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Background and Purpose— Blood–brain barrier dysfunction may be an early phenomenon in the development of the small vessel disease, which underlies white matter lesions. Because vitamin B12 plays a role in maintaining the integrity of the blood–brain barrier, we studied serum vitamin B12 level in relation to such lesions. Methods— In 124 patients with first lacunar stroke, we measured serum vitamin B12 level and rated the degree of white matter lesions on MRI. Results— Mean vitamin B12 level was 202 pmol/L (SD, 68.9). Thirty-nine patients (31.5%) had a vitamin B12 level less than the lower reference value of 150 pmol/L. Lower vitamin B12 level was (statistically significant) associated with more severe periventricular white matter lesions (odds ratio/100 pmol/L decrease, 1.773; 95% CI, 1.001–3.003), but not with deep white matter lesions (odds ratio/100 pmol/L decrease, 1.441; 95% CI, 0.881–2.358; ordered multivariate regression analysis). Conclusions— More severe periventricular white matter lesions in lacunar stroke patients relate to lower vitamin B12 levels. A possible causal relationship should now be studied prospectively.

Cerebral small vessel disease results in silent ischemic lesions (SIL) among which is leukoaraiosis. In this process, endothelial damage is probably involved. Endothelial progenitor cells (EPC), are involved in endothelial repair. By restoring the damaged endothelium, EPC could mitigate SIL and cerebral small vessel disease. Haptoglobin 1-1, one of three phenotypes of haptoglobin, relates to SIL and may therefore attenuate the endothelial repair by EPC. Our aim was to quantify EPC number and function and to assess haptoglobin phenotype and its effect on EPC function in patients with a high prevalence of SIL: lacunar stroke patients. We assessed EPC In 42 lacunar stroke patients and 18 controls by flow cytometry and culture with fetal calf serum, patient and control serum. We determined haptoglobin phenotype and cultured EPC with the three different haptoglobin phenotypes. We found that EPC cluster counts were lower in patients (96.9 clusters/well +/- 83.4 (mean +/- SD)), especially in those with SIL (85.0 +/- 64.3), than in controls (174.4 +/- 112.2). Cluster formation was inhibited by patient serum, especially by SIL patient serum, but not by control serum. Patients with haptoglobin 1-1 had less clusters in culture, and when haptoglobin 1-1 was added to EPC cultures, cluster numbers were lower than with the other haptoglobin phenotypes. We conclude that lacunar stroke patients, especially those with SIL, have impaired EPC cluster formation, which may point at decreased endothelial repair potential. The haptoglobin 1-1 phenotype is likely a causative factor in this impairment.

Haptoglobin (Hp) 2-2 phenotype has been associated with peripheral and coronary artery disease and risk of vascular complications in diabetic patients, but any association of Hp polymorphism with cerebrovascular disease has not been explored so far. We aimed to study Hp polymorphism in a sample of 124 patients with a rather homogeneous type of cerebrovascular disease, namely first symptomatic lacunar stroke due to small vessel disease, in comparison with a large (n=918) control group. Hp phenotypes were determined using starch gel electrophoresis. Hp1 allele frequency was significantly higher in patients than in controls (0.480 vs. 0.395, p < 0.05), mainly due to a lower Hp2-2 phenotype frequency (25.0 vs. 36.3 %; OR 0.59; 95%CI 0.38-0.90; p < 0.05). This was even more pronounced in younger (60 years) patients (Hp1 allele frequency 0.539). Concomitant asymptomatic lacunar lesions were present in 82 patients, extensive white matter lesions in 47 patients. The association between Hp1 and lacunar stroke suggests that Hp may serve different functions depending on the pathological processes in various types of vascular disease in different organs. The association between Hp1 and lacunar stroke may relate to blood-brain barrier dysfunction, to the association between hypertension and cerebral small vessel disease, or a special dependence of small vessel wall integrity on Hp2-2 related angiogenic potential. The presence of concomitant signs of cerebral small vessel disease weakened the association between Hp1 and lacunar stroke, which could reflect a difference in underlying vascular pathophysiology in which Hp phenotype may play a different role.

Background and Purpose— Stroke is the leading cause of disability in the Western world; however, few therapies are at hand to decrease this burden. Summary of Review— Endothelial progenitor cells (EPCs) have been introduced in cardiovascular medicine as factotums. EPCs can repair damaged endothelium and attenuate the development and progression of atherosclerosis. Also, EPCs can form new vessels in ischemic areas and thus promote recovery after ischemic events. In stroke, however, EPC research is limited. In our overview, we provide background information on EPC use as a risk marker and as a potential therapeutic agent. Conclusion— In our opinion, the lack of EPC studies in stroke should instigate vascular neurologists to participate in EPC research, as EPCs could also change pathophysiological concepts and improve clinical treatments in vascular neurology.

Seizures are a common complication after an intracerebral hemorrhage (ICH) and the epilepsy might even be drug resistant. It is not known which factors determine the treatment response in post-ICH epilepsy. We included ICH patients retrospectively who survived at least the first 7 days, in the period from 2004 to 2009 and assessed seizure occurrence up to May 2013. We defined early seizures (ES) as seizures occurring within the first 7 days after the ICH, and late seizures (LS) as seizures occurring later than 7 days after the ICH. We defined drug-resistant epilepsy as a non-response to two adequately chosen and dosed drug regimens. In 857 patients surviving at least 7 days after ICH 69 (8.1 %), patients developed ES whereas LS occurred in 84 (9.8 %) subjects. Patients with ES had higher odds to develop LS, as compared to patients without ES [OR 3.4; 95 % confidence interval (CI) 2.1–5.6]. Drug-resistant post-ICH epilepsy occurred in 19 patients (22.6 %). The most important independent risk factor was the occurrence of ES (OR 3.0; 95 %-CI 1.1–8.4). ES are the main independent risk factor for the development of LS and for the development of drug-resistant epilepsy. Thus, ES might hallmark the start of chronic epilepsy after intracerebral hemorrhage and are not to be considered of no significance.

BACKGROUND Hypertension is associated with the occurrence of cognitive deficits and dementia, probably because hypertension is a major risk factor for the occurrence of brain damage as a result of cerebral small vessel disease (cSVD). Endothelial activation and inflammation have been suggested to play an important role in the pathogenesis of cSVD. We investigated if compound scores of endothelial activation or inflammation, based on several blood markers, are associated with cognitive performance 3 years later in patients with essential hypertension. METHODS At baseline, levels of blood markers of endothelial activation (soluble vascular cellular adhesion molecule-1 (sVCAM-1), soluble intercellular adhesion molecule-1 (sICAM-1), sP-selectin, and sE-selectin) and markers of inflammation (neopterin, C-reactive protein, and sICAM-1) were measured and transformed into compound scores using z-scores. In addition, a brain magnetic resonance imaging (MRI) was performed to determine the presence of cSVD-related MRI markers. Three years later, patients underwent a neuropsychological assessment to determine cognitive performance. RESULTS A total of 101 patients with hypertension were included in the present study. In multiple linear regression analyses with correction for demographics and MRI markers, the compound score of endothelial activation (B = -0.19, 95% confidence interval = -0.34 to -0.04, P = 0.014), but not of inflammation (B = -0.09, 95% confidence interval = -0.22 to 0.05, P = 0.198), was associated with worse cognitive performance. CONCLUSIONS Our results show that an overall measure of endothelial activation is associated with cognitive performance in patients with essential hypertension. This indicates that a process involving endothelial activation might play a role in the pathogenesis of cognitive problems in patients with hypertension.

BACKGROUND: Health care-related adverse events (HCRAEs), which should not be confused with (blameworthy) medical errors, are common; they can lead to hospital admissions and can have grave consequences. Although they are sometimes potentially preventable, information is lacking on HCRAEs leading to admission to different departments. AIM: This study aimed to gain insight into the incidence, type, severity, and preventability of HCRAEs (including adverse drug events) leading to hospitalization to the departments of internal medicine, surgery, orthopedics, neurology, and neurosurgery. Further, we explore if there are differences regarding these HCRAEs between these departments. METHODS: We retrospectively evaluated the medical records of all patients admitted through the emergency department (ED) in a 6-month period to the departments of internal medicine, surgery, orthopedics, neurology, and neurosurgery. All patients admitted because of HCRAEs were included. RESULTS: More than one-fifth (21.8%; range 12.0%-47.8%) of all admissions to the 5 departments were due to a HCRAE. Half (49.9%) of these HCRAEs were medication-related and 30.5% were procedure-related. In 6.5% of patients, the HCRAE led to permanent disability and another 4.4% of patients died during hospitalization. HCRAEs treated by internists and neurologists were usually medication-related, whereas HCRAEs treated by surgeons, orthopedic surgeons, and neurosurgeons were usually procedure-related. CONCLUSION: Hospital admissions to different departments are often caused by HCRAEs, which sometimes lead to permanent disability or even death. Gaining insight into similarities and differences in HCRAEs occurring in different specialties is a starting point for improving clinical outcomes.

Introduction: Patients with medically refractory epilepsy treated with deep brain stimulation (DBS) of the anterior nucleus of the thalamus (ANT) vary highly in their therapy response. Proper positioning of the DBS lead is crucial to maximize efficacy and minimize side effects. For a correct implantation, the ANT is anatomically located using pre-operative 3T MRI and perioperative microelectrode recordings (MER). Neurons in the ANT have highly variable, yet characteristic patterns of firing in bursts. During DBS lead implantation, we noted differences among patients’ characteristic burst patterns along the electrode trajectory. In this study, we investigate whether electrophysiological characteristics of the target region could predict therapy response to DBS and could thus be used to improve ANT targeting during DBS surgery. Objectives: To determine whether perioperative neurophysiological characteristics relate to therapy response in DBS for patients with medically refractory epilepsy. Patients and methods: We included ten consecutive epilepsy patients planned for DBS surgery at Maastricht University Medical Center. All patients were diagnosed with medically refractory epilepsy and had incapacitating seizures. Patients failed trials of at least two reasonably tolerated and adequately chosen antiepileptic drug schedules. Using pre-operative 3T MRI, we planned an extraventricular approach to target. The ANT was defined as a grey matter structure at the top of the mamillothalamic tract. Along this trajectory, we performed stereotactic single cell MERs. The anatomical location of the recordings were verified using preoperative 3T MR images. We compared characteristics of the neural signals at different depths along the trajectory between DBS responders and non-responders. Responders were defined as patients with a seizure frequency reduction of more than 50% at one year follow-up. Results: Using MER data from 19 electrode trajectories of ten patients (one unilateral and nine bilateral trajectories), we found high-amplitude neuronal bursts around the target area or ANT. Responders to DBS (n = 5) had higher normalized mean firing rates and mean burst rates near the target area compared to non-responders (n = 5), with a clearer delineation between the target region and surroundings. Electrode trajectories and lead localization did not differ between responders and non-responders. Conclusion: Single cell firing patterns in the ANT relate to therapy response in DBS for patients with medically refractory epilepsy. Analysis of single cell firing patterns using MER may guide targeting or contribute to predicting therapy response to ANT DBS. Further exploration into the use of electrophysiological recordings is warranted to improve targeting or predict outcome in DBS for epilepsy patients.

Background and Purpose— Elevated blood pressure (BP) is associated with the presence of cerebral microbleeds (CMBs) in cross-sectional studies. However, longitudinal studies did not show a convincing relationship. We aimed to determine the association between elevated BP levels and the occurrence of new CMBs after a 2-year follow-up in first-ever lacunar stroke patients using ambulatory BP monitoring. Methods— Ninety-six first-ever lacunar stroke patients underwent brain MRI and ambulatory BP monitoring at baseline and after 2-year follow-up. We used logistic regression analyses to assess the association of BP levels with new CMBs. Results— We found new CMBs in 17 patients (18%). Higher 24-hour, day and night systolic BP (odds ratio, 2.69; 95% confidence interval, 1.40–5.21 per SD increase for 24-hour BP) and diastolic BP (odds ratio, 2.13; 95% confidence interval, 1.15–3.90 per SD increase for 24-hour BP) at baseline were associated with the development of new CMBs independent of age and sex. BP levels decreased during follow-up in both patients with and without new CMBs. Unlike BP levels at baseline, there was no difference in BP levels at follow-up between patients with and without new CMBs. Conclusions— Both higher systolic and diastolic BP levels were associated with the development of new CMBs in a population of lacunar stroke patients. Decrease of BP levels during follow-up did not halt progression of CMBs; however, it remains to be determined whether (early) intervention with antihypertensive drugs can slow down progression of CMBs.

We read the review by Moore et al. (2012), recently published in this journal, with great interest and compliment the authors for their thorough review of cognitive impairment and its relation to vitamin B12.

Background Positive family history of stroke is an independent risk factor for lacunar stroke. However, the magnitude of familial aggregation of a certain disease is better evaluated by the genetic relative risk. This is calculated by dividing the prevalence of specific disease in family members of patients by the prevalence of this disease in the general population. In a cohort of lacunar stroke patients, who were subtyped clinically and radiologically, we determined the genetic relative risk of stroke. Methods By questionnaire and additional interview, we obtained a complete first-degree family history of stroke. The prevalence of stroke in first-degree relatives of these lacunar stroke patients was compared to the self-reported prevalence of stroke in a Dutch community based cohort of elderly volunteers. Secondly, the influence of proband characteristics and family composition on parental and sibling history of stroke were evaluated. Principal Findings We collected data of 1066 first-degree relatives of 195 lacunar stroke patients. Strokes occurred in 13.5% of first-degree relatives. The genetic relative risk was 2.94 (95%CI 2.45–3.53) for overall first-degree relatives, 4.52 (95%CI 3.61–5.65) for patients' parents and 2.10 (95%CI 1.63–2.69) for patients' siblings. Age of proband and proband status for hypertension influenced the chance of having a parent with a history of stroke whereas the likelihood of having a concordant sibling increased with sibship size. Conclusions We found an increased genetic relative risk of stroke in first-degree relatives of patients with lacunar stroke. Our data warrant further genomic research in this well-defined high risk population for stroke.

Cerebral small vessel disease (CSVD) is considered to be caused by an increased permeability of the blood-brain barrier and results in enlargement of Virchow Robin spaces (VRs), white matter lesions, brain microbleeds, and lacunar infarcts. The increased permeability of the blood-brain barrier may relate to endothelial cell activation and activated monocytes/macrophages. Therefore, we hypothesized that plasma markers of endothelial activation (adhesion molecules) and monocyte/macrophage activation (neopterin) relate to CSVD manifestations. In 163 first-ever lacunar stroke patients and 183 essential hypertensive patients, we assessed CSVD manifestations on brain magnetic resonance imaging (MRI) and levels of C-reactive protein (CRP), neopterin, as well as circulating soluble adhesion molecules (sICAM-1, sVCAM-1, sE-selectin, sP-selectin). Neopterin, sICAM-1 and sVCAM-1 levels were higher in patients with extensive CSVD manifestations than in those without (p < 0.01). Neopterin levels independently related to higher numbers of enlarged Virchow Robin spaces (p < 0.001). An inflammatory process with activated monocytes/macrophages may play a role in the increased permeability of the blood brain barrier in patients with CSVD.

Background and Purpose— Oxidized low-density lipoprotein (oxLDL) induces endothelial dysfunction and antibody formation. Because endothelial dysfunction is involved in cerebral small vessel disease (CSVD) (dilated Virchow Robin spaces, lacunar infarcts, and white matter lesions), oxLDL antibodies could play a role in CSVD pathogenesis. Therefore, we studied oxLDL antibodies in patients with high prevalence of CSVD: lacunar stroke patients and essential hypertensive patients. Methods— A total of 158 lacunar stroke patients, 158 hypertensive patients, and 43 healthy controls were included. We determined levels of IgG and IgM against hypochlorite (HOCl) and malondialdehyde (MDA) oxLDL using ELISA (values in optical density). Results— Patients with CSVD had higher levels of IgG-HOCl-oxLDL (0.77 versus 0.70; P P P Conclusions— An autoinflammatory process with lower levels of IgM antibodies and higher levels of IgG antibodies against oxLDL may be involved in CSVD.

Background and Purpose— Lacunar stroke (LS) can be subtyped according to the absence (isolated lacunar infarct [ILA]) or presence of concomitant white matter lesions (WML) and/or asymptomatic lacunar infarcts. Endothelial activation is thought to play a pivotal role in the subtype with WML and/or asymptomatic lacunar infarcts. The aim of this study was to evaluate whether endothelial activation is associated with WML and/or asymptomatic lacunar infarcts in LS patients. Here, we determined levels of circulating blood markers of endothelial function in LS patients. Methods— In 149 patients, all of whom had brain-MRI, levels of tissue plasminogen activator (tPA), plasminogen activator inhibitor type 1 (PAI-1), tPA–PAI-1 complex, von Willebrand factor, tissue factor, thrombomodulin, and coagulation factor VIII were determined. Levels of blood markers were related to subtypes of LS and adjusted for age, gender, and vascular risk factors. Results— In subtypes of LS, tPA activity was increased in patients with WML (0.79 IU/mL vs 0.44 IU/mL for ILA; P =0.02) and PAI-1-antigen levels were lowest in patients with WML (27.5 ng/mL vs 44.0 ng/mL for ILA; P =0.02). The association between WML and PAI-1 remained significant after multivariable analysis (OR, 0.99; 95% CI, 0.98–1.00 per ng/mL change of PAI-1; P =0.04). Conclusions— We found further evidence for the hypothesis of endothelial activation in the subtype of LS caused by a diffuse small vessel vasculopathy, as we found higher levels of tPA in patients with concomitant extensive WML than in those with ILA. Second, low levels of PAI-1 were associated with WML. We postulate that differences in activity of components of the fibrinolytic system might contribute to WML development.

Virchow-Robin spaces (VRs) are perivascular spaces surrounding the deep perforating brain arteries. VRs dilatation is pathologic, and it could be a manifestation of cerebral small vessel disease. In the present study we assessed the relation between VRs and silent ischemic lesions in a cohort of patients with cerebral small vessel disease. We divided dilated VRs on MRI (1.5 Tesla) into three semi-quantitative categories in 165 first ever lacunar stroke patients. We counted asymptomatic lacunar infarcts and graded white matter lesions, and compared the prevalence of vascular risk factors in different categories of VRs. We also determined independent predictors of silent ischemic lesions. VRs at basal ganglia level related to age, hypertension, asymptomatic lacunar infarcts, and white matter lesions. VRs at basal ganglia level predicted silent ischemic lesions (odds ratio 10.58 per higher VRs category; 95 %- confidence interval 3.40 – 32.92). Dilated VRs in the basal ganglia relate to the severity of cerebral small vessel disease and might be a manifestation of the same small vessel abnormality that causes silent ischemic lesions. This adds a role for VRs as a potential marker for small vessel disease.

The blood-brain barrier (BBB) is the interface between the blood and brain tissue, which regulates the maintenance of homeostasis within the brain. Impaired BBB integrity is increasingly associated with various neurological diseases. To gain a better understanding of the underlying processes involved in BBB breakdown, magnetic resonance imaging (MRI) techniques are highly suitable for noninvasive BBB assessment. Commonly used MRI techniques to assess BBB integrity are dynamic contrast-enhanced and dynamic susceptibility contrast MRI, both relying on leakage of gadolinium-based contrast agents. A number of conceptually different methods exist that target other aspects of the BBB. These alternative techniques make use of endogenous markers, such as water and glucose, as contrast media. A comprehensive overview of currently available MRI techniques to assess the BBB condition is provided from a scientific point of view, including potential applications in disease. Improvements that are required to make these techniques clinically more easily applicable will also be discussed.