Post-stroke cognitive decline: an update and perspectives for clinical research

Right hemisphere ventral stream for emotional prosody identification: Evidence from acute stroke

OBJECTIVE

To determine whether right ventral stream and limbic structures (including posterior superior temporal gyrus [STG], STG, temporal pole, inferior frontal gyrus pars orbitalis, orbitofrontal cortex, amygdala, anterior cingulate, gyrus, and the sagittal stratum) are implicated in emotional prosody identification.

METHODS

Patients with MRI scans within 48 hours of unilateral right hemisphere ischemic stroke were enrolled. Participants were presented with 24 sentences with neutral semantic content spoken with happy, sad, angry, afraid, surprised, or bored prosody and chose which emotion the speaker was feeling based on tone of voice. Multivariable linear regression was used to identify individual predictors of emotional prosody identification accuracy from a model, including percent damage to proposed right hemisphere structures, age, education, and lesion volume across all emotions (overall emotion identification) and 6 individual emotions. Patterns of recovery were also examined at the chronic stage.

RESULTS

The overall emotion identification model was significant (adjusted r ² = 0.52; p = 0.043); greater damage to right posterior STG (p = 0.038) and older age (p = 0.009) were individual predictors of impairment. The model for recognition of fear was also significant (adjusted r ² = 0.77; p = 0.002), with greater damage to right amygdala (p = 0.047), older age (p < 0.001), and less education (p = 0.005) as individual predictors. Over half of patients with chronic stroke had residual impairments.

CONCLUSIONS

Right posterior STG in the right hemisphere ventral stream is critical for emotion identification in speech. Patients with stroke with damage to this area should be assessed for emotion identification impairment.

Addenbrooke's Cognitive Examination III (ACE-III) and mini-ACE for the detection of dementia and mild cognitive impairment

BACKGROUND

The number of new cases of dementia is projected to rise significantly over the next decade. Thus, there is a pressing need for accurate tools to detect cognitive impairment in routine clinical practice. The Addenbrooke's Cognitive Examination III (ACE-III), and the mini-ACE are brief, bedside cognitive screens that have previously reported good sensitivity and specificity. The quality and quantity of this evidence has not, however, been robustly investigated.

OBJECTIVES

To assess the diagnostic test accuracy of the ACE-III and mini-ACE for the detection of dementia, dementia sub-types, and mild cognitive impairment (MCI) at published thresholds in primary, secondary, and community care settings in patients presenting with, or at high risk of, cognitive decline.

SEARCH METHODS

We performed the search for this review on 13 February 2019. We searched MEDLINE (OvidSP), Embase (OvidSP), BIOSIS Previews (ISI Web of Knowledge), Web of Science Core Collection (ISI Web of Knowledge), PsycINFO (OvidSP), and LILACS (BIREME). We applied no language or date restrictions to the electronic searches; and to maximise sensitivity we did not use methodological filters. The search yielded 5655 records, of which 2937 remained after we removed duplicates. We identified a further four articles through PubMed 'related articles'. We found no additional records through reference list citation searching, or grey literature.

SELECTION CRITERIA

Cross-sectional studies investigating the accuracy of the ACE-III or mini-ACE in patients presenting with, or at high risk of, cognitive decline were suitable for inclusion. We excluded case-control, delayed verification and longitudinal studies, and studies which investigated a secondary cause of dementia. We did not restrict studies by language; and we included those with pre-specified thresholds (88 and 82 for the ACE-III, and 21 or 25 for the mini-ACE).

DATA COLLECTION AND ANALYSIS

We extracted information on study and participant characteristics and used information on dementia and MCI prevalence, sensitivity, specificity, and sample size to generate 2×2 tables in Review Manager 5. We assessed methodological quality of included studies using the QUADAS-2 tool; and we assessed the quality of study reporting with the STARDdem tool. Due to significant heterogeneity in the included studies and an insufficient number of studies, we did not perform meta-analyses.

MAIN RESULTS

This review identified seven studies (1711 participants in total) of cross-sectional design, four examining the accuracy of the ACE-III, and three of the mini-ACE. Overall, the majority of studies were at low or unclear risk of bias and applicability on quality assessment. Studies were at high risk of bias for the index test (n = 4) and reference standard (n = 2). Study reporting was variable across the included studies. No studies investigated dementia sub-types. The ACE-III had variable sensitivity across thresholds and patient populations (range for dementia at 82 and 88: 82% to 97%, n = 2; range for MCI at 88: 75% to 77%, n = 2), but with more variability in specificity (range for dementia: 4% to 77%, n = 2; range for MCI: 89% to 92%, n = 2). Similarly, sensitivity of the mini-ACE was variable (range for dementia at 21 and 25: 70% to 99%, n = 3; range for MCI at 21 and 25: 64% to 95%, n = 3) but with more variability specificity (range for dementia: 32% to 100%, n = 3; range for MCI: 46% to 79%, n = 3). We identified no studies in primary care populations: four studies were conducted in outpatient clinics, one study in an in-patient setting, and in two studies the settings were unclear.

AUTHORS' CONCLUSIONS

There is insufficient information in terms of both quality and quantity to recommend the use of either the ACE-III or mini-ACE for the screening of dementia or MCI in patients presenting with, or at high risk of, cognitive decline. No studies were conducted in a primary care setting so the accuracy of the ACE-III and mini-ACE in this setting are not known. Lower thresholds (82 for the ACE-III, and 21 for the mini-ACE) provide better specificity with acceptable sensitivity and may provide better clinical utility. The ACE-III and mini-ACE should only be used to support the diagnosis as an adjunct to a full clinical assessment. Further research is needed to determine the utility of the ACE-III and mini-ACE for the detection of dementia, dementia sub-types, and MCI. Specifically, the optimal thresholds for detection need to be determined in a variety of settings (primary care, secondary care (inpatient and outpatient), and community services), prevalences, and languages.

Increased microneedle-mediated transdermal delivery of tetramethylpyrazine to the brain, combined with borneol and iontophoresis, for MCAO prevention

The aim of this research was to improve transdermal delivery and distribution of tetramethylpyrazine (TMP) in the brain, by adding borneol (BN) and iontophoresis (ITP), and using microneedles (MN), to prevent middle cerebral artery occlusion (MCAO). BN was encapsulated into sulfobutylated-β-cyclodextrin (BN-SBE-β-CD), and then dispersed together with TMP. Four delivery groups were tested: passive (with no ITP and MN), ITP, MN, and MN combined with ITP (MN-ITP). In vitro transdermal fluxes of the drugs in those groups and in that corresponding order were 79.12 ± 14.5, 395.43 ± 12.37, 319.16 ± 29.99, and 1018.07 ± 108.92 μg/cm² (for TMP), and 39.34 ± 1.31, 202.81 ± 53.56, 715.47 ± 75.52, and 1088.60 ± 53.90 μg/cm² (for BN), respectively, which indicated that the use of MN-ITP greatly enhanced transdermal TMP and BN delivery compared to the other groups. The AUC_0-t for the combined use of TMP and BN drugs was measured using two in vivo studies, cutaneous microdialysis and pharmacodynamic, yielding increased folds of 3.69 and 1.98 in ITP, 6.05 and 2.73 in MN, and 12.43 and 7.47 in MN-ITP groups, respectively, as compared to those in the passive group. In addition, the combined use of TMP and BN increased TMP distribution in the heart and the brain, indicated by TMP C_max of 1.76- and 1.59-fold higher (p < 0.05), and TMP AUC_0-t of 1.50 times and 1.19-fold higher (p < 0.01), than with administration of TMP in absence of BN, respectively. The brain infarction area and IL-β expression in the MCAO rat were significantly decreased in the MN-ITP group, compared with the control group (p < 0.05). In conclusion, combination of MN and ITP resulted in a synergistic enhancement of transdermal delivery and distribution of TMP in the brain, when in combination with BN, thereby significantly decreasing the infarct volumes and improving the neurological scores of MCAO.

Neurogenesis promoted by the CD200/CD200R signaling pathway following treadmill exercise enhances post-stroke functional recovery in rats

Stroke is a leading cause of long-term disability worldwide; survivors often show sensorimotor and cognitive deficits. Therapeutic exercise is the most common treatment strategy for rehabilitating patients with stroke via augmentation of neurogenesis, angiogenesis, neurotrophic factors expression, and synaptogenesis. Neurogenesis plays important roles in sensorimotor and cognitive functional recovery, and can be promoted by exercise; however, the mechanism underlying this phenomenon remains unclear. In this study, we explored the effects of treadmill exercise on sensorimotor and cognitive functional recovery, as well as the potential molecular mechanisms underlying the promotion of neurogenesis in a rat model of transient middle cerebral artery occlusion (tMCAO). We found that treadmill exercise facilitated sensorimotor and cognitive functional recovery after tMCAO, and that neural stem/progenitor cell proliferation, differentiation, and migration were enhanced in the ipsilateral subventricular and subgranular zones after tMCAO. Meanwhile, the newborn neurons induced by treadmill exercise after tMCAO had the similar function with pre-existing neurons. Treadmill exercise significantly increased CD200 and CD200 receptor (CD200R) levels in the ipsilateral hippocampus and cortex. Further study revealed that treadmill exercise-induced neurogenesis and functional recovery were clearly inhibited, while Il-β and Tnf-α expression were upregulated, following lentivirus (LV)-induced suppression of post-stroke CD200R expression. Consistent with the effect of treadmill exercise, CD200Fc (a CD200R agonist) markedly promoted neurogenesis and functional recovery after stroke. In addition, CD200Fc could further enhance the functional recovery induced by treadmill exercise after stroke. Our results demonstrate the beneficial role of treadmill exercise in promoting neurogenesis and functional recovery via activating the CD200/CD200R signaling pathway and improving the inflammatory environment after stroke. Thus, the CD200/CD200R signaling pathway is a potential therapeutic target for functional recovery after stroke.

Cognitive impairment and medication adherence post-stroke: A five-year follow-up of the ASPIRE-S cohort

BACKGROUND

Control of vascular risk factors is essential for secondary stroke prevention. However, adherence to secondary prevention medications is often suboptimal, and may be affected by cognitive impairment. Few studies to date have examined associations between cognitive impairment and medication adherence post-stroke, and none have considered whether adherence to secondary prevention medications might affect subsequent cognitive function. The aim of this study was to explore prospective associations between cognitive impairment and medication non-adherence post-stroke.

METHODS

A five-year follow-up of 108 stroke survivors from the Action on Secondary Prevention Interventions and Rehabilitation in Stroke (ASPIRE-S) prospective observational cohort study. Cognitive function was assessed using the Montreal Cognitive Assessment at 6 months, and a neuropsychological test battery at 5 years. Adherence to antihypertensive, antithrombotic and lipid-lowering medications was assessed using prescription refill data.

RESULTS

The prevalence of cognitive impairment at five years was 35.6%. The prevalence of non-adherence ranged from 15.1% for lipid-lowering agents to 30.2% for antithrombotics. There were no statistically significant associations between medication non-adherence in the first year post-stroke and cognitive impairment at 5 years, nor between cognitive impairment at 6 months and non-adherence at 5 years. Stroke survivors with cognitive impairment were significantly more likely to report receiving help with taking medications [OR (95% CI): 4.84 (1.17, 20.07)].

CONCLUSIONS

This is the first study to explore the potential impact of non-adherence to secondary prevention medications on cognitive impairment in stroke survivors. Findings highlight the role of family members and caregivers in assisting stroke survivors with medication administration, particularly in the context of deficits in cognitive function. Involving family members and caregivers may be a legitimate and cost-effective strategy to improve medication adherence in stroke survivors.

Tau Protein Dysfunction after Brain Ischemia

Brain ischemia comprises blood-brain barrier, glial, and neuronal cells. The blood–brain barrier controls permeability of different substances and the composition of the neuronal cells ‘milieu’, which is required for their physiological functioning. Recent evidence indicates that brain ischemia itself and ischemic blood-brain barrier dysfunction is associated with the accumulation of neurotoxic molecules within brain tissue, e.g., different parts of amyloid-β protein precursor and changed pathologically tau protein. All these changes due to ischemia can initiate and progress neurodegeneration of the Alzheimer’s disease-type. This review presents brain ischemia and ischemic blood-brain barrier as a trigger for tau protein alterations. Thus, we hypothesize that the changes in pattern of phosphorylation of tau protein are critical to microtubule function especially in neurons, and contribute to the neurodegeneration following brain ischemia-reperfusion episodes with Alzheimer’s disease phenotype.

Multiple biomarkers covering several pathways improve predictive ability for cognitive impairment among ischemic stroke patients with elevated blood pressure

BACKGROUND AND AIMS

We aimed to evaluate the ability of multiple novel biomarkers representing several pathophysiological pathways to improve risk prediction of post-stroke cognitive impairment.

METHODS

We conducted a prospective multicenter study in 638 ischemic stroke patients with elevated blood pressure based on a random subsample from China Antihypertensive Trial in Acute Ischemic Stroke and measured 12 circulating biomarkers in these participants. Cognitive impairment was assessed at 3 months after stroke with definitions of Mini-Mental State Examination (MMSE) score <27 or Montreal Cognitive Assessment (MoCA) score <25.

RESULTS

According to MMSE score, 1 SD increase of rheumatoid factor (odds ratio [OR] 1.22, 95% confidence interval [CI] 1.02-1.46), matrix metalloproteinase-9 (OR 1.47, 95% CI 1.22-1.77) and total homocysteine (OR 1.22, 95% CI 1.01-1.49) after log transformation was significantly associated with the risk of post-stroke cognitive impairment. The ORs associated with their simultaneously high levels were 4.89 (95% CI, 2.31-10.35; p_trend<0.001) and 3.09 (95% CI, 1.60-5.98; p_trend<0.001) for cognitive impairment and the severity of cognitive impairment, respectively. Adding these 3 biomarkers to conventional model significantly improved the risk prediction of cognitive impairment (C statistic 0.729 vs. 0.688, p = 0.004; net reclassification improvement = 33.67%, p < 0.001; integrated discrimination index = 4.61%; p < 0.001). Similar significant findings were observed when cognitive impairment was defined by MoCA score.

CONCLUSIONS

Combination of rheumatoid factor, matrix metalloproteinase-9 and total homocysteine can improve the risk prediction of cognitive impairment among ischemic stroke patients with elevated blood pressure. Further studies are warranted to validate our findings and explore their roles as potential therapeutic targets.

Preliminary Screening Recommendations for Patients at Risk of Depression and/or Anxiety more than 1 year Poststroke

GOAL

Depression and anxiety are important complications of stroke but are underdiagnosed in community settings. The current study identified which patients were at increased risk of developing either disorder more than1 year poststroke to assist in targeted screening.

METHODS

Crosssectional survey of 147 adults who had a stroke more than 1 year ago were recruited from stroke advocacy/support groups and an outpatient register. Participants completed the Hospital Anxiety and Depression Scale (HADS) and reported whether they had emotional problems as a stroke inpatient (single item: yes/no). Standardized self-report measures evaluated medical (physical independence, health-related quality of life), cognitive (memory, executive functioning), and psychological (social support) variables. Demographic and stroke-related (stroke type, year) information were also recorded.

FINDINGS

Between 53% and 80% of respondents (n = 117) screened positive for depressed mood and/or anxiety (HADS subscale cut-offs: ≥8 or ≥4). Logistic regression analyses indicated that stroke survivors who reported having emotional problems as inpatients (odds ratio [OR]: 0.23), were female (OR: 3.42), and had poor health-related quality of life (OR: 0.45-0.53) and cognitive problems (OR: 0.68-0.74), were more likely to screen positive for either disorder. Models based on these variables predicted screening outcomes with 91% accuracy.

CONCLUSIONS

Community-based stroke survivors who reported experiencing emotional problems as inpatients, were female, or had poor health-related quality of life (chronic pain, disturbed sleep, communication difficulties) and/or cognitive issues were at greater risk of being depressed/anxious. Targeted screening of these patients may help to identify those who are most in need of more comprehensive clinical assessments and evidence-based interventions.

Association between Striatal Brain Iron Deposition, Microbleeds and Cognition 1 Year After a Minor Ischaemic Stroke

Brain iron deposits (IDs) are inversely associated with cognitive function in community-dwelling older people, but their association with cognition after ischemic stroke, and whether that differs from microbleeds, is unknown. We quantified basal ganglia IDs (BGID) and microbleeds (BMBs) semi-automatically on brain magnetic resonance images from patients with minor stroke (NIHSS < 7), at presentation and 12 months after stroke. We administered the National Adult Reading Test (NART, estimates premorbid or peak adult cognition) and the Revised Addenbrooke's Cognitive Examination (ACE-R; current cognition) at 1 and 12 months after stroke. We adjusted analyses for baseline cognition, age, gender, white matter hyperintensity (WMH) volume and vascular risk factors. In 200 patients, mean age 65 years, striatal IDs and BMBs volumes did not change over the 12 months. Baseline BGID volumes correlated positively with NART scores at both times (ρ = 0.19, p < 0.01). Baseline and follow-up BGID volumes correlated positively with age (ρ = 0.248, p < 0.001 and ρ = 0.271, p < 0.001 respectively), but only baseline (and not follow-up) BMB volume correlated with age (ρ = 0.129, p < 0.05). Both smoking and baseline WMH burden predicted verbal fluency and visuospatial abilities scores (B = -1.13, p < 0.02 and B = -0.22, p = 0.001 respectively) at 12 months after stroke. BGIDs and BMBs are associated differently with cognition post-stroke; studies of imaging and post-stroke cognition should adjust for premorbid cognition. The positive correlation of BGID with NART may reflect the lower premorbid cognition in patients with stroke at younger vs older ages.

Abolition of aberrant neurogenesis ameliorates cognitive impairment after stroke in mice

Poststroke cognitive impairment is considered one of the main complications during the chronic phase of ischemic stroke. In the adult brain, the hippocampus regulates both encoding and retrieval of new information through adult neurogenesis. Nevertheless, the lack of predictive models and studies based on the forgetting processes hinders the understanding of memory alterations after stroke. Our aim was to explore whether poststroke neurogenesis participates in the development of long-term memory impairment. Here, we show a hippocampal neurogenesis burst that persisted 1 month after stroke and that correlated with an impaired contextual and spatial memory performance. Furthermore, we demonstrate that the enhancement of hippocampal neurogenesis after stroke by physical activity or memantine treatment weakened existing memories. More importantly, stroke-induced newborn neurons promoted an aberrant hippocampal circuitry remodeling with differential features at ipsi- and contralesional levels. Strikingly, inhibition of stroke-induced hippocampal neurogenesis by temozolomide treatment or using a genetic approach (Nestin-CreERT2/NSE-DTA mice) impeded the forgetting of old memories. These results suggest that hippocampal neurogenesis modulation could be considered as a potential approach for treatment of poststroke cognitive impairment.

Neuroprotective and Neurological/Cognitive Enhancement Effects of Curcumin after Brain Ischemia Injury with Alzheimer's Disease Phenotype

In recent years, ongoing interest in ischemic brain injury research has provided data showing that ischemic episodes are involved in the development of Alzheimer's disease-like neuropathology. Brain ischemia is the second naturally occurring neuropathology, such as Alzheimer's disease, which causes the death of neurons in the CA1 region of the hippocampus. In addition, brain ischemia was considered the most effective predictor of the development of full-blown dementia of Alzheimer's disease phenotype with a debilitating effect on the patient. Recent knowledge on the activation of Alzheimer's disease-related genes and proteins-e.g., amyloid protein precursor and tau protein-as well as brain ischemia and Alzheimer's disease neuropathology indicate that similar processes contribute to neuronal death and disintegration of brain tissue in both disorders. Although brain ischemia is one of the main causes of death in the world, there is no effective therapy to improve the structural and functional outcomes of this disorder. In this review, we consider the promising role of the protective action of curcumin after ischemic brain injury. Studies of the pharmacological properties of curcumin after brain ischemia have shown that curcumin has several therapeutic properties that include anti-excitotoxic, anti-oxidant, anti-apoptotic, anti-hyperhomocysteinemia and anti-inflammatory effects, mitochondrial protection, as well as increasing neuronal lifespan and promoting neurogenesis. In addition, curcumin also exerts anti-amyloidogenic effects and affects the brain's tau protein. These results suggest that curcumin may be able to serve as a potential preventive and therapeutic agent in neurodegenerative brain disorders.

The Norwegian Cognitive impairment after stroke study (Nor-COAST): study protocol of a multicentre, prospective cohort study

BACKGROUND

Early and late onset post-stroke cognitive impairment (PCI) contributes substantially to disability following stroke, and is a high priority within stroke research. The aetiology for PCI is complex and related to the stroke itself, brain resilience, comorbid brain diseases, prestroke vulnerability and complications during the hospital stay. The aim of the Norwegian Cognitive Impairment After Stroke study (Nor-COAST) is to quantify and measure levels of cognitive impairments in a general Norwegian stroke population and to identify biological and clinical markers associated with prognosis for cognitive disorders following incident stroke. The study will be organised within five work packages: 1) Incidence and trajectories 2) Pathological mechanisms 3) Development of a risk score 4) Impact of physical activity and 5) Adherence to secondary prevention.

METHODS

Nor-COAST is an ongoing multicentre (five participating hospitals), prospective, cohort study with consecutive inclusion during the acute phase and with follow-up at three and 18 months, and at three years. Inclusion criteria are stroke defined according to the WHO criteria. During the recruitment period from 18.05.2015 to 31.03.2017, 816 participants have been included. Cognitive impairment will be classified according to the DSM-5 criteria using a consensus group. Cognitive function is assessed by a standardised neuropsychological test battery, the Montreal Cognitive Assessment, Trail making A and B, ten-word immediate and delayed recall test, the Controlled Oral Word Association, Global Deterioration Scale and proxy based information by and the Ascertain Dementia 8 item informant questionnaire. Biomarkers include magnetic resonance imaging, routine blood samples and bio-banking. Clinical assessments include characteristics of the stroke, comorbidity, delirium, frailty and tests for cognitive and physical function, sensor based activity monitoring and adherence to secondary prophylaxis.

DISCUSSION

Nor-COAST is the first Norwegian multicentre study to quantify burden of PCI that will provide reliable estimates in a general stroke population. A multidisciplinary approach aiming to identify biomarkers and clinical markers of overall prognosis will add new knowledge about risk profiles, including pre-stroke vulnerability and modifiable factors such as physical activity and secondary prophylaxis of relevance for clinical practice and later intervention studies.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT02650531 . Retrospectively registered January 8, 2016. First participant included May 18, 2015.

Sensorimotor stroke alters hippocampo-thalamic network activity

Many stroke survivors experience persisting episodic memory disturbances. Since hippocampal and para-hippocampal areas are usually spared from the infarcted area, alterations of memory processing networks remote from the ischemic brain region might be responsible for the observed clinical symptoms. To pinpoint changes in activity of hippocampal connections and their role in post-stroke cognitive impairment, we induced ischemic stroke by occlusion of the middle cerebral artery (MCAO) in adult rats and analyzed the functional and structural consequences using activity-dependent manganese (Mn²⁺) enhanced MRI (MEMRI) along with behavioral and histopathological analysis. MCAO caused stroke lesions of variable extent along with sensorimotor and cognitive deficits. Direct hippocampal injury occurred in some rats, but was no prerequisite for cognitive impairment. In healthy rats, injection of Mn²⁺ into the entorhinal cortex resulted in distribution of the tracer within the hippocampal subfields into the lateral septal nuclei. In MCAO rats, Mn²⁺ accumulated in the ipsilateral thalamus. Histopathological analysis revealed secondary thalamic degeneration 28 days after stroke. Our findings provide in vivo evidence that remote sensorimotor stroke modifies the activity of hippocampal-thalamic networks. In addition to potentially reversible alterations in signaling of these connections, structural damage of the thalamus likely reinforces dysfunction of hippocampal-thalamic circuitries.

Causal Relationships Between Modifiable Risk Factors of Cognitive Impairment, Cognitive Function, Self-Management, and Quality of Life in Patients With Rheumatic Diseases

BACKGROUND

Rheumatic diseases are one of the most common types of chronic conditions that affect cognitive functions.

PURPOSE

To develop and verify a hypothetical model of causal relationships between modifiable risk factors for cognitive impairment, cognitive function, self-management, and quality of life in patients with rheumatic diseases.

METHODS

A hypothetical model was developed on the basis of empirical evidence. The fitness of the model was verified on 210 patients with rheumatic diseases.

RESULTS

The prevalence of cognitive impairment was 49.0%. Smoking, underlying diseases, pain, and fatigue had a significant direct effect on cognitive impairment. Only cognitive impairment had a significant direct effect on self-management. Fatigue, anxiety, depression, and cognitive function had a significant direct effect on quality of life.

CONCLUSIONS

The importance of proper management of symptoms and health habits should be emphasized to prevent and delay the progression of cognitive impairment and improve adherence to self-management regimens and quality of life.

Multidomain intervention for the prevention of cognitive decline after stroke - a pooled patient-level data analysis

Background and purpose

The aim of this pooled patient‐level data analysis was to test if multidomain interventions, addressing several modifiable vascular risk factors simultaneously, are more effective than usual post‐stroke care for the prevention of cognitive decline after stroke.

Methods

This pooled patient‐level data analysis included two randomized controlled trials using a multidomain approach to target vascular risk factors in stroke patients and cognition as primary outcome. Changes from baseline to 12 months in the trail making test (TMT)‐A, TMT‐B and 10‐words test were analysed using stepwise backward linear mixed models with study as random factor. Two analyses were based on the intention‐to‐treat (ITT) principle using different imputation approaches and one was based on complete cases.

Results

Data from 322 patients (157 assigned to multidomain intervention and 165 to standard care) were analysed. Differences between randomization groups for TMT‐A scores were found in one ITT model (P = 0.014) and approached significance in the second ITT model (P = 0.087) and for complete cases (P = 0.091). No significant intervention effects were found for any of the other cognitive variables.

Conclusion

We found indications that multidomain interventions compared with standard care can improve the scores in TMT‐A at 1 year after stroke but not those for TMT‐B or the 10‐words test. These results have to be interpreted with caution due to the small number of patients.

Effects of Blood Pressure in the Early Phase of Ischemic Stroke and Stroke Subtype on Poststroke Cognitive Impairment

BACKGROUND AND PURPOSE

Blood pressure (BP) control in the early phase of stroke is controversial to reduce the risk of poststroke cognitive impairment (PSCI). This study was to investigate the impact of BP levels in the early phase of ischemic stroke and stroke subtype on PSCI.

METHODS

Seven hundred and ninety-six patients with acute ischemic stroke were included. Cognitive function was assessed after stroke onset using the Montreal Cognitive Assessment. Patients were divided into quintiles according to systolic BP and diastolic BP levels in the early phase. Subtype analyses were according to Trial of ORG 10172 in Acute Stroke Treatment classification (infarct cause) and Oxfordshire Community Stroke Project classification (infarct location).

RESULTS

After adjusting for multiple variables, the quintiles with the lowest systolic BP (Q1, 102-127 mm Hg) and with the highest systolic BP (Q5, 171-215 mm Hg) were associated with increased PSCI risk (odds ratio, 1.83; 95% confidence interval, 1.64-2.28; P=0.007 in Q1; odds ratio, 2.32; 95% confidence interval, 1.74-2.90; P<0.001 in Q5) at 3 months as compared with the middle quintile (Q3, 143-158 mm Hg). Similar association was found in diastolic BP quintiles. The analysis of cerebral infarction subtype demonstrated that both large artery atherosclerosis and total anterior circulation infarct were associated with increased risk of PSCI at 3 months after adjusting for multiple variables (large artery atherosclerosis: odds ratio, 1.42; 95% confidence interval, 1.06-1.90; P=0.031; total anterior circulation infarct: odds ratio, 1.68; 95% confidence interval, 1.32-2.15; P=0.001).

CONCLUSIONS

Lower or higher BP in the early phase of ischemic stroke was correlated with increased PSCI risk at 3 months. Maintaining systolic/diastolic BP in the levels of 143 to 158/93 to 102 mm Hg might be beneficial to reduce the occurrence of PSCI. Moreover, large artery atherosclerosis subtype and total anterior circulation infarct subtype were correlated with increased PSCI risk at 3 months.

CLINICAL TRIAL REGISTRATION

URL: https://www.chictr.org. Unique identifier: ChiCTR-TRC-14004804.

Route of Feeding as a Proxy for Dysphagia After Stroke and the Effect of Transdermal Glyceryl Trinitrate: Data from the Efficacy of Nitric Oxide in Stroke Randomised Controlled Trial

Post-stroke dysphagia is common, associated with poor outcome and often requires non-oral feeding/fluids. The relationship between route of feeding and outcome, as well as treatment with glyceryl trinitrate (GTN), was studied prospectively. The Efficacy of Nitric Oxide in Stroke (ENOS) trial assessed transdermal GTN (5 mg versus none for 7 days) in 4011 patients with acute stroke and high blood pressure. Feeding route (oral = normal or soft diet; non-oral = nasogastric tube, percutaneous endoscopic gastrostomy tube, parenteral fluids, no fluids) was assessed at baseline and day 7. The primary outcome was the modified Rankin Scale (mRS) measured at day 90. At baseline, 1331 (33.2%) patients had non-oral feeding, were older, had more severe stroke and more were female, than 2680 (66.8%) patients with oral feeding. By day 7, 756 patients had improved from non-oral to oral feeding, and 119 had deteriorated. Non-oral feeding at baseline was associated with more impairment at day 7 (Scandinavian Stroke Scale 29.0 versus 43.7; 2p < 0.001), and worse mRS (4.0 versus 2.7; 2p < 0.001) and death (23.6 versus 6.8%; 2p = 0.014) at day 90. Although GTN did not modify route of feeding overall, randomisation ≤6 h of stroke was associated with a move to more oral feeding at day 7 (odds ratio = 0.61, 95% confidence intervals 0.38, 0.98; 2p = 0.040). As a proxy for dysphagia, non-oral feeding is present in 33% of patients with acute stroke and associated with more impairment, dependency and death. GTN moved feeding route towards oral intake if given very early after stroke. Clinical Trial Registration Clinical Trial Registration-URL: http://www.controlled-trials.com . Unique identifier: ISRCTN99414122.

Recurrent Hypoglycemia Exacerbates Cerebral Ischemic Damage in Diabetic Rats via Enhanced Post-Ischemic Mitochondrial Dysfunction

Diabetes significantly increases the risk of stroke and post-stroke mortality. Recurrent hypoglycemia (RH) is common among diabetes patients owing to glucose-lowering therapies. Earlier, we showed that RH in a rat model of insulin-dependent diabetes exacerbates cerebral ischemic damage. Impaired mitochondrial function has been implicated as a central player in the development of cerebral ischemic damage. Hypoglycemia is also known to affect mitochondrial functioning. The present study tested the hypothesis that prior exposure of insulin-treated diabetic (ITD) rats to RH exacerbates brain damage via enhanced post-ischemic mitochondrial dysfunction. In a rat model of streptozotocin-induced diabetes, we evaluated post-ischemic mitochondrial function in RH-exposed ITD rats. Rats were exposed to five episodes of moderate hypoglycemia prior to the induction of cerebral ischemia. We also evaluated the impact of RH, both alone and in combination with cerebral ischemia, on cognitive function using the Barnes circular platform maze test. We observed that RH exposure to ITD rats leads to increased cerebral ischemic damage and decreased mitochondrial complex I activity. Exposure of ITD rats to RH impaired spatial learning and memory. Our results demonstrate that RH exposure to ITD rats potentially increases post-ischemic damage via enhanced post-ischemic mitochondrial dysfunction.

Changes in motor function, cognition, and emotion-related behavior after right hemispheric intracerebral hemorrhage in various brain regions of mouse

Intracerebral hemorrhage (ICH) is a detrimental type of stroke. Mouse models of ICH, induced by collagenase or blood infusion, commonly target striatum, but not other brain sites such as ventricular system, cortex, and hippocampus. Few studies have systemically investigated brain damage and neurobehavioral deficits that develop in animal models of ICH in these areas of the right hemisphere. Therefore, we evaluated the brain damage and neurobehavioral dysfunction associated with right hemispheric ICH in ventricle, cortex, hippocampus, and striatum. The ICH model was induced by autologous whole blood or collagenase VII-S (0.075 units in 0.5 µl saline) injection. At different time points after ICH induction, mice were assessed for brain tissue damage and neurobehavioral deficits. Sham control mice were used for comparison. We found that ICH location influenced features of brain damage, microglia/macrophage activation, and behavioral deficits. Furthermore, the 24-point neurologic deficit scoring system was most sensitive for evaluating locomotor abnormalities in all four models, especially on days 1, 3, and 7 post-ICH. The wire-hanging test was useful for evaluating locomotor abnormalities in models of striatal, intraventricular, and cortical ICH. The cylinder test identified locomotor abnormalities only in the striatal ICH model. The novel object recognition test was effective for evaluating recognition memory dysfunction in all models except for striatal ICH. The tail suspension test, forced swim test, and sucrose preference test were effective for evaluating emotional abnormality in all four models but did not correlate with severity of brain damage. These results will help to inform future preclinical studies of ICH outcomes.

Neuropsychological testing

Neuropsychological testing is a key diagnostic tool for assessing people with dementia and mild cognitive impairment, but can also help in other neurological conditions such as Parkinson’s disease, stroke, multiple sclerosis, traumatic brain injury and epilepsy. While cognitive screening tests offer gross information, detailed neuropsychological evaluation can provide data on different cognitive domains (visuospatial function, memory, attention, executive function, language and praxis) as well as neuropsychiatric and behavioural features. We should regard neuropsychological testing as an extension of the neurological examination applied to higher order cortical function, since each cognitive domain has an anatomical substrate. Ideally, neurologists should discuss the indications and results of neuropsychological assessment with a clinical neuropsychologist. This paper summarises the rationale, indications, main features, most common tests and pitfalls in neuropsychological evaluation.

Efficacy of electrical acupuncture on vascular cognitive impairment with no dementia: study protocol for a randomized controlled trial

BACKGROUND

Vascular cognitive impairment with no dementia (VCIND), manifested mainly as mild impairment of concentration and executive function, is the early phase of vascular dementia (VD). Currently, there is no specific treatment for VCIND. We hypothesize that electrical acupuncture can improve the mental and motor functions of patients with VCIND. Thus, we designed this randomized controlled trial to test this hypothesis by comparing the therapeutic effect of electrical acupuncture versus sham acupuncture in patients with VCIND.

METHOD/DESIGN

In this single-center 3-year study, 120 eligible patients will be recruited and randomly assigned to receive electrical acupuncture treatment (n = 60) or sham acupuncture (n = 60) for 8 consecutive weeks (24 sessions in total), with the same acupoint prescription (DU20, EX-HN3, DU24, DU17, DU26, EX-HN1, HT7, PC6, GB20, SP6). The primary assessment is the Montreal Cognitive Assessment. The secondary assessments are the Modified Barthel Index and Event-Related Potential. All outcomes will be assessed at baseline, endpoint, and follow-up at 8 and 24 weeks after the end of treatment.

DISCUSSION

If the outcome confirms the effectiveness and safety of electrical acupuncture in treating VCIND, this treatment is expected to be promoted in clinical practice to treat such patients.

TRIAL REGISTRATION

Chinese Clinical Trial Registry identifier: ChiCTR-IIR-17011513 ; Registered on 27 May 2017.

A 2-year prospective follow-up study of temporal changes associated with post-stroke cognitive impairment

AIMS

To explore temporal patterns of change in cognitive impairments during the 2 years following stroke and to identify factors that affect these temporal changes.

BACKGROUND

Despite the prognostic importance, temporal changes in post-stroke cognitive impairment have not been systematically investigated.

DESIGN

A non-experimental, prospective, longitudinal descriptive study design.

METHODS

Fifty-two stroke patients were enrolled. Data were collected from April 2015 to September 2017. Cognitive function was evaluated at 5 different times (immediately, and at 3, 6, 12, and 24 months post-stroke).

RESULTS

Significant changes in cognitive function following stroke exhibited an "s-shaped" curve, and the most rapid changes were observed between 3 and 6 months after stroke. The incidence of post-stroke cognitive impairment ranged from 23.1% to 42.3% and was highest at 3 months and lowest at 6 months. Gender, educational level, pre-stroke cognitive and functional abilities, haematoma, and brain surgery were associated with incidence of post-stroke cognitive impairment.

CONCLUSIONS

The ongoing changes exhibited by patterns of cognitive impairment provide evidence that consistent efforts are required to achieve positive changes in post-stroke cognitive function. Our findings may be helpful to develop nursing care strategies aimed at improving cognitive ability and consequently the quality of life of stroke patients.

Does cognitive impairment impact adherence? A systematic review and meta-analysis of the association between cognitive impairment and medication non-adherence in stroke

BACKGROUND

While medication adherence is essential for the secondary prevention of stroke, it is often sub-optimal, and can be compromised by cognitive impairment. This study aimed to systematically review and meta-analyse the association between cognitive impairment and medication non-adherence in stroke.

METHODS

A systematic literature search of longitudinal and cross-sectional studies of adults with any stroke type, which reported on the association between any measure of non-adherence and cognitive impairment, was carried out according to PRISMA guidelines. Odds ratios and 95% confidence intervals were the primary measure of effect. Risk of bias was assessed using the Cochrane Bias Methods Group's Tool to Assess Risk of Bias in Cohort Studies, with evidence quality assessed according to the GRADE approach. We conducted sensitivity analyses according to measure of cognitive impairment, measure of medication adherence, population, risk of bias and adjustment for covariates. The protocol was registered with PROSPERO.

RESULTS

From 1,760 titles and abstracts, we identified 9 studies for inclusion. Measures of cognitive impairment varied from dementia diagnosis to standardised cognitive assessments. Medication adherence was assessed through self-report or administrative databases. The majority of studies were of medium risk of bias (n = 6); two studies had low risk of bias. Findings were mixed; when all studies were pooled, there was no evidence of an association between cognitive impairment and medication non-adherence post-stroke [OR (95% CI): 0.85 (0.66, 1.03)]. However, heterogeneity was substantial [I2 = 90.9%, p < .001], and the overall evidence quality was low.

CONCLUSIONS

Few studies have explored associations between cognitive impairment and medication adherence post-stroke, with substantial heterogeneity in study populations, and definitions and assessments of non-adherence and cognitive impairment. Further research using clear, standardised and objective assessments is needed to clarify the association between cognitive impairment and medication non-adherence in stroke.

Protocol for a feasibility randomised controlled trial of Screening and Enhanced Risk management for Vascular Event-related Decline in Memory (SERVED Memory)

INTRODUCTION

Stroke is a leading cause of death and disability. The development of dementia after stroke is common. Vascular risk factors (VRF) which contribute to stroke risk can also contribute to cognitive decline, especially in vascular dementia (VaD). There is no established treatment for VaD, therefore strategies for prevention could have major health resource implications. This study was designed to assess whether patients with early cognitive decline after stroke/transient ischaemic attack (TIA) can be easily identified and whether target-driven VRF management can prevent progression to dementia.

OBJECTIVES

The primary objective is to establish the feasibility of recruitment and retention of patients with early cognitive decline to a randomised controlled trial of enhanced VRF management. Secondary objectives include: (a) to determine the potential clinical benefit of the intervention; (b) to estimate the sample size for a future definitive multicentre randomised controlled trial; (c) to inform a future economic evaluation; (d) to explore the link between VRF control and the incidence of cognitive impairment on longitudinal follow-up in a UK population after stroke/TIA with current routine management.

METHODS

100 patients with cognitive decline poststroke/TIA will be recruited from stroke services at the Norfolk and Norwich University Hospital. After collection of baseline data, they will be randomised to intervention (3 monthly follow-up with enhanced management) or control (treatment as usual by the general practitioner). At 12 months outcomes (repeat cognitive testing, VRF assessment) will be assessed. A further 100 patients without cognitive decline will be recruited to a parallel observational group from the same site. At 12 months they will have repeat cognitive testing.

ETHICS AND DISSEMINATION

Ethical approval has been granted in England. Dissemination is planned via publication in peer-reviewed medical journals and presentation at relevant conferences.

TRIAL REGISTRATION NUMBER

42688361; Pre-results.

Early Cognitive Impairment after Intracerebral Hemorrhage in the INTERACT1 Study

Background: Data on cognitive impairment after acute intracerebral hemorrhage (ICH) are limited. This study is aimed at determining the frequency and predictors of cognitive impairment among participants of the pilot phase, Intensive Blood Pressure (BP) Reduction in Acute Cerebral Hemorrhage Trial (INTERACT1). Methods: INTERACT1 was an open randomized trial of early intensive (target systolic BP <140 mm Hg) compared with contemporaneous guideline-recommended BP lowering in 404 patients with elevated systolic BP (150–220 mm Hg) within 6 h of ICH onset. Cognitive impairment was defined by scores ≤24 on the Mini-Mental State Examination (MMSE) assessed by interview on follow-up at 90 days. Results: A total of 231 (64.5%) of 358 90-day survivors had MMSE scores for analyses, and 75 (32.5%) had cognitive impairment. In multivariable analysis, older age (OR 2.48, 95% CI 1.73–3.56 per 10-year increase; p < 0.001), female sex (OR 2.06, 95% CI 1.00–4.23; p = 0.049), prior ICH (OR 2.87, 95% CI 1.08–7.65; p = 0.035), high baseline National Institute of Health Stroke Scale score (OR 1.06, 95% CI 1.00–1.13; p = 0.044), and high mean systolic BP over the first 24 h post-randomization (OR 1.34, 95% CI 1.07–1.68/10 mm Hg increase; p = 0.011) were independently associated with cognitive impairment. Conclusions: One third of patients have significant cognitive impairment early after ICH, which is more frequent in the elderly, females, those with prior ICH, and more severe initial neurological deficit and with persistently high early systolic BP.

Hippocampal Deformations and Entorhinal Cortex Atrophy as an Anatomical Signature of Long-Term Cognitive Impairment: from the MCAO Rat Model to the Stroke Patient

Stroke patients have an elevated risk of developing long-term cognitive disorders or dementia. The latter is often associated with atrophy of the medial temporal lobe. However, it is not clear whether hippocampal and entorhinal cortex atrophy is the sole predictor of long-term post-stroke dementia. We hypothesized that hippocampal deformation (rather than atrophy) is a predictive marker of long-term post-stroke dementia on a rat model and tested this hypothesis in a prospective cohort of stroke patients.Male Wistar rats were subjected to transient middle cerebral artery occlusion and assessed 6 months later. Ninety initially dementia-free patients having suffered a first-ever ischemic stroke were prospectively included in a clinical study. In the rat model, significant impairments in hippocampus-dependent memories were observed. MRI studies did not reveal significant atrophy of the hippocampus volume, but significant deformations were indeed observed-particularly on the ipsilateral side. There, the neuronal surface area was significantly lower in ischemic rats and was associated with a lower tissue density and a markedly thinner entorhinal cortex. At 6 months post-stroke, 49 of the 90 patients displayed cognitive impairment (males 55.10%). Shape analysis revealed marked deformations of their left hippocampus, a significantly lower entorhinal cortex surface area, and a wider rhinal sulcus but no hippocampal atrophy. Hence, hippocampal deformations and entorhinal cortex atrophy were associated with long-term impaired cognitive abilities in a stroke rat model and in stroke patients. When combined with existing biomarkers, these markers might constitute sensitive new tools for the early prediction of post-stroke dementia.

Cognitive assessment in stroke: feasibility and test properties using differing approaches to scoring of incomplete items

OBJECTIVES

Cognitive screening is recommended in stroke, but test completion may be complicated by stroke related impairments. We described feasibility of completion of three commonly used cognitive screening tools and the effect on scoring properties when cognitive testing was entirely/partially incomplete.

METHODS

We performed a cross-sectional study, recruiting sequential stroke patient admissions from two University Hospital stroke rehabilitation services. We assessed Folstein's mini-mental state examination (MMSE), Montreal cognitive assessment (MoCA) and Addenbrooke's cognitive examination (ACE-III). The multidisciplinary team gave an independent diagnostic formulation. We recorded numbers fully/partially completing tests, assistance and time required for testing. We calculated test discrimination metrics in relation to clinical assessment using four differing statistical approaches to account for incomplete testing.

RESULTS

We recruited 51 patients. Direct assistance to complete cognitive tests was required for 33 (63%). At traditional cut-offs, the majority screened "positive" for cognitive impairment (ACE-III: 98%; MoCA: 98%; MMSE: 81%). Comparing against a clinical diagnosis, ACE-III and MoCA had excellent sensitivity but poor specificity. Partial completion of cognitive tests was common (ACE-III: 14/51, MMSE: 22/51; MoCA: 20/51 fully complete); greatest non completion was for test items that required copying or drawing. Adapting analyses to account for these missing data gave differing results; MMSE sensitivity ranged from 0.66 to 0.85, and specificity ranged from 0.44 to 0.71 depending on the approach employed.

CONCLUSIONS

For cognitive screening in stroke, even relatively brief tools are associated with substantial incompletion. The way these missing data are accounted for in analyses impacts on apparent test properties. When choosing a cognitive screening tool, feasibility should be considered and approaches to handling missing data made explicit. Copyright © 2016 John Wiley & Sons, Ltd.

Adult hippocampal neurogenesis poststroke: More new granule cells but aberrant morphology and impaired spatial memory

Stroke significantly stimulates neurogenesis in the adult dentate gyrus, though the functional role of this postlesional response is mostly unclear. Recent findings suggest that newborn neurons generated in the context of stroke may fail to correctly integrate into pre-existing networks. We hypothesized that increased neurogenesis in the dentate gyrus following stroke is associated with aberrant neurogenesis and impairment of hippocampus-dependent memory. To address these questions we used the middle cerebral artery occlusion model (MCAO) in mice. Animals were housed either under standard conditions or with free access to running wheels. Newborn granule cells were labelled with the thymidine analoque EdU and retroviral vectors. To assess memory performance, we employed a modified version of the Morris water maze (MWM) allowing differentiation between hippocampus dependent and independent learning strategies. Newborn neurons were morphologically analyzed using confocal microscopy and Neurolucida system at 7 weeks. We found that neurogenesis was significantly increased following MCAO. Animals with MCAO needed more time to localize the platform and employed less hippocampus-dependent search strategies in MWM versus controls. Confocal studies revealed an aberrant cell morphology with basal dendrites and an ectopic location (e.g. hilus) of new granule cells born in the ischemic brain. Running increased the number of new neurons but also enhanced aberrant neurogenesis. Running, did not improve the general performance in the MWM but slightly promoted the application of precise spatial search strategies. In conclusion, ischemic insults cause hippocampal-dependent memory deficits which are associated with aberrant neurogenesis in the dentate gyrus indicating ischemia-induced maladaptive plasticity in the hippocampus.

Cognitive function in stroke survivors: A 10-year follow-up study

OBJECTIVES

Post-stroke cognitive impairment (PSCI) has considerable impact on patients and society. However, long-term studies on PSCI are scarce and may be influenced by assessment methods and selection bias. We aimed to (i) assess the prevalence of long-term PSCI; (ii) compare two common cognitive assessment instruments; and (iii) compare cognitive function of long-term stroke survivors with non-stroke persons.

METHODS

Mini-Mental State Examination (MMSE) and Montreal Cognitive Assessment (MoCA) were administered to 10-year survivors from a population-based cohort of first-ever stroke patients included in the Lund Stroke Register, Sweden, in 2001-2002. PSCI was defined as MMSE<27 and/or MoCA<25 and severe cognitive impairment as MMSE<23. Age- and sex-matched non-stroke control subjects who had performed MMSE (but not MoCA) were recruited from the longitudinal population study "Good Ageing in Skåne." The odds of having cognitive impairment for stroke survivors compared to controls were examined with logistic regression analyses adjusting for education.

RESULTS

Of 145 stroke survivors after 10 years, 127 participated. MMSE showed PSCI in 46%, whereas MoCA displayed PSCI in 61%. Among the stroke survivors with MoCA<25, 35% had MMSE≥27 (P<.001). The odds of having severe cognitive impairment defined as MMSE<23 were higher among the stroke survivors compared to 354 controls (education-adjusted; OR=2.5; P=.004).

CONCLUSIONS

Post-stroke cognitive impairment was prevalent among 10-year stroke survivors, and the odds of having severe cognitive impairment were higher among the stroke survivors compared to non-stroke persons. The burden of long-term PSCI might have been underestimated previously, and MoCA may be more suitable than MMSE to detect long-term PSCI.

Alemtuzumab in the long-term treatment of relapsing-remitting multiple sclerosis: an update on the clinical trial evidence and data from the real world

Alemtuzumab is a humanized monoclonal antibody approved for the treatment of relapsing-remitting multiple sclerosis (RRMS), given as two annual courses on five consecutive days at baseline and on three consecutive days 12 months later. Here we provide an update on the long-term efficacy and safety of alemtuzumab in RRMS, including real-world experience, and advances in our understanding of its mechanism of action. Recent data from the phase II/III extension study have demonstrated that alemtuzumab reduces relapse rates, disability worsening, and the rate of brain volume loss over the long term, with many patients achieving no evidence of disease activity. In high proportions of patients, preexisting disability remained stable or improved. Alemtuzumab is associated with a consistent safety profile over the long term, with no new safety signals emerging and the overall annual incidence of reported adverse events decreasing after the first year on treatment. Acyclovir prophylaxis reduces herpetic infections, and monitoring has been shown to mitigate the risk of autoimmune adverse events, allowing early detection and overall effective management. Data from clinical practice and ongoing observational studies are providing additional information on the real-world use of alemtuzumab. Recent evidence on the mechanism of action of alemtuzumab indicates that in addition to its previously known effects of inducing depletion and repopulation of T and B lymphocytes, it also results in a relative increase of cells with memory and regulatory phenotypes and a decrease in cells with a proinflammatory signature, and may further promote an immunoregulatory environment through an impact on other innate immune cells (e.g. dendritic cells) that play a role in MS. These effects may allow preservation of innate immunity and immunosurveillance. Together, these lines of evidence help explain the durable clinical efficacy of alemtuzumab, in the absence of continuous treatment, in patients with RRMS.

[Functional neuroimaging of the brain structures associated with language in healthy individuals and patients with post-stroke aphasia]

The introduction of non-invasive functional neuroimaging techniques such as functional magnetic resonance imaging (fMRI), in the practice of scientific and clinical research can increase our knowledge about the organization of cognitive processes, including language, in normal and reorganization of these cognitive functions in post-stroke aphasia. The article discusses the results of fMRI studies of functional organization of the cortex of a healthy adult's brain in the processing of various voice information as well as the main types of speech reorganization after post-stroke aphasia in different stroke periods. The concepts of 'effective' and 'ineffective' brain plasticity in post-stroke aphasia were considered. It was concluded that there was an urgent need for further comprehensive studies, including neuropsychological testing and several complementary methods of functional neuroimaging, to develop a phased treatment plan and neurorehabilitation of patients with post-stroke aphasia.

ARTEMIDA Trial (A Randomized Trial of Efficacy, 12 Months International Double-Blind Actovegin): A Randomized Controlled Trial to Assess the Efficacy of Actovegin in Poststroke Cognitive Impairment

Supplemental Digital Content is available in the text.

Background and Purpose—

Poststroke cognitive impairment is a debilitating consequence of stroke. The aim of this study was to assess whether Actovegin confers cognitive benefit in patients who have had an ischemic stroke.

Methods—

This was a 12-month, parallel-group, randomized, multicenter, double-blind, placebo-controlled study. Eligible patients were ≥60 years of age with a Montreal Cognitive Assessment test score of ≤25 points. Patients were randomized into 2 groups within 1 week of acute supratentorial ischemic stroke in a 1:1 ratio: Actovegin (a deproteinized hemoderivative of calf blood, 2000 mg/d for ≤20 intravenous infusions followed by 1200 mg/d orally) or placebo for 6 months. Patients were treated in accordance with standard clinical practice for a further 6 months. The primary end point was the change from baseline in Alzheimer’s Disease Assessment Scale, cognitive subscale, extended version at 6 months.

Results—

Two-hundred forty-eight patients were randomized to Actovegin and 255 patients to placebo. At month 6, the least squares mean change from baseline in Alzheimer’s Disease Assessment Scale, cognitive subscale, extended version was −6.8 for Actovegin and −4.6 for placebo; the estimated treatment difference was −2.3 (95% confidence interval, −3.9, −0.7; P=0.005). Recurrent ischemic stroke was the most frequently reported serious adverse event, with a nonsignificantly higher number for Actovegin versus placebo.

Conclusions—

Actovegin had a beneficial effect on cognitive outcomes in patients with poststroke cognitive impairment. The safety experience was consistent with the known safety and tolerability profile of the drug. These results warrant confirmation in additional robustly designed studies.

Clinical Trial Registration—

URL: http://www.clinicaltrials.gov. Unique identifier: NCT01582854.

Inadequate food and water intake determine mortality following stroke in mice

Experimental stroke models producing clinically relevant functional deficits are often associated with high mortality. Because the mechanisms that underlie post-stroke mortality are largely unknown, results obtained using these models are often difficult to interpret, thereby limiting their translational potential. Given that specific forms of post-stroke care reduce mortality in patients, we hypothesized that inadequate food and water intake may underlie mortality following experimental stroke. C57BL/6 mice were subjected to 1 h of intraluminal filament middle cerebral artery occlusion. Nutritional support beginning on the second day after filament middle cerebral artery occlusion reduced the 14-day mortality rate from 59% to 15%. The surviving mice in the post-stroke support group had the same infarct size as non-surviving control mice, suggesting that post-stroke care was not neuroprotective and that inadequate food and/or water intake are the main reasons for filament middle cerebral artery occlusion-induced mortality. This notion was supported by the presence of significant hypoglycemia, ketonemia, and dehydration in control mice. Taken together, these data suggest that post-filament middle cerebral artery occlusion mortality in mice is not primarily caused by ischemic brain damage, but secondarily by inadequate food and/or water intake. Thus, providing nutritional support following filament middle cerebral artery occlusion greatly minimizes mortality bias and allows the study of long-term morphological and functional sequelae of stroke in mice.

Towards the concept of disease-modifier in post-stroke or vascular cognitive impairment: a consensus report

BACKGROUND

Vascular cognitive impairment (VCI) is a complex spectrum encompassing post-stroke cognitive impairment (PSCI) and small vessel disease-related cognitive impairment. Despite the growing health, social, and economic burden of VCI, to date, no specific treatment is available, prompting the introduction of the concept of a disease modifier.

CONSENSUS AND SUGGESTIONS

Within this clinical spectrum, VCI and PSCI remain advancing conditions as neurodegenerative diseases with progression of both vascular and degenerative lesions accounting for cognitive decline. Disease-modifying strategies should integrate both pharmacological and non-pharmacological multimodal approaches, with pleiotropic effects targeting (1) endothelial and brain-blood barrier dysfunction; (2) neuronal death and axonal loss; (3) cerebral plasticity and compensatory mechanisms; and (4) degenerative-related protein misfolding. Moreover, pharmacological and non-pharmacological treatment in PSCI or VCI requires valid study designs clearly stating the definition of basic methodological issues, such as the instruments that should be used to measure eventual changes, the biomarker-based stratification of participants to be investigated, and statistical tests, as well as the inclusion and exclusion criteria that should be applied.

CONCLUSION

A consensus emerged to propose the development of a disease-modifying strategy in VCI and PSCI based on pleiotropic pharmacological and non-pharmacological approaches.

Big data and data repurposing - using existing data to answer new questions in vascular dementia research

INTRODUCTION

Traditional approaches to clinical research have, as yet, failed to provide effective treatments for vascular dementia (VaD). Novel approaches to collation and synthesis of data may allow for time and cost efficient hypothesis generating and testing. These approaches may have particular utility in helping us understand and treat a complex condition such as VaD.

METHODS

We present an overview of new uses for existing data to progress VaD research. The overview is the result of consultation with various stakeholders, focused literature review and learning from the group's experience of successful approaches to data repurposing. In particular, we benefitted from the expert discussion and input of delegates at the 9th International Congress on Vascular Dementia (Ljubljana, 16-18th October 2015).

RESULTS

We agreed on key areas that could be of relevance to VaD research: systematic review of existing studies; individual patient level analyses of existing trials and cohorts and linking electronic health record data to other datasets. We illustrated each theme with a case-study of an existing project that has utilised this approach.

CONCLUSIONS

There are many opportunities for the VaD research community to make better use of existing data. The volume of potentially available data is increasing and the opportunities for using these resources to progress the VaD research agenda are exciting. Of course, these approaches come with inherent limitations and biases, as bigger datasets are not necessarily better datasets and maintaining rigour and critical analysis will be key to optimising data use.

Preventive effects of multiple domain interventions on lifestyle and risk factor changes in stroke survivors: Evidence from a two-year randomized trial

Background and aim

Behavioral and lifestyle interventions in stroke patients need to be intense enough to result in sustainable treatment differences among groups of a randomized trial. Therefore, we report the effects of multidomain interventions on lifestyle and laboratory parameters after 12 and 24 months from a trial that examined whether intensive risk factor management can prevent cognitive decline in ischemic stroke patients.

Methods

This prospective randomized, open-label, blinded endpoint trial recruited patients within three months after acute stroke in five Austrian neurological clinics during June 2010 and November 2012. One hundred and one patients were randomized into multidomain intervention and 101 into standard care. Lifestyle interventions were individualized to match predefined targets of regular physical activity, healthy diet, and adequate physiological risk factor control.

Results

A total of 167 participants (80 intervention, 87 control) completed the 12-month visit and 155 (76 intervention, 79 control) the 24-month visit. During the first 12 months, adherence to healthy lifestyle and adequately controlled physiological parameters (measured by summary scores) improved significantly in the intervention group compared to controls (p < 0.01). The consumption of reduced-fat milk (p = 0.031), reduced-fat spreads (p = 0.007), and fish (p = 0.021) increased in the intervention group from baseline to 12 months but not in controls. After 24 months, the group difference was significant for the lifestyle summary score but no longer for the combined laboratory lifestyle score.

Conclusions

These results demonstrate that intensified individualized multidomain lifestyle interventions in stroke patients are effective in promoting healthy lifestyle in stroke care.

Secondary prevention and cognitive function after stroke: a study protocol for a 5-year follow-up of the ASPIRE-S cohort

INTRODUCTION

Cognitive impairment is common following stroke and can increase disability and levels of dependency of patients, potentially leading to greater burden on carers and the healthcare system. Effective cardiovascular risk factor control through secondary preventive medications may reduce the risk of cognitive decline. However, adherence to medications is often poor and can be adversely affected by cognitive deficits. Suboptimal medication adherence negatively impacts secondary prevention targets, increasing the risk of recurrent stroke and further cognitive decline. The aim of this study is to profile cognitive function and secondary prevention, including adherence to secondary preventive medications and healthcare usage, 5 years post-stroke. The prospective associations between cognition, cardiovascular risk factors, adherence to secondary preventive medications, and rates of recurrent stroke or other cardiovascular events will also be explored.

METHODS AND ANALYSIS

This is a 5-year follow-up of a prospective study of the Action on Secondary Prevention Interventions and Rehabilitation in Stroke (ASPIRE-S) cohort of patients with stroke. This cohort will have a detailed assessment of cognitive function, adherence to secondary preventive medications and cardiovascular risk factor control.

ETHICS AND DISSEMINATION

Ethical approval for this study was granted by the Research Ethics Committees at Beaumont Hospital, Dublin and Connolly Hospital, Dublin, Mater Misericordiae University Hospital, Dublin, and the Royal College of Surgeons in Ireland. Findings will be disseminated through presentations and peer-reviewed publications.

Attitudes to Stem Cell Therapy Among Ischemic Stroke Survivors in the Lund Stroke Recovery Study

Preclinical studies suggest that stem cell therapy (SCT) may improve poststroke recovery, and clinical trials investigating safety are ongoing. However, knowledge about patients' attitudes to SCT in stroke is limited. We evaluated the knowledge and attitudes to this therapeutic approach as well as possible factors influencing this among stroke patients potentially suitable for SCT. Consecutive first-ever acute ischemic stroke patients aged 20-75 years with NIH stroke scale scores 1-18 were included. Exclusion criteria were severe comorbidities or infratentorial stroke. Clinical follow-up after 3-5 years assessed severity of residual stroke symptoms, cognitive function, functional status, patient-reported outcome, and comorbidity, and after receiving standardized information, the participants also completed an eight-item questionnaire on knowledge and attitudes about SCT. The relationships between clinical variables and positive attitude to SCT were assessed with logistic regression analyses. Of 108 patients included at baseline, 84 participated at follow-up and completed the questionnaire. In total, 12% had prior knowledge of SCT. When informed, 63% were positive toward it and 36% reported willingness to participate in SCT trials. Only 5%-8% expressed ethical considerations regarding different stem cell sources. Positive attitudes to SCT were associated with male gender (OR: 3.74; 95% CI: 1.45-9.61; P < 0.01) and better patient-reported outcome (OR: 1.02; 95% CI: 1.00-1.04; P < 0.05). In conclusion, stroke patients had limited prior knowledge of SCT, yet attitudes were positive among the majority after receiving standardized and neutral information. Gender and degree of stroke recovery may influence attitudes to SCT, indicating a need for targeted information to improve knowledge about SCT.

Post-stroke dementia - a comprehensive review

Post-stroke dementia (PSD) or post-stroke cognitive impairment (PSCI) may affect up to one third of stroke survivors. Various definitions of PSCI and PSD have been described. We propose PSD as a label for any dementia following stroke in temporal relation. Various tools are available to screen and assess cognition, with few PSD-specific instruments. Choice will depend on purpose of assessment, with differing instruments needed for brief screening (e.g., Montreal Cognitive Assessment) or diagnostic formulation (e.g., NINDS VCI battery). A comprehensive evaluation should include assessment of pre-stroke cognition (e.g., using Informant Questionnaire for Cognitive Decline in the Elderly), mood (e.g., using Hospital Anxiety and Depression Scale), and functional consequences of cognitive impairments (e.g., using modified Rankin Scale). A large number of biomarkers for PSD, including indicators for genetic polymorphisms, biomarkers in the cerebrospinal fluid and in the serum, inflammatory mediators, and peripheral microRNA profiles have been proposed. Currently, no specific biomarkers have been proven to robustly discriminate vulnerable patients ('at risk brains') from those with better prognosis or to discriminate Alzheimer's disease dementia from PSD. Further, neuroimaging is an important diagnostic tool in PSD. The role of computerized tomography is limited to demonstrating type and location of the underlying primary lesion and indicating atrophy and severe white matter changes. Magnetic resonance imaging is the key neuroimaging modality and has high sensitivity and specificity for detecting pathological changes, including small vessel disease. Advanced multi-modal imaging includes diffusion tensor imaging for fiber tracking, by which changes in networks can be detected. Quantitative imaging of cerebral blood flow and metabolism by positron emission tomography can differentiate between vascular dementia and degenerative dementia and show the interaction between vascular and metabolic changes. Additionally, inflammatory changes after ischemia in the brain can be detected, which may play a role together with amyloid deposition in the development of PSD. Prevention of PSD can be achieved by prevention of stroke. As treatment strategies to inhibit the development and mitigate the course of PSD, lowering of blood pressure, statins, neuroprotective drugs, and anti-inflammatory agents have all been studied without convincing evidence of efficacy. Lifestyle interventions, physical activity, and cognitive training have been recently tested, but large controlled trials are still missing.

Regulation of mRNA following brain ischemia and reperfusion

There is growing appreciation that mRNA regulation plays important roles in disease and injury. mRNA regulation and ribonomics occur in brain ischemia and reperfusion (I/R) following stroke and cardiac arrest and resuscitation. It was recognized over 40 years ago that translation arrest (TA) accompanies brain I/R and is now recognized as part of the intrinsic stress responses triggered in neurons. However, neuron death correlates to a prolonged TA in cells fated to undergo delayed neuronal death (DND). Dysfunction of mRNA regulatory processes in cells fated to DND prevents them from translating stress-induced mRNAs such as heat shock proteins. The morphological and biochemical studies of mRNA regulation in postischemic neurons are discussed in the context of the large variety of molecular damage induced by ischemic injury. Open issues and areas of future investigation are highlighted. A sober look at the molecular complexity of ischemia-induced neuronal injury suggests that a network framework will assist in making sense of this complexity. The ribonomic network sits between the gene network and the various protein and metabolic networks. Thus, targeting the ribonomic network may prove more effective at neuroprotection than targeting specific molecular pathways, for which all efforts have failed to the present time to stop DND in stroke and after cardiac arrest. WIREs RNA 2017, 8:e1415. doi: 10.1002/wrna.1415 For further resources related to this article, please visit the WIREs website.

Are stroke survivors with delirium at higher risk of post-stroke dementia? Current evidence and future directions

OBJECTIVES

The idea that delirium is a risk factor for dementia, broadly defined, is derived from heterogeneous patient samples. We reviewed available evidence as to whether stroke survivors who developed delirium during the acute phase of treatment are at a higher prospective risk of incident post-stroke cognitive impairment or dementia.

DESIGN

We searched 8721 records in the Cochrane database for reviews or protocols dealing with the study objective, Medline, EMBASE, PsycInfo and CINAHL for observational studies in the general adult population and PubMed for in-process articles. Additional searches of the reference lists of retrieved articles were also undertaken. Qualitative syntheses and meta-analysis were conducted according to conventional guidelines.

RESULTS

Twelve relevant articles were fully appraised. Four out of these studies, comprising 743 stroke survivors, including 199 with delirium, met criteria for qualitative syntheses. Overall, the studies presented low to moderate level evidence suggesting an association between post-stroke delirium and dementia.

CONCLUSIONS

There is a need for further studies to investigate the association of post-stroke delirium and dementia using well-defined cohorts of patients and controlling for factors such as pre-stroke cognition, stroke severity and location and the presence of persistent delirium. Such studies will help understand the place of delirium identification and prevention in reducing the risk of dementia after stroke. © 2016 The Authors. International Journal of Geriatric Psychiatry Published by John Wiley & Sons Ltd.

Informant Questionnaire on Cognitive Decline in the Elderly (IQCODE) for the early diagnosis of dementia across a variety of healthcare settings

BACKGROUND

The Informant Questionnaire for Cognitive Decline in the Elderly (IQCODE) is a structured interview based on informant responses that is used to assess for possible dementia. IQCODE has been used for retrospective or contemporaneous assessment of cognitive decline. There is considerable interest in tests that may identify those at future risk of developing dementia. Assessing a population free of dementia for the prospective development of dementia is an approach often used in studies of dementia biomarkers. In theory, questionnaire-based assessments, such as IQCODE, could be used in a similar way, assessing for dementia that is diagnosed on a later (delayed) assessment.

OBJECTIVES

To determine the diagnostic accuracy of IQCODE in a population free from dementia for the delayed diagnosis of dementia (test accuracy with delayed verification study design).

SEARCH METHODS

We searched these sources on 16 January 2016: ALOIS (Cochrane Dementia and Cognitive Improvement Group), MEDLINE Ovid SP, Embase Ovid SP, PsycINFO Ovid SP, BIOSIS Previews on Thomson Reuters Web of Science, Web of Science Core Collection (includes Conference Proceedings Citation Index) on Thomson Reuters Web of Science, CINAHL EBSCOhost, and LILACS BIREME. We also searched sources specific to diagnostic test accuracy: MEDION (Universities of Maastricht and Leuven); DARE (Database of Abstracts of Reviews of Effects, in the Cochrane Library); HTA Database (Health Technology Assessment Database, in the Cochrane Library), and ARIF (Birmingham University). We checked reference lists of included studies and reviews, used searches of included studies in PubMed to track related articles, and contacted research groups conducting work on IQCODE for dementia diagnosis to try to find additional studies. We developed a sensitive search strategy; search terms were designed to cover key concepts using several different approaches run in parallel, and included terms relating to cognitive tests, cognitive screening, and dementia. We used standardised database subject headings, such as MeSH terms (in MEDLINE) and other standardised headings (controlled vocabulary) in other databases, as appropriate.

SELECTION CRITERIA

We selected studies that included a population free from dementia at baseline, who were assessed with the IQCODE and subsequently assessed for the development of dementia over time. The implication was that at the time of testing, the individual had a cognitive problem sufficient to result in an abnormal IQCODE score (defined by the study authors), but not yet meeting dementia diagnostic criteria.

DATA COLLECTION AND ANALYSIS

We screened all titles generated by the electronic database searches, and reviewed abstracts of all potentially relevant studies. Two assessors independently checked the full papers for eligibility and extracted data. We determined quality assessment (risk of bias and applicability) using the QUADAS-2 tool, and reported quality using the STARDdem tool.

MAIN RESULTS

From 85 papers describing IQCODE, we included three papers, representing data from 626 individuals. Of this total, 22% (N = 135/626) were excluded because of prevalent dementia. There was substantial attrition; 47% (N = 295) of the study population received reference standard assessment at first follow-up (three to six months) and 28% (N = 174) received reference standard assessment at final follow-up (one to three years). Prevalence of dementia ranged from 12% to 26% at first follow-up and 16% to 35% at final follow-up.The three studies were considered to be too heterogenous to combine, so we did not perform meta-analyses to describe summary estimates of interest. Included patients were poststroke (two papers) and hip fracture (one paper). The IQCODE was used at three thresholds of positivity (higher than 3.0, higher than 3.12 and higher than 3.3) to predict those at risk of a future diagnosis of dementia. Using a cut-off of 3.0, IQCODE had a sensitivity of 0.75 (95%CI 0.51 to 0.91) and a specificity of 0.46 (95%CI 0.34 to 0.59) at one year following stroke. Using a cut-off of 3.12, the IQCODE had a sensitivity of 0.80 (95%CI 0.44 to 0.97) and specificity of 0.53 (95C%CI 0.41 to 0.65) for the clinical diagnosis of dementia at six months after hip fracture. Using a cut-off of 3.3, the IQCODE had a sensitivity of 0.84 (95%CI 0.68 to 0.94) and a specificity of 0.87 (95%CI 0.76 to 0.94) for the clinical diagnosis of dementia at one year after stroke.In generaI, the IQCODE was sensitive for identification of those who would develop dementia, but lacked specificity. Methods for both excluding prevalent dementia at baseline and assessing for the development of dementia were varied, and had the potential to introduce bias.

AUTHORS' CONCLUSIONS

Included studies were heterogenous, recruited from specialist settings, and had potential biases. The studies identified did not allow us to make specific recommendations on the use of the IQCODE for the future diagnosis of dementia in clinical practice. The included studies highlighted the challenges of delayed verification dementia research, with issues around prevalent dementia assessment, loss to follow-up over time, and test non-completion potentially limiting the studies. Future research should recognise these issues and have explicit protocols for dealing with them.

Cerebral small vessel disease, medial temporal lobe atrophy and cognitive status in patients with ischaemic stroke and transient ischaemic attack

BACKGROUND AND PURPOSE

Small vessel disease (SVD) and Alzheimer's disease (AD) are two common causes of cognitive impairment and dementia, traditionally considered as distinct processes. The relationship between radiological features suggestive of AD and SVD was explored, and the association of each of these features with cognitive status at 1 year was investigated in patients with stroke or transient ischaemic attack.

METHODS

Anonymized data were accessed from the Virtual International Stroke Trials Archive (VISTA). Medial temporal lobe atrophy (MTA; a marker of AD) and markers of SVD were rated using validated ordinal visual scales. Cognitive status was evaluated with the Mini Mental State Examination (MMSE) 1 year after the index stroke. Logistic regression models were used to investigate independent associations between (i) baseline SVD features and MTA and (ii) all baseline neuroimaging features and cognitive status 1 year post-stroke.

RESULTS

In all, 234 patients were included, mean (±SD) age 65.7 ± 13.1 years, 145 (62%) male. Moderate to severe MTA was present in 104 (44%) patients. SVD features were independently associated with MTA (P < 0.001). After adjusting for age, sex, disability after stroke, hypertension and diabetes mellitus, MTA was the only radiological feature independently associated with cognitive impairment, defined using thresholds of MMSE ≤ 26 (odds ratio 1.94; 95% confidence interval 1.28-2.94) and MMSE ≤ 23 (odds ratio 2.31; 95% confidence interval 1.48-3.62).

CONCLUSION

In patients with ischaemic cerebrovascular disease, SVD features are associated with MTA, which is a common finding in stroke survivors. SVD and AD type neurodegeneration coexist, but the AD marker MTA, rather than SVD markers, is associated with post-stroke cognitive impairment.

Neuroimaging in vascular cognitive impairment: a state-of-the-art review

Imaging is critical in the diagnosis and treatment of dementia, particularly in vascular cognitive impairment, due to the visualization of ischemic and hemorrhagic injury of gray and white matter. Magnetic resonance imaging (MRI) and positron emission tomography (PET) provide structural and functional information. Clinical MRI is both generally available and versatile - T2-weighted images show infarcts, FLAIR shows white matter changes and lacunar infarcts, and susceptibility-weighted images reveal microbleeds. Diffusion MRI adds another dimension by showing graded damage to white matter, making it more sensitive to white matter injury than FLAIR. Regions of neuroinflammatory disruption of the blood-brain barrier with increased permeability can be quantified and visualized with dynamic contrast-enhanced MRI. PET shows metabolism of glucose and accumulation of amyloid and tau, which is useful in showing abnormal metabolism in Alzheimer's disease. Combining MRI and PET allows identification of patients with mixed dementia, with MRI showing white matter injury and PET demonstrating regional impairment of glucose metabolism and deposition of amyloid. Excellent anatomical detail can be observed with 7.0-Tesla MRI. Imaging is the optimal method to follow the effect of treatments since changes in MRI scans are seen prior to those in cognition. This review describes the role of various imaging modalities in the diagnosis and treatment of vascular cognitive impairment.