Progression of cognitive impairment in stroke patients

Cognitive reserve and individual differences in brain tumour patients

The aim of the paper is to determine the effects of the cognitive reserve on brain tumour patients' cognitive functions and, specifically, if cognitive reserve helps patients cope with the negative effects of brain tumours on their cognitive functions. We retrospectively studied a large sample of around 700 patients, diagnosed with a brain tumour. Each received an MRI brain examination and performed a battery of tests measuring their cognitive abilities before they underwent neurosurgery. To account for the complexity of cognitive reserve, we construct our cognitive reserve proxy by combining three predictors of patients' cognitive performance, namely, patients' education, occupation, and the environment where they live. Our statistical analysis controls for the type, side, site, and size of the lesion, for fluid intelligence quotient, and for age and gender, in order to tease out the effect of cognitive reserve on each of these tests. Clinical neurological variables have the expected effects on cognitive functions. We find a robust positive effect of cognitive reserve on patients' cognitive performance. Moreover, we find that cognitive reserve modulates the effects of the volume of the lesion: the additional negative impact of an increase in the tumour size on patients' performance is less severe for patients with higher cognitive reserve. We also find substantial differences in these effects depending on the cerebral hemisphere where the lesion occurred and on the cognitive function considered. For several of these functions, the positive effect of cognitive reserve is stronger for patients with lesions in the left hemisphere than for patients whose lesions are in the right hemisphere. The development of prevention strategies and personalized rehabilitation interventions will benefit from our contribution to understanding the role of cognitive reserve, in addition to that of neurological variables, as one of the factors determining the patients' individual differences in cognitive performance caused by brain tumours.

Working Memory Impairment in Transient Ischaemic Attack: N-back as a Sensitive Measure for Detection

BACKGROUND

Transient ischaemic attack (TIA) can lead to lasting changes in brain structure and function resulting in cognitive impairment. Cognitive screening tools may lack sensitivity for detecting cognitive impairments, particularly executive function, which tends to be the earliest affected domain in vascular cognitive impairment.

AIM

In this preliminary study, we examine a working memory (WMem) task as a sensitive measure of cognitive impairment in TIA.

METHOD

Patients referred to a TIA clinic for transient neurological symptoms completed a general cognitive screening tool (Montreal Cognitive Assessment; MoCA), and a WMem task (2-N-back) in a cross-sectional design.

RESULTS

TIA patients (n = 12) showed significantly reduced WMem performance on the N-back compared to patients diagnosed with mimic clinical conditions with overlapping symptoms (n = 16). No group differences were observed on the MoCA.

CONCLUSIONS

Assessing WMem may provide a sensitive measure of cognitive impairment after TIA, with implications for cognitive screening in TIA services to triage patients for further neuropsychological support, or for interventions to prevent vascular dementia.

Effect of an exercise intervention on global cognition after transient ischemic attack or minor stroke: the MoveIT randomized controlled trial

Background

Patients with a transient ischemic attack (TIA) or ischemic stroke are at increased risk of developing cognitive impairment in the subacute phase. At present, the effects of exercise on cognitive functioning following a TIA or stroke are not fully known. The purpose of this trial was to investigate the effect of exercise on global cognition.

Methods

The MoveIT trial is a single-centre, observer-blinded, randomized controlled trial involving a 1-year exercise intervention consisting of a 12-week group exercise program, combined with three counselling visits to the physiotherapists over a 9-month period. The control group received standard care. The primary outcome was global cognitive functioning, assessed at one year, using the Montreal Cognitive Assessment (MoCA). Secondary outcomes included cardiorespiratory fitness, the cardiovascular profile, and attainment of secondary prevention targets, anxiety, depression and fatigue at one and two years.

Results

The experimental group consisted of 60 patients, while the control group consisted of 59 patients. The mean age was 64.3 years and 41% were female. No between-group differences were found on global cognitive functioning (MD, 0.7 out of 30, 95% CI, − 0.2 to 1.6) or on secondary outcome measures at 12 months. The only significant between-group difference was found for fatigue, in favour of the experimental group at 12 months (MD, 0.6 out of 63, 95% CI, 0.1 to 1.1).

Conclusions

No benefit of this exercise intervention was found regarding global cognition. Future studies need to focus on optimizing rehabilitation strategies for this vulnerable group of patients.

Trial registration

http://www.trialregister.nl. Unique identifier: NL3721.

Date first registration: 06-03-2013.

Prevalence and Predictors of Vascular Cognitive Impairment in Patients With CADASIL

BACKGROUND AND OBJECTIVES

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is the most common monogenic form of stroke and early-onset dementia. We determined the prevalence of vascular cognitive impairment (VCI) in a group of patients with CADASIL and investigated which factors were associated with VCI risk, including clinical, genetic, and MRI parameters.

METHODS

Cognition was assessed in patients with genetically confirmed CADASIL (n = 176) and healthy controls (n = 265) (mean [SD] age 50.95 [11.35] vs 52.37 [7.93] years) using the Brief Memory and Executive Test (BMET) and the Montreal Cognitive Assessment (MoCA). VCI was defined according to previously validated cutoffs. We determined the prevalence of VCI and its associations with clinical risk factors, mutation location (epidermal growth factor-like repeats [EGFr] 1-6 vs EGFr 7-34), and MRI markers of small vessel disease.

RESULTS

VCI was more common in patients with CADASIL than in controls; 39.8 vs 10.2% on the BMET and 47.7% vs 19.6% on the MOCA. Patients with CADASIL had worse performance across all cognitive domains. A history of stroke was associated with VCI on the BMET (OR 2.12, 95% CI [1.05, 4.27] p = 0.04) and MoCA (OR 2.55 [1.21, 5.41] p = 0.01), after controlling for age and sex. There was no association of VCI with mutation site. Lacune count was the only MRI parameter independently associated with VCI on the BMET (OR: 1.63, 95% CI [1.10, 2.41], p = 0.014), after controlling for other MRI parameters. These associations persisted after controlling for education in the sensitivity analyses.

DISCUSSION

VCI is present in almost half of the patients with CADASIL with a mean age of 50 years. Stroke and lacune count on MRI were both independent predictors of VCI on the BMET.

Memory Trajectories Before and After First and Recurrent Strokes

BACKGROUND AND OBJECTIVES

Evidence on timing of memory change after first and recurrent strokes is limited and inconsistent. We investigated memory trajectories before and after first and recurrent strokes in 18 European countries and tested whether the country-level acute stroke care was associated with memory change after stroke.

METHODS

Data were from the Survey of Health, Ageing and Retirement in Europe (2004-2019). Incident first and recurrent strokes were identified among baseline stroke-free individuals. Within each country, each participant with incident stroke (case group) was matched with a stroke-free individual (control group) using propensity score matching. We applied multilevel segmented linear regression to quantify acute and accelerated memory changes (measured by the sum score of immediate and delayed word recall tests; 0-20 words) before and after first and recurrent strokes in both groups. Associations between stroke and memory were compared between countries with different levels of acute stroke care indicators.

RESULTS

The final analytical sample included 35,164 participants who were stroke-free at baseline (≥50 years). A total of 2,362 incident first and 341 recurrent strokes between 2004 and 2019 were identified. In case groups, mean acute decreases in memory scores were 0.48 (95% confidence interval [CI] 0.31, 0.65) and 1.14 (95% CI 0.80, 1.48) words after first and recurrent stroke, respectively, independent of a range of confounders. No such acute decreases were observed in the control group after a hypothetical nonstroke onset date. In both groups, memory declined over time but decline rates were similar (-0.07 [95% CI -0.10, -0.05] vs -0.06 [95% CI -0.08, -0.05] words per year). The mean acute decreases in memory scores after first and recurrent strokes were smaller in countries with better access to endovascular treatment.

DISCUSSION

We found acute decreases but not accelerated declines in memory after first and recurrent strokes. Improved endovascular therapy might be associated with smaller memory loss after stroke but more evidence based on individual-level data is needed. More effort should be made in early assessment and intensive prevention of stroke among the ageing population and promoting access to and delivery of acute stroke care among patients with stroke.

Effect of Cognition by Repetitive Transcranial Magnetic Stimulation on Ipsilesional Dorsolateral Prefrontal Cortex in Subacute Stroke Patients

Objective

To demonstrate the efficacy of high-frequency repetitive transcranial magnetic stimulation (rTMS) over the ipsilesional dorsolateral prefrontal cortex (DLPFC) on neurological recovery in patients with subacute phase stroke.

Methods

Patients with supratentorial hemispheric stroke who were hospitalized for intensive rehabilitation in the subacute phase were enrolled for this retrospective analysis. Two groups of patients were selected: the rTMS group who received high-frequency (20 Hz) rTMS ≥ 5 times over the ipsilesional DLPFC, and a control group who did not receive any rTMS. The patients were further divided into groups with right- or left-side brain lesions. Functional measurements for cognitive ability, mood, speech, and activities of daily living, which were assessed at baseline and at the 1-month follow-up as a routine clinical practice, were used for analyses.

Results

Among 270 patients with available clinical data, 133 (women, 51; age, 61.0 ± 13.8 years) met the inclusion criteria and were enrolled for analysis. There were no differences in demographic data and functional scores at baseline between the rTMS (n = 49) and control (n = 84) groups. The rTMS group showed a higher gain in the mini-mental status examination (MMSE) total score and subscores of all domains, forward digit span, and FIM-cognition than the control group (P < 0.05). Among the patients with left hemispheric lesions (n = 57), the rTMS group showed better outcomes in cognition and depression through scores of total and “attention and concentration” subscores of MMSE, FIM-cognition, and the geriatric depression scale (P < 0.05). Among the patients with right hemispheric lesions (n = 76), the rTMS group showed better outcomes in cognition through the MMSE total score and subscores of “attention and concentration,” “registration,” and “recall,” and scores of both forward and backward digit spans (P < 0.05).

Conclusion

High-frequency rTMS over the ipsilesional DLPFC has beneficial effects on the recovery of cognition on both sides as well as mood in patients with left-sided hemispheric lesions.

The influence of cognitive reserve in the protection of the cognitive status after an acquired brain injury: A systematic review

BACKGROUND

Cognitive Reserve (CR) hypothesis was introduced to account for the variability in cognitive performance of patients with similar degrees of brain injury or pathology. The individual variability of CR is modulated by the interaction of innate capacities and exposures throughout life, which can act as protectors against neuropathology's clinical effects. Individuals with higher CR appear to have better cognitive performance after a brain injury. The present review aimed to identify and map the scientific evidence available in literature regarding CR's influence in protecting the cognitive status after an Acquired Brain Injury (ABI).

METHOD

A systematic review was performed for published studies until October 2020 in PubMed, Scopus, and CINAHL electronic databases. Studies regarding CR's influence in protecting the cognitive status after an ABI were included in this review. The Newcastle-Ottawa Scale was used to assess risk of bias in the included studies. This systematic review was recorded in the International Prospective Register of Systematic Reviews (PROSPERO) under the number CRD42021236594.

RESULTS

Twenty-one studies published between 2003 and 2020 were selected and analyzed. The literature analysis showed that CR has a positive effect on cognitive status after an ABI. Various proxies were used to estimate CR, including estimated premorbid IQ, education, occupation attainment, socioeconomic status, leisure activities, bilingualism, and social integration. CR proxies constitute a set of variables that may have a significant influence on cognitive status. Higher CR levels were associated with lower cognitive impairment after an ABI.

CONCLUSIONS

Although more research is necessary for a complete understanding of CR's impact on cognition, the synthesis of these studies confirmed that there is evidence on the beneficial impact of CR on cognitive status after an ABI. These findings support CR's cognitive status role following an ABI and may provide additional information for prognosis and rehabilitation plans.

Comparing Vascular Brain Injury and Stroke by Cranial Magnetic Resonance Imaging, Physician-Adjudication, and Self-Report: Data from the Strong Heart Study

BACKGROUND

Epidemiologic studies often use self-report as proxy for clinical history. However, whether self-report correctly identifies prevalence in minority populations with health disparities and poor health-care access is unknown. Furthermore, overlap of clinical vascular events with covert vascular brain injury (VBI), detected by imaging, is largely unexamined.

METHODS

The Strong Heart Study recruited American Indians from 3 regions, with surveillance and adjudication of stroke events from 1989 to 2013. In 2010-2013, all 817 survivors, aged 65-95 years, underwent brain imaging, neurological history interview, and cognitive testing. VBI was defined as imaged infarct or hemorrhage.

RESULTS

Adjudicated stroke was prevalent in 4% of participants and separately collected, self-reported stroke in 8%. Imaging-defined VBI was detected in 51% and not associated with any stroke event in 47%. Compared with adjudication, self-report had 76% sensitivity and 95% specificity. Participants with adjudicated or self-reported stroke had the poorest performance on cognitive testing; those with imaging-only (covert) VBI had intermediate performance.

CONCLUSION

In this community-based cohort, self-report for prior stroke had good performance metrics. A majority of participants with VBI did not have overt, clinically recognized events but did have neurological or cognitive symptoms. Data collection methodology for studies in a resource-limited setting must balance practical limitations in costs, accuracy, feasibility, and research goals.

Altered Functional Connectivity and Cognition Persists 4 Years After a Transient Ischemic Attack or Minor Stroke

Background and Purpose: Altered executive functions and resting-state functional connectivity (rsFC) are common following a minor stroke or transient ischemic attack (TIA). However, the long-term persistence of these abnormalities is not well-studied. We investigated whether there were cognitive and rsFC differences between (a) controls and minor cerebrovascular event (CVE) patients and (b) between CVE patients with and without an imaging confirmed infarct (i.e., minor stroke and TIA, respectively) at an average of 3.8 years following their event.

Methods: Structural and resting-state imaging and cognitive assessments including the Montreal Cognitive Assessment, the Trail Making Task and the National Institute of Health (NIH) Cognition Toolbox were conducted on 42 patients (minor stroke = 17, TIA = 25) and 20 healthy controls (total N = 62).

Results: Controls performed better than patients on two measures of executive functioning (both p < 0.046) and had reduced rsFC between the frontoparietal and default mode networks (FPN and DMN, respectively; p = 0.035). No cognitive differences were found between minor stroke and TIA patients, however, rsFC differences were found within the FPN and the DMN (both p < 0.013). Specifically, increased connectivity within the FPN was associated with faster performance in the minor stroke group but not the TIA group (p = 0.047).

Conclusions: These findings suggest that transient or relatively minor cerebrovascular events are associated with persistent disruption of functional connectivity of neural networks and cognitive performance. These findings suggest a need for novel interventions beyond secondary prevention to reduce the risk of persistent cognitive deficits.

Age-Related Diseases and Driving Safety

Due to demographic changes, the number of older drivers is steadily increasing. Mobility is highly relevant for leading an independent life in the elderly. It largely depends on car driving, which is a complex task requiring a multitude of cognitive and motor skills vulnerable to age- related functional deterioration. The almost inevitable effects of senescence may be potentiated by age-related diseases, such as stroke or diabetes mellitus. Respective pharmacological treatment may cause side effects, additionally affecting driving safety. The present article reviews the impact of age-related diseases and drug treatment of these conditions on driving fitness in elderly drivers. In essence, we focus on diseases of the visual and auditory systems, diseases of the central nervous system (i.e., stroke, depression, dementia and mild cognitive disorder, and Parkinson's disease), sleep disorders, as well as cardiovascular diseases, diabetes mellitus, musculoskeletal disorders, and frailty. We will outline the role of functional tests and the assessment of driving behavior (by a driving simulator or in real traffic), as well as the clinical interview including questions about frequency of (near) accidents, etc. in the evaluation of driving fitness of the elderly. We also address the impact of polypharmacy on driving fitness and end up with recommendations for physicians caring for older patients.

Cognitive Reserve Proxies Do Not Differentially Account for Cognitive Performance in Patients with Focal Frontal and Non-Frontal Lesions

OBJECTIVE

Cognitive reserve (CR) suggests that premorbid efficacy, aptitude, and flexibility of cognitive processing can aid the brain's ability to cope with change or damage. Our previous work has shown that age and literacy attainment predict the cognitive performance of frontal patients on frontal-executive tests. However, it remains unknown whether CR also predicts the cognitive performance of non-frontal patients.

METHOD

We investigated the independent effect of a CR proxy, National Adult Reading Test (NART) IQ, as well as age and lesion group (frontal vs. non-frontal) on measures of executive function, intelligence, processing speed, and naming in 166 patients with focal, unilateral frontal lesions; 91 patients with focal, unilateral non-frontal lesions; and 136 healthy controls.

RESULTS

Fitting multiple linear regression models for each cognitive measure revealed that NART IQ predicted executive, intelligence, and naming performance. Age also significantly predicted performance on the executive and processing speed tests. Finally, belonging to the frontal group predicted executive and naming performance, while membership of the non-frontal group predicted intelligence.

CONCLUSIONS

These findings suggest that age, lesion group, and literacy attainment play independent roles in predicting cognitive performance following stroke or brain tumour. However, the relationship between CR and focal brain damage does not differ in the context of frontal and non-frontal lesions.

Executive Dysfunction Related to Binge Drinking in Ischemic Stroke

BACKGROUND

Recent evidence has shown that cognitive dysfunction is associated with a history of binge drinking in adolescents who do not have an alcohol use disorder. Most previous studies with adults, however, have failed to show a link between cognitive dysfunction and subdiagnostic binge drinking, nor have any studies investigated the additive cognitive effect of binge drinking to ischemic stroke.

OBJECTIVE

To examine whether a pattern of cognitive dysfunction, especially executive and memory dysfunction, in patients with a first-ever ischemic stroke is associated with a history of subdiagnostic binge drinking.

METHODS

We studied 206 first-ever ischemic stroke patients (18-65 years) and 50 healthy, demographically comparable adults-both groups with no alcohol use disorder. After exclusion by matching, 189 patients and 39 healthy participants were included in our study (228 participants). The binge-drinking group included 76 participants; the non-binge-drinking group included 152. A multivariate analysis of covariance was used to compare nine cognitive functions between the two groups, with age, education, and stroke severity used as covariates.

RESULTS

Binge drinking had a significant negative effect on executive functions (P<0.001). The non-binge-drinking group outperformed the binge-drinking group on the Stroop Test (P=0.001), Trail Making Test (P=0.002), and a phonemic fluency test (P=0.005). The Binge×Stroke Severity interaction (P=0.037) indicated that a history of binge drinking increased the negative effect of stroke on executive functions.

CONCLUSIONS

Subdiagnostic binge drinking may exacerbate the adverse effects of ischemic stroke on executive dysfunction.

Cognitive Reserve as an Emerging Concept in Stroke Recovery

Stroke is a leading cause of death and disability. It is a complex and largely heterogeneous condition. Prognosis for variations in impairment and recovery following stroke continues to be challenging and inaccurate, highlighting the need to examine the influence of other currently unknown variables to better predict and understand interindividual differences in stroke impairment and recovery. The concept of "cognitive reserve," a feature of brain function said to moderate the relationship between brain pathology and clinical outcomes, might provide a partial explanation. This review discusses the potential significance of cognitive reserve in the context of stroke, with reference to reduced burden of disability poststroke, health promotion, intervention and secondary prevention of cognitive impairment, ease and challenges of translation into clinical practice, prognosis and prediction of recovery, and clinical decisions and trial stratification. Discussions from the review aim to encourage stroke clinicians and researchers to better consider the role of premorbid, lifestyle-related variables, such as cognitive reserve, in facilitating successful neurological outcomes and recovery following stroke.

Effect of Cognitive Reserve on Risk of Cognitive Impairment and Recovery After Stroke: The KOSCO Study

Supplemental Digital Content is available in the text.

The theory of cognitive reserve (CR) was introduced to account for individual differences in the clinical manifestation of neuropathology. This study investigated whether CR has a modulating effect on cognitive impairment and recovery after stroke.

Cognitive reserve as a useful variable to address robotic or conventional upper limb rehabilitation treatment after stroke: a multicentre study of the Fondazione Don Carlo Gnocchi

BACKGROUND AND PURPOSE

Rehabilitation plays a central role in stroke recovery. Besides conventional therapy, technological treatments have become available. The effectiveness and appropriateness of technological rehabilitation are not yet well defined; hence, research focused on different variables impacting recovery is needed. Results from the literature identified cognitive reserve (CR) as a variable impacting on the cognitive outcome. In this paper, the aim was to evaluate whether CR influences the motor outcome in patients after stroke treated with conventional or robotic therapy and whether it may influence one treatment rather than another.

METHODS

Seventy-five stroke patients were enrolled in five Italian neurological rehabilitation centres. Patients were assigned either to a robotic group, rehabilitation by means of robotic devices, or to a conventional group, where a traditional approach was used. Patients were evaluated at baseline and after rehabilitation treatment of 6 weeks through the Action Research Arm Test (ARAT), the Motricity Index (MI) and the Barthel Index (BI). CR was assessed at baseline using the Cognitive Reserve Index (CRI) questionnaire.

RESULTS

Considering all patients, a weak correlation was found between the CRI related to leisure time and MI evolution (r = 0.276; P = 0.02). Amongst the patients who performed a robotic rehabilitation, a moderate correlation emerged between the CRI related to working activities and MI evolution (r = 0.422; P = 0.02).

CONCLUSIONS

Our results suggest that CR may influence the motor outcome. For each patient, CR and its subcategories should be considered in the choice between conventional and robotic treatment.

A Positive Relationship between Cognitive Reserve and Cognitive Function after Stroke: Dynamic Proxies Correlate Better than Static Proxies

OBJECTIVES

How brain damage after stroke is related to specific clinical manifestation and recovery is incompletely understood. We studied cognitive reserve (CR) in stroke patients by two types of measurements: (i) objectively verifiable static proxies (i.e., education, occupational attainment), and (ii) subjective, dynamic proxies based on patient testimony in response to a questionnaire. We hypothesized that one or both of these types of CR measurements might correlate positively with patient cognitive performance during the post-acute and chronic phases of recovery.

METHOD

Thirty-four stroke patients underwent neuropsychological assessment at 2, 6 and 24 months after stroke onset. In chronic stage at 24+ months, self-rating assessments of cognitive performance in daily life and social integration were obtained. CR before and after stroke was estimated using static proxies and dynamic proxies were obtained using the Cognitive Reserve Scale (CRS-Pre-stroke, CRS-Post-stroke).

RESULTS

CRS-Pre-stroke and CRS-Post-stroke showed significant mean differences. Dynamic proxies showed positive correlation with self-assessment of attention, metacognition, and functional ability in chronic stage. In contrast, significant correlations between static proxies and cognitive recovery were not found.

CONCLUSIONS

Dynamic proxies of CR were positively correlated with patients' perception of their functional abilities in daily life. To best guide cognitive prognosis and treatment, we propose that dynamic proxies of CR should be included in neuropsychological assessments of patients with brain damage.

A Methodological Perspective on the Longitudinal Cognitive Change after Stroke

BACKGROUND/AIMS

Most studies of poststroke cognitive impairment (PSCI) have analyzed cognitive levels at specific time points rather than their changes over time. Furthermore, they seldom consider correlations between cognitive domains. We aimed to investigate the effects of these methodological considerations on determining significant PSCI predictors in a longitudinal stroke cohort.

METHODS

In patients who underwent neuropsychological tests at least twice after stroke, we adopted a multilevel hierarchical mixed-effects model with domain-specific cognitive changes and a multivariate model for multiple outcomes to reflect their correlations.

RESULTS

We enrolled 375 patients (median follow-up of 34.1 months). Known predictors of PSCI were generally associated with cognitive levels; however, most of the statistical significances disappeared when cognitive changes were set as outcomes, except age for memory, prior stroke and baseline cognition for executive/attention domain, and baseline cognition for visuospatial function. The multivariate analysis which considered multiple outcomes simultaneously further altered these associations.

CONCLUSIONS

This study shows that defining outcomes as changes over time and reflecting correlations between outcomes may affect the identification of predictors of PSCI.

Comprehensive Cardiac Rehabilitation for Secondary Prevention After Transient Ischemic Attack or Mild Stroke: PSYCHOLOGICAL PROFILE AND OUTCOMES

PURPOSE

Having previously reported that comprehensive cardiac rehabilitation (CCR) is effective for secondary prevention post-transient ischemic attack (TIA)/mild nondisabling stroke (MNDS), we present psychometric findings for the same sample that elucidate subacute TIA/MNDS psychological outcomes and test whether CCR would be independently associated with psychological improvements.

METHODS

In this prospective cohort trial patients with ≥1 risk factor, recruited from a stroke prevention clinic within 12 months (mean = 11.5 weeks) post-TIA/MNDS, entered CCR.

RESULTS

Of the 110 recruited patients, 100 (mean age = 65.4 years; 46 females) entered CCR and 80 completed CCR (mean duration = 7.6 months). At CCR entry, 16.5% and 39.2% screened positively for depression and anxiety, decreasing nonsignificantly at exit to 4.2%, and significantly to 16.9% (P = .008), respectively. Age-corrected deficits occurred more frequently than expected (P ≤ .03); at entry, mental health status (13.3%), clock-drawing (31.6%), oral-verbal fluency (16.9%), word-list learning (11.2%), and recall (12.6%); at exit, clock-drawing (30.0%). Entry-to-exit, mean depression, anxiety, mental and physical health status, word-list learning, memory, digit-symbol coding, and oral-verbal fluency scores improved significantly (P ≤ .031). No reliable change indices were significant. Psychological service recipients improved significantly more than nonrecipients in depression (P = .049). Baseline North American Adult Reading Test score predicted exercise attendance (R = 0.275; P = .044); New York Heart Association (NYHA) class and depression score predicted exit physical health status (R = 0.770, P < .001); and depression score predicted exit mental health status (R = 0.523, P < .001).

CONCLUSIONS

Anxiety and executive dysfunction persisted post-TIA/MNDS. Although promising for secondary prevention post-TIA/MNDS, CCR was not independently associated with psychological improvements. CCR psychological treatment may benefit depression. Subacute NYHA class and depression may later affect quality of life.

Texture Analysis of T1-Weighted and Fluid-Attenuated Inversion Recovery Images Detects Abnormalities That Correlate With Cognitive Decline in Small Vessel Disease

Supplemental Digital Content is available in the text.

Background and Purpose—

Magnetic resonance imaging may be useful to assess disease severity in cerebral small vessel disease (SVD), identify those individuals who are most likely to progress to dementia, monitor disease progression, and act as surrogate markers to test new therapies. Texture analysis extracts information on the relationship between signal intensities of neighboring voxels. A potential advantage over techniques, such as diffusion tensor imaging, is that it can be used on clinically obtained magnetic resonance sequences. We determined whether texture parameters (TP) were abnormal in SVD, correlated with cognitive impairment, predicted cognitive decline, or conversion to dementia.

Methods—

In the prospective SCANS study (St George’s Cognition and Neuroimaging in Stroke), we assessed TP in 121 individuals with symptomatic SVD at baseline, 99 of whom attended annual cognitive testing for 5 years. Conversion to dementia was recorded for all subjects during the 5-year period. Texture analysis was performed on fluid-attenuated inversion recovery and T1-weighted images. The TP obtained from the SVD cohort were cross-sectionally compared with 54 age-matched controls scanned on the same magnetic resonance imaging system.

Results—

There were highly significant differences in several TP between SVD cases and controls. Within the SVD population, TP were highly correlated to other magnetic resonance imaging parameters (brain volume, white matter lesion volume, lacune count). TP correlated with executive function and global function at baseline and predicted conversion to dementia, after controlling for age, sex, premorbid intelligence quotient, and magnetic resonance parameters.

Conclusions—

TP, which can be obtained from routine clinical images, are abnormal in SVD, and the degree of abnormality correlates with executive dysfunction and global cognition at baseline and decline during 5 years. TP may be useful to assess disease severity in clinically collected data. This needs testing in data clinically acquired across multiple sites.

Validity and reliability of two alternate versions of the Montreal Cognitive Assessment (Hong Kong version) for screening of Mild Neurocognitive Disorder

Objective

Repeated testing using the Montreal Cognitive Assessment (MoCA) increases risks for practice effects which may bias measurements of cognitive change. The objective of this study is to develop two alternate versions of the MoCA (Hong Kong version; HK-MoCA) and to investigate the validity and reliability of the alternate versions in patients with DSM-5 Mild Neurocognitive Disorder (Mild NCD) and cognitively healthy controls.

Methods

Concurrent validity and inter-scale agreement were examined by Pearson correlation of the total scores between the original and alternate versions and the Bland-Altman Method. Criterion validity of the two alternate versions in differentiating patients with Mild NCD was tested using receiver operating characteristic curve (ROC) analysis. One-month test-retest and inter-rater reliability were examined in 20 participants. Internal consistency of the alternate versions was measured by the Cronbach’s α.

Results

30 controls (age 73.4 [4.5] years, 60% female) and 30 patients (age 75.4 [5.5] years, 73% female) with Mild NCD were recruited. Both alternate versions significantly correlated with the original version (r = 0.79–0.87, p<0.001). Mean differences of 0.17 and -0.40 points were found between the total scores of the alternate with the original versions with a consistent level of agreement observed throughout the range of cognitive abilities. Both alternate versions significantly differentiated patients with Mild NCD from healthy controls (area under ROC 0.922 and 0.724, p<0.001) and showed good one-month test-retest reliability (intra-class correlation [ICC] = 0.92 and 0.82) and inter-rater reliability (ICC = 0.99 and 0.87) and high internal consistency (Cronbach α = 0.79 and 0.75).

Conclusion

The two alternate versions of the HK-MoCA are useful for Mild NCD screening.

Prediction of post-stroke functional mobility from the initial assessment of cognitive function

BACKGROUND

Cognitive impairment is frequently seen in patients with stroke. The possible correlation between cognitive function and functional mobility has been proposed; however, the prognostic importance of early cognitive function in recovery of mobility has not been investigated in patients with stroke.

OBJECTIVE

The objective of this study is to investigate whether the cognitive function in the acute phase can independently predict the recovery of mobility after stroke, and to determine the cut-off value of each cognitive evaluation test for community ambulation at six months.

METHODS

Seventy two patients underwent four domain-specific neuropsychological evaluation tests at about two weeks after stroke; these included the word list memory test (WMT), construction praxis test (CPT), verbal fluency test (VFT) and Boston naming test (BNT). The Functional Ambulation Category (FAC) and ambulatory zone (AZ) at six months after stroke were investigated as outcome variables. The domain-specific cognitive function, along with other possible predictors for functional mobility, was analyzed with regression analysis.

RESULTS

The z-scores of WMT (p = 0.018) and VFT (p = 0.012) were related to the independence in ambulation. The z-scores of VFT (p = 0.006) and CPT (p = 0.009) were predictors for community ambulation, with the cut-off values of -2.215 for VFT, and of -0.845 for CPT.

CONCLUSIONS

Cognitive impairment in the acute phase of stroke can be an independent prognostic factor of functional mobility. Domain-specific neuropsychological evaluation tests should be considered in the acute phase of stroke to predict the recovery of functional mobility.

Correlation Between Montreal Cognitive Assessment and Functional Outcome in Subacute Stroke Patients With Cognitive Dysfunction

Objective

To investigate the correlation between the Montreal Cognitive Assessment (MoCA) and functional outcome among subacute stroke patients with cognitive dysfunction.

Methods

Records of 61 inpatients were reviewed. Patients were divided into two groups based on their initial MoCA score. MoCA score of 11 was set as the differentiating criterion. We compared the improvements in Modified Barthel Index (MBI) from initial assessment to discharge between the two groups.

Results

There were no significant differences between the two groups in relation to age, duration from onset to admission, hospitalization period, or years of education. In a comparison of the results of Mini-Mental Status Examinations (MMSE) administered at admission and again at discharge, there was significantly more improvement in MMSE scores in the group with low MoCA scores than in the group with high MoCA scores. However, the group with high MoCA scores also showed high MBI scores at discharge and exhibited greater MBI improvement.

Conclusion

Higher initial MoCA scores (which reflect preservation of executive function) indicate better functional outcome in the subacute stroke phase.

Domain-Specific Cognitive Recovery after First-Ever Stroke: A 2-Year Follow-Up

OBJECTIVES

The aim of this work was to study the change in different cognitive domains after stroke during a 2-year follow-up.

METHOD

We evaluated both neuropsychologically and neurologically a consecutive cohort of working-age patients with a first-ever stroke at baseline (within the first weeks), 6 months, and 2 years after stroke-onset. A total of 153 patients participated in all examinations and were compared to 50 healthy controls.

RESULTS

Forty-nine percent of the patients were cognitively impaired at baseline, 41% at 6 months, and 39% at 2-year follow-up. We analyzed seven cognitive domains (impairment rates at baseline and 2-year follow-up): psychomotor speed (34%; 23%), executive functions (27%; 17%), visual memory (21%; 4%), visuospatial function (20%; 14%), verbal memory (18%; 12%), basic language processing (baseline 11%; 6 months 5%), and reasoning (2 years 14%). The patients who were cognitively impaired at baseline improved more within 6 months, than either the controls or cognitively intact patients in all cognitive domains (all p<.05). Later on, between 6 months and 2 years, the domain-specific change scores did not differ between patients who were cognitively intact and impaired at 6 months. Also, the cognitive status (intact or impaired) remained the same in 90% of patients between 6-month and 2-year follow-ups. At 2 years, half of the patients, who were categorized cognitively impaired, were rated as well-recovered according to neurological evaluation.

CONCLUSIONS

Most of the cognitive improvement took place within 6 months. Long-lasting cognitive impairment was common even after good neurological recovery. An early neuropsychological examination is essential in evaluating cognitive dysfunction and need for rehabilitation. (JINS, 2018, 24, 117-127).

Effect of Formal Education on Vascular Cognitive Impairment after Stroke: A Meta-analysis and Study in Young-Stroke Patients

OBJECTIVES

The extent of vascular cognitive impairment (VCI) after stroke varies greatly across individuals, even when the same amount of brain damage is present. Education level is a potentially protective factor explaining these differences, but results on its effects on VCI are inconclusive.

METHODS

First, we performed a meta-analysis on formal education and VCI, identifying 21 studies (N=7770). Second, we examined the effect of formal education on VCI in young-stroke patients who were cognitively assessed on average 11.0 (SD=8.2) years post-stroke (the FUTURE study cohort). The total sample consisted of 277 young-stroke patients with a mean age at follow-up 50.9 (SD=10.3). Age and education-adjusted expected scores were computed using 146 matched stroke-free controls.

RESULTS

The meta-analysis showed an overall effect size (z') of 0.25 (95% confidence interval [0.18-0.31]), indicating that formal education level had a small to medium effect on VCI. Analyses of the FUTURE data showed that the effect of education on post-stroke executive dysfunction was mediated by age (β age -0.015; p<.05). Below-average performance in the attention domain was more frequent for low-education patients (χ2(2)=9.8; p<.05).

CONCLUSIONS

While education level was found to be related to post-stroke VCI in previous research, the effects were small. Further analysis in a large stroke cohort showed that these education effects were fully mediated by age, even in relatively young stroke patients. Education level in and of itself does not appear to be a valid indicator of cognitive reserve. Multi-indicator methods may be more valid, but have not been studied in relation to VCI. (JINS, 2017, 23, 223-238).

Cognitive reserve and cognitive performance of patients with focal frontal lesions

The Cognitive reserve (CR) hypothesis was put forward to account for the variability in cognitive performance of patients with similar degrees of brain pathology. Compensatory neural activity within the frontal lobes has often been associated with CR. For the first time we investigated the independent effects of two CR proxies, education and NART IQ, on measures of executive function, fluid intelligence, speed of information processing, verbal short term memory (vSTM), naming, and perception in a sample of 86 patients with focal, unilateral frontal lesions and 142 healthy controls. We fitted multiple linear regression models for each of the cognitive measures and found that only NART IQ predicted executive and naming performance. Neither education nor NART IQ predicted performance on fluid intelligence, processing speed, vSTM or perceptual abilities. Education and NART IQ did not modify the effect of lesion severity on cognitive impairment. We also found that age significantly predicted performance on executive tests and the majority of our other cognitive measures, except vSTM and GNT. Age was the only predictor for fluid intelligence. This latter finding suggests that age plays a role in executive performance over and above the contribution of CR proxies in patients with focal frontal lesions. Overall, our results suggest that the CR proxies do not appear to modify the relationship between cognitive impairment and frontal lesions.

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Effect of cognitive reserve (CR) proxies in focal unilateral lesions.

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NART IQ accounts for a larger proportion of variance in executive and naming skills.

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Age predicts performance on executive, fluid intelligence, speed and perception tests.

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Education and NART IQ did not modify the effect of lesion severity on cognitive impairment.

Performance on Specific Cognitive Domains and Cause of Death: A Prospective Population-Based Study in Non-Demented Older Adults (NEDICES)

Evidence regarding the relationship between performance on specific cognitive domains and cause of death is scarce. We assessed whether specific cognitive domains predicted mortality and the presence of any association with specific causes of death in a population-dwelling sample of non-demented older adults. In this population-based, prospective study (NEDICES), 2,390 non-demented subjects ≥65 years completed a brief neuropsychological battery. Cox's proportional hazards models, adjusted by sociodemographic and comorbidity factors, global cognitive performance, educational level, and premorbid intelligence were used to assess the risk of death. Participants were followed for a median of 9.2 years (range 0.01-10.7), after which the death certificates of those who died were examined. 880 (36.8%) of 2,390 participants died over a median follow-up of 5.5 years (range 0.01-10.5). Using adjusted Cox regression models, we found that hazard ratios for mortality in participants within the lowest tertiles (worse performance) were 1.31 (speed of cognitive processing, p = 0.03); 1.22 (semantic fluency, p = 0.04), 1.32 (delayed free recall, p = 0.003), and 1.23 (delayed logical memory, p = 0.03). Poor performance on delayed recall and speed of cognitive processing tests were associated with dementia and cerebrovascular disease mortality, respectively. Further, poor performance on semantic fluency was associated with decreased cancer mortality. In this study of community dwelling non-demented older adults, worse neuropsychological performance was associated with increased risk of mortality. Performance on specific cognitive domains were related to different causes of death. Of particular note there appears to be an inverse association between poor semantic fluency and cancer mortality.

White matter hyperintensity volume predicts persistent cognitive impairment in transient ischemic attack and minor stroke

Background Temporary and permanent cognitive changes following transient ischemic attack/minor stroke have been described previously. It is unknown if persisting cognitive deficits in these patients are correlated with acute infarction identified using magnetic resonance imaging. Aims We tested the hypothesis that persistent cognitive impairment after transient ischemic attack/minor stroke can be predicted by the volume of diffusion-weighted imaging lesions. Methods Acute transient ischemic attack/minor stroke (NIH stroke scale score ≤ 3) patients were prospectively recruited within 72 h of onset. Patients underwent Montreal cognitive assessment and magnetic resonance imaging, including diffusion-weighted imaging and Fluid-Attenuated Inverse Recovery sequences, at baseline, days 7 and 30. Cognitive testing was repeated at day 90. Diffusion-weighted imaging lesion and Fluid-Attenuated Inverse Recovery chronic white matter hyperintensity volumes were measured planimetrically. Cognitive impairment was defined a priori as Montreal cognitive assessment score < 26. Results One hundred fifteen patients were imaged at a median (inter-quartile range) of 24.0 (16.6) h after onset. Acute ischemic lesions were present in 91 (79%) patients. Cognitive impairment rates were similar in patients with (47/91, 52%) and without diffusion-weighted imaging lesions (13/24, 54%; p = 0.83). Although linear regression indicated no relationship between acute diffusion-weighted imaging lesion volume and day 30 Montreal cognitive assessment scores (β = -0.163, [-2.243, 0.334], p = 0.144), white matter hyperintensity volumes at baseline were predictive of persistent cognitive deficits after 30 days (β = 2.24, [1.956, 45.369], p = 0.005). Conclusions In most transient ischemic attack/minor stroke patients who suffer acute cognitive impairment post event, deficits are temporary. Deficits after 30 days of onset are correlated with chronic white matter hyperintensity, suggesting subclinical cognitive impairment and/or impaired ability to compensate for the effects of acute ischemic infarcts.

The Impact of Acute Phase Domain-Specific Cognitive Function on Post-stroke Functional Recovery

Objective

To assess whether the cognitive function in the acute stage evaluated by domain-specific neuropsychological assessments would be an independent predictor of functional outcome after stroke.

Methods

Forty patients underwent 4 domain-specific neuropsychological examinations about 3 weeks after the onset of stroke. The tests included the Boston Naming Test (BNT), the construction recall test (CRT), the construction praxis test (CPT), and the verbal fluency test (VFT). The Korean version of Modified Barthel Index (K-MBI) at 3 months and the modified Rankin Scale (mRS) at 6 months were investigated as functional outcome after stroke. Functional improvement was assessed using the change in K-MBI during the first 3 months and subjects were dichotomized into 'good status' and 'poor status' according to mRS at 6 months. The domain-specific cognitive function along with other possible predictors for functional outcome was examined using regression analysis.

Results

The z-score of CPT (p=0.044) and CRT (p<0.001) were independent predictors for functional improvement measured by the change in K-MBI during the first 3 months after stroke. The z-score of CPT (p=0.049) and CRT (p=0.048) were also independent predictors of functional status at post-stroke 6 months assessed by mRS.

Conclusion

Impairment in visuospatial construction and memory within one month after stroke can be an independent prognostic factor of functional outcome. Domain-specific neuropsychological assessments could be considered in patients with stroke in the acute phase to predict long-term functional outcome.

Higher Education Is Associated with a Lower Risk of Dementia after a Stroke or TIA. The Rotterdam Study

BACKGROUND

Higher education is associated with a lower risk of dementia, possibly because of a higher tolerance to subclinical neurodegenerative pathology. Whether higher education also protects against dementia after clinical stroke or transient ischemic attack (TIA) remains unknown.

METHODS

Within the population-based Rotterdam Study, 12,561 participants free of stroke, TIA and dementia were followed for occurrence of stroke, TIA and dementia. Across the levels of education, associations of incident stroke or TIA with subsequent development of dementia and differences in cognitive decline following stroke or TIA were investigated.

RESULTS

During 124,862 person-years, 1,463 persons suffered a stroke or TIA, 1,158 persons developed dementia, of whom 186 developed dementia after stroke or TIA. Risk of dementia after a stroke or TIA, compared to no stroke or TIA, was highest in the low education category (hazards ratio [HR] 1.46, 95% CI 1.18-1.81) followed by intermediate education category (HR 1.36, 95% CI 1.03-1.81). No significant association was observed in the high education category (HR 0.62, 95% CI 0.25-1.54). In gender stratified analyses, decrease in risk of dementia with increasing education was significant only in men.

CONCLUSION

Higher education is associated with a lower risk of dementia after stroke or TIA, particularly in men, which might be explained by a higher cognitive reserve.

Role of tDCS in potentiating poststroke computerized cognitive rehabilitation: Lessons learned from a case study

Cognitive impairment after stroke is quite common and can cause important disability with a relevant impact on quality of life. Cognitive rehabilitation (CR) and related assistive technology may improve functional outcomes. A 30-year-old woman came to our research institute for an intensive CR cycle following a right parieto-temporal stroke. Because the patient was in the chronic phase, we decided to use 3 different rehabilitative protocols: (a) traditional cognitive training (TCT), (b) computerized cognitive training (CCT), and (c) CCT combined with transcranial direct stimulation (CCT plus) with a 2-week interval separating each session. Cognitive and language deficits were investigated using an ad-hoc psychometric battery at baseline (T0), post-TCT (T1), post-CCT (T2), and post-CCT plus (T3). Our patient showed the best neuropsychological improvement, with regard to attention processes and language domain, after T3. Our data showed that CCT plus should be considered a promising tool in the treatment of poststroke neuropsychological deficits.

Pattern and Rate of Cognitive Decline in Cerebral Small Vessel Disease: A Prospective Study

Objectives

Cognitive impairment, predominantly affecting processing speed and executive function, is an important consequence of cerebral small vessel disease (SVD). To date, few longitudinal studies of cognition in SVD have been conducted. We determined the pattern and rate of cognitive decline in SVD and used the results to determine sample size calculations for clinical trials of interventions reducing cognitive decline.

Methods

121 patients with MRI confirmed lacunar stroke and leukoaraiosis were enrolled into the prospective St George’s Cognition And Neuroimaging in Stroke (SCANS) study. Patients attended one baseline and three annual cognitive assessments providing 36 month follow-up data. Neuropsychological assessment comprised a battery of tests assessing working memory, long-term (episodic) memory, processing speed and executive function. We calculated annualized change in cognition for the 98 patients who completed at least two time-points.

Results

Task performance was heterogeneous, but significant cognitive decline was found for the executive function index (p<0.007). Working memory and processing speed decreased numerically, but not significantly. The executive function composite score would require the smallest samples sizes for a treatment trial with an aim of halting decline, but this would still require over 2,000 patients per arm to detect a 30% difference with power of 0.8 over a three year follow-up.

Conclusions

The pattern of cognitive decline seen in SVD over three years is consistent with the pattern of impairments at baseline. Rates of decline were slow and sample sizes would need to be large for clinical trials aimed at halting decline beyond initial diagnosis using cognitive scores as an outcome measure. This emphasizes the importance of more sensitive surrogate markers in this disease.

Treatment of Vascular Cognitive Impairment

OPINION STATEMENT

Cerebrovascular disease (CVD) is an important cause of cognitive dysfunction and dementia. The term vascular cognitive impairment (VCI) is used to describe the entire spectrum of cognitive dysfunction-ranging from mild impairment to dementia-attributable to all forms of cerebrovascular disease. Accurate assessment and management of vascular risk factors are a top priority in the treatment of VCI, particularly early in the disease when prevention strategies may prove to be more effective. There are limited treatment options to improve cognition and function in VCI. Several acetylcholinesterase inhibitors and the NMDA receptor antagonist memantine have been studied in large, well-designed trials. These agents are safe and provide modest cognitive benefits in vascular dementia (VaD) but have demonstrated inconsistent efficacy on functional measures. Other therapies, such as aspirin, calcium channel blockers, and vitamin supplementation, have less evidence to support their use in improving cognition in VCI. Although primary prevention trials suggest that treatment of hypertension, adherence to a Mediterranean diet, physical activity, and smoking cessation may reduce the risk of cognitive decline, there is limited evidence regarding these interventions in helping improve cognition in VCI. The pathophysiology and treatment of cerebral autosomal dominant arteriopathy with subcortical infarcts (CADASIL), cerebral amyloid angiopathy (CAA), and subcortical white matter disease (SWMD) deserves special consideration.

A randomised controlled trial of aerobic exercise after transient ischaemic attack or minor stroke to prevent cognitive decline: the MoveIT study protocol

INTRODUCTION

Patients with transient ischaemic attack (TIA) or stroke are at risk for cognitive impairment and dementia. Currently, there is no known effective strategy to prevent this cognitive decline. Increasing evidence exists that physical exercise is beneficial for cognitive function. However, in patients with TIA or stroke who are at risk of cognitive impairment and dementia, only a few trials have been conducted. In this study, we aim to investigate whether a physical exercise programme (MoveIT) can prevent cognitive decline in patients in the acute phase after a TIA or minor ischaemic stroke.

METHODS AND ANALYSIS

A single-blinded randomised controlled trial will be conducted to investigate the effect of an aerobic exercise programme on cognition compared with usual care. 120 adult patients with a TIA or minor ischaemic stroke less than 1 month ago will be randomly allocated to an exercise programme consisting of a 12-week aerobic exercise programme and regular follow-up visits to a specialised physiotherapist during the period of 1 year or to usual care. Outcome measures will be assessed at the baseline, and at the 1-year and 2-year follow-up. The primary outcome is cognitive functioning measured with the Montreal Cognitive Assessment (MoCA) test and with additional neuropsychological tests. Secondary outcomes include maximal exercise capacity, self-reported physical activity and measures of secondary prevention.

ETHICS AND DISSEMINATION

The study received ethical approval from the VU University Amsterdam Ethics committee (2011/383). The results of this study will be published in peer-reviewed journals and presented at international conferences. We will also disseminate the main results to our participants in a letter.

TRIAL REGISTRATION NUMBER

The Nederlands Trial Register NTR3884.

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

The close relationship between stroke and dementia is an important health issue. Ischaemic stroke can facilitate the onset of vascular dementia as well as aggravate pre-existing cognitive decline. The onset of cognitive decline may become manifest immediately following the onset of ischaemic stroke, but often there is a delay in the development of cognitive decline after a stroke. This delay can be seen as a therapeutic time window allowing interventions to be applied to preserve cognition following stroke. Both neurodegenerative and vascular mechanisms are activated and probably result in overlapping processes within the neurovascular unit. This review focuses on the incidence and prevalence of cognitive decline following stroke, predisposing stroke aetiologies, pre-stroke decline, imaging factors and biomarkers. Outcomes are discussed in relation to timing of assessment and neuropsychological tests used for evaluation of cognitive decline in ischaemic stroke patients. Including such tests in routine evaluations of stroke patients after some weeks or months is recommended. Finally, an outlook on ongoing and planned intervention trials is added and some recommendations for future research are proposed.

Progression of cognitive impairment in stroke/TIA patients over 3 years

OBJECTIVES

To examine how cognitive deficits progress in the years following a stroke or transient ischaemic attack (TIA).

METHODS

A follow-up study, with neuropsychological and MRI assessments undertaken 3 years after baseline assessments made 3-6 months poststroke in 183 stroke/TIA patients and 97 healthy controls participating in the Sydney Stroke Study. Additional measures included cardiovascular risk factors and apolipoprotein E (APOE) genotype.

RESULTS

Stroke/TIA patients had poorer cognitive function and more vascular risk factors than controls at baseline, but did not show greater decline in cognitive function over 3 years except for verbal memory. Patients with a subsequent stroke/TIA showed greater decline in global cognitive function and a number of domains. Rates of incident dementia were 5.9% per year in patients and 0.4% in controls. Both groups showed increased atrophy of the hippocampus, amygdala and whole brain, and an increase in white matter hyperintensities over 3 years; whole brain atrophy was greater in patients. Cognitive decline was greater in women and in those with smaller hippocampi at baseline. For patients without a subsequent stroke/TIA, those with smaller hippocampi or the APOE ε4 allele had greater global cognitive and verbal memory decline.

CONCLUSIONS

In poststroke patients, cognitive decline was not greater than in comparison subjects, except for verbal memory, unless they had another stroke/TIA. However, dementia incidence was higher in patients, as might be expected from their poorer baseline cognitive functioning. Smaller hippocampi were associated with an increased risk of decline in memory, and APOE ε4 was a risk factor in those without a subsequent stroke/TIA.

Factors Associated with Cognitive Decline in Transient Ischemic Attack Patients

Chronic cerebrovascular disease and large ischemic stroke are both associated with cognitive impairment. Much less is known about the acute cognitive sequelae of transient ischemic attack (TIA). Although often overlooked, there is increasing evidence that cognitive impairment does occur following TIA. In some patients, cognitive changes persist after resolution of focal neurological deficits, but the temporal profile of these symptoms is unknown. In addition, clinical and imaging correlates of cognitive impairment after TIA have not been systematically studied. This under-studied and recognized problem has significant implications for TIA patient management. In this review, we summarize the evidence currently available and identify future research priorities.

Cognitive reserve in stroke and traumatic brain injury patients

Cognitive reserve (CR) is defined as the ability to cope with brain damage due to pre-existing cognitive processes or to the development of new compensatory processes. Existing research on CR is mostly based on the study of neurodegenerative disorders, such as Alzheimer's disease. Recently, however, this construct has also been applied to other neurological conditions, including multiple sclerosis, Parkinson's disease, epilepsy, stroke, and traumatic brain injury. The present review provides an overview of the studies that have investigated the influence of CR on neuropsychological outcome in stroke and traumatic brain injury patients. We performed a selective search on MEDLINE, CINAHL, and Web of Science Core Collection, using specific keywords including "cognitive reserve", "stroke", and "traumatic brain injury". The review is organized as follows: the first section focuses on works investigating the effect of CR on neuropsychological outcomes in post-stroke patients; the second section discusses studies which support the CR theory in traumatic brain injury. This review suggests that the study of CR in adult brain injury is still insufficient. Future research should investigate the role of other variables, like cognitive and social activities, as markers of CR in patients with brain injury, functional brain correlates of CR in brain activity, and the effect of CR on brain injury rehabilitative outcomes.

Cognitive performance after stroke--the Framingham Heart Study

BACKGROUND

Individuals with a high risk of stroke are also more prone to cognitive impairment perhaps because of concomitant vascular risk factors. In addition, clinical stroke increases the risk of subsequent dementia. Nevertheless, the relationship between clinical stroke and subsequent cognitive function in initially nondemented individuals remains less clear as most prior studies examined case series without controls.

AIMS

To specify among nondemented individuals the cognitive domains affected by clinical stroke, independently of vascular risk factors and prestroke cognition.

METHODS

One hundred thirty-two Framingham study participants (mean age = 77 ± 9 years, 54% women) with prospectively validated initial strokes, as well as age- and gender-matched controls, underwent identical cognitive evaluations ∼six-months after the stroke. Linear regression models were used to assess the differences in cognitive scores between stroke cases and controls adjusting for prestroke cognitive function as assessed by Mini-Mental State Examination scores, and with and without adjustment for vascular risk factors.

RESULTS

Adjusting for prestroke cognition and vascular risk factors, persons with stroke had poorer cognitive function in the domains of immediate recall of logical and visual memories (β = -1·27 ± 0·60, P = 0·035; β = -1·03 ± 0·47, P = 0·028, respectively), verbal learning (paired associate test; β = -1·31 ± 0·57, P = 0·023), language (Boston naming test; β = -0·27 ± 0·08, P = 0·002), executive function (digit span backward; β = -0·53 ± 0·21, P = 0·015), and visuospatial and motor skills (block design; β = -3·02 ± 1·06, P = 0·005).

CONCLUSIONS

Clinical stroke is associated with subsequent poorer performance in multiple cognitive domains. This association cannot be entirely explained by the individual's cognitive function prior to stroke or by concomitant vascular risk factor levels.

Regular group exercise is associated with improved mood but not quality of life following stroke

Purpose. People with stroke living in the community have an increased prevalence of depression and lower quality of life than healthy older adults. This cross-sectional observational study investigated whether participation in regular exercise was associated with improved mood and quality of life.

Methods. We recruited three groups of community dwelling participants: 13 healthy older adults, 17 adults post-stroke who regularly participated in group exercise at a community fitness facility and 10 adults post-stroke who did not regularly exercise. We measured mood using the Depression, Anxiety, Stress Scale (DASS) and quality of life using the Assessment of Quality of Life (AQoL) scale.

Results. Levels of stress and depression were significantly greater in the people with stroke who did not undertake regular exercise (p = 0.004 and p = 0.004 respectively), although this group had more recent strokes (p < 0.001). Both stroke groups had lower quality of life scores (p = 0.04) than the healthy adults.

Conclusions. This small, community-based study confirms that people following stroke report poorer quality of life than stroke-free individuals. However, those who exercise regularly have significantly lower stress and depression compared to stroke survivors who do not. Future research should focus on the precise type and amount of exercise capable of improving mood following stroke.

Cognitive assessments for the early diagnosis of dementia after stroke

The early detection of poststroke dementia (PSD) is important for medical practitioners to customize patient treatment programs based on cognitive consequences and disease severity progression. The aim is to diagnose and detect brain degenerative disorders as early as possible to help stroke survivors obtain early treatment benefits before significant mental impairment occurs. Neuropsychological assessments are widely used to assess cognitive decline following a stroke diagnosis. This study reviews the function of the available neuropsychological assessments in the early detection of PSD, particularly vascular dementia (VaD). The review starts from cognitive impairment and dementia prevalence, followed by PSD types and the cognitive spectrum. Finally, the most usable neuropsychological assessments to detect VaD were identified. This study was performed through a PubMed and ScienceDirect database search spanning the last 10 years with the following keywords: "post-stroke"; "dementia"; "neuro-psychological"; and "assessments". This study focuses on assessing VaD patients on the basis of their stroke risk factors and cognitive function within the first 3 months after stroke onset. The search strategy yielded 535 articles. After application of inclusion and exclusion criteria, only five articles were considered. A manual search was performed and yielded 14 articles. Twelve articles were included in the study design and seven articles were associated with early dementia detection. This review may provide a means to identify the role of neuropsychological assessments as early PSD detection tests.

Prevention of Poststroke Cognitive Decline: ASPIS – a Multicenter, Randomized, Observer-Blind, Parallel Group Clinical Trial to Evaluate Multiple Lifestyle Interventions – Study Design and Baseline Characteristics

Background

Cognitive impairment after stroke is a considerable burden to patients and their caregivers and occurs in one-third of stroke survivors. No strategy to prevent cognitive decline after stroke exists thus far. Established vascular risk factors have been associated with cognitive decline and may be a target for therapeutic interventions in stroke survivors.

Aim

To test whether intensive multifactorial non-pharmacologic interventions based on lifestyle modification can reduce the risk of cognitive decline in patients who recently suffered ischemic stroke.

Methods

A randomized, controlled, multicenter, observer-blind trial was designed. The reference group obtains stroke care according to standard guidelines. The intervention group additionally receives intensive control and motivation for better compliance with prescribed evidence-based medication, regular blood pressure measurements, healthy diet, regular physical activity and cognitive training. Primary outcomes are the rate of cognitive decline at 24 months, assessed by a neuropsychological test battery and the cognitive subscale of the Alzheimer's Disease Assessment Scale.

Results

202 patients (29% women), aged 62 ± 9 years, were recruited during 2010 to 2012. Stroke related impairment at inclusion was low (mean National Institutes of Health Stroke Scale: 1.9±1.8, median modified Rankin Scale: 1 (0-1)). At baseline, groups did not differ significantly in demographic, clinical or lifestyle characteristics.

Conclusion

The recruitment was successful and the groups are balanced regarding potential confounding variables. The study will provide essential data about the feasibility and efficacy of lifestyle intervention after stroke in order to develop a new approach to prevent cognitive decline in patients with mild ischemic stroke.

Risk factors for late-life cognitive decline and variation with age and sex in the Sydney Memory and Ageing Study

Introduction

An aging population brings increasing burdens and costs to individuals and society arising from late-life cognitive decline, the causes of which are unclear. We aimed to identify factors predicting late-life cognitive decline.

Methods

Participants were 889 community-dwelling 70–90-year-olds from the Sydney Memory and Ageing Study with comprehensive neuropsychological assessments at baseline and a 2-year follow-up and initially without dementia. Cognitive decline was considered as incident mild cognitive impairment (MCI) or dementia, as well as decreases in attention/processing speed, executive function, memory, and global cognition. Associations with baseline demographic, lifestyle, health and medical factors were determined.

Results

All cognitive measures showed decline and 14% of participants developed incident MCI or dementia. Across all participants, risk factors for decline included older age and poorer smelling ability most prominently, but also more education, history of depression, being male, higher homocysteine, coronary artery disease, arthritis, low health status, and stroke. Protective factors included marriage, kidney disease, and antidepressant use. For some of these factors the association varied with age or differed between men and women. Additional risk and protective factors that were strictly age- and/or sex-dependent were also identified. We found salient population attributable risks (8.7–49.5%) for older age, being male or unmarried, poor smelling ability, coronary artery disease, arthritis, stroke, and high homocysteine.

Discussion

Preventing or treating conditions typically associated with aging might reduce population-wide late-life cognitive decline. Interventions tailored to particular age and sex groups may offer further benefits.

Mechanisms of cognitive impairment in cerebral small vessel disease: multimodal MRI results from the St George's cognition and neuroimaging in stroke (SCANS) study

Cerebral small vessel disease (SVD) is a common cause of vascular cognitive impairment. A number of disease features can be assessed on MRI including lacunar infarcts, T2 lesion volume, brain atrophy, and cerebral microbleeds. In addition, diffusion tensor imaging (DTI) is sensitive to disruption of white matter ultrastructure, and recently it has been suggested that additional information on the pattern of damage may be obtained from axial diffusivity, a proposed marker of axonal damage, and radial diffusivity, an indicator of demyelination. We determined the contribution of these whole brain MRI markers to cognitive impairment in SVD. Consecutive patients with lacunar stroke and confluent leukoaraiosis were recruited into the ongoing SCANS study of cognitive impairment in SVD (n = 115), and underwent neuropsychological assessment and multimodal MRI. SVD subjects displayed poor performance on tests of executive function and processing speed. In the SVD group brain volume was lower, white matter hyperintensity volume higher and all diffusion characteristics differed significantly from control subjects (n = 50). On multi-predictor analysis independent predictors of executive function in SVD were lacunar infarct count and diffusivity of normal appearing white matter on DTI. Independent predictors of processing speed were lacunar infarct count and brain atrophy. Radial diffusivity was a stronger DTI predictor than axial diffusivity, suggesting ischaemic demyelination, seen neuropathologically in SVD, may be an important predictor of cognitive impairment in SVD. Our study provides information on the mechanism of cognitive impairment in SVD.

Long-term post-stroke changes include myelin loss, specific deficits in sensory and motor behaviors and complex cognitive impairment detected using active place avoidance

Persistent neurobehavioral deficits and brain changes need validation for brain restoration. Two hours middle cerebral artery occlusion (tMCAO) or sham surgery was performed in male Sprague-Dawley rats. Neurobehavioral and cognitive deficits were measured over 10 weeks included: (1) sensory, motor, beam balance, reflex/abnormal responses, hindlimb placement, forepaw foot fault and cylinder placement tests, and (2) complex active place avoidance learning (APA) and simple passive avoidance retention (PA). Electroretinogram (ERG), hemispheric loss (infarction), hippocampus CA1 neuronal loss and myelin (Luxol Fast Blue) staining in several fiber tracts were also measured. In comparison to Sham surgery, tMCAO surgery produced significant deficits in all behavioral tests except reflex/abnormal responses. Acute, short lived deficits following tMCAO were observed for forelimb foot fault and forelimb cylinder placement. Persistent, sustained deficits for the whole 10 weeks were exhibited for motor (p<0.001), sensory (p<0.001), beam balance performance (p<0.01) and hindlimb placement behavior (p<0.01). tMCAO produced much greater and prolonged cognitive deficits in APA learning (maximum on last trial of 604±83% change, p<0.05) but only a small, comparative effect on PA retention. Hemispheric loss/atrophy was measured 10 weeks after tMCAO and cross-validated by two methods (e.g., almost identical % ischemic hemispheric loss of 33.4±3.5% for H&E and of 34.2±3.5% for TTC staining). No visual dysfunction by ERG and no hippocampus neuronal loss were detected after tMCAO. Fiber tract damage measured by Luxol Fast Blue myelin staining intensity was significant (p<0.01) in the external capsule and striatum but not in corpus callosum and anterior commissure. In summary, persistent neurobehavioral deficits were validated as important endpoints for stroke restorative research in the future. Fiber myelin loss appears to contribute to these long term behavioral dysfunctions and can be important for cognitive behavioral control necessary for complex APA learning.

Predicting recovery of cognitive function soon after stroke: differential modeling of logarithmic and linear regression

Cognitive disorders in the acute stage of stroke are common and are important independent predictors of adverse outcome in the long term. Despite the impact of cognitive disorders on both patients and their families, it is still difficult to predict the extent or duration of cognitive impairments. The objective of the present study was, therefore, to provide data on predicting the recovery of cognitive function soon after stroke by differential modeling with logarithmic and linear regression. This study included two rounds of data collection comprising 57 stroke patients enrolled in the first round for the purpose of identifying the time course of cognitive recovery in the early-phase group data, and 43 stroke patients in the second round for the purpose of ensuring that the correlation of the early-phase group data applied to the prediction of each individual's degree of cognitive recovery. In the first round, Mini-Mental State Examination (MMSE) scores were assessed 3 times during hospitalization, and the scores were regressed on the logarithm and linear of time. In the second round, calculations of MMSE scores were made for the first two scoring times after admission to tailor the structures of logarithmic and linear regression formulae to fit an individual's degree of functional recovery. The time course of early-phase recovery for cognitive functions resembled both logarithmic and linear functions. However, MMSE scores sampled at two baseline points based on logarithmic regression modeling could estimate prediction of cognitive recovery more accurately than could linear regression modeling (logarithmic modeling, R(2) = 0.676, P<0.0001; linear regression modeling, R(2) = 0.598, P<0.0001). Logarithmic modeling based on MMSE scores could accurately predict the recovery of cognitive function soon after the occurrence of stroke. This logarithmic modeling with mathematical procedures is simple enough to be adopted in daily clinical practice.