Cognitive Impairment After Ischemic and Hemorrhagic Stroke: A Scientific Statement From the American Heart Association/American Stroke Association

PURPOSE

Cognitive impairment is a common consequence of stroke and has direct implications for poststroke functioning and quality of life, including the ability to maintain a job, live independently, sustain interpersonal relationships, and drive a vehicle. In this scientific statement, we critically appraise the literature on the prevalence, diagnosis, and management of poststroke cognitive impairment (PSCI) and provide a framework for clinical care while highlighting gaps that merit further study.

METHODS

We performed a scoping literature review of randomized controlled clinical trials, prospective and retrospective cohort studies, case-control studies, clinical guidelines, review articles, and editorials on the incidence and prevalence, natural history, diagnosis, and management of PSCI. Scoping reviews determine the scope of a body of literature on a given topic to indicate the volume of literature and the studies currently available and provide an overview of its focus.

RESULTS

PSCI is common after stroke, especially in the first year, and ranges from mild to severe. Although cognitive impairment is reversible in some cases early after stroke, up to one-third of individuals with stroke develop dementia within 5 years. The pathophysiology is not yet fully elucidated but is likely attributable to an acute stroke precipitating a series of pathological events, often in the setting of preexisting microvascular and neurodegenerative changes. Screening for associated comorbidities and interdisciplinary management are integral components of the care of individuals with PSCI. There is a need for prospective studies evaluating the individual trajectory of PSCI and the role of the acute vascular event in the predisposition for Alzheimer disease and related dementias, as well as high-quality, randomized clinical trials focused on PSCI management.

Dual-task gait and white matter hyperintensities in Lewy body diseases: An exploratory analysis

Background

Parkinson’s disease (PD) and dementia with Lewy bodies (DLB) are part of a spectrum of Lewy body disorders, who exhibit a range of cognitive and gait impairments. Cognitive-motor interactions can be examined by performing a cognitive task while walking and quantified by a dual task cost (DTC). White matter hyperintensities (WMH) on magnetic resonance imaging have also been associated with both gait and cognition. Our goal was to examine the relationship between DTC and WMH in the Lewy body spectrum, hypothesizing DTC would be associated with increased WMH volume.

Methods

Seventy-eight participants with PD, PD with mild cognitive impairment (PD-MCI), PD with dementia or DLB (PDD/DLB), and 20 cognitively unimpaired participants were examined in a multi-site study. Gait was measured on an electronic walkway during usual gait, counting backward, animal fluency, and subtracting sevens. WMH were quantified from magnetic resonance imaging using an automated pipeline and visual rating. A median split based on DTC was performed. Models included age as well as measures of global cognition and cardiovascular risk.

Results

Compared to cognitively unimpaired participants, usual gait speed was lower and DTC was higher in PD-MCI and PDD/DLB. Low DTC participants had higher usual gait speed. WMH burden was greater in high counting DTC participants. Frontal WMH burden remained significant after adjusting for age, cardiovascular risk and global cognition.

Conclusion

Increased DTC was associated with higher frontal WMH burden in Lewy body disorders after adjusting for age, cardiovascular risk, and global cognition. Higher DTC was associated with age.

Gait and falls in cerebral small vessel disease: a systematic review and meta-analysis

BACKGROUND

Gait impairment contributes to falls and frailty. Some studies suggest that cerebral small vessel disease (CSVD) is associated with gait impairment in the general population. We systematically reviewed and meta-analysed the literature on associations of CSVD with gait impairment and falls.

METHODS

The protocol was published in PROSPERO (CRD42021246009). Searches of Medline, Cochrane and Embase databases were conducted on 30 March 2022. Cross-sectional and longitudinal studies of community-dwelling adults were included, reporting relationships between diagnosis or neuroimaging markers of CSVD and outcomes related to gait or falls. Partial correlation coefficients were calculated and pooled using a random-effects model for meta-analysis.

RESULTS

The search retrieved 73 studies (53 cross-sectional; 20 longitudinal). Most studies reported an association between CSVD and gait impairments or falls risk: 7/7 studies on CSVD score or diagnosis, 53/67 studies on white matter hyperintensities (WMHs), 11/21 studies on lacunar infarcts, 6/15 studies on cerebral microbleeds and 1/5 studies on perivascular spaces. Meta-analysis of 13 studies found that higher WMH volume was mildly correlated with lower gait speed, in all studies (r = -0.23, 95% confidence interval: -0.33 to -0.14, P < 0.0001). However, there was significant heterogeneity between studies (I2 = 82.95%; tau2 = 0.02; Q = 79.37, P < 0.0001), which was unexplained by variation in age, sex, study quality or if the study adjusted for age.

CONCLUSIONS

Findings suggest that CSVD severity is associated with gait impairment, history of falls and risk of future falls. Prevention of CSVD should be part of a comprehensive public health strategy to improve mobility and reduce risk of falls in later life.

Validating the Mild Behavioral Impairment Checklist in a Cognitive Clinic: Comparisons With the Neuropsychiatric Inventory Questionnaire

OBJECTIVE

To compare the utility of the Mild Behavioral Impairment-Checklist (MBI-C) and Neuropsychiatric Inventory Questionnaire (NPI-Q) to capture NPS in subjective cognitive decline (SCD), mild cognitive impairment (MCI), and dementia.

METHODS

In this cross-sectional memory clinic study, linear regression models compared MBI-C (n = 474) and NPI-Q (n = 1040) scores in relation to Montreal Cognitive Assessment (MoCA) score.

RESULTS

MBI prevalence was 37% in subjective cognitive decline, 54% in mild cognitive impairment, and 62% in dementia. Worse diagnostic status was associated with higher MBI-C and NPI-Q score (P < .001), lower MoCA (P < .001), and greater age (P < .001). Higher MBI-C (β -.09; 95% CI -.13, -.05) and NPI-Q (β -.17; 95% CI -.23, -.10) scores were associated with lower MoCA scores, with psychosis most strongly associated (β -1.11; 95% CI -1.56, -.65 vs β -1.14; 95% CI -1.55, -.73).

CONCLUSIONS

The MBI-C captures global and domain-specific NPS across cognitive stages. Both the MBI-C and NPI-Q have utility in characterizing NPS.

Abstract 160: Etiologies Of Intracerebral Hemorrhage In Patients With Atrial Fibrillation On Or Off Oral Anticoagulants: The Neuro-Afib Study

Background: Intracerebral hemorrhage (ICH) is the most feared complication of oral anticoagulants (OAC) used to prevent ischemic strokes (IS) in patients with atrial fibrillation (AF). As different ICH etiologic factors correspond to different ICH risks, we aimed to present the causes of ICH in AF patients who were or were not using OAC, based on data from a multicenter contemporary cohort.

Methods: The Neuro-AFib study is a multicenter effort to elucidate the current causes and consequences of IS and ICH in AF patients. Detailed clinical, laboratory and multimodal imaging data were collected from consecutive patients with AF admitted to 15 US stroke centers with an IS or ICH between 1/2018-12/2019. Etiologic factors of AF patients who were admitted with ICH on OAC (OAC-ICH) and off OAC (nonOAC-ICH) will be compared.

Results: A total of 868 patients presented with ICH and had a diagnosis of AF, either previously known (88%) or diagnosed during admission (12%). 571 patients (66%) were on OAC at the time of their ICH of whom 58% were on direct OAC (DOAC), 40% on warfarin and 2% on heparin. OAC-ICH patients were older than nonOAC-ICH (76.6±10 vs 74.4±13, p=0.006) while sex distribution was the same in both groups (43% female). CHA 2 DS 2 -VASC was higher in OAC-ICH (4.3±1.6 vs 3.9±1.9, p=0.001) but HAS-BLED score was the same in both groups (2.7±1.1). Cerebral amyloid angiopathy (CAA) was diagnosed in 42.5% of the ICH patients based on modified Boston criteria while hypertensive cerebral small vessel disease (HTN-cSVD) in 57.5%. HTN-cSVD was the more common ICH etiology among OAC-ICH (65%) compared to nonOAC-ICH (49%). Among OAC-ICHs, DOAC-related ICHs tended to be more commonly of hypertensive etiology when compared to warfarin-ICH (p=0.09).

Conclusions: Our study is the first to report the etiologic mechanisms of ICH in AF patients on or off OAC. CAA is known to be a major cause of OAC-ICH with exceedingly high recurrence rates. Despite this fact, HTN-cSVD was more common among OAC-ICH (especially DOAC-ICH) patients, supporting the view that the presence/absence of HTN-cSVD risk markers such as deep microbleeds are as important as CAA-markers in determining the optimal stroke prevention method in AF patients (left atrial appendage closure vs lifelong OAC).

Treatment of Vascular and Neurodegenerative Forms of Cognitive Impairment and Dementias

Ideally, dementia care should be provided by a collaborative team. Eligible patients should be treated with the cognitive-enhancing medications, the cholinesterase inhibitors and memantine. For most of the common causes of dementia, there are no disease-modifying medications, with the exception that vascular dementia can be prevented by treating vascular risk factors to prevent stroke. There is hope that Alzheimer disease can be treated by using monoclonal antibodies that target amyloid beta, although more trials are needed. Holistic, patient-centered care can enhance quality and extend the time that the patient can live safely in the community.

Abstract WP242: Transcriptomic Changes In Peripheral Blood Leukocytes Associated With The Cerebral Amyloid Angiopathy Small Vessel Disease Score

Introduction: Cerebral amyloid angiopathy (CAA) is a cerebrovascular disease characterized by beta-amyloid deposition within cerebral vessels. Clinical markers of CAA severity include recurrent ICH, cognitive decline, and imaging features of CAA including microhemorrhage, dilated perivascular spaces, cortical superficial siderosis, and white matter hyperintensities. CAA is an important cause of cognitive decline and intracerebral hemorrhage in the elderly, leading to the need for CAA treatments. The contribution of the immune system to CAA severity is not well understood. This study sought to evaluate changes in peripheral leukocyte gene expression associated with CAA severity.

Methods: In 22 patients with CAA peripheral blood was collected into PAXgene tubes. RNA was isolated, and sequencing performed. Differentially expressed genes based on CAA small vessel disease (CAA-SVD) score as a marker of CAA severity were identified using ANOVA and functional pathway analysis. The relationship between leukocyte gene expression and CAA severity were assessed.

Results: ANOVA was used to identify genes that were associated with CAA-SVD score (p≤0.05, partial correlation coefficient ≥;|0.5|). HDAC11, IL23A, TRAIL, TRAILR1 , TRAILR2 , and ICAM-1 were associated with CAA severity (CAA-SVD score). Canonical pathway analysis identified included induction of T lymphocytes, binding of antigen presentation cells, IL-12 signaling in macrophages/monocytes, activation of phagocytes, tight junction signaling, and activation of antigen presenting cells to be associated with CAA severity (p≤0.05).

Conclusion: An association between the peripheral immune system and CAA severity was identified. Changes in neutrophil, monocyte, and Th17 cell gene expression in peripheral blood was associated with CAA severity. Further evaluation of immune system changes associated with CAA severity is needed to understand contribution to cerebral small vessel disease, cognitive decline, and potential roles as treatment targets or risk stratification markers in CAA.

Abstract 33: Risk Scores And Brain Mri Markers In Distinguishing Ischemic Stroke And Intracerebral Hemorrhage Risk Among Atrial Fibrillation Patients: The Neuro-Afib Study

Background: Recent studies cast doubt on the accuracy of the most-commonly used risk scores (CHA 2 DS 2 -VASC and HAS-BLED) in differentiating the risk of acute ischemic stroke (AIS) and intracerebral hemorrhage (ICH) among patients with fibrillation (AF). Because of the importance of AIS/ICH risk determination for choice of proper preventive approaches, we aimed to compare the value of these risk scores and brain MRI markers to differentiate the occurrence of AIS and ICH in a large cohort of AF-related strokes.

Methods: The Neuro-AFib study is a multicenter effort to elucidate the causes and consequences of AIS and ICH in AF patients. Demographics, CHA 2 DS 2 -VASC and HAS-BLED scores, and ischemic/hemorrhagic brain MRI markers were compared between AF patients admitted with AIS and ICH to 15 academic stroke centers in the US between 1/2018-12/2019.

Results: Of 5694 stroke admissions with AF, 4826 (84.8%) had AIS and 868 (15.2%) ICH. Mean age was similar between groups (75.9±11.5 vs 76.6±11.9, p=0.1), more ICH patients were male (57% vs 50%). Pre-index event CHA 2 DS 2 -VASC (4.14±1.6 vs 4.22±1.6) and HAS-BLED (2.71±1.09 vs 2.68±1.13) were similar between groups [both p>0.2]. Cerebral microbleeds (CMB, 56% vs 33.5%), cortical superficial siderosis (cSS, 15% vs 9.4%), and moderate-to-severe leukoaraiosis (41% vs 33.4%) were more commonly found among ICH patients compared to AIS (all p<0.001). Chronic lacunar infarcts (43.5% vs 39.5%, p=0.03) and chronic non-lacunar infarcts (29% vs 18%, p<0.001) were more commonly found in AIS. In a multivariable logistic regression model that included all variables above, male sex, presence of CMBs, cSS, moderate-to-severe leukoaraiosis were associated with ICH, chronic non-lacunar infarcts with AIS (all p<0.005), while CHA 2 DS 2 -VASC (p=0.9) and HAS-BLED (p=0.9) were not related to the stroke type.

Conclusions: Data from our multicenter study confirm the lack of specificity of CHA 2 DS 2 -VASC and HAS-BLED to categorize the risk of AIS vs ICH in AF patients. The chronic MRI findings (CMB, cSS, moderate-to-severe leukoaraiosis, chronic infarcts) should be incorporated into risk scores, and their predictive value for AIS and ICH should be investigated in prospective studies to select optimal stroke prevention methods in AF patients.

Abstract 67: Endovascular Thrombectomy In Patients With Acute Ischemic Stroke And Recent Use Of Oral Vitamin K-Antagonists: The Get With The Guidelines-Stroke Program

Introduction: Emergent endovascular thrombectomy (EVT) is effective in improving outcomes in patients with stroke caused by large vessel occlusion. However, there are limited data on the use of EVT in patients taking an oral vitamin K antagonist (VKA), constraining guideline development around EVT use in this vulnerable population.

Methods: To address this knowledge gap, we performed a retrospective, observational, cohort study based on a population-based sample of stroke admissions in the US (the AHAs “Get With The Guidelines-Stroke" Program) between October 2015 and March 2020. We aimed to determine whether use of VKA was associated with the risk of symptomatic intracranial hemorrhage (sICH) and functional outcomes in patients undergoing EVT within 6 hours of time last known well after adjusting for pre-specified confounders.

Results: Of 32,715 patients (median age 72 years; 50.7% female), 3,087 were taking a VKA and 29,628 were not on an OAC prior to stroke. Patients taking VKAs were older (median age 78 vs. 71 years) but stroke severity was similar between the groups (median NIHSS 18 vs. 17). Of patients taking a VKA, 211 (6.8%) suffered a sICH whereas 1,904 (6.4%) patients not on OAC developed a sICH. VKA was not associated with sICH (adjusted odds ratio 1.20, 95% CI: 0.96-1.49). VKA use was associated with a higher risk of life-threatening systemic hemorrhage (1.2% vs. 1.02%; aOR 1.93 (1.17-3.19)) but not with mortality/discharge to hospice (27.1% vs. 20.6%; aOR 1.02 (0.90-1.14)). Patients taking a VKA prior to EVT were more likely to be able to be ambulatory at discharge (aOR 1.24 [1.11-1.39]) and to have an mRS of 0-2 (aOR 1.23 [1.07-1.42]).

Conclusions: Among patients with acute ischemic stroke on VKA, EVT appears to be well tolerated without prohibitive risks of sICH. Our results provide support for the deployment of this critical, disability-reducing therapy in this population of patients with a large vessel occlusion presenting within 6 hours of time last known well.

Abstract 25: Safety And Outcomes Of Endovascular Thrombectomy In Acute Ischemic Stroke Patients With Recent Use Of Non-vitamin K Antagonist Oral Anticoagulants

Introduction: An increasing number of patients with acute ischemic stroke (AIS) have recently used non-vitamin K antagonist oral anticoagulants (NOACs). However, there are limited data on safety of endovascular therapy (EVT) in these patients.

Methods: We performed a retrospective, observational, cohort study of patients treated with EVT within 6 hours of symptom onset in the American Heart Association’s “Get With The Guideline-Stroke Program” between October 2015 and March 2020 to compare safety and functional outcomes in patients who were or were not taking NOACs in the 7 days prior to stroke.

Results: Of 33,355 patients (median age 72 years (60,81); 50.8% female), 3,727 (11.2%) were taking NOACs, and 29,628 (88.8%) were not taking any oral anticoagulants (OAC) prior to stroke. Compared with those not on OAC, patients taking NOACs were older (median age 75 vs. 71 years) and had a higher prevalence of comorbidities including cardiovascular risk factors, although stroke severity was similar between the groups (median NIHSS 18 vs. 17). After adjusting for baseline clinical factors including intravenous alteplase, patients taking NOACs were not at a significantly higher risk of sICH compared with patients not taking anticoagulants (4.9% vs 6.4%; aOR, 0.93 [95% CI, 0.75-1.14]) or in-hospital mortality (14.1% vs 13.1%; aOR, 0.90 [95% CI, 0.78-1.02]). Of the secondary discharge outcomes, 3 of 7 showed significant differences in favor of the NOAC group including ambulating independently (33.7% vs 38.7%; aOR, 1.15 [95% CI, 1.02-1.30]) and freedom from disability (modified Rankin Scale [mRS] 0-1, 13.0% vs 16.2%; aOR, 1.23 [95% CI, 1.04-1.46]) at discharge. In a subset of patients with documented time of last NOACs dose (n=213), sICH rate was 3.1% (6/196) with last dose ≤2 days and 0% (0/17) with >2 days.

Conclusions: Among patients with acute ischemic stroke treated with EVT within 6 hours, use of NOACs within the preceding 7 days, compared with no use of anticoagulants, was not associated with a significantly increased risk of adverse events and was associated with better functional outcomes at discharge.

Abstract WP223: Identification Of Cerebral Amyloid Angiopathy With A Leukocyte Gene Expression Profile

Introduction: Cerebral amyloid angiopathy (CAA) is a cerebral small vessel disease featuring beta-amyloid deposits within the cerebral vasculature. It is a major cause of cognitive decline and intracerebral hemorrhage in the elderly. This study evaluated whether gene expression profiles in peripheral blood can differentiate patients with CAA from vascular risk factor and healthy controls.

Methods: In 27 patients with CAA blood cell gene expression was compared to 55 controls. Total RNA was isolated from PAXgene tubes and measured by RNA sequencing. Differentially expressed genes between CAA and controls were identified by ANOVA adjusting for age and sex. Functional pathway analysis identified pathways associated with CAA. A prediction model to distinguish CAA from controls was developed using linear discriminant analysis with feature selection by forward selection. Model performance was evaluated by 10-fold leave-one-out cross validation.

Results: 686 differentially expressed genes were identified (p<0.05, fold change >|1.2|), of interest ADAM15, CAMK1D, CAP1 and TGFB1 . Canonical pathway analysis identified cell movement of phagocytes, activation of phagocytes, CREB, degranulation of leukocytes, immune response of cells, inflammatory response, and IL-23 signaling. A 24 gene panel differentiated patients with CAA from controls with >95% sensitivity and specificity. The identified genes reveal differences in immune system regulation in patients with CAA compared to vascular risk factor and healthy control patients. Differences identified include a potential shift in beta-amyloid uptake by phagocytes ( TGFB1, CREB, CAMK1D ), an increase in vascular extracellular matrix disruption ( ADAM15, CAP1 ), and a possible alteration in amyloid precursor processing ( BRI3BP, SORCS3 ).

Conclusion: Differences in peripheral leukocyte gene expression are present in patients with CAA compared to control patients. These relate to differences in immune activation and signaling associated with CAA. The differences in blood cell gene expression shows promise to distinguish CAA from controls, though further evaluation in larger cohorts is required to further evaluate potential diagnostic utility of this gene expression profile.

Amyloid-PET of the white matter: Relationship to free water, fiber integrity, and cognition in patients with dementia and small vessel disease

White matter (WM) injury is frequently observed along with dementia. Positron emission tomography with amyloid-ligands (Aβ-PET) recently gained interest for detecting WM injury. Yet, little is understood about the origin of the altered Aβ-PET signal in WM regions. Here, we investigated the relative contributions of diffusion MRI-based microstructural alterations, including free water and tissue-specific properties, to Aβ-PET in WM and to cognition. We included a unique cohort of 115 participants covering the spectrum of low-to-severe white matter hyperintensity (WMH) burden and cognitively normal to dementia. We applied a bi-tensor diffusion-MRI model that differentiates between (i) the extracellular WM compartment (represented via free water), and (ii) the fiber-specific compartment (via free water-adjusted fractional anisotropy [FA]). We observed that, in regions of WMH, a decrease in Aβ-PET related most closely to higher free water and higher WMH volume. In contrast, in normal-appearing WM, an increase in Aβ-PET related more closely to higher cortical Aβ (together with lower free water-adjusted FA). In relation to cognitive impairment, we observed a closer relationship with higher free water than with either free water-adjusted FA or WM PET. Our findings support free water and Aβ-PET as markers of WM abnormalities in patients with mixed dementia, and contribute to a better understanding of processes giving rise to the WM PET signal.

Association Between Duration of Transient Neurological Events and Diffusion-Weighted Brain Lesions

Background The relationship between duration of transient neurological events and presence of diffusion-weighted lesions by symptom type is unclear. Methods and Results This was a substudy of SpecTRA (Spectrometry for Transient Ischemic Attack Rapid Assessment), a multicenter prospective cohort of patients with minor ischemic cerebrovascular events or stroke mimics at academic emergency departments in Canada. For this study we included patients with resolved symptoms and determined the presence of diffusion-weighted imaging (DWI) lesion on magnetic resonance imaging within 7 days. Using logistic regression, we evaluated the association between symptom duration and DWI lesion, assessing for interaction with symptom type (focal only versus nonfocal/mixed), and adjusting for age, sex, education, comorbidities, and systolic blood pressure. Of 658 patients included, a DWI lesion was present in 232 (35.1%). There was a significant interaction between symptom duration and symptom type. For those with focal-only symptoms, there was a continuous increase in DWI probability up to 24 hours in duration (ranging from ≈40% to 80% probability). In stratified analyses, the increase in probability of DWI lesion with increased duration of focal symptoms was seen in women but not men. For those with nonfocal or mixed symptoms, predicted probability of DWI lesion was ≈35% and was greater in men, but did not increase with longer duration. Conclusions Increased duration of neurological deficits is associated with greater probability of DWI lesion in those with focal symptoms only. For individuals with nonfocal or mixed symptoms, about one-third had DWI lesions, but the probability did not increase with duration. These results may be important to improve risk stratification of transient neurological events.

Functional connectivity and mild behavioral impairment in dementia-free elderly

Background

Mild behavioral impairment (MBI) is a syndrome that uses later-life emergent and persistent neuropsychiatric symptoms (NPS) to identify a group at high risk for incident dementia. MBI is associated with neurodegenerative disease markers in advance of syndromic dementia. Functional connectivity (FC) correlates of MBI are understudied and could provide further insights into mechanisms early in the disease course. We used resting-state functional magnetic resonance imaging (rs-fMRI) to test the hypothesis that FC within the default mode network (DMN) and salience network (SN) of persons with MBI (MBI+) is reduced, relative to those without (MBI-).

Methods

From two harmonized dementia-free cohort studies, using a score of ≥6 on the MBI Checklist to define MBI status, 32 MBI+ and 63 MBI- individuals were identified (mean age: 71.7 years; 54.7% female). Seed-based connectivity analysis was implemented in each MBI group using the CONN fMRI toolbox (v20.b), with the posterior cingulate cortex (PCC) as the seed region within the DMN and anterior cingulate cortex (ACC) as the seed within the SN. The average time series from the PCC and ACC were used to determine FC with other regions within the DMN (medial prefrontal cortex, lateral inferior parietal cortex) and SN (anterior insula, supramarginal gyrus, rostral prefrontal cortex), respectively. Age, sex, years of education, and Montreal Cognitive Assessment scores were included as model covariates. The false discovery rate approach was used to correct for multiple comparisons, with a p-value of .05 considered significant.

Results

For the DMN, MBI+ individuals exhibited reduced FC between the PCC and the medial prefrontal cortex, compared to MBI-. For the SN, MBI+ individuals exhibited reduced FC between the ACC and left anterior insula.

Conclusion

MBI in dementia-free older adults is associated with reduced FC in networks known to be disrupted in dementia. Our results complement the evidence linking MBI with Alzheimer's disease biomarkers.

Highlights

Resting-state functional magnetic resonance imaging was completed in 95 dementia-free persons from FAVR and COMPASS-ND studies.Participants were stratified by informant-rated Mild Behavioral Impairment Checklist (MBI-C) score, ≥6 for MBI+.MBI+ participants showed reduced functional connectivity (FC) within the default mode network and salience network.These FC changes are consistent with those seen in early-stage Alzheimer's disease.MBI may help identify persons with early-stage neurodegenerative disease.

Sex Differences in Intensity of Care and Outcomes After Acute Ischemic Stroke Across the Age Continuum

BACKGROUND AND OBJECTIVES

Sex differences in stroke care and outcomes have been previously reported, but it is not known whether these associations vary across the age continuum. We evaluated whether the magnitude of female-male differences in care and outcomes varied with age.

METHODS

In a population-based cohort study, we identified patients hospitalized with ischemic stroke between 2012 and 2019 and followed through 2020 in Ontario, Canada, using administrative data. We evaluated sex differences in receiving intensive care unit services, mechanical ventilation, gastrostomy tube insertion, comprehensive stroke center care, stroke unit care, thrombolysis, and endovascular thrombectomy using logistic regression and reported odds ratios (ORs) and 95% CIs. We used Cox proportional hazard models and reported the hazard ratios (HRs) and 95% CI of death within 90 or 365 days. Models were adjusted for covariates and included an interaction between age and sex. We used restricted cubic splines to model the relationship between age and care and outcomes. Where the p-value for interaction was statistically significant (p < 0.05), we reported age-specific OR or HR.

RESULTS

Among 67,442 patients with ischemic stroke, 45.9% were female and the median age was 74 years (64-83). Care was similar between both sexes, except female patients had higher odds of receiving endovascular thrombectomy (OR 1.35, 95% CI [1.19-1.54] comparing female with male), and these associations were not modified by age. There was no overall sex difference in hazard of death (HR 95% CI 0.99 [0.95-1.04] for death within 90 days; 0.99 [0.96-1.03] for death within 365 days), but these associations were modified by age with the hazard of death being higher in female than male patients between the ages of 50-70 years (most extreme difference around age 57, HR 95% CI 1.25 [1.10-1.40] at 90 days, p-interaction 0.002; 1.15 [1.10-1.20] at 365 days, p-interaction 0.002).

DISCUSSION

The hazard of death after stroke was higher in female than male patients aged 50-70 years. Examining overall sex differences in outcomes without accounting for the effect modification by age may miss important findings in specific age groups.

A Causal Classification System for Intracerebral Hemorrhage Subtypes

OBJECTIVE

Determining the underlying causes of intracerebral hemorrhage (ICH) is of major importance, because risk factors, prognosis, and management differ by ICH subtype. We developed a new causal CLASsification system for ICH Subtypes, termed CLAS-ICH, based on recent advances in neuroimaging.

METHODS

CLAS-ICH defines 5 ICH subtypes: arteriolosclerosis, cerebral amyloid angiopathy, mixed small vessel disease (SVD), other rare forms of SVD (genetic SVD and others), and secondary causes (macrovascular causes, tumor, and other rare causes). Every patient is scored in each category according to the level of diagnostic evidence: (1) well-defined ICH subtype; (2) possible underlying disease; and (0) no evidence of the disease. We evaluated CLAS-ICH in a derivation cohort of 113 patients with ICH from Massachusetts General Hospital, Boston, USA, and in a derivation cohort of 203 patients from Inselspital, Bern, Switzerland.

RESULTS

In the derivation cohort, a well-defined ICH subtype could be identified in 74 (65.5%) patients, including 24 (21.2%) with arteriolosclerosis, 23 (20.4%) with cerebral amyloid angiopathy, 18 (15.9%) with mixed SVD, and 9 (8.0%) with a secondary cause. One or more possible causes were identified in 42 (37.2%) patients. Interobserver agreement was excellent for each category (kappa value ranging from 0.86 to 1.00). Despite substantial differences in imaging modalities, we obtained similar results in the validation cohort.

INTERPRETATION

CLAS-ICH is a simple and reliable classification system for ICH subtyping, that captures overlap between causes and the level of diagnostic evidence. CLAS-ICH may guide clinicians to identify ICH causes, and improve ICH classification in multicenter studies. ANN NEUROL 2023;93:16-28.

The global burden of cerebral small vessel disease in low- and middle-income countries: A systematic review and meta-analysis

BACKGROUND

Cerebral small vessel disease (cSVD) is a major cause of stroke and dementia. Previous studies on the prevalence of cSVD are mostly based on single geographically defined cohorts in high-income countries. Studies investigating the prevalence of cSVD in low- and middle-income countries (LMICs) are expanding but have not been systematically assessed.

AIM

This study aims to systematically review the prevalence of cSVD in LMICs.

RESULTS

Articles were searched from the Ovid MEDLINE and EMBASE databases from 1 January 2000 to 31 March 2022, without language restrictions. Title/abstract screening, full-text review, and data extraction were performed by two to seven independent reviewers. The prevalence of cSVD and study sample size were extracted by pre-defined world regions and health status. The Risk of Bias for Non-randomized Studies tool was used. The protocol was registered on PROSPERO (CRD42022311133). A meta-analysis of proportion was performed to assess the prevalence of different magnetic resonance imaging markers of cSVD, and a meta-regression was performed to investigate associations between cSVD prevalence and type of study, age, and male: female ratio. Of 2743 studies identified, 42 studies spanning 12 global regions were included in the systematic review. Most of the identified studies were from China (n = 23). The median prevalence of moderate-to-severe white matter hyperintensities (WMHs) was 20.5%, 40.5%, and 58.4% in the community, stroke, and dementia groups, respectively. The median prevalence of lacunes was 0.8% and 33.5% in the community and stroke groups. The median prevalence of cerebral microbleeds (CMBs) was 10.7% and 22.4% in the community and stroke groups. The median prevalence of moderate-to-severe perivascular spaces was 25.0% in the community. Meta-regression analyses showed that the weighted median age (51.4 ± 0.0 years old; range: 36.3-80.2) was a significant predictor of the prevalence of moderate-to-severe WMH and lacunes, while the type of study was a significant predictor of the prevalence of CMB. The heterogeneity of studies was high (>95%). Male participants were overrepresented.

CONCLUSIONS

This systematic review and meta-analysis provide data on cSVD prevalence in LMICs and demonstrated the high prevalence of the condition. cSVD research in LMICs is being published at an increasing rate, especially between 2010 and 2022. More data are particularly needed from Sub-Saharan Africa and Central Europe, Eastern Europe, and Central Asia.

Mediators of cognitive impairment in cerebral amyloid angiopathy

BACKGROUND

Cerebral amyloid angiopathy (CAA) is associated with cognitive decline. CAA has diverse impacts on brain structure and function; however, the brain lesions that mediate the association of CAA with cognition are not understood well.

AIMS

To determine the degree to which CAA neuroimaging biomarkers mediate the association of CAA with cognitive dysfunction.

METHODS

We analyzed cross-sectional data of patients with probable CAA and controls without cognitive impairment from the Functional Assessment of Vascular Reactivity study. Neuropsychological tests were grouped into domains of memory, executive function, and processing speed. Candidate CAA neuroimaging biomarkers were pre-specified based on prior literature, consisting of white matter hyperintensity volume, peak width of skeletonized mean diffusivity (PSMD) on diffusion tensor magnetic resonance imaging (MRI), cerebrovascular reactivity (CVR), cortical thickness, and cortical thickness in a meta-region of interest typically affected by Alzheimer's disease (AD). Cognitive scores and neuroimaging markers were standardized and reported in relation to values in controls. Mediation analysis was used to estimate the total effect of CAA on cognition and the proportion of the total effect that was mediated by neuroimaging biomarkers, controlling for age, sex, and education.

RESULTS

There were 131 participants (67 CAA and 64 controls). Mean age was 72.1 ± 7.7 years, and 54.2% were women. As expected, compared to controls, CAA was associated with lower cognition. In mediation analyses, CAA had direct unmediated effects of 48%, 46%, and 52% on all three cognitive domains. The association of CAA with memory was partially mediated by CVR and PSMD, accounting for 18% and 36% of the total effect of CAA. The association of CAA with executive function was partially mediated by PSMD and mean cortical thickness in the AD meta-region of interest (ROI), accounting for 33% and 31% of the total effect of CAA. The association of CAA with processing speed was partially mediated by CVR and PSMD, accounting for 8% and 34% of the total effect of CAA. Among CAA participants, the presence of cortical superficial siderosis was associated with lower processing speed.

CONCLUSION

Altered white matter diffusivity (i.e. PSMD), CVR, and atrophy, taken together, account for about half the effect of CAA on cognition.

Brain iron content in cerebral amyloid angiopathy using quantitative susceptibility mapping

Introduction

Cerebral amyloid angiopathy (CAA) is a small vessel disease that causes covert and symptomatic brain hemorrhaging. We hypothesized that persons with CAA would have increased brain iron content detectable by quantitative susceptibility mapping (QSM) on magnetic resonance imaging (MRI), and that higher iron content would be associated with worse cognition.

Methods

Participants with CAA (n = 21), mild Alzheimer's disease with dementia (AD-dementia; n = 14), and normal controls (NC; n = 83) underwent 3T MRI. Post-processing QSM techniques were applied to obtain susceptibility values for regions of the frontal and occipital lobe, thalamus, caudate, putamen, pallidum, and hippocampus. Linear regression was used to examine differences between groups, and associations with global cognition, controlling for multiple comparisons using the false discovery rate method.

Results

No differences were found between regions of interest in CAA compared to NC. In AD, the calcarine sulcus had greater iron than NC (β = 0.99 [95% CI: 0.44, 1.53], q < 0.01). However, calcarine sulcus iron content was not associated with global cognition, measured by the Montreal Cognitive Assessment (p > 0.05 for all participants, NC, CAA, and AD).

Discussion

After correcting for multiple comparisons, brain iron content, measured via QSM, was not elevated in CAA compared to NC in this exploratory study.

Arterial spin labelling reveals multi-regional cerebral hypoperfusion in patients with transient ischemic attack that are unrelated to ischemia location: A proof-of-concept study

Background and Aims

Patients with transient ischemic attack (TIA) have a substantially increased risk of early dementia. In this exploratory study, we aim to determine whether patients with TIA have 1) measurable regional cerebral hypoperfusion unrelated to the location of ischemia, and 2) determine the relationship of regional cerebral blood flow (rCBF) with their cognitive profiles.

Methods

Patients with TIA (N = 49) and seventy-nine (N = 79) age and sex matched controls underwent formal neuropsychological testing and MRI. Quantitative arterial spin labelling rCBF maps (mL/min/100 g) were registered to the corresponding high resolution T1-weighted image. Linear regression was used to determine the association between demographic, clinical and cognitive variables and rCBF.

Results

Patients with TIA had significantly (p < 0.05) lower cognitive scores in the MMSE, MOCA, ACE-R, WAIS-IV DS Coding and Trail Making Tests A and B compared to controls. TIA patients had significantly lower rCBF in the left entorhinal cortex (p = 0.03), right posterior cingulate (p = 0.04), and right precuneus (p = 0.05), after adjusting for age and sex, that were unrelated to the regional anatomical volume and DWI positivity. Regional hypoperfusion in the right posterior cingulate and right precuneus was associated with impaired visual memory (BVMT total, p = 0.05 for both regions) and slower processing speed (TMT A, p = 0.04 and p = 0.01), respectively after adjusting for age and sex.

Conclusions

TIA patients have patterns of regional hypoperfusion in multiple cortical regions unrelated to the parcellated regional anatomical volume or the presence of a DWI lesion. Regional hypoperfusion in patients with TIA may be an early marker conferring risk of future cognitive decline that needs to be confirmed by future studies.

Acute Infarcts on Brain MRI Following Aortic Arch Repair With Circulatory Arrest: Insights From the ACE CardioLink-3 Randomized Trial

BACKGROUND

to investigate the frequency and distribution of new ischemic brain lesions detected by diffusion-weighted imaging on brain magnetic resonance imaging after aortic arch surgery.

METHODS

This preplanned secondary analysis of the randomized, controlled ACE (Aortic Surgery Cerebral Protection Evaluation) CardioLink-3 trial compared the safety and efficacy of innominate versus axillary artery cannulation during elective proximal aortic arch surgery. Participants underwent pre and postoperative magnetic resonance imaging. New ischemic lesions were defined as lesions visible on postoperative, but not preoperative diffusion weighted imaging.

RESULTS

Of the 111 trial participants, 102 had complete magnetic resonance imaging data. A total of 391 new ischemic lesions were observed on diffusion-weighted imaging in 71 (70%) patients. The average number of lesions in patients with ischemic lesion were 5.5±4.9 with comparable numbers in the right (2.9±2.0) and left (3.0±2.3) hemispheres (P=0.49). Half the new lesions were in the middle cerebral artery territory; 63% of the cohort had ischemic lesions in the anterior circulation, 49% in the posterior circulation, 42% in both, and 20% in watershed areas. A probability mask of all diffusion-weighted imaging lesions revealed that the cerebellum was commonly involved. More severe white matter hyperintensity on preoperative magnetic resonance imaging (odds ratio, 1.80 [95% CI, 1.10-2.95]; P=0.02) and lower nadir nasopharyngeal temperature during surgery (odds ratio per 1°C decrease, 1.15 [95% CI, 1.00-1.32]; P=0.05) were associated with the presentation of new ischemic lesion; older age (risk ratio per 1-year increase, 1.02 [95% CI, 1.00-1.04]; P=0.03) and lower nadir temperature (risk ratio per 1°C decrease, 1.06 [95% CI, 1.00-1.14]; P=0.06) were associated with greater number of lesions.

CONCLUSIONS

In patients who underwent elective proximal aortic arch surgery, new ischemic brain lesions were common, and predominantly involved the middle cerebral artery territory or cerebellum. Underlying small vessel disease, lower temperature nadir during surgery, and advanced age were risk factors for perioperative ischemic lesions.

REGISTRATION

URL: https://www.

CLINICALTRIALS

gov; Unique identifier: NCT02554032.

Vitamin D supplementation and incident dementia: Effects of sex, APOE, and baseline cognitive status

Introduction

Despite the association of vitamin D deficiency with incident dementia, the role of supplementation is unclear. We prospectively explored associations between vitamin D supplementation and incident dementia in 12,388 dementia-free persons from the National Alzheimer's Coordinating Center.

Methods

Baseline exposure to vitamin D was considered D+; no exposure prior to dementia onset was considered D-. Kaplan-Meier curves compared dementia-free survival between groups. Cox models assessed dementia incidence rates across groups, adjusted for age, sex, education, race, cognitive diagnosis, depression, and apolipoprotein E (APOE) ε4. Sensitivity analyses examined incidence rates for each vitamin D formulation. Potential interactions between exposure and model covariates were explored.

Results

Across all formulations, vitamin D exposure was associated with significantly longer dementia-free survival and lower dementia incidence rate than no exposure (hazard ratio = 0.60, 95% confidence interval: 0.55-0.65). The effect of vitamin D on incidence rate differed significantly across the strata of sex, cognitive status, and APOE ε4 status.

Discussion

Vitamin D may be a potential agent for dementia prevention.

Highlights

In a prospective cohort study, we assessed effects of Vitamin D on dementia incidence in 12,388 participants from the National Alzheimer's Coordinating Center dataset.Vitamin D exposure was associated with 40% lower dementia incidence versus no exposure.Vitamin D effects were significantly greater in females versus males and in normal cognition versus mild cognitive impairment.Vitamin D effects were significantly greater in apolipoprotein E ε4 non-carriers versus carriers.Vitamin D has potential for dementia prevention, especially in the high-risk strata.

Subcortical volumes in cerebral amyloid angiopathy compared with Alzheimer's disease and controls

Background

Previous reports have suggested that patients with cerebral amyloid angiopathy (CAA) may harbor smaller white matter, basal ganglia, and cerebellar volumes compared to age-matched healthy controls (HC) or patients with Alzheimer's disease (AD). We investigated whether CAA is associated with subcortical atrophy.

Methods

The study was based on the multi-site Functional Assessment of Vascular Reactivity cohort and included 78 probable CAA (diagnosed according to the Boston criteria v2.0), 33 AD, and 70 HC. Cerebral and cerebellar volumes were extracted from brain 3D T1-weighted MRI using FreeSurfer (v6.0). Subcortical volumes, including total white matter, thalamus, basal ganglia, and cerebellum were reported as proportion (%) of estimated total intracranial volume. White matter integrity was quantified by the peak width of skeletonized mean diffusivity.

Results

Participants in the CAA group were older (74.0 ± 7.0, female 44%) than the AD (69.7 ± 7.5, female 42%) and HC (68.8 ± 7.8, female 69%) groups. CAA participants had the highest white matter hyperintensity volume and worse white matter integrity of the three groups. After adjusting for age, sex, and study site, CAA participants had smaller putamen volumes (mean differences, -0.024% of intracranial volume; 95% confidence intervals, -0.041% to -0.006%; p = 0.005) than the HCs but not AD participants (-0.003%; -0.024 to 0.018%; p = 0.94). Other subcortical volumes including subcortical white matter, thalamus, caudate, globus pallidus, cerebellar cortex or cerebellar white matter were comparable between all three groups.

Conclusion

In contrast to prior studies, we did not find substantial atrophy of subcortical volumes in CAA compared to AD or HCs, except for the putamen. Differences between studies may reflect heterogeneity in CAA presenting syndromes or severity.