Cognitive profile of subcortical ischaemic vascular disease

Assessment of behavioral flexibility after middle cerebral artery occlusion in mice

Middle cerebral artery occlusion (MCAO) is the most common animal model of cerebral ischemia and induces various functional impairments. Long-lasting deficits resulting from MCAO however, remain insufficiently characterized, especially regarding cognition. Yet, behavioral flexibility, a prominent cognitive process is found impaired after stroke in humans. We thus used an operant-based task to assess behavioral flexibility in mice after MCAO. Three weeks after 30 min MCAO surgery, mice were subjected to a battery of sensorimotor tests (rotarod, vertical pole test, spontaneous locomotion and grip-strength test). Behavioral flexibility was then assessed in an operant task, in which mice, rewarded according to a FR5 schedule of reinforcement, had to alternate their operant responses between two levers from trial to trial. Regarding sensory and motor functioning, only the pole test yielded a significant difference between MCAO and sham mice. In the operant flexibility task, results showed a behavioral flexibility deficit in MCAO mice; neither the operant response acquisition nor the appeal for food rewards was altered. In conclusion, our operant-based task revealed a long-lasting behavioral flexibility deficit after MCAO in mice.

Cognitive patterns of normal elderly subjects are consistent with frontal cortico-subcortical and fronto-parietal neuropsychological models of brain aging

Three neuropsychological theories have been developed according to a possible existence of a similar pattern of cognitive decline in elderly individuals and patients with brain damage. The respective neuropsychological theories attribute age-related deficits to: (a) dysfunction of the frontal lobes, (b) temporo-parietal dysfunction, or (c) decline of right-hemisphere functions. In the present study, we examined which of these theories best explains the cognitive patterns of normal elderly subjects older than 80 years of age (old elderly). Thirty normal old elderly subjects, 14 patients with subcortical vascular dementia, 14 with mild Alzheimer's disease, 15 with damage of the right hemisphere of the brain, and 20 young elderly controls participated. A test battery covering the main cognitive domains was administered to all participants. A hierarchical cluster analysis revealed five groups of individuals with different cognitive patterns across the whole sample. Old elderly subjects were assigned to four groups according to: (a) preserved overall cognitive performance, (b) processing speed decline, (c) attention decline, or (d) executive impairment. The results of the study are most congruent with models emphasizing frontal-lobe cortical-subcortical and fronto-parietal changes in old age. The results also indicate considerable heterogeneity in the cognitive patterns of normal old elderly adults.

Trials to improve blood pressure through adherence to antihypertensives in stroke/TIA: systematic review and meta-analysis

Background

The purpose of this study was to determine whether interventions including components to improve adherence to antihypertensive medications in patients after stroke/transient ischemic attack (TIA) improve adherence and blood pressure control.

Methods and Results

We searched MEDLINE, EMBASE, CINAHL, BNI, PsycINFO, and article reference lists to October 2012. Search terms included stroke/TIA, adherence/prevention, hypertension, and randomized controlled trial (RCT). Inclusion criteria were participants with stroke/TIA; interventions including a component to improve adherence to antihypertensive medications; and outcomes including blood pressure, antihypertensive adherence, or both. Two reviewers independently assessed studies to determine eligibility, validity, and quality. Seven RCTs were eligible (n=1591). Methodological quality varied. All trials tested multifactorial interventions. None targeted medication adherence alone. Six trials measured blood pressure and 3 adherence. Meta‐analysis of 6 trials showed that multifactorial programs were associated with improved blood pressure control. The difference between intervention versus control in mean improvement in systolic blood pressure was −5.3 mm Hg (95% CI, −10.2 to −0.4 mm Hg, P=0.035; I²=67% [21% to 86%]) and in diastolic blood pressure was −2.5 mm Hg (−5.0 to −0.1 mm Hg, P=0.046; I²=47% [0% to 79%]). There was no effect on medication adherence where measured.

Conclusions

Multifactorial interventions including a component to improve medication adherence can lower blood pressure after stroke/TIA. However, it is not possible to say whether or not this is achieved through better medication adherence. Trials are needed of well‐characterized interventions to improve medication adherence and clinical outcomes with measurement along the hypothesized causal pathway.

Processing speed in normal aging: effects of white matter hyperintensities and hippocampal volume loss

Changes in cognitive functioning are said to be part of normal aging. Quantitative MRI has made it possible to measure structural brain changes during aging which may underlie these decrements which include slowed information processing and memory loss. Much has been written on white matter hyperintensities (WMH), which are associated with cognitive deficits on tasks requiring processing speed and executive functioning, and hippocampal volume loss, which is associated with memory decline. Here we examine volumetric MRI measures of WMH and hippocampal volume loss together in relation to neuropsychological tests considered to be measures of executive functioning and processing speed in 81 non-demented elderly individuals, aged 75-90. Correlational analysis showed that when controlling for age, both greater WMH volume and smaller hippocampal volume were correlated with slower performances on most tests with the exception of a battery of continuous performance tests in which only WMH was correlated with slower reaction time (RT). We then performed a series of hierarchical multiple regression analyses to examine the independent contributions of greater WMH volume and reduced hippocampal volume to executive functioning and processing speed. The results showed that for the four measures requiring executive functioning and speed of processing, WMH volume and hippocampal volume combined predicted between 21.4% and 37% of the explained variance. These results suggest that WM integrity and hippocampal volume influence cognitive decline independently on tasks involving processing speed and executive function independent of age.

Geriatric syndromes--vascular disorders?

The term geriatric syndrome is used to characterize multifactorial clinical conditions among older people which are not subsumed readily into disease entities, but which nevertheless predispose older people to disability and death. Commonly included are frailty, dementia, delirium, incontinence, falls, and dizziness. Geriatric syndromes are common among older people: in a recent survey, 50% of those aged more than 65 had one or more of these conditions. Better methods for prevention and treatment are needed, but current strategies have lacked a coherent conceptual and diagnostic framework. Prevention and interventions need to be targeted at earlier ages, with geriatrics expertise needed in the definition and operationalization of these complex entities. In this review we consolidate evidence that vascular disorders, including vascular ageing and vascular diseases, are key etiological factors of geriatric syndromes. Identifying this vascular dimension would offer opportunities for more efficient preventive strategies and mandates earlier intervention, especially for women, among whom vascular disease is often expressed more insidiously than among men. This would entail a sensitization of the health care system to the systematic detection of the syndromes, which are currently underdiagnosed. Further disentangling of the mechanisms of vascular ageing may offer therapies for vascular diseases and geriatric syndromes alike.

Electroacupuncture ameliorates cognitive impairment through inhibition of NF-κB-mediated neuronal cell apoptosis in cerebral ischemia-reperfusion injured rats

Cognitive impairment is a serious mental deficit following stroke that severely affects the quality of life of stroke survivors. Nuclear factor‑κB (NF-κB)-mediated neuronal cell apoptosis is involved in the development of post-stroke cognitive impairment; therefore, it has become a promising target for the treatment of impaired cognition. Acupuncture at the Baihui (DU20) and Shenting (DU24) acupoints is commonly used in China to clinically treat post‑stroke cognitive impairment; however, the precise mechanism of its action is largely unknown. In the present study, we evaluated the therapeutic efficacy of electroacupuncture against post-stroke cognitive impairment and investigated the underlying molecular mechanisms using a rat model of focal cerebral ischemia-reperfusion (I/R) injury. Electroacupuncture at Baihui and Shenting was identified to significantly ameliorate neurological deficits and reduce cerebral infarct volume. Additionally, electroacupuncture improved learning and memory ability in cerebral I/R injured rats, demonstrating its therapeutic efficacy against post-stroke cognitive impairment. Furthermore, electroacupuncture significantly suppressed the I/R-induced activation of NF-κB signaling in ischemic cerebral tissues. The inhibitory effect of electroacupuncture on NF-κB activation led to the inhibition of cerebral cell apoptosis. Finally, electroacupuncture markedly downregulated the expression of pro-apoptotic Bax and Fas, two critical downstream target genes of the NF-κB pathway. Collectively, our findings suggest that inhibition of NF-κB‑mediated neuronal cell apoptosis may be one mechanism via which electroacupuncture at Baihui and Shenting exerts a therapeutic effect on post-stroke cognitive impairment.

Reliability, validity, and optimal cutoff score of the montreal cognitive assessment (changsha version) in ischemic cerebrovascular disease patients of hunan province, china

BACKGROUND/AIMS

The goal of this study was to examine the reliability and validity of the Changsha version of the Montreal Cognitive Assessment (MoCA-CS) in ischemic cerebrovascular disease patients of Hunan Province, China, and to explore the optimal cutoff score for detecting vascular cognitive impairment-no dementia (VCI-ND) and vascular dementia (VD).

METHODS

Three hundred and thirty-eight ischemic cerebrovascular disease patients (131 with normal cognition, 111 with VCI-ND, and 96 with VD) and 132 healthy controls were recruited. All participants accepted examination by the MoCA-CS, Mini-Mental State Examination (MMSE), and other related scales. A detailed neuropsychological battery was used for making a final cognitive diagnosis. SPSS 16.0 statistical software was used for reliability, validity examination, and optimal cutoff score detection.

RESULTS

Cronbach's α of the MoCA-CS was 0.884, and test-retest and interrater reliability of the MoCA-CS were 0.966 and 0.926, respectively. MoCA-CS scores were highly correlated with MMSE scores (r = 0.867) and simplified intelligence quotients (r = 0.822). The results indicate that 1 point should be added for subjects with less than 6 years of education, and that the optimal cutoff score for detecting VCI-ND is 26/27 (sensitivity 96.1%, specificity 75.6%), whereas the optimal cutoff score for detecting VD is 16/17 (sensitivity 92.7%, specificity 96.3%).

CONCLUSION

The MoCA-CS has good reliability and validity, and is a useful cognitive screening instrument for detecting VCI in the Chinese population.

The effects of gallic acid on pain and memory following transient global ischemia/reperfusion in Wistar rats

OBJECTIVE

It is generally agreed that most of the phenomena observed during brain ischemia and reperfusion can be explained by the damage to membrane structure. Oxidative stress is resulted in an imbalance between high consumption of oxygen and low levels of endogenous antioxidants. It is known that gallic acid (GA) is a strong antioxidant. The present study was carried out to evaluate the effect of GA on ischemia/reperfusion (I/R)-induced brain injury in rats.

MATERIALS AND METHODS

Wistar adult male rats weighing 200-250 g were divided into six groups as sham operated (Sh), ischemia/reperfusion (I/R) received normal saline (I+Veh), I/R groups treated with gallic acid (I+GA, 50, 100, or 200 mg/kg, orally, respectively), or with 100 mg /kg phenytoin (I+Phen). The global cerebral I/R injury was induced by occluding bilateral common carotid arteries (BCCA) for 20 min, followed by 5 days reperfusion in adult male rats.

RESULTS

It was found that administration of 100 mg/kg GA for 5 days before and 5 days after I/R induction reversed gait performance, sensorimotor disorders (p<0.01), and hypoalgesia (p<0.001) while dose of 50 mg/kg increased passive avoidance memory significantly (p<0.05).

CONCLUSION

Our findings clearly demonstrate that GA has beneficial effects on behavioral impairments after brain injury induced by I/R. The results of this study show that GA pretreatment ameliorates cerebral ischemia/reperfusion injury and enhances the antioxidant defense against BCCA occlusion-induced I/R in rats, so it exhibits cerebroprotective property.

White matter hyperintensities and quality of life in acute lacunar stroke

White matter hyperintensities (WMH) are common in stroke. The influence of WMH on health-related quality of life (HRQoL) following a lacunar stroke is unknown. This study evaluated the impact of WMH on HRQoL in acute lacunar stroke. A cohort of 160 patients with acute lacunar stroke admitted to the stroke unit of a university-affiliated regional hospital in Hong Kong was recruited. Three months after the index stroke, a research assistant administered the Short Form-36 (SF-36) to assess HRQoL. The severity of WMH was evaluated with magnetic resonance imaging (MRI). In univariate analysis, the severity of deep WMH (DWMH) negatively correlated with patients' vitality (VT; p < 0.05), social function (SF; p < 0.001), role-emotional (RE; p < 0.01), mental health (MH; p < 0.01), and mental component summary (MCS; p < 0.001) scores of HRQoL. DWMH was independently associated with all of the above five SF-36 scores (p < 0.05) in linear regression analysis. These findings suggest that DWMH has a significant impact on the HRQoL of stroke survivors. The importance of DWMH in the long-term HRQoL in lacunar stroke warrants further investigation.

Ginger pharmacopuncture improves cognitive impairment and oxidative stress following cerebral ischemia

Recent findings have demonstrated that acupuncture and ginger can each improve memory impairment following cerebral ischemia. We hypothesized that ginger pharmacopuncture, a combination of these two treatments, could increase the beneficial effects. Due to the limitation of supporting evidence, we aimed to determine whether ginger pharmacopuncture could improve cognitive function and oxidative stress following cerebral ischemia. Male Wistar rats were induced by right middle cerebral artery occlusion (Rt. MCAO) and subjected to either acupuncture or ginger pharmacopuncture once daily over a period of 14 days after Rt. MCAO. Cognitive function was determined every 7 days, using escape latency and retention time as indices, and the oxidative stress status of the rats was determined at the end of the study. Rats subjected either to acupuncture or to ginger pharmacopuncture at GV20 demonstrated enhanced spatial memory, and the activities of catalase and glutathione peroxidase in both cerebral cortex and hippocampus were improved. Elevation of superoxide dismutase activity was observed only in the hippocampus. Cognitive enhancement was observed sooner with ginger pharmacopuncture than with acupuncture. The cognitive enhancing effect of acupuncture and ginger pharmacopuncture is likely to be at least partially attributable to decreased oxidative stress. However, other mechanisms may also be involved, and this requires further study.

Cognitive deficits after subcortical infarction are comparable with deficits after cortical infarction

BACKGROUND AND PURPOSE

Cerebral cortical infarctions are often considered to be associated with more severe cognitive deficits than subcortical infarctions, but the evidence is conflicting. We compared early and late cognitive deficits between cortical and subcortical lesions.

METHODS

Consecutive patients with first-ever cortical (n = 61) or subcortical (n = 71) cerebral infarctions were assessed neuropsychologically after a mean of 8 days and again at 6 months after infarction. Examinations included evaluation of verbal memory, executive functions, psychomotor speed and visuospatial function as well as orientation, insight and mood state. At 6 months, verbal and non-verbal reasoning were also evaluated. Neurological examinations included National Institutes of Health Stroke Scale and Barthel Index at both time-points and the modified Rankin Scale at 6 months.

RESULTS

In the acute phase, memory (P = 0.007), especially delayed verbal recall (P = 0.005), was more severely affected in patients with subcortical infarctions than in those with cortical infarctions, and this trend persisted at 6 months post-infarction. Psychomotor speed (P = 0.040) was lower in the subcortical group in the acute phase than in the cortical group. Neurological scores did not differ between the two groups either in the acute phase or at 6 months.

CONCLUSIONS

Patients with subcortical cerebral infarctions may have even worse cognitive profiles than patients with cortical infarctions.

Association of chronic obstructive pulmonary disease with cognitive decline in very elderly men

Aim

To determine the change in cognitive function in very elderly men with chronic obstructive pulmonary disease (COPD) over a 3-year period relative to age-and education-matched controls.

Methods

In this hospital-based, prospective case-control study, we evaluated a consecutive series of 110 very elderly men with COPD and 110 control subjects who were hospitalized between January and December 2007. All the subjects performed cognitive tests at baseline and underwent annual evaluations (for 3 years), which included the Mini-Mental State Examination, word list recall, delayed recall, animal category fluency, and the symbol digit modalities test.

Results

In mixed-effects models adjusted for hypertension and coronary heart disease, COPD was associated with a more rapid rate of cognitive decline based on the Mini-Mental State Examination, word list recall, delayed recall, animal category fluency, and the symbol digit modalities test (all p < 0.01) compared to controls.

Conclusion

COPD is associated with a more rapid rate of cognitive decline in very elderly persons.

Small vessel cerebrovascular disease in older adults

‘Cerebral small vessel disease’ is common in older adults and is an important cause of morbidity, functional impairment and cognitive decline. Small vessel disease is a collective term used to describe a number of underlying pathological processes and neuroimaging findings, such as lacunar infarcts, white matter lesions and microhaemorrhages.

With readily available neuroimaging, diagnostic accuracy has improved; however, the management of small vessel disease and prevention of cognitive decline remains uncertain. Treatment of conventional vascular risk factors may be appropriate, but future research is required to provide definitive answers. We have conducted a comprehensive literature review of cerebral small vessel disease in older adults. This highlights the clinical sequelae and underlying pathological processes, whilst discussing novel diagnostic neuroimaging and therapeutic strategies.

Neurobehavioral dysfunction in patients with subcortical vascular mild cognitive impairment and subcortical vascular dementia

Amnestic mild cognitive impairment (MCI) is considered to be a prodromal stage of Alzheimer's disease. Likewise, subcortical vascular MCI (svMCI) is considered as a prodromal stage of subcortical vascular dementia (SVaD). The objective of this study was to investigate neuropsychiatric features in patients with svMCI compared to healthy controls and patients with SVaD. We evaluated 31 patients with svMCI, 42 with SVaD, and 28 healthy controls who underwent neuropsychiatric assessments using the Neuropsychiatric Inventory (NPI) and the Frontal Behavioral Inventory (FBI). On both the NPI and FBI, SVaD patients had the most severe neuropsychiatric symptoms, followed by svMCI patients and then healthy controls, suggesting that svMCI might be a prodromal stage of SVaD in terms of neuropsychiatric abnormalities. When we compared the differences of mean scores between negative and positive symptoms in FBI, negative symptoms tended to be more predominant than positive symptoms in both svMCI and SVaD patients, but the tendency was stronger in SVaD patients than in svMCI patients. These results suggest that vascular cognitive impairment with small vessel disease would start with both negative and positive neuropsychiatric symptoms and progress to present more severe negative symptoms. These behavioral ratings may be useful for early detection of vascular cognitive impairment associated with small vessel disease.

Cognitive dysfunction and depression in adult kidney transplant recipients: baseline findings from the FAVORIT Ancillary Cognitive Trial (FACT)

OBJECTIVE

Hyperhomocysteinemia and B-vitamin deficiency may be treatable risk factors for cognitive impairment and decline. Hyperhomocysteinemia, cognitive impairment, and depression are all common in individuals with kidney disease, including kidney transplant recipients. Accordingly, we assessed the prevalence of cognitive impairment and depressive symptoms in transplant recipients and their association with kidney function, plasma total homocysteine, and B-vitamin concentrations.

SETTING

Cross-sectional analysis of baseline data from the Folic Acid for Vascular Outcome Reduction In Transplantation (FAVORIT) Ancillary Cognitive Trial (FACT), which included 183 participants in FAVORIT who underwent detailed neuropsychological assessment before the study intervention.

RESULTS

The mean age was 54.0 ± 9.5 years (range: 7 to 386 months). Men comprised 55.2% of the cohort, and the mean time between the current transplant and cognitive testing was 7.0 ± 5.8 years. Twenty-four percent of participants reported neurological or psychiatric complaints, and 30% exhibited symptoms of mild to severe depression. Testing revealed evidence of significant and selective deficits in this population: 33% performed more than 1 standard deviation (SD) below normed means on a memory test, 58% fell lower than 1 SD below the norms on a test of attention and mental processing speed, and 33% to 42% fell lower than 1 SD below the norms on several tests of executive function. Lower estimated glomerular filtration rate and lower folate were associated with poorer performance on tests of memory and executive function.

CONCLUSIONS

These observations confirm previous reports of mood and cognitive impairments in adult kidney transplant recipients. Further research is needed to determine the benefit of B-vitamin supplementation and other interventions in this patient population.

Heterogeneity in age-related white matter changes

White matter changes occur endemically in routine magnetic resonance imaging (MRI) scans of elderly persons. MRI appearance and histopathological correlates of white matter changes are heterogeneous. Smooth periventricular hyperintensities, including caps around the ventricular horns, periventricular lining and halos are likely to be of non-vascular origin. They relate to a disruption of the ependymal lining with subependymal widening of the extracellular space and have to be differentiated from subcortical and deep white matter abnormalities. For the latter a distinction needs to be made between punctate, early confluent and confluent types. Although punctate white matter lesions often represent widened perivascular spaces without substantial ischemic tissue damage, early confluent and confluent lesions correspond to incomplete ischemic destruction. Punctate abnormalities on MRI show a low tendency for progression, while early confluent and confluent changes progress rapidly. The causative and modifying pathways involved in the occurrence of sporadic age-related white matter changes are still incompletely understood, but recent microarray and genome-wide association approaches increased the notion of pathways that might be considered as targets for therapeutic intervention. The majority of differentially regulated transcripts in white matter lesions encode genes associated with immune function, cell cycle, proteolysis, and ion transport. Genome-wide association studies identified six SNPs mapping to a locus on chromosome 17q25 to be related to white matter lesion load in the general population. We also report first and preliminary data that demonstrate apolipoprotein E (ApoE) immunoreactivity in white matter lesions and support epidemiological findings indicating that ApoE is another factor possibly related to white matter lesion occurrence. Further insights come from modern MRI techniques, such as diffusion tensor and magnetization transfer imaging, as they provide tools for the characterization of normal-appearing brain tissue beyond what can be expected from standard MRI scans. There is a need for additional pre- and postmortem studies in humans, including these new imaging techniques.

Influence of education on subcortical hyperintensities and global cognitive status in vascular dementia

Subcortical hyperintensities (SH) on neuroimaging are a prominent feature of vascular dementia (VaD) and SH severity correlates with cognitive impairment in this population. Previous studies demonstrated that SH burden accounts for a degree of the cognitive burden among VaD patients, although it remains unclear if individual factors such as cognitive reserve influence cognitive status in VaD. To address this issue, we examined 36 individuals diagnosed with probable VaD (age = 77.56; education = 12). All individuals underwent MMSE evaluations and MRI brain scans. We predicted that individuals with higher educational attainment would exhibit less cognitive difficulty despite similar levels of SH volume, compared to individuals with less educational attainment. A regression analysis revealed that greater SH volume was associated with lower scores on the MMSE. Additionally, education moderated the relationship between SH volume and MMSE score, demonstrating that individuals with higher education had higher scores on the MMSE despite similar degrees of SH burden. These results suggest that educational attainment buffers the deleterious effects of SH burden on cognitive status among VaD patients.

Prevention of cerebral ischemia-induced memory deficits by inhibition of phosphodiesterase-4 in rats

Inhibition of phosphodiesterase-4 (PDE4) by rolipram, a prototypical PDE4 inhibitor, reverses memory impairment produced pharmacologically or genetically. Comparably, much less is known about the effect of rolipram on cerebral ischemia-induced memory deficits. The objective of this study was to determine the effects of rolipram on ischemia-induced memory deficit, neuronal damage, and alteration of PDE4 activity in the hippocampus. Memory was examined using Morris water-maze and step-through passive avoidance tests in rats subjected to global cerebral ischemia with or without repeated treatment with rolipram (0.3 or 1 mg/kg, i.p.); neuronal damage in the hippocampus and PDE4 activity in hippocampal tissues were determined using Nissl staining and HPLC, respectively. In the water-maze test, cerebral ischemia significantly increased the escape latency to reach the platform during acquisition training and decreased the exploration time in the target quadrant in the probe trial test; these were blocked by rolipram in a dose-dependent manner. Rolipram also reduced the distracted platform searches induced by cerebral ischemia. In the passive avoidance test, ischemia decreased the 24-h latency to the dark compartment, which was also blocked by rolipram treatment. In addition, Nissl staining revealed ischemia-induced neuron loss in hippocampal CA1; this was blocked by rolipram. Further, cerebral ischemia led to increases in activity of PDE, primarily PDE4, in the hippocampus, which also was antagonized by rolipram. These results suggest that rolipram prevents cerebral ischemia-induced memory deficits via inhibition of increased PDE4 activity and attenuation of hippocampal, neuronal damages induced by ischemia. PDE4 may be a target for treatment of cognitive disorders associated with cerebral ischemia.

Association of white matter lesions and lacunar infarcts with executive functioning: the SMART-MR study

The authors investigated the association of white matter lesions and lacunar infarcts with cognitive performance and whether brain atrophy mediates these associations. Within the Second Manifestations of Arterial Disease-Magnetic Resonance study (2001-2005, the Netherlands), cross-sectional analyses of 522 patients were performed (mean age, 57 years (standard deviation, 10); 76% male). Brain segmentation was used to quantify volumes of brain tissue, cerebrospinal fluid, and white matter lesions. Infarcts were rated visually. Brain volume, ventricular volume, and gray matter volume were divided by intracranial volume to obtain indicators of brain atrophy. Neuropsychological tests assessing executive functioning and memory were performed, and scores were transformed into z scores. The authors used linear regression analyses, adjusted for age, sex, education, intelligence, and vascular risk factors, to investigate the association of white matter lesions and number of lacunar infarcts with cognitive performance. A 1-standard-deviation higher volume of white matter lesions (beta = -0.12, 95% confidence interval: -0.20, -0.04) and the presence of >or=2 lacunar infarcts (beta = -0.48, 95% confidence interval: -0.87, -0.09) were associated with worse executive functioning. These associations remained after adjusting for brain atrophy. Both were not associated with worse memory. Results suggest that subcortical ischemic vascular lesions are associated with decreased executive functioning, but not with memory functioning, independent of brain atrophy.

Retinal microvascular abnormalities and cognitive decline: the ARIC 14-year follow-up study

BACKGROUND

Because retinal and cerebral arterioles share similar pathologic processes, retinal microvascular changes are expected to be markers of cerebral small vessel disease (SVD). To better understand the role of SVD in cognitive function, we investigated the relationship between retinal microvascular abnormalities and longitudinal changes in cognitive function in a community-based study.

METHODS

A total of 803 participants underwent 4 cognitive assessments between 1990-1992 and 2004-2006, using the Word Fluency (WF) test, Digit Symbol Substitution (DSS), and Delayed Word Recall as well as retinal photography in 1993-1995. Covariate adjusted random effects linear models for repeated measures were used to determine the associations of cognitive change with specific retinal vascular abnormalities.

RESULTS

Individuals with retinopathy showed declines in executive function and psychomotor speed, with 1) an average decline in WF of -1.64 words per decade (95% confidence interval [CI] -3.3, -0.02) compared to no decline in those without retinopathy +0.06 (95% CI -0.6, 0.8) and 2) a higher frequency of rapid decliners on the DSS test.

CONCLUSION

Signs of retinal vascular changes, as markers of the cerebral microvasculature, are associated with declines in executive function and psychomotor speed, adding to the growing evidence for the role of microvascular disease in cognitive decline in the elderly.

A multicenter, open-label, 24-week follow-up study for efficacy on cognitive function of donepezil in Binswanger-type subcortical vascular dementia

OBJECTIVES

To evaluate the efficacy and tolerability of donepezil in patients with Binswanger type subcortical vascular dementia.

METHODS

Patients (n = 34, mean age = 71.8 + 7.12) with Binswanger type subcortical vascular dementia from 8 multicenter, according to clinical and neuroradiological working criteria, were selected to receive donepezil 5 mg/day (n = 2) or donepezil 10 mg/day (n = 32, after 5 mg/day) for 24 weeks. Our primary endpoints were change from baseline to weeks 12 and 24 in the Seoul Neuropsychological Screening Battery-Dementia version (SNSB-D) and the Korean version of neuropsychiatric inventory (K-NPI).

RESULTS

A total of 24 patients received donepezil completed the study (mean age = 72.0 + 7.5 K-Mini-Mental State Examination [MMSE] = 21.0 + 5.1). After 12 weeks and 24 weeks, patients showed improvements in cognitive function on the SNSB-D compared baseline of 16.29 points at 12 weeks (P < .05) and 12.44 points at 24 weeks (P < .05). Significant improvements were shown in only memory domain, immediate verbal recall and delayed recall tests. Subgroup with better cognitive function (SNSB-D > 100) were more effective in frontal and memory domains than the other subgroup (SNSB-D < 100). Withdrawal rates due to adverse events were very low (4.16%).

CONCLUSIONS

Donepezil-treated patients with Binswanger type subcortical vascular dementia demonstrated significant improvement in cognition compared with baseline, and donepezil was well tolerated.

Current Concepts in Vascular Cognitive Impairment and Pharmacotherapeutic Implications

Objective:

To review evolution of the vascular cognitive impairment (VCI) construct, including diagnosis, pharmacotherapeutic implications, and address challenges that will shape future developments.

Data Sources:

Literature retrieval was accessed through PubMed, from 1966 to December 2008, using the terms vascular cognitive impairment, vascular dementia, post-stroke dementia, vascular cognitive disorder, mild cognitive impairment, criteria, disease progression, outcomes, treatment, prevention, biomarkers, and neuroimaging.

Study Selection and Data Extraction:

All articles in published English identified from the data sources were evaluated for inclusion. Regarding pharmacotherapy, prospective double-blind, placebo-controlled studies were included as well as extensions or relevant post hoc analyses.

Data Synthesis:

In the 1970s, “senile dementia due to hardening of the arteries” was used to describe dementia due to vascular causes. This was a narrow view of what is now known to be a common form of cognitive impairment in older people. Multiple infarct dementia (MID) was first proposed to describe dementia attributable to multiple cerebral infarcts, followed by the vascular dementia (VaD) construct, itself meant to be an improvement over MID. The VaD construct had limitations, not the least of which was that, by the time a patient was diagnosed with VaD, the opportunity for prevention was lost. Thus arose the concept of VCI, representing a group of heterogeneous disorders that share presumed vascular causes. The importance of VCI is centered on the fact that vascular risk factors are treatable, and thus should lead to a reduction in the incidence of cognitive impairment due to vascular causes. There is evidence that treatment of hypertension can lead to a reduction in the incidence of cognitive impairment and dementia, and that treatment of VaD with acetylcholinesterase inhibitors may be beneficial.

Conclusions:

Careful attention needs to be given to controlling vascular risk factors in at-risk patients. Pharmacists should play an active role in this important area of geriatric pharmacotherapy.

A comparison of neurocognitive impairment in younger and older adults with major depression

BACKGROUND

Neurocognitive impairment is a well-recognized feature of depression that has been reported in younger and older adults. Similar deficits occur with ageing and it is unclear whether the greater deficits in late-life depression are an ageing-related phenomenon or due to a difference in the nature of late-life depression itself. We hypothesized that ageing alone would not fully explain the increased neurocognitive impairment in late-life depression but that differences in the illness explain the greater decrements in memory and executive function.

METHOD

Comparison of the neuropsychological performance of younger (<60 years) and older (60 years) adults with major depressive disorder (MDD) and healthy comparison subjects. Scores for each depression group were normalized against their respective age-matched control group and the primary comparisons were on four neurocognitive domains: (i) attention and executive function; (ii) verbal learning and memory; (iii) visuospatial learning and memory; and (iv) motor speed.

RESULTS

We recruited 75 subjects with MDD [<60 years (n=44), 60 years (n=31)] and 82 psychiatrically healthy comparison subjects [<60 years (n=42), 60 years (n=40)]. The late-life depression group had greater impairment in verbal learning and memory and motor speed but not in executive function. The two depressed groups did not differ in depression severity, global cognitive function, intelligence or education.

CONCLUSIONS

Late-life depression is associated with more severe impairment in verbal learning and memory and motor speed than depression in earlier adult life and this is not due to ageing alone.

Single and combined effects of cerebral white matter lesions and lacunar infarctions on cognitive function in an elderly population

BACKGROUND

This study is to investigate the association between single and combined vascular brain changes (white matter lesions [WMLs], lacunar infarctions) and the cognitive domains of memory, processing speed, and motor function in the elderly adults.

METHODS

In a sample of 268 participants aged 65-83 years of the MEMO (Memory and Morbidity in Augsburg Elderly) population-based study in Augsburg, Germany, cerebral magnetic resonance imaging (MRI) was performed and a detailed neuropsychological test battery applied. Analysis of covariance determined the effects of vascular brain changes on domains of cognitive functioning.

RESULTS

Strong associations of large WMLs and of MRI-defined lacunar infarction with three different domains of cognitive function even after adjustment for age, gender, and education were found. The combined occurrence of both lesions affected about one in 10 participants and was associated with a strong decrease in cognitive function in all domains. The difference between the groups with only one lesion type (either large WMLs or MRI-defined infarction) and participants affected by both was significant in the domains of processing speed and memory, even after adjustment for important confounders such as age, gender, education, and comorbidities. The effects of both lesion types on cognitive function were not more than additive.

CONCLUSIONS

Our study shows that both large WMLs and MRI-defined lacunar infarction contribute to impairments in different cognitive domains. The results suggest that their combined occurrence is associated with stronger reductions in cognitive function than each of the two brain lesion types alone.

White matter lesion severity is associated with reduced cognitive performances in patients with normal CSF Abeta42 levels

OBJECTIVE

To identify possible associations between white matter lesions (WML) and cognition in patients with memory complaints, stratified in groups with normal and low cerebrospinal fluid (CSF) Abeta42 values.

MATERIAL AND METHODS

215 consecutive patients with subjective memory complaints were retrospectively included. Patients were stratified into two groups with normal (n = 127) or low (n = 88) CSF Abeta42 levels (cut-off is 450 ng/l). Cognitive scores from the Mini-Mental State Examination (MMSE) and the Neurobehavioral Cognitive Status Examination (Cognistat) were used as continuous dependent variables in linear regression. WML load was used as a continuous independent variable and was scored with a visual rating scale. The regression model was corrected for possible confounding factors.

RESULTS

WML were significantly associated with MMSE and all Cognistat subscores except language (repetition and naming) and attention in patients with normal CSF Abeta42 levels. No significant associations were observed in patients with low CSF Abeta42.

CONCLUSIONS

WML were associated with affection of multiple cognitive domains, including delayed recall and executive functions, in patients with normal CSF Abeta42 levels. The lack of such associations for patients with low CSF Abeta42 (i.e. with evidence for amyloid deposition), suggests that amyloid pathology may obscure cognitive effects of WML.

Within-person across-neuropsychological test variability and incident dementia

CONTEXT

Neuropsychological tests are used to predict and diagnose dementia. However, to our knowledge, no studies to date have examined whether within-person across-neuropsychological test variability predicts dementia.

OBJECTIVE

To examine whether within-person across-neuropsychological test variability predicts future dementia.

DESIGN

The Einstein Aging Study (EAS) is a population-based longitudinal study of aging and dementia located in Bronx County, New York. We used Cox proportional hazards models using age as the time scale to estimate hazard ratios (HRs) for performance on individual neuropsychological tests (Free and Cued Selective Reminding Test, Digit Symbol Substitution subtest of the Wechsler Adult Intelligence Scale Revised, and the Vocabulary subtest of the Wechsler Adult Intelligence Scale Revised) and for within-person across-neuropsychological test variability as predictors of incident dementia. Analyses were stratified by sex, and controlled for education and medical illness.

SETTING AND PARTICIPANTS

A total of 1797 participants (age > or = 70 years) enrolled in the EAS between October 1993 and December 2007. Participants seen for the baseline visit only (n = 750), prevalent dementia cases (n = 72), and those with missing follow-up information (n = 78) were excluded. A total of 897 individuals were included in this investigation. Participants had follow-up visits every 12 to 18 months.

MAIN OUTCOME MEASURE

Incident dementia.

RESULTS

Sixty-one cases of incident dementia were identified during follow-up (mean [SD], 3.3 [2.4] years), of which 26 were in the highest quartile of within-person across-neuropsychological test variability. Adjusting for sex, education, and medical illness, variability was associated with incident dementia (HR for 1-point difference in variability, 3.93 [95% confidence interval {CI}, 2.04-7.56]). The association persisted even after adjusting for level of performance on individual neuropsychological tests (HR for 1-point difference in variability, 2.10 [95% CI, 1.04-4.23]). Comparing Cox models using neuropsychological tests with and without within-person across-neuropsychological test variability showed that the former improved the prediction of dementia. Sensitivity in a model predicting dementia at 1 year also improved when neuropsychological test variability was included.

CONCLUSIONS

In this population, within-person across-neuropsychological test variability was associated with development of incident dementia independent of neuropsychological test performance. This finding needs to be confirmed in future studies.

Classifying late-onset dementia with MRI: is arteriosclerotic brain degeneration the most common cause of Alzheimer's syndrome?

Our aim was to use early magnetic resonance imaging (MRI) to investigate the causes of cognitive decline in elderly people with mild cognitive impairment (MCI). Baseline structural and flow quantification MR sequences, and clinical and neuropsychological follow-up for at least two years, were performed on 62 elderly subjects with MCI. Of these subjects, 17 progressed to dementia, and 15 of these progressed to dementia of the Alzheimer type (DAT). Conversion to clinically diagnosed DAT was related to six distinct MR profiles, including one profile suggesting severe AD (20% of these converters) and five profiles suggesting severe cerebrovascular dysfunction. Two profiles suggested arteriosclerotic brain degeneration, one profile suggested severe venous windkessel dysfunction, and two suggested marked cerebral hypoperfusion associated with very low craniospinal compliance or marked brain atrophy. As compared with vascular MR type converters, AD MR type converters showed high executive and mobility predementia performances. Severe whole anteromesial temporal atrophy and predominantly left brain atrophy on visual MR analysis was only observed in AD MR type converters. In conclusion, these observations enhance the pathogenic complexity of the Alzheimer syndrome, and suggest that the role of arteriosclerotic brain degeneration in late life dementia is underestimated.

Alzheimer’s disease in late-life dementia: A minor toxic consequence of devastating cerebrovascular dysfunction

Alzheimer's disease (AD) is thought to be the most common cause of late-life dementia. But pure AD is infrequent whereas AD pathology is often insufficient to explain dementia in the elderly. Conversely, cerebrovascular disease is omnipresent and the crucial role of microvascular alterations increasingly recognized in late dementia or "Alzheimer syndrome". Pathomechanisms of vascular cognitive impairment are still debated but recent data indicate that the initial concept of chronic low grade cerebral hypoxia should not have been abandoned. Thus, it is proposed that windkessel dysfunction is the missing link between vascular and craniospinal senescence on the one hand, and chronic low grade cerebral hypoxia, "senile brain degeneration" and "Alzheimer syndrome" on the other hand. An age-related decrease in the buffering capacity of both the vessels and the craniospinal cavity favours cerebral hypoxia; due to increased capillary pulsatility with disturbances in capillary exchanges or due to a marked reduction in craniospinal compliance with a mechanical reduction in cerebral arterial inflow. "Invisible" windkessel dysfunction, most often related to "hardening of the arteries" may be the most frequent pathomechanism of late-onset dementia whereas associated mild or moderate AD may be merely a toxic manifestation of a primarily hypoxic disease. Structural patterns of arteriosclerotic dementia fit well with an underlying arterial windkessel dysfunction: with secondary mechanical damage to the cerebral small vessels and the brain and predominantly deep hypoxia. The clinical significance of leukoaraïosis, small foci of necrosis, ventricular dilatation, hippocampal and cortical atrophy is in good agreement with their value as indirect markers of windkessel dysfunction. An age-related "invisible" reduction in craniospinal compliance may also contribute to the associations between heart failure, arterial hypotension and cognitive impairment in the elderly and to the high percentage of dementia of unknown origin in the very old. Both neuropathological and clinical overlap between AD and windkessel dysfunction can explain that cerebrovascular dysfunction remains misdiagnosed for AD in the elderly. Evidence of the key role of cerebrovascular dysfunction should markedly facilitate and widen therapeutic research in late-life dementia. Routine MRI including direct assessment of intracranial dynamics should be increasingly used to define etiological subtypes of the "Alzheimer syndrome" and develop a well-targeted therapeutic strategy.

Profile of Cognitive Impairment in Chronic Heart Failure

OBJECTIVES

To determine the frequency and pattern of cognitive dysfunction in outpatients with chronic congestive heart failure (CHF) and to identify the corresponding demographic and clinical correlates.

DESIGN

Case-control study.

SETTING

Outpatient clinic in a community hospital.

PARTICIPANTS

Sixty-two outpatients with CHF, 53 controls diagnosed with cardiovascular disease uncomplicated by CHF (cardiac controls), and 42 healthy controls were investigated.

MEASUREMENTS

Neuropsychological assessment included tests of mental speed, executive function, memory, language, and visuospatial function. Composite z-scores for five cognitive domains and mean z-score for overall cognitive performance were computed. The cutoff score to indicate cognitive impairment was defined as the overall healthy participants' cognitive z-score minus 2 standard deviations. Independent demographic and clinical predictors of cognitive impairment were identified using linear regression analysis.

RESULTS

Patients with CHF showed a pattern of general cognitive impairment, including impairment of executive function, memory, language, mental speed, and attention. Twenty-five percent (P=.04) of patients with CHF were classified as cognitively impaired, compared with 15% of the cardiac controls and 4% of the healthy controls. Independent predictors of cognitive impairment in patients with CHF were estimated intelligence, New York Heart Association class, and presence of the apolipoprotein (Apo)E epsilon4 allele.

CONCLUSION

Cognitive dysfunction is relatively common in patients with CHF, with deficits being most prominent in the domains of executive function, memory, language, and mental speed. Disease severity and ApoE genotype are likely to be important determinants for cognitive impairment in patients with chronic CHF.

Mild cognitive impairment after lacunar infarction: voxel-based morphometry and neuropsychological assessment

BACKGROUND

The aim of the present study was to investigate whether there were differences in neuroradiological features, including white-matter lesions and gray-matter volumes, between patients with lacunar infarction with and without mild cognitive impairment of the vascular type (MCI-V).

METHODS

A total of 40 patients with lacunar infarction were studied within 1 month after stroke.

RESULTS

MCI-V was found in 22 patients, who in comparison with patients without cognitive impairment were significantly older and had fewer years of formal education. MRI subcortical hyperintensities especially in the basal ganglia (putamen and thalamus) were significantly more frequent in the MCI-V group. In the voxel-based morphometric study, patients with MCI-V showed more atrophy bilaterally in the middle temporal gyrus, right and left frontal and posterior bilateral occipitoparietal regions including the posterior cingulate as well as in the cerebellum. A region of interest analysis restricted to the parahippocampi and hippocampi showed further reduced bilateral parahippocampal gyrus and right hippocampus volume reductions in this group of patients. Finally, the amount of white-matter lesions among MCI-V showed negative correlations with gray-matter volume in frontal and temporal areas as well as with the thalamus and mesencephalon.

CONCLUSIONS

The present findings provide support for an anatomical substrate of the MCI entity in patients with lacunar infarction. Both gray- and white-matter changes seem to contribute to the cognitive impairment of such patients.

Poststroke memory function in nondemented patients: a systematic review on frequency and neuroimaging correlates

BACKGROUND AND PURPOSE

Poststroke memory dysfunction is a prerequisite for the diagnosis of poststroke dementia. This diagnosis is made within months after a stroke, apparently assuming a relatively stable course of the poststroke memory function. Clinical experience added to anecdotal evidence from the literature suggests that poststroke memory function may be reversible. The aim of the present study was to systematically review the available data on the time course of poststroke memory function in nondemented stroke survivors. In addition, we wanted to investigate the role of (pre-)stroke characteristics on poststroke memory function.

METHODS

We performed systematic literature search of PubMed with the following medical subject heading terms: memory and stroke. The search strategy yielded 798 articles of which 65 fulfilled our inclusion criteria and went on to the data extraction stage.

RESULTS

Five studies reported the prevalence of poststroke memory dysfunction at different poststroke intervals. The prevalence of poststroke memory dysfunction varied from 23% to 55% 3 months poststroke, which declined from 11% to 31% 1 year poststroke. Larger stroke volume, prestroke medial temporal lobe atrophy, and white matter lesions were related with decreased poststroke memory function.

CONCLUSIONS

Not all patients with poststroke memory dysfunction 3 months after a stroke had memory dysfunction 1 year poststroke. Consequently, not all criteria for the dementia diagnosis were fulfilled any more. This may indicate that poststroke dementia may be reversible in a substantial proportion of patients with stroke. Preferably, standardized reassessment of cognitive function should be performed in each patient diagnosed with poststroke dementia.