with higher odds for 90 days favorable outcome (mRS 0-2) (aOR 3.15 (1.34-7.39); p = 0.008). Conclusion: In our case, an adaptive SOC that combined both preference for CS and postprocedural care in SU was associated with better functional outcomes and reduced healthcare resource use for patients undergoing EVT.

Endothelial NO synthase 786T/T polymorphism increases hemorrhagic transformation after endovascular thrombectomy.

BACKGROUND AND PURPOSE: This study examined whether the 786 NOS3 polymorphism is associated with the risk of hemorrhagic transformation (HT) in stroke patients with anterior large vessel occlusion (ALVO) treated using endovascular thrombectomy (EVT). METHODS: We performed an observational cohort study that included 118 patients with ALVO who underwent EVT. HT was assessed in follow-up CT and MRI. HT and non-HT patients were compared in terms of the 786 NOS3 polymorphism, flow mediated dilation (FMD) values within 3 days after the stroke, and collateral status based on three grading scales. Demographics, vascular risk factors, additional radiological data including ASPECT score, thrombus length and infarct size, and EVT procedure and outcome variables were also included. RESULTS: Radiological HT occurred in 55 (46.6%) patients and the 786T/T NOS3 polymorphism was associated with HT (unadjusted OR of 2.33, 95%CI: 1.05-5.20, adjusted OR of 3.14, 95%CI: 1.16-8.54). Collateral status and systemic endothelial function assessed by FMD were not mediators of this relationship as no differences were seen in the median FMD percentage values or collateral status between NOS3 genotypes. CONCLUSIONS: Our results suggest that genetic variations affecting the NO pathway, such as the 786 NOS3 polymorphism, may contribute to individual variability in the occurrence of HT and these results support involvement of this pathway in the pathogenesis of ischemia-reperfusion injury after EVT.

Frequency, Predictors, Etiology, and Outcomes for Deep Intracerebral Hemorrhage without Hypertension.

OBJECTIVES: Some patients with deep intracerebral hemorrhage (ICH) have a transient hypertensive response and they may be erroneously classified as secondary to hypertension. We investigated frequency, risk factors, and outcomes for patients with deep ICH without hypertension. MATERIALS AND METHODS: We consecutively recruited patients with spontaneous ICH attending two Spanish stroke centers (January 2015-June 2019). Excluded were patients with lobar/infratentorial ICH and patients who died during hospitalization. We defined deep ICH without hypertension when the bleeding was in a deep structure, no requirement for antihypertensive agents during follow-up and no evident chronic hypertension markers evaluated by transthoracic echocardiography, 24 h ambulatory blood pressure monitoring and/or electrocardiography. We compared clinical, radiological, and 3-month functional outcome data for deep-ICH patients with hypertension versus those without hypertension. RESULTS: Of 759 patients with ICH, 219 (mean age 69.6 ± 15.4 years, 54.8% men) met the inclusion criteria and 36 (16.4%) did not have hypertension. Of these 36 patients, 19 (52.7%) had a transient hypertensive response. Independent predictors of deep ICH without hypertension were age (adjusted OR:0.94;95%CI:0.91-0.96) and dyslipidemia (adjusted OR:0.27;95% CI:0.08-0.85). One third of deep ICH without hypertension were secondary to vascular malformations. Favorable outcomes (modified Rankin Scale 0-2) were more frequent in patients with deep ICH without hypertension compared to those with hypertension (70.9% vs 33.8%; p < 0.001). CONCLUSION: Of patients with deep ICH, 16.4% were unrelated with hypertension, around half showed hypertensive response, and around a third had vascular malformations. We suggest studying hypertension markers and performing a follow-up brain MRI in those patients with deep ICH without prior hypertension.

Delayed Neurological Improvement After Full Endovascular Reperfusion in Acute Anterior Circulation Ischemic Stroke.

Background and Purpose: We aimed to determine the prevalence and predictors of delayed neurological improvement (DNI) after complete endovascular reperfusion in anterior circulation acute ischemic stroke (AIS). Methods: Retrospective analysis of an online multicenter prospective reperfusion registry of patients with consecutive anterior circulation AIS treated with endovascular thrombectomy (EVT) from January 2018 to June 2019 in tertiary stroke centers of the NORDICTUS (NORD-Spain Network for Research and Innovation in ICTUS) network. We included patients with AIS with a proximal occlusion in whom a modified Thrombolysis in Cerebral Infarction 3 reperfusion pattern was obtained. DNI was defined if, despite absence of early neurological improvement during the first 24 hours, patients achieved functional independence on day 90. Clinical and radiological variables obtained before EVT were analyzed as potential predictors of DNI. Results: Of 1565 patients with consecutive AIS treated with EVT, 1381 had proximal anterior circulation occlusions, 803 (58%) of whom achieved a modified Thrombolysis in Cerebral Infarction 3. Of these, 628 patients fulfilled all selection criteria and were included in the study. Mean age was 73.8 years, 323 (51.4%) were female, and median baseline National Institutes of Health Stroke Scale was 16. Absence of early neurological improvement was observed in 142 (22.6%) patients; 32 of these (22.5%) achieved good long-term outcome and constitute the DNI group. Predictors of DNI in multivariable-adjusted logistic regression were male sex (odds ratio, 6.4 [95% CI, 2.1­22.3] P=0.002), lower pre-EVT National Institutes of Health Stroke Scale score (odds ratio, 1.4 [95% CI, 1.2­1.5], P<0.001), and intravenous thrombolysis (odds ratio, 9.1 [95% CI, 2.7­30.90], P<0.001). Conclusions: One-quarter of patients with anterior circulation AIS who do not clinically improve within the first 24 hours after complete cerebral endovascular recanalization will achieve long-term functional independence, regardless of the poor early clinical course. Male sex, lower initial clinical severity, and use of intravenous thrombolysis before EVT predicted this clinical pattern.

Circulating AQP4 Levels in Patients with Cerebral Amyloid Angiopathy-Associated Intracerebral Hemorrhage.

Cerebral amyloid angiopathy (CAA) is a major cause of lobar intracerebral hemorrhage (ICH) in elderly patients. Growing evidence suggests a potential role of aquaporin 4 (AQP4) in amyloid-beta-associated diseases, including CAA pathology. Our aim was to investigate the circulating levels of AQP4 in a cohort of patients who had suffered a lobar ICH with a clinical diagnosis of CAA. AQP4 levels were analyzed in the serum of 60 CAA-related ICH patients and 19 non-stroke subjects by enzyme-linked immunosorbent assay (ELISA). The CAA-ICH cohort was divided according to the time point of the functional outcome evaluation: mid-term (12 ± 18.6 months) and long-term (38.5 ± 32.9 months) after the last ICH. Although no differences were found in AQP4 serum levels between cases and controls, lower levels were found in CAA patients presenting specific hemorrhagic features such as ≥2 lobar ICHs and ≥5 lobar microbleeds detected by magnetic resonance imaging (MRI). In addition, CAA-related ICH patients who presented a long-term good functional outcome had higher circulating AQP4 levels than subjects with a poor outcome or controls. Our data suggest that AQP4 could potentially predict a long-term functional outcome and may play a protective role after a lobar ICH.

Impact of Mediterranean Diet prior to Stroke on the Prognosis of Patients Undergoing Endovascular Treatment.

INTRODUCTION: Mediterranean diet (MeDiet) has been associated with lower risk of stroke. Additionally, animal models suggested that some components of MeDiet are associated with better outcomes after ischemic stroke (IS). We aimed to evaluate the association between global adherence to the MeDiet and the consumption of particular components of the MeDiet with stroke outcomes. MATERIAL AND METHODS: Multicenter observational study of consecutive IS patients treated with endovascular therapy. Inclusion criteria were large anterior circulation vessel occlusion and pre-stroke modified Rankin scale (mRS) <2. Adherence to MeDiet prior to stroke was evaluated using MEDAS 14-item scale. We evaluated the total score and also individual components of the scale. Clinical, radiological, and prognostic variables were collected. Good functional prognosis was considered as mRS ≤2 and complete recanalization as thrombolysis in cerebral infarction 3. RESULTS: From January 1 to October 30, 2018, 239 patients were included (mean age 71 years, 48% women, median baseline NIHSS 16). Median MEDAS scale was 8 points (7-10). Patients with a higher adherence to MeDiet had significantly lower total and LDL-cholesterol levels. Total adherence score was not associated with stroke outcomes. In multivariate analyses, consumption of olive oil as the principal source of fat was independently associated with good functional outcome at 3 months, OR 3.2 (1.1-10.1) and daily consumption of wine was independently associated with complete recanalization, OR 2.0 (1.1-3.8). CONCLUSIONS: Our study suggests that some components of MeDiet, such as olive oil and wine consumption, are related to better prognosis after stroke. More studies are needed to confirm these findings.

Comparison of Plasma Lipoprotein Composition and Function in Cerebral Amyloid Angiopathy and Alzheimer's Disease.

Cerebral amyloid angiopathy (CAA) refers to beta-amyloid (Aß) deposition in brain vessels and is clinically the main cause of lobar intracerebral hemorrhage (ICH). Aß can also accumulate in brain parenchyma forming neuritic plaques in Alzheimer's disease (AD). Our study aimed to determine whether the peripheral lipid profile and lipoprotein composition are associated with cerebral beta-amyloidosis pathology and may reflect biological differences in AD and CAA. For this purpose, lipid and apolipoproteins levels were analyzed in plasma from 51 ICH-CAA patients (collected during the chronic phase of the disease), 60 AD patients, and 60 control subjects. Lipoproteins (VLDL, LDL, and HDL) were isolated and their composition and pro/antioxidant ability were determined. We observed that alterations in the lipid profile and lipoprotein composition were remarkable in the ICH-CAA group compared to control subjects, whereas the AD group presented no specific alterations compared with controls. ICH-CAA patients presented an atheroprotective profile, which consisted of lower total and LDL cholesterol levels. Plasma from chronic ICH-CAA patients also showed a redistribution of ApoC-III from HDL to VLDL and a higher ApoE/ApoC-III ratio in HDL. Whether these alterations reflect a protective response or have a causative effect on the pathology requires further investigation.

Impact of COVID-19 outbreak on ischemic stroke admissions and in-hospital mortality in North-West Spain.

BACKGROUND AND PURPOSE: Spain has been one of the countries heavily stricken by COVID-19. But this epidemic has not affected all regions equally. We analyzed the impact of the COVID-19 pandemic on hospital stroke admissions and in-hospital mortality in tertiary referral hospitals from North-West Spain. METHODS: Spanish multicenter retrospective observational study based on data from tertiary hospitals of the NORDICTUS network. We recorded the number of patients admitted for ischemic stroke between 30 December 2019 and 3 May 2020, the number of IVT and EVT procedures, and in-hospital mortality. RESULTS: In the study period, 2737 patients were admitted with ischemic stroke. There was a decrease in the weekly mean admitted patients during the pandemic (124 vs. 173, p<0.001). In-hospital mortality of stroke patients increased significantly (9.9% vs. 6.5%, p = 0.003), but there were no differences in the proportion of IVT (17.3% vs. 16.1%, p = 0.405) or EVT (22% vs. 23%, p = 0.504). CONCLUSION: We found a decrease in the number of ischemic stroke admissions and an increase in in-hospital mortality during the COVID-19 epidemic in this large study from North-West Spain. There were regional changes within the network, not fully explained by the severity of the pandemic in different regions.

COL4A1 Mutation as a Cause of Familial Recurrent Intracerebral Hemorrhage.

The COL4A1 mutation is a very rare monogenic cause of small vessel disease related to recurrent intracerebral hemorrhage. We report a family in which the index case presented with two intracerebral hemorrhages in the basal ganglia with severe periventricular leukoaraiosis and a cataract and vascular tortuosity in the ophthalmological study. His twin brother also had severe leukoaraiosis and multiple subcortical microhemorrhages as well as a congenital cataract and vascular tortuosity in the retina. The older sister had a porencephalic cyst and involvement of the periventricular white matter and intracerebral hemorrhage. In single-gene testing, all three were found to have the same COL4A1 mutation. Intracerebral subcortical hemorrhages or microhemorrhages and severe subcortical leukoaraiosis in familial cases may be related to COL4 mutations.

Bilingual aphasia: Assessing cross-linguistic asymmetries and bilingual advantage in sentence comprehension deficits.

People with aphasia frequently have difficulties understanding semantically reversible sentences presented in derived word order. This impairment may be related to the inconsistent processing of morphological information, as well as to difficulties inhibiting the inverse interpretation of the sentence. Studies on bilingual aphasia may contribute to our understanding of these issues by shedding light on i) differences in processing of morphology across languages; ii) enhanced control mechanisms. We studied early Basque-Spanish bilingual speakers with aphasia and monolingual Spanish speakers with aphasia, as well as unimpaired individuals. Using comparable sets of materials across languages, we combined behavioural and eye-tracking methods. Results indicate that i) at the group level, bilingual speakers perform better in Spanish than in Basque, particularly in sentences with Theme-Agent argument order. Individual case analysis shows a pattern of weak dissociation across languages in several participants; ii) bilingual people with aphasia do not outperform monolingual people with aphasia in comprehension accuracy, although gaze data suggests that bilingual speakers exhibit higher inhibition and monitoring abilities.

Internal Carotid Artery Web as the Cause of Recurrent Cryptogenic Ischemic Stroke.

Carotid artery web is considered an exceptional cause of recurrent ischemic strokes in the affected arterial territory. The underlying pathology proposed for this entity is an atypical fibromuscular dysplasia. We present the case of a 43-year-old woman with no cardiovascular risk factors who had experienced 2 cryptogenic ischemic strokes in the same arterial territory within an 11-month period. Although all diagnostic tests initially yielded normal results, detailed analysis of the computed tomography angiography images revealed a carotid web; catheter angiography subsequently confirmed the diagnosis. Carotid surgery was performed, since which time the patient has remained completely asymptomatic. The histological finding of intimal hyperplasia is consistent with previously reported cases of carotid artery web. Carotid artery web is an infrequent cause of stroke, and this diagnosis requires a high level of suspicion plus a detailed analysis of vascular imaging studies.

GRECOS Project (Genotyping Recurrence Risk of Stroke): The Use of Genetics to Predict the Vascular Recurrence After Stroke.

BACKGROUND AND PURPOSE: Vascular recurrence occurs in 11% of patients during the first year after ischemic stroke (IS) or transient ischemic attack. Clinical scores do not predict the whole vascular recurrence risk; therefore, we aimed to find genetic variants associated with recurrence that might improve the clinical predictive models in IS. METHODS: We analyzed 256 polymorphisms from 115 candidate genes in 3 patient cohorts comprising 4482 IS or transient ischemic attack patients. The discovery cohort was prospectively recruited and included 1494 patients, 6.2% of them developed a new IS during the first year of follow-up. Replication analysis was performed in 2988 patients using SNPlex or HumanOmni1-Quad technology. We generated a predictive model using Cox regression (GRECOS score [Genotyping Reurrence Risk of Stroke]) and generated risk groups using a classification tree method. RESULTS: The analyses revealed that rs1800801 in the MGP gene (hazard ratio, 1.33; P=9×10-03), a gene related to artery calcification, was associated with new IS during the first year of follow-up. This polymorphism was replicated in a Spanish cohort (n=1.305); however, it was not significantly associated in a North American cohort (n=1.683). The GRECOS score predicted new IS (P=3.2×10-09) and could classify patients, from low risk of stroke recurrence (1.9%) to high risk (12.6%). Moreover, the addition of genetic risk factors to the GRECOS score improves the prediction compared with previous Stroke Prognosis Instrument-II score (P=0.03). CONCLUSIONS: The use of genetics could be useful to estimate vascular recurrence risk after IS. Genetic variability in the MGP gene was associated with vascular recurrence in the Spanish population.

Nontraditional Lipid Variables Predict Recurrent Brain Ischemia in Embolic Stroke of Undetermined Source.

OBJECTIVE: The aims of this study are, first, to calculate the risk of brain ischemia recurrence and embolic source diagnosis in the follow-up of patients with ESUS (embolic stroke of undetermined source) and, second, to identify the predictors of these events including cardiologic, laboratory, and clinical factors. METHODS: A retrospective observational cohort study of stroke patients admitted to the stroke unit in a single tertiary hospital from 2012 to 2014 was performed. Patients fulfilling ESUS criteria were identified and followed by medical history review until March 2016. Statistical analysis comprised Kaplan-Meier analysis and Cox proportional hazards multivariate analysis including clinical characteristics, cardiologic data, and blood test results. RESULTS: One hundred and thirteen patients, 8.3% of the overall stroke patients, filled ESUS criteria and they were younger, had less vascular risk factors, and suffered milder strokes than the remainder of stroke patients. Median follow-up of ESUS was 25.6 months. Risk of brain ischemia recurrence was 8.4, 10.8, and 15% at 12, 24, and 36 months, respectively, and was associated to age (HR 1.07, P = .027) and to a higher total cholesterol (TC)/high-density lipoprotein (HDL)-cholesterol (HR = 1.38, P = .002) and low-density lipoprotein (LDL)-cholesterol/HDL-cholesterol ratios (HR = 1.48, P = .001). The risk of major embolic source diagnosis was 6.7, 7.8, 13.6% at 12, 24, and 36 months, and was associated to female sex (HR = 6.05, P = .021). CONCLUSIONS: Brain ischemia recurrence increases with age and increased values of nontraditional lipid variables, TCHDLr and LDLHDLr, in ESUS patients, and women are more frequently diagnosed with a major embolic source in the follow-up.

Combination of Thrombolysis and Statins in Acute Stroke Is Safe: Results of the STARS Randomized Trial (Stroke Treatment With Acute Reperfusion and Simvastatin).

BACKGROUND AND PURPOSE: The STARS trial (Stroke Treatment With Acute Reperfusion and Simvastatin) was conducted to demonstrate the efficacy and safety of simvastatin treatment in acute stroke. METHODS: STARS07 was a multicentre, phase IV, prospective, randomized, double-blind, placebo-controlled trial. Patients with Acute ischemic stroke recruited within 12 hours from symptom onset were randomized to oral simvastatin 40 mg or placebo, once daily for 90 days. Primary outcome was proportion of independent patients (modified Rankin Scale score of ≤2) at 90 days. Safety end points were hemorrhagic transformation, hemorrhagic events, death, infections, and serious adverse events. RESULTS: From April 2009 to March 2014, 104 patients were included. Fifty-five patients received intravenous tissue-type plasminogen activator. No differences were found between treatment arms regarding the primary outcome (adjusted odds ratio, 0.99 [0.35-2.78]; P=0.98). Concerning safety, no significant differences were found in the rate of hemorrhagic transformation of any type, nor symptomatic hemorrhagic transformation. There were no differences in other predefined safety outcomes. In post hoc analyses, for patients receiving tissue-type plasminogen activator, a favorable effect for simvastatin treatment was noted with higher proportion of patients experiencing major neurological recovery (adjusted odds ratio, 4.14 [1.18-14.4]; P=0.02). CONCLUSIONS: Simvastatin plus tissue-type plasminogen activator combination seems safe in acute stroke, with low rates of bleeding complications. Because of the low recruitment, the STARS trial was underpowered to detect differences in simvastatin efficacy. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT01073007.

Initial experience using the 3MAX cerebral reperfusion catheter in the endovascular treatment of acute ischemic stroke of distal arteries.

INTRODUCTION: The advancement of technology has allowed the development of new catheters that may provide safe intracranial navigation. OBJECTIVE: To report our first experience with the direct aspiration first pass technique in small arteries as the primary method for recanalization with the Penumbra 3MAX cerebral reperfusion catheter. METHODS: A retrospective case series analysis study of patients with acute ischemic stroke endovascularly treated with the direct aspiration technique using the 3MAX reperfusion catheter in our hospital in the past year. RESULTS: We treated six patients in our hospital for acute ischemic stroke using the 3MAX aspiration catheter as first choice. The patients had a median National Institutes of Health Strokes Scale (NIHSS) score of 12 (range 10-17) at admission, with occlusions of an M2 segment of a middle cerebral artery (MCA) treated through an anterior communicating artery, pericallosal artery, P2 artery, and M2-MCA and M3-MCA arteries. Recanalization (TICI 2b-3) was achieved in all cases and no complications occurred. It was not necessary to combine treatment with a stent retriever in any of the patients. All the patients showed early neurological improvement. The median NIHSS score at discharge was 1 (0-3) and 5/6 (83%) patients had a modified Rankin Scale score 0-2 at discharge. CONCLUSIONS: Our initial experience suggests that treatment of distal cerebrovascular occlusions with the 3MAX catheter is feasible. We achieved complete recanalization in all cases without unexpected complications while obtaining good clinical results. However, larger studies are necessary to establish its benefits and its safety.

Obesity and ischemic stroke modulate the methylation levels of KCNQ1 in white blood cells.

Obesity and stroke are multifactorial diseases in which genetic, epigenetic and lifestyle factors are involved. The research aims were, first, the description of genes with differential epigenetic regulation obtained by an 'omics' approach in patients with ischemic stroke and, second, to determine the importance of some regions of these selected genes in biological processes depending on the body mass index. A case-control study using two populations was designed. The first population consisted of 24 volunteers according to stroke/non-stroke and normal weight/obesity conditions. The second population included 60 stroke patients and 55 controls classified by adiposity. DNA from the first population was analyzed with a methylation microarray, showing 80 cytosine-guanine dinucleotides (CpG) sites differentially methylated in stroke and 96 CpGs in obesity, whereas 59 CpGs showed interaction. After validating these data by MassArray Epityper, the promoter region of peptidase M20 domain containing 1 (PM20D1) gene was significantly hypermethylated in stroke patients. One CpG site at Caldesmon 1 (CALD1) gene showed an interaction between stroke and obesity. Two CpGs located in the genes Wilms' tumor 1 (WT1) and potassium voltage-gated channel, KQT-like subfamily, member 1 (KCNQ1) were significantly hypermethylated in obese patients. In the second population, KCNQ1 was also hypermethylated in the obese subjects. Two CpGs of this gene were subsequently validated by methylation-sensitive high-resolution melting. Moreover, KCNQ1 methylation levels were associated with plasma KCNQ1 protein concentrations. In conclusion, obesity induced changes in the KCNQ1 methylation pattern which were also dependent on stroke. Furthermore, the epigenetic marks differentially methylated in the stroke patients were dependent on the previous obese state. These DNA methylation patterns could be used as future potential stroke biomarkers.