An updated definition of stroke for the 21st century: a statement for healthcare professionals from the American Heart Association/American Stroke Association

Association of CYP2C19 Polymorphisms with the Clinical Efficacy of Clopidogrel Therapy in Patients Undergoing Carotid Artery Stenting in Asia

The CYP2C19 gene plays a detrimental role in the metabolism of clopidogrel. This study aimed to investigate the association between CYP2C19 polymorphisms and the clinical efficacy of clopidogrel therapy in patients who have undergone carotid artery stenting (CAS). CYP2C19 genotype screening was performed on 959 ischemic stroke patients. Of these patients, 241 who had undergone CAS were enrolled in the study. They were all followed up for 1 year after stent surgery, and the primary clinical end-points were ischemic events. The frequencies of the CYP2C19*2 and *3 alleles among the 959 patients were 31.80% and 5.06%, respectively. Regarding the 241 participants who had undergone CAS, multivariate Cox regression analysis showed that the CYP2C19 loss-of-function (LOF) alleles (*2 and *3) were risk factors for post-CAS prognosis. Within 1 year of follow-up, the patients carrying the CYP2C19 LOF alleles were more likely to experience ischemic events than those carrying none. The occurrence of ischemic events did not significantly differ between the *2 and *3 allele carriers. Our results suggest that CYP2C19 LOF alleles (*2 and *3) significantly impact the prognosis of patients on clopidogrel therapy after CAS and that the CYP2C19*2 and CYP2C19*3 alleles have the same effects on prognosis.

Cerebrovascular disease in children with HIV-1 infection

An estimated 3.2 million children worldwide have human immunodeficiency virus (HIV) infection. Antiretroviral therapy (ART) has resulted in prolonged survival, leading to an increase in complications previously recognized in adults. Children with HIV infection have increased risk of cerebrovascular disease from multiple aetiologies including HIV-associated vasculopathy, opportunistic vasculitis, cardioembolism or coagulopathy, all of which may be secondary to the infection. Prevalence of cerebrovascular disease in HIV-infected children is underestimated because of limited neuroimaging in low and middle income countries, silent events without overt motor manifestations, and mislabeling as HIV encephalopathy for non-motor manifestations such as behavioural and cognitive difficulties. No management guidelines for cerebrovascular disease in HIV-infected children exist but common practices target risk factors for stroke in low and middle income countries. Where capacity permits, screening for opportunistic infections, vasculitis, coagulopathy and cardioembolism is important. Optimising virological suppression, correction of anaemia, control of seizures and aspirin prophylaxis are management priorities. Neurosurgical interventions may have a role.

Brain Aging in African-Americans: The Atherosclerosis Risk in Communities (ARIC) Experience

Reported rates of dementia differ by race, although most studies have not focused on carefully measured outcomes, confounding by education or other demographic factors, nor have they studied other outcomes other than dementia. In this review we will discuss the experience in the Atherosclerosis Risk in Communities (ARIC) study evaluating racial disparities relating to stroke, subclinical brain infarction, leukoaraiosis, as well as cognitive change and dementia. ARIC is a biracial cohort of 15,792 participants from four U.S. communities, initially recruited in 1987-1989, and seen at a total of 5 in-person visits (most recently seen in 2011-2013) with annual follow-up phone calls. We will provide evidence from ARIC studies that disproportionate rates of vascular risk factors explain at least some of these observed disparities by race, but particular risk factors, including diabetes, may differentially affect the brain in African-American versus white participants. In addition, we will review some of the disparities by race in studies focusing on the genetics of stroke, small vessel disease, and dementia.

Symptoms of Poststroke Depression among Stroke Survivors: An Appraisal of Psychiatry Needs and Care during Physiotherapy Rehabilitation

Purpose. To identify stroke survivors with symptoms of poststroke depression and the extent of psychiatry needs and care they have received while on physiotherapy rehabilitation. Participants. Fifty stroke survivors (22 females and 28 males) at the outpatient unit of Physiotherapy Department, University of Nigeria Teaching Hospital, Enugu, who gave their informed consent, were randomly selected. Their age range and mean age were 26-66 years and 54.76 ± 8.79 years, respectively. Method. A multiple case study of 50 stroke survivors for symptoms of poststroke depression was done with Beck's Depression Inventory, mini mental status examination tool, and Modified Motor Assessment Scale. The tests were performed independently by the participants except otherwise stated and scored on a scale of 0-6. Data were analyzed using Z-test for proportional significance and chi-square test for determining relationship between variables, at p < 0.05. Results. Twenty-one (42.0%) stroke survivors had symptoms of PSD, which was significantly dependent on duration of stroke (χ (2) = 21.680, df = 6, and p = 0.001), yet none of the participants had a psychiatry review. Conclusions. Symptoms of PSD may be common in cold compared to new cases of stroke and may need psychiatry care while on physiotherapy rehabilitation.

Air pollution and stroke - an overview of the evidence base

Air pollution is being increasingly recognized as a significant risk factor for stroke. There are numerous sources of air pollution including industry, road transport and domestic use of biomass and solid fuels. Early reports of the association between air pollution and stroke come from studies investigating health effects of severe pollution episodes. Several daily time series and case-crossover studies have reported associations with stroke. There is also evidence linking chronic air pollution exposure with stroke and with reduced survival after stroke. A conceptual framework linking air pollution exposure and stroke is proposed. It links acute and chronic exposure to air pollution with pathways to acute and chronic effects on stroke risk. Current evidence regarding potential mechanisms mainly relate to particulate air pollution. Whilst further evidence would be useful, there is already sufficient evidence to support consideration of reduction in air pollution as a preventative measure to reduce the stroke burden globally.

A Human-machine-interface Integrating Low-cost Sensors with a Neuromuscular Electrical Stimulation System for Post-stroke Balance Rehabilitation

A stroke is caused when an artery carrying blood from heart to an area in the brain bursts or a clot obstructs the blood flow to brain thereby preventing delivery of oxygen and nutrients. About half of the stroke survivors are left with some degree of disability. Innovative methodologies for restorative neurorehabilitation are urgently required to reduce long-term disability. The ability of the nervous system to reorganize its structure, function and connections as a response to intrinsic or extrinsic stimuli is called neuroplasticity. Neuroplasticity is involved in post-stroke functional disturbances, but also in rehabilitation. Beneficial neuroplastic changes may be facilitated with non-invasive electrotherapy, such as neuromuscular electrical stimulation (NMES) and sensory electrical stimulation (SES). NMES involves coordinated electrical stimulation of motor nerves and muscles to activate them with continuous short pulses of electrical current while SES involves stimulation of sensory nerves with electrical current resulting in sensations that vary from barely perceivable to highly unpleasant. Here, active cortical participation in rehabilitation procedures may be facilitated by driving the non-invasive electrotherapy with biosignals (electromyogram (EMG), electroencephalogram (EEG), electrooculogram (EOG)) that represent simultaneous active perception and volitional effort. To achieve this in a resource-poor setting, e.g., in low- and middle-income countries, we present a low-cost human-machine-interface (HMI) by leveraging recent advances in off-the-shelf video game sensor technology. In this paper, we discuss the open-source software interface that integrates low-cost off-the-shelf sensors for visual-auditory biofeedback with non-invasive electrotherapy to assist postural control during balance rehabilitation. We demonstrate the proof-of-concept on healthy volunteers.

Pioglitazone after Ischemic Stroke or Transient Ischemic Attack

BACKGROUND

Patients with ischemic stroke or transient ischemic attack (TIA) are at increased risk for future cardiovascular events despite current preventive therapies. The identification of insulin resistance as a risk factor for stroke and myocardial infarction raised the possibility that pioglitazone, which improves insulin sensitivity, might benefit patients with cerebrovascular disease.

METHODS

In this multicenter, double-blind trial, we randomly assigned 3876 patients who had had a recent ischemic stroke or TIA to receive either pioglitazone (target dose, 45 mg daily) or placebo. Eligible patients did not have diabetes but were found to have insulin resistance on the basis of a score of more than 3.0 on the homeostasis model assessment of insulin resistance (HOMA-IR) index. The primary outcome was fatal or nonfatal stroke or myocardial infarction.

RESULTS

By 4.8 years, a primary outcome had occurred in 175 of 1939 patients (9.0%) in the pioglitazone group and in 228 of 1937 (11.8%) in the placebo group (hazard ratio in the pioglitazone group, 0.76; 95% confidence interval [CI], 0.62 to 0.93; P=0.007). Diabetes developed in 73 patients (3.8%) and 149 patients (7.7%), respectively (hazard ratio, 0.48; 95% CI, 0.33 to 0.69; P<0.001). There was no significant between-group difference in all-cause mortality (hazard ratio, 0.93; 95% CI, 0.73 to 1.17; P=0.52). Pioglitazone was associated with a greater frequency of weight gain exceeding 4.5 kg than was placebo (52.2% vs. 33.7%, P<0.001), edema (35.6% vs. 24.9%, P<0.001), and bone fracture requiring surgery or hospitalization (5.1% vs. 3.2%, P=0.003).

CONCLUSIONS

In this trial involving patients without diabetes who had insulin resistance along with a recent history of ischemic stroke or TIA, the risk of stroke or myocardial infarction was lower among patients who received pioglitazone than among those who received placebo. Pioglitazone was also associated with a lower risk of diabetes but with higher risks of weight gain, edema, and fracture. (Funded by the National Institute of Neurological Disorders and Stroke; ClinicalTrials.gov number, NCT00091949.).

Validating screening tools for depression in stroke and transient ischemic attack patients

OBJECTIVE

The best screening questionnaires for detecting post-stroke depression have not been identified. We aimed to validate four commonly used depression screening tools in stroke and transient ischemic attack patients.

METHODS

Consecutive stroke and transient ischemic attack patients visiting an outpatient stroke clinic in Calgary, Alberta (Canada) completed a demographic questionnaire and four depression screening tools: Patient Health Questionnaire (PHQ)-9, PHQ-2, Hospital Anxiety and Depression Scale (HADS-D), and Geriatric Depression Scale (GDS-15). Participants then completed the Structured Clinical Interview for DSM-IV (SCID), the gold-standard for diagnosing major depression. The questionnaires were validated against the SCID and sensitivity and specificity were calculated at various cut-points. Optimal cut-points for each questionnaire were determined using receiver-operating curve analyses.

RESULTS

Among 122 participants, 59.5% were diagnosed with stroke and 40.5% with transient ischemic attack. The point prevalence of SCID-diagnosed current major depression was 9.8%. At the optimal cut-points, the sensitivity and specificity for each screening tool were as follows: PHQ-9 (sensitivity: 81.8%, specificity: 97.1%), PHQ-2 (sensitivity: 75.0%, specificity: 96.3%), HADS-D (sensitivity: 63.6%, specificity: 98.1%), and GDS-15 (sensitivity: 45.5%, specificity: 84.8%). Areas under the receiver operating characteristic curves were as follows: PHQ-9 86.6%, PHQ-2 86.7%, HADS-D 85.9%, and GDS-15 66.3%.

CONCLUSIONS

The PHQ-2 and PHQ-9 are both suitable depression screening tools, taking less than 5 minutes to complete. The HADS-D does not appear to have any advantage over the PHQ-based scales, even though it was designed specifically for medically ill populations. The GDS-15 cannot be recommended for general use in a stroke clinic based on this study as it had worse discrimination due to low sensitivity.

Retrospective study on prognostic importance of serum procalcitonin and amino-terminal pro-brain natriuretic peptide levels as compared to Acute Physiology and Chronic Health Evaluation IV Score on Intensive Care Unit admission, in a mixed Intensive Care Unit population

BACKGROUND

Timely decision making in Intensive Care Unit (ICU) is very essential to improve the outcome of critically sick patients. Conventional scores like Acute Physiology and Chronic Health Evaluation (APACHE IV) are quite cumbersome with calculations and take minimum 24 hours. Procalcitonin has shown to have prognostic value in ICU/Emergency department (ED) in disease states like pneumonia, sepsis etc. NTproBNP has demonstrated excellent diagnostic and prognostic importance in cardiac diseases. It has also been found elevated in non-cardiac diseases. We chose to study the prognostic utility of these markers on ICU admission.

SETTINGS AND DESIGN

Retrospective observational study.

MATERIALS AND METHODS

A Retrospective analysis of 100 eligible patients was done who had undergone PCT and NTproBNP measurements on ICU admission. Their correlations with all cause mortality, length of hospital stay, need for ventilator support, need for vasopressors were performed.

RESULTS

Among 100 randomly selected ICU patients, 28 were non-survivors. NTproBNP values on admission significantly correlated with all cause mortality (P = 0.036, AUC = 0.643) and morbidity (P = 0.000, AUC = 0.763), comparable to that of APACHE-IV score. PCT values on admission did not show significant association with mortality, but correlated well with morbidity and prolonged hospital length of stay (AUC = 0.616, P = 0.045).

CONCLUSION

The current study demonstrated a good predictive value of NTproBNP, in terms of mortality and morbidity comparable to that of APACHE-IV score. Procalcitonin, however, was found to have doubtful prognostic importance. These findings need to be confirmed in a prospective larger study.

Associations of serum n-3 and n-6 PUFA and hair mercury with the risk of incident stroke in men: the Kuopio Ischaemic Heart Disease Risk Factor Study (KIHD)

PUFA have been associated with lower risk of CVD, but less is known about their association with stroke risk. Fish, a major source of n-3 PUFA, may also contain methylmercury, which has been associated with higher risk of CVD and attenuation of the benefits of long-chain n-3 PUFA. We investigated the associations of serum n-3 and n-6 PUFA and hair Hg with risk of stroke in men. A total of 1828 men from the prospective, population-based Kuopio Ischaemic Heart Disease Risk Factor Study, aged 42-60 years and free of CVD at baseline in 1984-1989 were studied. Cox regression models were used for the analyses. During the mean follow-up of 21·2 years, 202 stroke cases occurred, of which 153 were ischaemic strokes. After adjustment for age and examination year, the only statistically significant association among the n-3 and n-6 PUFA was observed between the n-3 PUFA α-linolenic acid and risk of haemorrhagic stroke (hazard ratio in the highest v. the lowest quartile 0·33; 95 % CI 0·13, 0·86; P trend=0·03). However, further adjustments attenuated the association to statistically non-significant. Hair Hg was not associated with stroke risk, but among those with hair Hg above the median level, higher serum long-chain n-3 PUFA concentrations were associated with a higher risk of ischaemic stroke. In our cohort of men, serum n-3 or n-6 PUFA or hair Hg were not associated with stroke risk; however, the interaction between Hg and long-chain n-3 PUFA with regard to ischaemic stroke risk warrants further investigation.

Risk of stroke and transient ischaemic attack after herpes zoster

We assessed the association of herpes zoster (HZ) with stroke/transient ischaemic attack (TIA) in the general population according to age with controlling risk factors for stroke, using a nationwide representative cohort. The study was based on a prospective dynamic cohort consisting of 1 million Koreans representing all age groups, genders and geographical areas in the Korea Health Insurance Database. New events of stroke/TIA and HZ were identified using the diagnostic codes in the International Classification of Diseases, tenth revision. The risk for stroke/TIA after HZ was compared with HZ-free stroke/TIA individuals according to age group. A total of 766 179 adults were followed up for 11 years from 2003. The incidence of the first-diagnosed HZ cases was 9.40 per 1000 person-years, and that of the first-diagnosed stroke/TIA cases was 9.77 per 1000 person-years. The risk for stroke/TIA was higher in patients who had previous HZ episodes than in those who had never experienced HZ (incidence rate ratio 1.90; 95% CI 1.85-1.95). In addition, this risk persisted for several years after HZ. The risk of stroke/TIA after HZ gradually decreased with age; adjusted hazard ratio (HR) 2.04 in 18- to 30-year-olds, HR 1.74 in 30- to 40-year-olds, HR 1.43 in 40- to 50-year-olds, HR 1.23 in 50- to 60-year-olds, HR 1.24 in 60- to 70-year-olds, and HR 1.29 in those >70 years old, after controlling risk factors for stroke/TIA. Our findings provide evidence that HZ carries an increased risk of stroke or TIA and that the effect of HZ on stroke decreases with increasing age.

Thiamine as an adjunctive therapy in cardiac surgery: a randomized, double-blind, placebo-controlled, phase II trial

Background

Thiamine is a vitamin that is essential for adequate aerobic metabolism. The objective of this study was to determine if thiamine administration prior to coronary artery bypass grafting would decrease post-operative lactate levels as a measure of increased aerobic metabolism.

Methods

We performed a randomized, double-blind, placebo-controlled trial of patients undergoing coronary artery bypass grafting. Patients were randomized to receive either intravenous thiamine (200 mg) or placebo both immediately before and again after the surgery. Our primary endpoint was post-operative lactate levels. Additional endpoints included pyruvate dehydrogenase activity, global and cellular oxygen consumption, post-operative complications, and hospital and intensive care unit length of stay.

Results

Sixty-four patients were included. Thiamine levels were significantly higher in the thiamine group as compared to the placebo group immediately after surgery (1200 [683, 1200] nmol/L vs. 9 [8, 13] nmol/L, p < 0.001). There was no difference between the groups in the primary endpoint of lactate levels immediately after the surgery (2.0 [1.5, 2.6] mmol/L vs. 2.0 [1.7, 2.4], p = 0.75). Relative pyruvate dehydrogenase activity was lower immediately after the surgery in the thiamine group as compared to the placebo group (15 % [11, 37] vs. 28 % [15, 84], p = 0.02). Patients receiving thiamine had higher post-operative global oxygen consumption 1 hour after the surgery (difference: 0.37 mL/min/kg [95 % CI: 0.03, 0.71], p = 0.03) as well as cellular oxygen consumption. We found no differences in clinical outcomes.

Conclusions

There were no differences in post-operative lactate levels or clinical outcomes between patients receiving thiamine or placebo. Post-operative oxygen consumption was significantly increased among patients receiving thiamine.

Trial registration

clinicaltrials.gov NCT02322892, December 14, 2014

Electronic supplementary material

The online version of this article (doi:10.1186/s13054-016-1245-1) contains supplementary material, which is available to authorized users.

Stroke survivors in low- and middle-income countries: A meta-analysis of prevalence and secular trends

PURPOSE

To provide an up-to-date estimate on the changing prevalence of stroke survivors, and examines the geographic and socioeconomic variations in low and middle-income countries (LMICs).

METHODS

We searched MEDLINE, EMBASE, SCOPUS and Web of Science databases and systematically reviewed articles reporting stroke prevalence and risk factors from inception to July 2015. Pooled prevalence estimates and secular trends based on random-effects models were conducted across LMICs, World Bank regions and income groups.

RESULTS

Overall, 101 eligible community-based studies were included in the meta-analysis. The pooled crude prevalence of stroke survivors was highest in Latin America and Caribbean (21.2 per 1000, 95% CI 13.7 to 30.29) but lowest in sub-Saharan Africa (3.5 per 1000, 95% CI 1.9 to 5.7). Steepest increase in stroke prevalence occurred in low-income countries, increasing by 14.3% annually while the lowest increase occurred in lower-middle income countries (6% annually), and for every 10years increase in participants' mean age, the prevalence of stroke survivors increases by 62% (95% CI 6% to 147%).

CONCLUSION

The prevalence estimates of stroke survivors are significantly different across LMICs in both magnitude and secular trend. Improved stroke surveillance and care, as well as better management of the underlying risk factors, primarily undetected or uncontrolled high blood pressure (HBP) are needed.

A rat model of vascular dementia for evaluating Chinese medicine prescriptions

OBJECTIVE

To develop a new model of vascular dementia for evaluating Chinese medicine prescriptions.

METHODS

Eighty-eight male Wistar rats were randomly divided into 4 groups. At d00, d42, d70, d98 (ni=20, 20, 24, 24) during fatty-feeding, rats in each group were further divided into 10 or 12 subgroups (ni=2), respectively. Lacunar stroke were replicated with the injection of thrombi which coagulated artificially from itself blood. The median lethal doses (LD50) were regressed from accumulative mortality in each geometric thrombus doses (k=0.75, 0.5, 0.85, 0.85), respectively. The degree of vascular dementia was evaluated as exploratory, learning and memorizing abilities. The median effective dose of thrombus for replicating rat model was regressed from dementia scores which were derived from the abilities. The linear correlation was regressed between the values of LD50 or effective dose (ED50) and the durations (days) of hypercholesterolemia. This model of vascular dementia was pathologically confirmed as the neural injuries from lacunar stroke in rats.

RESULTS

The hypercholesterolemia was indicated as elevated total cholesterol, triglyeerides low-density lipoprotein cholesterol, and decreased high-density lipoprotein cholesterol. The values of LD50 with its 95% confidence intervals (CI) were 1525.0 (1361.0-1709.0), 584.3 (490.1-696.6), 168.7 (163.7-173.8), or 62.4 (59.5-65.4) mg/mL, at d00, d42, d70, and d98, respectively. There is a linear regression between the values of LD50 and the durations of hypercholesterolemia (y=-15.33x+1390.0, r=0.963, P<0.05). The values of ED50 with its 95% CI were 528.8 (340.5-821.4), 217.0 (20.84-2259.0), 96.3 (23.4-402.6), or 47.0 (43.7-50.6) mg/mL from dementia score, at d00, d42, d70, and d98, respectively. There is a linear regression between the values of ED50 and the durations of hypercholesterolemia (y=-4.992x+484.2, r=0.965, P<0.05). The neural injuries were demonstrated as neural degeneration and necrosis.

CONCLUSIONS

For evaluating Chinese medicine, a model of vascular dementia in rats is set up with the lacunar stroke from self-thrombosis during hypercholesterolemia. This model from lacunar stroke is useful to investigate the pathogenesis and treatment of vascular dementia.

Motor and cognitive outcome after specific early lesions of the brain - a systematic review

The aim of this systematic review was to study motor and cognitive outcome in infants with severe early brain lesions and to evaluate effects of side of the lesion, sex, and social economic status on outcome. A literature search was performed using the databases Pubmed and Embase. Included studies involved infants with either cystic periventricular leukomalacia (cPVL), preterm, or term stroke (i.e. parenchymal lesion of the brain). Outcome was expressed as cerebral palsy (CP) and intellectual disability (mental retardation). Median prevalence rates of CP after cPVL, preterm, and term stroke were 86%, 71%, and 29% respectively; of intellectual disability 50%, 27%, and 33%. Most infants with cPVL developed bilateral CP, those with term stroke unilateral CP, whereas after preterm stroke bilateral and unilateral CP occurred equally often. Information on the effects of sex and social economic status on outcome after specific brain lesions was very limited. Our findings show that the risk for CP is high after cPVL, moderate after preterm stroke, and lowest after term stroke. The risk for intellectual disability after an early brain lesion is lower than that for CP. Predicting outcome at individual level remains difficult; new imaging techniques may improve predicting developmental trajectories.

Embolic Protection Devices in Transcatheter Aortic Valve Replacement

The initially reported periprocedural neurological events rates associated with transcatheter aortic valve replacement raised concerns that ultimately led to the development and to the clinical research of novel embolic protection devices. Although the reduction of clinical stroke is a desired goal, the current research design of embolic protection devices focuses on surrogate markers of the clinical disease, primarily on silent central nervous system lesions observed in postprocedural diffuse-weighted magnetic resonance imaging and cognitive function testing. As the mere presence of particulate debris in brain matter may not correlate with the extent of brain injury, cognitive function, or quality of life, the clinical significance of embolic protection devices has yet to be determined, and interpretation of study results with regard to real-life clinical use should be viewed accordingly. The purpose of this article is to provide an overview of the updated ongoing clinical research on embolic protection devices and present its major caveats.

Cerebral ischemia during surgery: an overview

Cerebral ischemia is the pathophysiological condition in which the oxygenated cerebral blood flow is less than what is needed to meet cerebral metabolic demand. It is one of the most debilitating complications in the perioperative period and has serious clinical sequelae. The monitoring and prevention of intraoperative cerebral ischemia are crucial because an anesthetized patient in the operating room cannot be neurologically assessed. In this paper, we provide an overview of the definition, etiology, risk factors, and prevention of cerebral ischemia during surgery.

Incremental prognostic value of computed tomography in stroke: rationale and design of the IMPACTS study

This study was designed to determine the prognostic value of coronary computed tomography angiography (CCTA) in ischemic stroke patients and to identify any incremental risk stratification benefits of CCTA findings compared with coronary artery calcium scoring (CACS) and traditional Framingham risk scores (FRS) in ischemic stroke patients without chest pain. IMPACTS is a prospective, multicenter, observational cohort study in which at least seven centers in Korea will participate. All participants will be enrolled in this study after providing informed consent. Nine hundred total ischemic stroke patients without chest pain will be enrolled and will undergo CACS and CCTA. All participants will be followed-up for a minimum of 24 months to determine the endpoints. The primary endpoint will be occurrence of major adverse cardiovascular events (MACEs), defined as all-cause mortality, cardiovascular death, myocardial infarction, or cardiovascular events requiring hospitalization and revascularization either by percutaneous coronary intervention or by coronary artery bypass graft after 90 days of index testing during the follow-up period. Patient enrollment should be completed within 2.5 years. We plan to analyze and identify the CCTA predictors of MACEs. In addition, we will compare several models used to assess independent relationships between the variables and MACEs using a shared frailty model and therefore determine the incremental prognostic value of CCTA findings compared with either the CACS or FRS. The results of IMPACTS will provide valuable information for risk stratification with CCTA in ischemic stroke patients without chest pain.

Effects of Oral Anticoagulant Therapy in Medical Inpatients ≥65 Years With Atrial Fibrillation

In this retrospective cohort observational study, we investigated mortality, ischemic, and hemorrhagic events in patients ≥65 years with atrial fibrillation consecutively discharged from an Acute Geriatric Ward in the period 2010 to 2013. Stroke and bleeding risk were evaluated using CHA2DS2-VASC (congestive heart failure/left ventricular dysfunction, hypertension, aged ≥75 years, diabetes mellitus, stroke/transient ischemic attack/systemic embolism, vascular disease, aged 65 to 74 years, gender category) and HAS-BLED (hypertension, abnormal renal/liver function, stroke, bleeding history or predisposition, labile international normalized ratio, elderly, drugs/alcohol concomitantly) scores. Co-morbidity, cognitive status, and functional autonomy were evaluated using standardized scales. Independent associations among clinical variables, including use of vitamin K antagonist-based oral anticoagulant therapy (OAT), all-cause mortality, and fatal and nonfatal ischemic and hemorrhagic events, were evaluated. Further clinical outcomes comparison between patients treated with OAT and those untreated was performed after adjustment for significant differences in patient baseline characteristics with propensity score matching. Of 980 patients discharged (mean age 83 years, 60% women, roughly 30% cognitively impaired or functionally dependent, mean CHA2DS2-VASC and HAS-BLED scores 4.8 and 2.1, respectively), 505 (51.5%) died during a mean follow-up period of 571 days; ischemic and hemorrhagic stroke occurred in 82 (12.3%) and 13 patients (1.3%), respectively, and major bleedings in 43 patients (4.4%). Vitamin K antagonists' use was independently associated with reduced mortality (odds ratio 0.524) and with a nonsignificant reduction in incidence of ischemic stroke, without excess in bleeding risk. Similar findings were observed in the 2 propensity score-matched cohorts of patients. In conclusion, among vulnerable patients with atrial fibrillation ≥65 years with high post-discharge death rate, OAT was associated, among other multiple factors, with reduced mortality.

Stroke injury, cognitive impairment and vascular dementia

The global burden of ischaemic strokes is almost 4-fold greater than haemorrhagic strokes. Current evidence suggests that 25–30% of ischaemic stroke survivors develop immediate or delayed vascular cognitive impairment (VCI) or vascular dementia (VaD). Dementia after stroke injury may encompass all types of cognitive disorders. States of cognitive dysfunction before the index stroke are described under the umbrella of pre-stroke dementia, which may entail vascular changes as well as insidious neurodegenerative processes. Risk factors for cognitive impairment and dementia after stroke are multifactorial including older age, family history, genetic variants, low educational status, vascular comorbidities, prior transient ischaemic attack or recurrent stroke and depressive illness. Neuroimaging determinants of dementia after stroke comprise silent brain infarcts, white matter changes, lacunar infarcts and medial temporal lobe atrophy. Until recently, the neuropathology of dementia after stroke was poorly defined. Most of post-stroke dementia is consistent with VaD involving multiple substrates. Microinfarction, microvascular changes related to blood–brain barrier damage, focal neuronal atrophy and low burden of co-existing neurodegenerative pathology appear key substrates of dementia after stroke injury. The elucidation of mechanisms of dementia after stroke injury will enable establishment of effective strategy for symptomatic relief and prevention. Controlling vascular disease risk factors is essential to reduce the burden of cognitive dysfunction after stroke. This article is part of a Special Issue entitled: Vascular Contributions to Cognitive Impairment and Dementia edited by M. Paul Murphy, Roderick A. Corriveau and Donna M. Wilcock.

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Ischaemic injury is common among long-term stroke survivors

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About 25% stroke survivors develop dementia with a much greater proportion developing cognitive impairment

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Risk factors of dementia after stroke include older age, vascular comorbidities, prior stroke and pre-stroke impairment

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Current imaging and pathological studies suggest 70% of dementia after stroke is vascular dementia

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Severe white matter changes and medial temporal lobe atrophy as sequelae after ischaemic injury are substrates of dementia

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Controlling vascular risk factors and prevention strategies related to lifestyle factors would reduce dementia after stroke

Association between tooth loss and medical costs related to stroke in healthy older adults aged over 75 years in Japan

AIM

Growing evidence suggests that tooth loss is associated with increased risk of stroke. In the current study, we investigated cumulative medical costs related to stroke using data from the Advanced Elderly Medical Service System. We hypothesized that tooth loss was associated with an increase in medical costs related to stroke among older Japanese adults.

METHODS

A total of 273 Japanese adults aged 80 years were enrolled in the current study. Baseline medical and dental examinations were carried out in June 2008. Medical care use and costs were monitored by linkage with National Health Insurance claim files from baseline to the end of February 2011. Medical costs related to stroke per month were calculated and examined for any association with the baseline number of remaining teeth using a linear regression model with robust standard errors.

RESULTS

A total of 19 individuals were admitted to hospital for stroke during the follow-up period. A significant negative association was found between the number of teeth and medical costs related to stroke per month. The regression coefficients of the number of teeth in relation to medical costs related to stroke was -248 (95% CI -438 to -58, P = 0.011) in the crude model and -226 (95% CI -413 to -38, P = 0.018) after adjusting for other confounders.

CONCLUSION

Within the limitations of the present study, the reported findings suggest an independent relationship of tooth loss with increase in medical cost related to stroke among older Japanese adults. Further studies are necessary to substantiate these findings. Geriatr Gerontol Int 2017; 17: 202-210.

Diagnostic evaluation for nontraumatic intracerebral hemorrhage

Intracerebral hemorrhage (ICH) is a devastating condition with multiple possible underlying causes. Early diagnosis of ICH associated with a precise diagnostic work-up is mandatory. Clinical signs may give clues to diagnosis but are not reliable enough and imaging remains the cornerstone of management. Noncontrast computed tomography and magnetic resonance imaging (MRI) are highly sensitive for ICH identification. Additionally, MRI may disclose brain parenchymal biomarkers that can contribute to the etiologic diagnosis. Vessel examination should be carried out whenever there is a clinical suspicion of underlying structural lesions, such as vascular malformations or tumors. To date, conventional angiography remains the gold standard to detect intracranial vascular malformations in patients with ICH.

Examining the relationship between fatigue and cognition after stroke: A systematic review

Many stroke survivors experience fatigue, which is associated with a variety of factors including cognitive impairment. A few studies have examined the relationship between fatigue and cognition and have obtained conflicting results. The aim of the current study was to review the literature on the relationship between fatigue and cognition post-stroke. The following databases were searched: EMBASE (1980-February, 2014), PsycInfo (1806-February, 2014), CINAHL (1937-February, 2014), MEDLINE (1946-February, 2014), Ethos (1600-February, 2014) and DART (1999-February, 2014). Reference lists of relevant papers were screened and the citation indices of the included papers were searched using Web of Science. Studies were considered if they were on adult stroke patients and assessed the following: fatigue with quantitative measurements (≥ 3 response categories), cognition using objective measurements, and the relationship between fatigue and cognition. Overall, 413 papers were identified, of which 11 were included. Four studies found significant correlations between fatigue and memory, attention, speed of information processing and reading speed (r = -.36 to .46) whereas seven studies did not. Most studies had limitations; quality scores ranged from 9 to 14 on the Critical Appraisal Skills Programme Checklists. There was insufficient evidence to support or refute a relationship between fatigue and cognition post-stroke. More robust studies are needed.

SmartEye: Developing a Novel Eye Tracking System for Quantitative Assessment of Oculomotor Abnormalities

Eye movements are a continuous and ubiquitous part of sensory perception. To properly generate highly accurate and co-ordinate ocular movements, a vast network of brain areas are engaged, from low-level visual processing to motor control of gaze orientation. This renders oculomotor system vulnerable to various neurological disorders with unique clinical patterns. Therefore, oculomotor examination can serve as an early and sensitive indicator for various neurological conditions. A simple-to-use, clinically valid system for objectively assessing the oculomotor function can thus bring a paradigm shift in diagnosis and treatment of brain disorders. In principal accordance, this paper presents a gaze assessment tool, called SmartEye, which is based on eye fixation, smooth pursuit, and blinking in response to both static and dynamic visual stimuli. The gaze related indices were evaluated in real-time by SmartEye and these were mapped to the reported pathological state in chronic ( > 3 months) patients with stroke. Our preliminary feasibility study with eight pairs of chronic ( > 3 months) stroke survivors and healthy individuals revealed that gaze related indices in response to both static and dynamic visual stimuli may serve as potential quantitative biomarkers for stroke assessment.

Preexisting Heart Disease Underlies Newly Diagnosed Atrial Fibrillation After Acute Ischemic Stroke

BACKGROUND AND PURPOSE

Whether newly diagnosed atrial fibrillation (nAF) after stroke reflects underlying heart disease and represents an increased risk of cardioembolic stroke, or whether it is triggered by neurogenic mechanisms remains uncertain. We investigated, whether cardiovascular risk factors and echocardiographic parameters in patients with nAF are similar to patients with known AF (kAF) and differ from patients without AF.

METHODS

Consecutive acute ischemic stroke patients were enrolled into a prospective stroke database. All patients with echocardiography were included and univariable and multivariable testing was applied to compare clinical characteristics and echocardiographic findings among patients with nAF, kAF, and no AF.

RESULTS

A total of 1397 patients were included (male, 62.3%; median age, 71 years). AF was present in 320 (22.9%) patients. Of those, nAF was present in 36.2% (116/320) and kAF in 63.8% (204/320). No clinical or echocardiographic factor was independently associated with detection of nAF compared with kAF but a trend toward larger left atrial diameters in patients with kAF was observed (P=0.070). In contrast, patients with nAF were more often female (P<0.001), older (P<0.001) and had a larger left atrial diameters (P<0.001) compared with patients without AF. While stroke severity in patients with nAF and kAF was similar, patients without AF had less severe strokes.

CONCLUSIONS

Stroke patients with nAF and with kAF share common cardiovascular risk factors, have similar echocardiographic findings and suffer equally severe strokes. We conclude that preexisting heart disease is the major cause of AF that is first diagnosed after stroke.

Poor drug adherence and lack of awareness of hypertension among hypertensive stroke patients in Kampala, Uganda: a cross sectional study

Background

Raised blood pressure (BP) remains an important risk factor for cardiovascular diseases such as stroke. Adherence to therapeutic recommendations especially antihypertensive drugs is important in BP control. The aim of the study was to assess the stroke risk factors and levels of adherence among hypertensive patients with stroke in Kampala Uganda.

Methods

In a cross-sectional study we describe 112 hypertensive subjects with stroke from two Kampala city hospitals. A standardized pre-tested questionnaire was used to collect medical history, clinical details, radiological findings and laboratory data.

Results

A total of 112 hypertensive subjects with stroke were enrolled between May 2013 and April 2014. The median ages were 63.5 years (52.5–75.0) for the cases. Seventy percent (78/112) of the study participants had ischemic strokes. Only 17 % were adherent to anti-hypertensive medications. The main cause of non-adherence appears to be lack of knowledge.

Conclusions

Poor adherence of anti-hypertensive medications among hypertensive patients remains a big challenge in our setting. This has been attributed to lack of adequate knowledge and cost of the prescribed drugs. There is therefore an urgent need to promptly diagnose and educate hypertensive patients with emphasis on adherence to anti hypertensive drugs.

Post-stroke dyskinesias

Strokes, whether ischemic or hemorrhagic, are among the most common causes of secondary movement disorders in elderly patients. Stroke-related (vascular) movement disorders, however, are uncommon complications of this relatively common disease. The spectrum of post-stroke movement disorders is broad and includes both hypo- and hyperkinetic syndromes. Post-stroke dyskinesias are involuntary hyperkinetic movements arising from cerebrovascular insults and often present with mixed phenotypes of hyperkinesia which can sometimes be difficult to classify. Nevertheless, identification of the most relevant motor phenotype, whenever possible, allows for a more specific phenomenological categorization of the dyskinesia and thus helps guide its treatment. Fortunately, post-stroke dyskinesias are usually self-limiting and resolve within 6 to 12 months of onset, but a short-term pharmacotherapy might sometimes be required for symptom control. Functional neurosurgical interventions targeting the motor thalamus or globus pallidus interna might be considered for patients with severe, disabling, and persistent dyskinesias (arbitrarily defined as duration longer than 12 months).

Small Molecule Copper and Its Relative Metabolites in Serum of Cerebral Ischemic Stroke Patients

BACKGROUND

Copper is a strong pro-oxidant. The most important pro-oxidative form in serum is small molecule copper (SMC), which is copper that is loosely bound to small molecules, such as amino acids and polypeptides. The association between copper and atherosclerotic diseases has been confirmed, but that between SMC and cerebral ischemic stroke (CIS), one of the most principal manifestations and causes of death of atherosclerotic disease, is not yet clear.

METHODS

We recruited 45 CIS patients and 25 age- and gender-matched healthy controls. We detected their serum levels of SMC, total copper, homocysteine (Hcy), and ceruloplasmin (CP), as well as urinary total copper, and analyzed the relationship of SMC with these aforementioned metabolites or compounds in CIS patients.

RESULTS

SMC was 4.2 ± .5 µg/L and 2.1 ± .9 µg/L; total copper in sera was 1345.5 ± 308.2 µg/L and 1180.3 ± 134.0 µg/L; and total copper in urine was 27.6 ± 9.3 µg/L and 18.8 ± 8.1 µg/L in patients and controls, respectively (all P < .05). Serum CP activity in CIS patients was 59.92 ± 12.11 U/L versus 37.76 ± 5.71 U/L in controls (P = .0001). The concentration of SMC was positively correlated with CP activity, Hcy concentration in sera, and urinary total copper.

CONCLUSION

The serum level of SMC and total copper is remarkably elevated, and SMC positively correlates with Hcy, CP activity, and urinary total copper in CIS patients.

Neurological complications in chronic kidney disease

Patients with chronic kidney disease (CKD) are frequently afflicted with neurological complications. These complications can potentially affect both the central and peripheral nervous systems. Common neurological complications in CKD include stroke, cognitive dysfunction, encephalopathy, peripheral and autonomic neuropathies. These conditions have significant impact not only on patient morbidity but also on mortality risk through a variety of mechanisms. Understanding the pathophysiological mechanisms of these conditions can provide insights into effective management strategies for neurological complications. This review describes clinical management of neurological complications in CKD with reference to the contributing physiological and pathological derangements. Stroke, cognitive dysfunction and dementia share several pathological mechanisms that may contribute to vascular impairment and neurodegeneration. Cognitive dysfunction and dementia may be differentiated from encephalopathy which has similar contributing factors but presents in an acute and rapidly progressive manner and may be accompanied by tremor and asterixis. Recent evidence suggests that dietary potassium restriction may be a useful preventative measure for peripheral neuropathy. Management of painful neuropathic symptoms can be achieved by pharmacological means with careful dosing and side effect considerations for reduced renal function. Patients with autonomic neuropathy may respond to sildenafil for impotence. Neurological complications often become clinically apparent at end-stage disease, however early detection and management of these conditions in mild CKD may reduce their impact at later stages.

Modulation of stroke risk in chronic kidney disease

Stroke is the second most common cause of death and the leading cause of neurological disability worldwide, with huge economic costs and tragic human consequences. Both chronic kidney disease (CKD) and end-stage kidney disease are associated with a significantly increased risk of stroke. However, to date this has generated far less interest compared with the better-recognized links between cardiac and renal disease. Common risk factors for stroke, such as hypertension, hypercholesterolaemia, smoking and atrial fibrillation, are shared with the general population but are more prevalent in renal patients. In addition, factors unique to these patients, such as disorders of mineral and bone metabolism, anaemia and its treatments as well as the process of dialysis itself, are all also postulated to further increase the risk of stroke. In the general population, advances in medical therapies mean that effective primary and secondary prevention therapies are available for many patients. The development of specialist stroke clinics and acute stroke units has also improved outcomes after a stroke. Emerging therapies such as thrombolysis and thrombectomy are showing increasingly beneficial results. However, patients with CKD and on dialysis have different risk profiles that must be taken into account when considering the potential benefits and risks of these treatments. Unfortunately, these patients are either not recruited or formally excluded from major clinical trials. There is still much work to be done to harness effective stroke treatments with an acceptable safety profile for patients with CKD and those on dialysis.

Predicting outcome of epilepsy after meningioma resection

BACKGROUND

Surgical excision is the standard treatment for intracranial meningiomas. Epilepsy is a major cause of morbidity in meningioma patients, but postoperative control of epilepsy is not achieved in a substantial fraction of patients. The purpose of this study was to define risk factors for postoperative epilepsy.

METHODS

Patients treated for histologically confirmed intracranial meningioma at the University Hospital Zurich between 2000 and 2013 were retrospectively analyzed. Demographic, clinical, imaging, and electroencephalographic data were assessed. A binary regression model was applied to identify risk factors for postoperative epilepsy.

RESULTS

Of the 779 patients analyzed, epileptic seizures occurred in 244 (31.3%) patients before surgery and in 204 (26.6%) patients after surgery. Of the 244 patients with preoperative epilepsy, 144 (59.0%) became seizure-free after surgery; of the 535 patients without preoperative seizures, 104 (19.4%) suffered from epilepsy after surgery. Risk factors for postoperative epilepsy were preoperative epilepsy (odds ratio [OR]: 3.46 [95% confidence interval {CI}: 2.32-5.16]), major surgical complications including CNS infections (OR: 5.89 [95% CI: 1.53-22.61]), hydrocephalus (OR: 3.27 [95% CI: 1.35-7.95]), recraniotomy (OR: 2.91 [95% CI: 1.25-6.78]), and symptomatic intracranial hemorrhage (OR: 2.60 [95% CI: 1.17-5.76]) as well as epileptiform EEG potentials (OR: 2.52 [95% CI: 1.36-4.67]), younger age (OR: 1.74 [(95% CI: 1.18-2.58]), and tumor progression (OR: 1.92 [95% CI: 1.16-3.18]). Postoperative improvement or recovery from preoperative neurologic deficits was associated with improved seizure control (OR: 0.46 [95% CI: 0.25-0.85], P = .013).

CONCLUSION

We suggest prospective validation of a score ("STAMPE2") based on clinical findings, EEG, and brain-imaging measures to estimate postoperative seizure risk and guide anticonvulsant treatment in meningioma patients.

Diagnostic Yield of Universal Urine Toxicology Screening in an Unselected Cohort of Stroke Patients

BACKGROUND

Illicit drug use increases the risk of cerebrovascular events by a variety of mechanisms. A recent report suggested that universal urine toxicology (UTox) screening of patients with stroke may be warranted. We aimed to evaluate the diagnostic yield of urine drug screening among unselected patients admitted with acute stroke or transient ischemic attack (TIA).

METHODS

Using a single-center prospective study design, we evaluated consecutive patients with acute ischemic stroke, TIA, intracerebral hemorrhage (ICH), or subarachnoid hemorrhage (SAH) over one year. Urine samples were collected within 48 hours of admission and analyzed for common classes of abused drugs. Prevalence of positive UTox screening was determined. We evaluated whether baseline demographics and clinical factors were associated with UTox results.

RESULTS

Of 483 eligible patients (acute ischemic stroke 66.4%; TIA 18.8%; ICH 7.7%; SAH 7.0%), 414 (85.7%) completed UTox screening. The mean (standard deviation) age was 65.1 (15.6) years, 52.7% were male, and 64.3% were Caucasian. Twenty-two (4.6%) patients had positive screening-cannabinoids were detected in 13 cases (3.1%), cocaine in 5 cases (1.2%), amphetamines in 1 case, and phencyclidine in 1 case. The highest yield (14.1%) was observed in patients < 60 years old with history of tobacco use while it was < 5% in the remaining subgroups (p<0.01).

CONCLUSIONS

Consistent with current guidelines, a selective approach to UTox screening should be pursued in acute stroke evaluation. The highest diagnostic yield is likely to be for cannabinoids and cocaine testing in younger patients with a history of concurrent tobacco use.

Validation of Siriraj Stroke Score in southeast Nigeria

The aim of the study is to validate the use of Siriraj Stroke Score (SSS) in the diagnosis of acute hemorrhagic and acute ischemic stroke in southeast Nigeria. This was a prospective study on validity of SSS in the diagnosis of stroke types in southeast Nigeria. Subjects diagnosed with stroke for whom brain computerized tomography (CT) scan was performed on admission were recruited during the study period. SSS was calculated for each subject, and the SSS diagnosis was compared with brain CT scan-based diagnosis. A total of 2,307 patients were admitted in the hospital medical wards during the study period, of whom 360 (15.6%) were stroke patients and of these, 113 (31.4%) adult subjects met the inclusion criteria. The mean age of the subjects was 66.5±2.6 years. The mean interval between ictus and presentation was 2.5±0.4 days. Ischemic stroke was confirmed by CT in 74 subjects; however, SSS predicted 60 (81.1%) of these subjects correctly (P<0.05). Hemorrhagic stroke was confirmed by CT in 39 subjects, and SSS predicted 36 (92.3%) of them correctly (P<0.05). In acute ischemic stroke, sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of SSS were 92%, 94%, 97%, 86%, and 93%, respectively, while in patients with hemorrhagic stroke, the corresponding percentages were 94%, 92%, 86%, 97%, and 93%, respectively. SSS is not reliable enough to clinically differentiate stroke types in southeast Nigeria to warrant interventions like thrombolysis in acute ischemic stroke.

Evaluation of the association between stroke/transient ischemic attack and atrial electromechanical delay in patients with paroxysmal atrial fibrillation

Objective:

This study aimed to evaluate the association between the history of stroke/transient ischemic attack (TIA) and inter- and intra-atrial electromechanical delay (EMD) in patients with paroxysmal atrial fibrillation (PAF).

Methods:

Patients diagnosed with PAF were included in this retrospective study. Patients who had a history of stroke or TIA were defined as the symptomatic group, whereas those who did not have such a history were defined as the asymptomatic group. On the basis of the transthoracic echocardiographic records, atrial electromechanical coupling (time interval from the onset of the P wave on the surface electrocardiogram to the beginning of the A’ wave interval with tissue Doppler echocardiography) and intra- and interatrial EMD were measured.

Results:

In this study, 160 patients were included, 52 of whom were symptomatic. While the intra-left atrial EMD was 68.2±6.1 ms in the symptomatic group, it was found to be 50.8±6.5 ms in the asymptomatic group (p<0.001). Interatrial EMD was 91.3±5.0 ms in the symptomatic group, whereas it was 71.5±7.0 ms in the asymptomatic group (p<0.001). In multiple logistic regression analysis, intra-left atrial [odds ratio (OR): 1.417, 95% confidence interval (CI): 1.193–1.684, p<0.001] and interatrial EMDs (OR:1.398, 95% CI: 1.177–1.661, p<0.001) were found to be independently associated with the presence of stroke/TIA.

Conclusion:

Prolonged inter- and intra-left atrial EMDs in patients with PAF is associated with stroke/TIA. Evaluating this parameter in addition to the CHA₂DS₂-VASc score in patients with PAF may be helpful in identifying patients who are at a high risk of stroke/TIA. (Anatol J Cardiol 2016; 16: 572-8)

Optimized real-time monitoring of glutathione redox status in single pyramidal neurons in organotypic hippocampal slices during oxygen-glucose deprivation and reperfusion

A redox-sensitive Grx1-roGFP2 fusion protein was introduced by transfection into single pyramidal neurons in the CA1 subfield of organotypic hippocampal slice cultures (OHSCs). We assessed changes in the GSH system in neuronal cytoplasm and mitochondria during oxygen-glucose deprivation and reperfusion (OGD/RP), an in vitro model of stroke. Pyramidal cells in a narrow range of depths below the surface of the OHSC were transfected by gene gun or single-cell electroporation with cyto- or mito-Grx1-roGFP2. To mimic the conditions of acute stroke, we developed an optimized superfusion system with the capability of rapid and reproducible exchange of the solution bathing the OHSCs. Measurements of pO2 as a function of tissue depth show that in the region containing the transfected cells, the pO2 is well-controlled. We also found that the pO2 changes on the same time scale as changes in intracranial pressure, cerebral blood flow, and pO2 during acute stroke. Determining the reduction potential, EGSH, from the ratiometric fluorescence signal requires an absolute intensity measurement during calibration of the Grx1-roGFP2. Using the signal from cotransfected tdTomato as an internal standard during calibration improves quantitative measurements of Grx1-roGFP2 redox status and allows EGSH to be determined. EGSH becomes more reducing during OGD and more oxidizing during RP in mitochondria while changes in cytoplasm are not significant compared with controls.

Role of Diffusion-weighted Imaging in Acute Stroke Management using Low-field Magnetic Resonance Imaging in Resource-limited Settings

A variety of imaging modalities exist for the diagnosis of stroke. Several studies have been carried out to ascertain their contribution to the management of acute stroke and to compare the benefits and limitations of each modality. Diffusion-weighted imaging (DWI) has been described as the optimal imaging technique for diagnosing acute ischemic stroke, yet limited evidence is available on the value of DWI in the management of ischemic stroke with low-field magnetic resonance (MR) systems. Although high-field MR imaging (MRI) is desirable for DWI, low-field scanners provide an acceptable clinical compromise which is of importance to developing countries posed with the challenge of limited availability of high-field units. The purpose of this paper was to systematically review the literature on the usefulness of DWI in acute stroke management with low-field MRI scanners and present the experience in Nigeria.

Predictors of Stroke After Transient Ischemic Attack in Children

BACKGROUND AND PURPOSE

Transient ischemic attack (TIA) in children has received far less attention compared with TIA in adults. The risk factors of stroke after TIA in children are relatively unknown. We aimed to determine the percentage of children who have stroke after TIA and the risk factors associated with stroke after TIA.

METHODS

We searched the medical records at Boston Children's Hospital for the year 2010 to find children who were evaluated for TIA to determine associated risk factors of stroke after TIA. We included children who were evaluated in 2009 through 2010 for TIA and had magnetic resonance imaging. We examined follow-up imaging through August 2014 for subsequent stroke. Logistic regression was used to calculate odds ratios for factors in our cohort who are associated with stroke after presentation with TIA.

RESULTS

We identified 63 children who experienced a TIA. The mean time of imaging follow-up was 4.5 years after TIA presentation. Of the 63 children, 10 (16%) developed radiological evidence of ischemic cerebral injury within the follow-up period. Four of the 10 (6%) demonstrated diffusion abnormalities on magnetic resonance imaging at TIA presentation, whereas 8 (13%) had a stroke after their TIA. Arteriopathy, female sex, and autoimmune disorders were significantly associated with stroke after TIA.

CONCLUSIONS

In our cohort of children, stroke occurred after TIA at a rate similar to that seen in adults, but the risk factors for stroke after TIA in children are different.