Vascular risk factors promote conversion from mild cognitive impairment to Alzheimer disease

Current management decisions in mild cognitive impairment

Efforts toward early detection of Alzheimer disease (AD) have focused on refinement and identification of diagnostic markers, with the goal of preventing or delaying disease progression. Mild cognitive impairment (MCI) has emerged as a potential precursor to dementia. Though not without controversy, MCI has been associated with an increased risk for conversion to AD. In this article, with emphasis on meta-analyses, randomized controlled trials, and extant literature reviews, considerations and recommendations for optimal clinical management of MCI are offered. Given the substantial heterogeneity of this patient population and inconsistent research methodologies, the need for informed, clinical judgment is critical.

Identification of a Novel Mutation in the Presenilin 1 Gene in a Chinese Alzheimer’s Disease Family

This study has identified a gene mutation in a Chinese family with Alzheimer's disease (AD). Family members were screened by a set of medical examinations and neuropsychological tests. Their DNA was extracted from blood cells and sequenced for gene mutation in the amyloid precursor protein (APP), the presenilin 1 (PS1) and the presenilin 2 (PS2) genes. Genetic analysis showed that the AD patients in the family harbored a T to G missense mutation at the position 314 in exon 4 of the PS1 gene, resulting in a change of F105C in amino acid sequence. Clinical manifestation of these patients included memory loss, counting difficulty, personality change, disorientation, dyscalculia, agnosia, aphasia, and apraxia, which was similar to that of the familial AD (FAD) patients harboring other PS1 mutations. We intend to add a novel mutation F105C of the PS1 gene to the pool of FAD mutations. With the current available genetic data, mutations of the PS1 gene account for the majority of gene mutations in Chinese FAD.

Cardiovascular disease contributes to Alzheimer's disease: evidence from large-scale genome-wide association studies

Alzheimer's disease (AD) is the most common and complex neurodegenerative disease in the elderly individuals. Recently, genome-wide association studies (GWAS) have been used to investigate AD pathogenesis. These GWAS have yielded important new insights into the genetic mechanisms of AD. However, these newly identified AD susceptibility loci exert only very small risk effects and cannot fully explain the underlying AD genetic risk. We hypothesize that combining the findings from different AD GWAS may have greater power than genetic analysis alone. To identify new AD risk factors, we integrated findings from 3 previous large-scale AD GWAS (n = 14,138) using a gene-based meta-analysis and subsequently conducted a pathway analysis using the kyoto encyclopedia of genes and genomes and gene ontology databases. Interestingly, we not only confirmed previous findings, but also highlighted, for the first time, the involvement of cardiovascular disease-related pathways in AD. Our results provided the clues as to the link between these diseases using pathway analysis methods. We believe that these findings will be very useful for future genetic studies of AD.

Dementia and cognitive decline in type 2 diabetes and prediabetic stages: towards targeted interventions

Type 2 diabetes is associated with dementia, and also with more slight cognitive decrements. In this Review we discuss trajectories from normal cognition to dementia in people with type 2 diabetes, and explore opportunities for treatment. Slight diabetes-associated cognitive decrements and dementia affect different age groups and show a different evolution. These cognitive entities should therefore not be regarded as a continuum, although their effects might be additive. Vascular damage is a key underlying process in both entities. Glucose-mediated processes and other metabolic disturbances might also have a role. No treatment has been established, but management of vascular risk factors and optimisation of glycaemic control could have therapeutic benefit. We identify possible opportunities for intervention to improve cognitive outcomes in people with type 2 diabetes, and suggest how treatment can be tailored to individual risk profiles and comorbidities.

Association of smoking and alcohol drinking with dementia risk among elderly men in China

BACKGROUND

Previous studies relating smoking and alcohol drinking with the incidence of dementia have been inconsistent.

OBJECTIVES

We assessed whether smoking and alcohol drinking was associated with the risk of dementia, including Alzheimer disease (AD) and vascular dementia (VaD) after seven years of follow-up.

DESIGN

We prospectively analysed the incidence of dementia from 2004 to 2011 among 2959 elderly men, according to their smoking and alcohol drinking status.

SETTING

six neighbourhoods from three districts mentioned in Chongqing city.

PARTICIPANTS

A total of 3170 men were followed up annually for 7 years.

MEASUREMENTS

Cox proportional hazards models were established to evaluate the association between smoking, alcohol drinking and the risk of dementia.

RESULTS

The incidences of AD and VaD were higher respectively in current smoking than never smoking, daily drinking than never drinking over 7 years of follow-up (p<0.01). After adjusting for age and other potential confounders, current smoking was associated with increased risk of AD (HR= 2.14, 95% CI 1.20-4.46) and VaD (HR= 3.28, 95% CI 1.14-4.52), meanwhile, daily drinking was related to increased risk of AD (HR= 2.25, 95% CI 1.43-3.97) and VaD (HR= 3.42, 95% CI 1.18-4.51). In addition, co-smoking and drinking were related to with a significantly higher risk of AD and VaD than non-smoking and drinking (HR= 3.03, 95% CI 1.65-4.19) and VaD (HR= 3.96, 95% CI 1.64-4.71). Moreover, co-smoking and drinking had higher risk of AD and VaD compared with current smoking and daily drinking.

CONCLUSIONS

Current smoking and daily drinking were found to be significantly associated with dementia in elderly men.

No association of SORT1 gene polymorphism with sporadic Alzheimer's disease in the Chinese Han population

Increasing evidence shows that sortilin (encoded by SORT1 gene), a member of the vacuolar protein sorting 10 family of sorting receptors, can modulate amyloid-β peptides (Aβ) metabolism and clearance, as well as mediate the neurotoxicity of the Aβ oligomer and proneurotrophins, thus playing diverse roles in the pathogenesis of Alzheimer's disease. To assess the association between single nucleotide polymorphism (SNP) of the SORT1 gene and sporadic Alzheimer's disease (sAD) in the Chinese Han population, a case-control study was carried out including 220 sAD patients and 245 controls. One tag SNP was selected from the entire SORT1 gene through construction of linkage disequilibrium blocks, and three SNPs located in the vicinity of SORT1 that affect its expression were also selected. The four target SNPs were genotyped using a multiplex PCR-ligase detection reaction method, yielding no significant association between them or haplotypes containing three of them, and the risk of sAD. The results of this study indicate that polymorphisms of the SORT1 gene are unlikely to confer the risk of sAD in the Chinese Han population.

Risk factors for the progression of mild cognitive impairment to dementia

The increasing prevalence of cognitive impairment among the older adult population warrants attention to the identification of practices that may minimize the progression of early forms of cognitive impairment, including the transitional stage of mild cognitive impairment (MCI), to permanent stages of dementia. This article identifies both markers of disease progress and risk factors linked to the progression of MCI to dementia. Potentially modifiable risk factors may offer researchers a point of intervention to modify the effect of the risk factor and to minimize the future burden of dementia.

Cardiovascular risk and hippocampal thickness in Alzheimer's disease

Cardiovascular risk factors influence onset and progression of Alzheimer's disease. Among cognitively healthy people, changes in brain structure and function associated with high blood pressure, diabetes, or other vascular risks suggest differential regional susceptibility to neuronal damage. In patients with Alzheimer's disease, hippocampal and medial temporal lobe atrophy indicate early neuronal loss preferentially in key areas for learning and memory. We wanted to investigate whether this regional cortical thinning would be modulated by cardiovascular risk factors. We utilized high-resolution magnetic resonance imaging and a cortical unfolding technique to determine the cortical thickness of medial temporal subregions in 30 patients with Alzheimer's disease. Cardiovascular risk was assessed using a sex-specific multivariable risk score. Greater cardiovascular risk was associated with cortical thinning in the hippocampus CA2/3/dentate gyrus area but not other hippocampal and medial temporal subregions. APOE genotype, a family history of Alzheimer's disease, and age did not influence cortical thickness. Alzheimer's disease-related atrophy could mask the influence of genetic risk factors or age on regional cortical thickness in medial temporal lobe regions, whereas the impact of vascular risk factors remains detectable. This highlights the importance of cardiovascular disease prevention and treatment in patients with Alzheimer's disease.

Rate of conversion from prodromal Alzheimer's disease to Alzheimer's dementia: a systematic review of the literature

Background

The purpose of this study was to summarize published estimates for conversion from mild cognitive impairment or amnestic mild cognitive impairment to Alzheimer's dementia. We carried out a systematic review of English language publications to identify cohort studies published since January 2006 that reported the risk or rate of conversion.

Summary

Thirty-two cohort studies were identified, of which 14 reported annualized conversion rates (ACRs). Conversions over 1 year ranged from 10.2 to 33.6% (5 studies, median: 19.0%), and over 2 years from 9.8 to 36.3% (7 studies, median: 18.6%). ACRs ranged from 7.5 to 16.5% (7 studies, median: 11.0%) per person-year for studies recruiting from clinics, and from 5.4 to 11.5% (7 studies, median: 7.1%) for community samples.

Key Message

Extensive variation was observed in conversion rates due to the population sampled, diagnostic criteria, and duration, and because many studies did not account for loss to follow-up.

Impaired structural correlates of memory in Alzheimer's disease mice

The healthy adult brain demonstrates robust learning-induced neuroanatomical plasticity. While altered neuroanatomical plasticity is suspected to be a factor mitigating the progressive cognitive decline in Alzheimer's disease (AD), it is not known to what extent this plasticity is affected by AD. We evaluated whether spatial learning and memory-induced neuroanatomical plasticity are diminished in an adult mouse model of AD (APP mice) featuring amyloid beta-driven cognitive and cerebrovascular dysfunction. We also evaluated the effect of early, long-term pioglitazone-treatment on functional hyperemia, spatial learning and memory, and associated neuroanatomical plasticity. Using high-resolution post-mortem MRI and deformation-based morphometry, we demonstrate spatial learning and memory-induced focal volume increase in the hippocampus of wild-type mice, an effect that was severely attenuated in APP mice, consistent with their unsuccessful performance in the spatial Morris water maze. These findings implicate impaired neuroanatomical plasticity as an important contributing factor to cognitive deficits in the APP mouse model of AD. Pioglitazone-treatment in APP mice completely rescued functional hyperemia and exerted beneficial effects on spatial learning and memory-recall, but it did not improve hippocampal plasticity.

Medication adherence survey of drugs useful in prevention of dementia of Alzheimer's type among Indian patients

BACKGROUND

Good medication adherence is the cornerstone of therapeutic success. Alzheimer's disease (AD) is the most common type of dementia and most patients are old and on multiple drugs, and good compliance therefore is even more important in this population. Dementia of Alzheimer's type (DAT) at present is yet to find a cure. Anticholinesterases and N-methyl-D-aspartate blockers are specific anti-AD therapies available. Hypertension, diabetes, and dyslipidemia can contribute to cognitive worsening. Keeping hypertension, diabetes, and dyslipidemia in control can therefore possibly prevent further cognitive decline.

METHODS

Patients with subjective memory complaints (n = 75) were chosen randomly. Upon thorough neurological diagnostic work up for dementia, those with mild cognitive impairment/questionable dementia (Clinical Dementia Rating = 0.5) or those with AD were recruited in this study (n = 67). Those with hypertension, diabetes, and deranged lipid profile were further interviewed if they were able to take medicines regularly or not. An attempt was made to know causes of non-compliance.

RESULTS

Forty-one percent of patients were not taking the drugs that have potential to prevent cardiovascular complications or ability to slow down cognitive decline in AD on regular basis. The lack of awareness, ignorance, medicines being "too expensive," and the pressure of taking medicines regularly were cited as the reasons for non-compliance. Being illiterate and having low education contributed majorly to poor compliance in this study.

CONCLUSION

Compliance to drugs that have potential or real ability to slow down cognitive decline is low in elderly people with DAT.

Does vascular burden contribute to the progression of mild cognitive impairment to dementia?

AIMS

To investigate the contribution of vascular risk factors (VRFs), vascular diseases (VDs) and white matter lesions (WMLs) to the progression of mild cognitive impairment (MCI) to dementia and Alzheimer's disease (AD).

METHODS

Two hundred forty-five consecutive subjects with MCI (age 74.09 ± 6.92 years) were followed for an average of 2.4 years. The Hachinski Ischemic Score and the Framingham Stroke Risk Profile were used to summarize VRFs and VDs. WMLs were graded using the Age-Related White Matter Changes Scale.

RESULTS

One hundred twenty-nine (52.6%) out of 245 subjects at risk converted to dementia, including 87 cases of AD. When hypertension occurred in MCI with deep WMLs, a 1.8-fold increased risk of dementia was observed (95% CI = 1.0-3.4). When deep WMLs occurred in MCI with high scores (≥4) on the Hachinski scale, a 3.5-fold (95% CI = 1.6-7.4) and 3.8-fold (95% CI = 1.2-11.5) risk of progression to dementia and AD was observed, respectively. Analogously, the joint effect of WMLs and high scores (≥14) on the Framingham scale nearly doubled the risk of dementia (hazard ratio = 1.9, 95% CI = 1.1-3.3).

CONCLUSIONS

Accelerated progression of MCI to dementia and AD is to be expected when VRFs and VDs occur together with WMLs.

Dyslipidemia and the risk of Alzheimer's disease

Whether cholesterol is implicated in the pathogenesis of Alzheimer's disease (AD) is still controversial. Several studies that explored the association between lipids and/or lipid-lowering treatment and AD indicate a harmful effect of dyslipidemia on AD risk. The findings are supported by genetic linkage and association studies that have clearly identified several genes involved in cholesterol metabolism or transport as AD susceptibility genes, including apolipoprotein E (APOE), apolipoprotein J (APOJ, CLU), ATP-binding cassette subfamily A member 7(ABCA7), and sortilin-related receptor (SORL1). Functional cell biology studies further support a critical involvement of lipid raft cholesterol in the modulation of Aβ precursor protein processing by β-secretase and γ-secretase resulting in altered Aβ production. However, conflicting evidence comes from epidemiological studies showing no or controversial association between dyslipidemia and AD risk, randomized clinical trials observing no beneficial effect of statin therapy, and cell biology studies suggesting that there is little exchange between circulating and brain cholesterol, that increased membrane cholesterol level is protective by inhibiting loss of membrane integrity through amyloid cytotoxicity, and that cellular cholesterol inhibits colocalization of β-secretase 1 and Aβ precursor protein in nonraft membrane domains, thereby increasing generation of plasmin, an Aβ-degrading enzyme. The aim of this article is to provide a comprehensive review of the findings of epidemiological, genetic, and cell biology studies aiming to elucidate the role of cholesterol in the pathogenesis of AD.

Cardiovascular risk in cognitively preserved elderlies is associated with glucose hypometabolism in the posterior cingulate cortex and precuneus regardless of brain atrophy and apolipoprotein gene variations

Cardiovascular risk factors (CVRF) possibly contribute to the emergence of Alzheimer's disease (AD). Fluorodeoxyglucose-positron emission tomography (FDG-PET) has been widely used to demonstrate specific patterns of reduced cerebral metabolic rates of glucose (CMRgl) in subjects with AD and in non-demented carriers of the apolipoprotein ε4 (APOE ε4) allele, the major genetic risk factor for AD. However, functional neuroimaging studies investigating the impact of CVRF on cerebral metabolism have been scarce to date. The present FDG-PET study investigated 59 cognitively preserved elderlies divided into three groups according to their cardiovascular risk based on the Framingham 10-year risk Coronary Heart Disease Risk Profile (low-, medium-, and high-risk) to examine whether different levels of CVRF would be associated with reduced CMRgl, involving the same brain regions affected in early stages of AD. Functional imaging data were corrected for partial volume effects to avoid confounding effects due to regional brain atrophy, and all analyses included the presence of the APOE ε4 allele as a confounding covariate. Significant cerebral metabolism reductions were detected in the high-risk group when compared to the low-risk group in the left precuneus and posterior cingulate gyrus. This suggests that findings of brain hypometabolism similar to those seen in subjects with AD can be detected in association with the severity of cardiovascular risk in cognitively preserved individuals. Thus, a greater knowledge about how such factors influence brain functioning in healthy subjects over time may provide important insigths for the future development of strategies aimed at delaying or preventing the vascular-related triggering of pathologic brain changes in the AD.

Diabetes mellitus and risk of dementia: A meta-analysis of prospective observational studies

AIMS/INTRODUCTION

The aim of the present study was to investigate the association between diabetes and the risk of all type dementia (ATD), Alzheimer's disease (AD) and vascular dementia (VaD).

MATERIALS AND METHODS

Prospective observational studies describing the incidence of ATD, AD and VaD in patients with diabetes mellitus were extracted from PubMed, EMBASE and other databases up to January 2012. Pooled relative risk (RR) estimates and 95% confidence intervals (CIs) were calculated using the random-effects model. Subgroup analyses and sensitivity analysis were also carried out.

RESULTS

A total of 28 studies contributed to the analysis. Pooled RR of developing ATD (n = 20) was 1.73 (1.65-1.82, I (2) = 71.2%), AD (n = 20) was 1.56 (1.41-1.73, I (2) = 9.8%) and VaD (n = 13) was 2.27 (1.94-2.66, I (2) = 0%) in patients with diabetes mellitus. Higher and medium quality studies did not show any significant difference for pooled RR for ATD, AD or VaD. Sensitivity analyses showed robustness of pooled RR among ATD, AD and VaD, showing no single study had a major impact on pooled RR.

CONCLUSIONS

The results showed a 73% increased risk of ATD, 56% increase of AD and 127% increase of VaD in diabetes patients.

Effects of carotid artery stenting on cognitive function in patients with mild cognitive impairment and carotid stenosis

Carotid stenosis is known to be an independent risk factor in the transformation process of mild cognitive impairment (MCI) to dementia and is treated by carotid artery stenting (CAS); however, the effects of CAS on cognitive function are unclear. In this study, 240 patients were prospectively assigned to a CAS or control group according to patient preference and underwent detailed neuropsychological examinations (NPEs) before and 6 months after treatment. Cerebral perfusion was assessed with computed tomography perfusion (CTP). Among the 240 patients included in the study, 208 patients completed NPEs at baseline and 6 months after therapy. The patients in the two groups did not differ with regard to baseline characteristics, educational level, vascular risk factors (VRFs) and NPEs prior to therapy. Significant improvements in the Mini-Mental State Examination (MMSE; before, 24.6±1.7 vs. after, 24.8±1.9; P=0.016), Montreal Cognitive Assessment (MOCA; before, 23.7±1.7 vs. after, 24.1±2.0; P=0.006), Fuld Object Memory Evaluation (FOME; before, 13.8±2.2 vs. after, 14.0±2.3; P=0.031) and Wechsler Adult Intelligence Scale-digital span (WAIS-DS; before, 6.7±2.1 vs. after, 6.9±2.3; P=0.040) were observed in the CAS group; however, improvements were not observed in the control group. Of the 84 patients in the CAS group who received CTP follow-up, 72 (86%) presented improvements in ipsilateral brain perfusion 6 months after the procedure; however, no improvement was observed in the control group. Close correlations were identified between the change in perfusion and the change in MMSE (r=0.575) and MOCA (r=0.574). CAS improves global cognitive function in patients with carotid stenosis and MCI and the improvement of cognition is closely related to the improvement of cerebral perfusion.

Efficacy of cognitive rehabilitation therapies for mild cognitive impairment (MCI) in older adults: working toward a theoretical model and evidence-based interventions

To evaluate the efficacy of cognitive rehabilitation therapies (CRTs) for mild cognitive impairment (MCI). Our review revealed a need for evidence-based treatments for MCI and a lack of a theoretical rehabilitation model to guide the development and evaluation of these interventions. We have thus proposed a theoretical rehabilitation model of MCI that yields key intervention targets-cognitive compromise, functional compromise, neuropsychiatric symptoms, and modifiable risk and protective factors known to be associated with MCI and dementia. Our model additionally defines specific cognitive rehabilitation approaches that may directly or indirectly target key outcomes-restorative cognitive training, compensatory cognitive training, lifestyle interventions, and psychotherapeutic techniques. Fourteen randomized controlled trials met inclusion criteria and were reviewed. Studies markedly varied in terms of intervention approaches and selected outcome measures and were frequently hampered by design limitations. The bulk of the evidence suggested that CRTs can change targeted behaviors in individuals with MCI and that CRTs are associated with improvements in objective cognitive performance, but the pattern of effects on specific cognitive domains was inconsistent across studies. Other important outcomes (i.e., daily functioning, quality of life, neuropsychiatric symptom severity) were infrequently assessed across studies. Few studies evaluated long-term outcomes or the impact of CRTs on conversion rates from MCI to dementia or normal cognition. Overall, results from trials are promising but inconclusive. Additional well-designed and adequately powered trials are warranted and required before CRTs for MCI can be considered evidence-based.

Cognitive impairment associated with atrial fibrillation: a meta-analysis

BACKGROUND

Atrial fibrillation (AF) has been linked with an increased risk for cognitive impairment and dementia.

PURPOSE

To complete a meta-analysis of studies examining the association between AF and cognitive impairment.

DATA SOURCES

Search of MEDLINE, PsycINFO, Cochrane Library, CINAHL, and EMBASE databases and hand search of article references.

STUDY SELECTION

Prospective and nonprospective studies reporting adjusted risk estimates for the association between AF and cognitive impairment.

DATA EXTRACTION

Two abstracters independently extracted data on study characteristics, risk estimates, methods of AF and outcome ascertainment, and methodological quality.

DATA SYNTHESIS

Twenty-one studies were included in the meta-analysis. Atrial fibrillation was significantly associated with a higher risk for cognitive impairment in patients with first-ever or recurrent stroke (relative risk [RR], 2.70 [95% CI, 1.82 to 4.00]) and in a broader population including patients with or without a history of stroke (RR, 1.40 [CI, 1.19 to 1.64]). The association in the latter group remained significant independent proof of clinical stroke history (RR, 1.34 [CI, 1.13 to 1.58]). However, there was significant heterogeneity among studies of the broader population (I2 = 69.4%). Limiting the analysis to prospective studies yielded similar results (RR, 1.36 [CI, 1.12 to 1.65]). Restricting the analysis to studies of dementia eliminated the significant heterogeneity (P = 0.137) but did not alter the pooled estimate substantially (RR, 1.38 [CI, 1.22 to 1.56]).

LIMITATIONS

There is an inherent bias because of confounding variables in observational studies. There was significant heterogeneity among included studies.

CONCLUSION

Evidence suggests that AF is associated with a higher risk for cognitive impairment and dementia, with or without a history of clinical stroke. Further studies are required to elucidate the association between AF and subtypes of dementia as well as the cause of cognitive impairment.

A population-based study of dosing and persistence with anti-dementia medications

PURPOSE

Cholinesterase inhibitors and memantine are the mainstay of pharmacological intervention for the cognitive symptoms of Alzheimer's disease (AD). This study assessed the adequacy of dosing and persistence with AD medications and the predictors of these variables in the 'real world' (outside the clinical trial setting).

METHODS

The Health Service Executive-Primary Care Reimbursement Services prescription claims database in the Republic of Ireland contains prescription information for 1.6 million people. Patients aged >70 years who received at least two prescriptions for donepezil, rivastigmine, galantamine and memantine between January 2006 and December 2010 were included in the study. Rates of dose-maximisation were recorded by examining the initiation dose of each AD drug commenced during the study period and any subsequent dose titrations. Non-persistence was defined by a gap in prescribing of more than 63 consecutive days. Predictors of dose-maximisation and non-persistence were also analysed.

RESULTS

Between January 2006 and December 2010, 20,729 patients aged >70 years received a prescription for an AD medication. Despite most patients on donepezil and memantine receiving a prescription for the maximum drug dose, this dose was maintained for 2 consecutive months in only two-thirds of patients. Patients were significantly more likely to have their doses of donepezil and memantine maximised if prescribed in more recent years (2010 vs. 2007). Rates of non-persistence were 30.1 % at 6 months and 43.8 % at 12 months. Older age [75+ vs. <75 years; hazards ratio (HR) 1.16, 95 % confidence interval (CI) 1.06-1.27] and drug type (rivastigmine vs. donepezil; HR 1.15, 95 % CI 1.03-1.27) increased the risk of non-persistence. Non-persistence was lower for those commencing therapy in more recent years (2010 vs. 2007; HR 0.81, 95 % CI 0.73-0.89, p < 0.001) and for those on multiple anti-dementia medications (HR 0.59, 95 % CI 0.54-0.65, p < 0.001). Persistence was significantly higher when memantine was co-prescribed with donepezil (p < 0.0001).

CONCLUSION

Future studies should explore the reasons underlying non-persistence and failure to maintain dose-maximisation in patients on AD medications. There may be scope to improve the dosing and persistence with these medications in the community.

Physical activity and brain function in older adults at increased risk for Alzheimer's disease

Leisure-time physical activity (PA) and exercise training are known to help maintain cognitive function in healthy older adults. However, relatively little is known about the effects of PA on cognitive function or brain function in those at increased risk for Alzheimer's disease through the presence of the apolipoproteinE epsilon4 (APOE-ε4) allele, diagnosis of mild cognitive impairment (MCI), or the presence of metabolic disease. Here, we examine the question of whether PA and exercise interventions may differentially impact cognitive trajectory, clinical outcomes, and brain structure and function among individuals at the greatest risk for AD. The literature suggests that the protective effects of PA on risk for future dementia appear to be larger in those at increased genetic risk for AD. Exercise training is also effective at helping to promote stable cognitive function in MCI patients, and greater cardiorespiratory fitness is associated with greater brain volume in early-stage AD patients. In APOE-ε4 allele carriers compared to non-carriers, greater levels of PA may be more effective in reducing amyloid burden and are associated with greater activation of semantic memory-related neural circuits. A greater research emphasis should be placed on randomized clinical trials for exercise, with clinical, behavioral, and neuroimaging outcomes in people at increased risk for AD.

High blood pressure and cognitive decline in mild cognitive impairment

OBJECTIVES

To determine whether high blood pressure (BP) levels are associated with faster decline in specific cognitive domains.

DESIGN

Prospective longitudinal cohort.

SETTING

Uniform Data Set of the National Institutes of Health, National Institute on Aging Alzheimer's Disease Centers.

PARTICIPANTS

One thousand three hundred eighty-five participants with a diagnosis of mild cognitive impairment (MCI) and measured BP values at baseline and two annual follow-up visits.

MEASUREMENTS

Neuropsychological test scores and Clinical Dementia Rating Sum of Boxes (CDR Sum) score.

RESULTS

Participants with MCI with two or three annual occasions of high BP values (systolic BP ≥140 mmHg or diastolic BP ≥90 mmHg) had significantly faster decline on neuropsychological measures of visuomotor sequencing, set shifting, and naming than those who were normotensive on all three occasions. High systolic BP values were associated as well with faster decline on the CDR Sum score.

CONCLUSION

Hypertension is associated with faster cognitive decline in persons at risk for dementia.

Association of cerebral small vessel disease with delusions in patients with Alzheimer's disease

BACKGROUND

Cerebral small vessel disease (SVD) is frequently observed in patients with Alzheimer's disease (AD). However, the association between SVD and clinical symptoms exhibited by patients with AD remains unclear. This study examined the association of SVD as observed on magnetic resonance imaging (MRI) with behavioural and psychological symptoms of dementia and cognitive function of patients with probable AD.

METHODS

A total of 163 consecutive patients (55 men, 108 women) with probable AD were included in this cross-sectional study of a prospective cohort. Patients were divided into two groups based on the presence or absence of cerebral SVD [white matter hyperintensities (WMH) grade 0/1 (Fazekas scale) and no lacunes: SVD absent, WMH grade 2/3 (Fazekas scale) or the number of lacunes ≥1: SVD present]. Cognitive functions were assessed using the Mini mental state examination, word recall and recognition subtests in the Alzheimer's Disease Assessment Scale-Cognitive Subscale, as well as the letter fluency task and the category fluency task. Psychiatric symptoms were rated according to Neuropsychiatric Inventory.

RESULTS

Patients with probable AD with cerebral SVD had significantly more delusions and depression than those without SVD. No significant differences were observed in other neuropsychiatric symptoms, MMSE or word recall and recognition tests between both groups.

CONCLUSIONS

Our results suggest that cerebral SVD observed on MRI of patients with AD is associated with delusions and depression.

Dyslipidemia and dementia: current epidemiology, genetic evidence, and mechanisms behind the associations

The role of cholesterol in the etiology of Alzheimer's disease (AD) is still controversial. Some studies exploring the association between lipids and/or lipid lowering treatment and AD indicate a harmful effect of dyslipidemia and a beneficial effect of statin therapy on AD risk. The findings are supported by genetic linkage and association studies that have clearly identified several genes involved in cholesterol metabolism or transport as AD susceptibility genes, including apolipoprotein E, apolipoprotein J, and the sortilin-related receptor. Functional cell biology studies support a critical involvement of lipid raft cholesterol in the modulation of amyloid-β protein precursor (AβPP) processing by β- and γ-secretase resulting in altered amyloid-β production. Contradictory evidence comes from epidemiological studies showing no or controversial association between dyslipidemia and AD risk. Additionally, cell biology studies suggest that there is little exchange between circulating and brain cholesterol, that increased membrane cholesterol is protective by inhibiting loss of membrane integrity through amyloid cytotoxicity, and that cellular cholesterol inhibits co-localization of BACE1 and AβPP in non-raft membrane domains, thereby increasing generation of plasmin, an amyloid-β-degrading enzyme. The aim of this review is to summarize the findings of epidemiological and cell biological studies to elucidate the role of cholesterol in AD etiology.

Cerebrovascular protection of β-asarone in Alzheimer's disease rats: a behavioral, cerebral blood flow, biochemical and genic study

AIM OF THE STUDY

Recent studies have suggested that β-asarone have neuroprotective and cardiovascular protective effects in animal model. However, the influence of β-asarone on cerebrovascular system has not been explored so far. Therefore, present study was designed to determine whether repeated exposures to β-asarone resulted in positive effects on cerebrovascular function in AD rats.

MATERIALS AND METHODS

Alzheimer's disease induced rats was established by injecting both D-galactose (D-gal) and aluminum chloride (AlCl(3)) into abdominal cavity for 42 days. After injection of AlCl(3) and D-gal or saline for 28 days, the rats were treated with volume-matched vehicle or β-asarone (25mg/kg, 50mg/kg or 100mg/kg, i.h.) or Nimodipine (40mg/kg, i.g) once daily for consecutive 14 days, respectively. Behavioral responses of animals were assessed in a Morris water maze. CBF was measured by laser Doppler flowmetry. At the end of this period all rats were sacrificed, lactic acid, pyruvic acid content, Na+K+ATPase activity were determined in brain tissue homogenate to estimate the brain biochemical changes and mRNA expression of ET-1, eNOS and APP was measured with real-time RT-PCR method.

RESULTS

The spatial navigation task latencies, the times through platform zone and the time for the first through platform zone in the target quadrant in probe task, rCBF of right parietal lobe, the contents of lactic acid, pyruvic acid, and the activity of Na-K-ATP of cortex, and ET-1 and eNOS mRNA expression in hippocampus of AG rats were different from those of BG, P<0.05; The level of APP mRNA expression in model control group rats was higher than that in BG, though there was not a statistically significant difference, P>0.05; Compared with AG, HG rats spatial navigation task latencies were shorter, in probe task the times through platform zone in the target quadrant were bigger, rCBF and blood cell concentration of right parietal lobe were higher, the contents of pyruvic acid was lower, the activity of Na-K-ATP was higher, and ET-1 mRNA expression in hippocampus was lower, P<0.05; The level of eNOS and APP mRNA expression in HG rats was lower than that in AG, though there was not a statistically significant difference, P>0.05;

CONCLUSION

The present results suggested that β-asarone may be useful in memory impairment due to its cerebrovascular protection in AD rats and may develop as a therapeutic drug for treatment of AD patients.

Epidemiology of dementias and Alzheimer's disease

BACKGROUND AND AIMS

Global population aging has been one of the defining processes of the twentieth century, with profound economic, political and social consequences. It is driving the current epidemic of dementia, both in terms of its extent and global distribution. The aim of the study was to summarize recent findings relevant to the epidemiological knowledge of dementia and Alzheimer's disease (AD).

METHODS

A narrative mini-review of the literature relevant to the epidemiology of dementia and AD is presented, summarizing important findings and analyzing their implications.

RESULTS

It was estimated that in 2010 there were 36.5 million people living with dementia, with 7.7 million new cases yearly and a new case of dementia every 4 sec. The number of persons living with dementia will nearly double every 20 years. Most of these persons will be living in low- and middle-income countries (LMIC).

CONCLUSIONS

There are a substantial number of people with dementia worldwide and these numbers will continue to increase mainly in LMIC, producing a wide range of impacts. It is important to make dementia a national public health and social care priority worldwide. Recent reviews and meta-analyses have failed to clearly identify a singular causal or preventive pathway for AD that seems to be a multicausal, heterogeneous and age-related condition.

Effect of Western medicine therapy assisted by Ginkgo biloba tablet on vascular cognitive impairment of none dementia

OBJECTIVE

To discuss the clinical effects of Western medicine therapy assisted by Ginkgo biloba tablet (GBT) on patients with vascular cognitive impairment of none dementia (VCIND).

METHODS

A total of 80 patients with VCIND were divided into two groups randomly: Conventional treatment group (control group) and combined treatment group. Conventional treatment group was given conventional treatment with anti-platelet aggregation. In this group, 75 mg aspirin was given three times a day for 3 months. While in combined treatment group, 19.2 mg GBT was given three times a day for 3 months together with conventional treatment (anti-platelet aggregation drugs). Montreal cognitive assessment (MoCA) and transcranial Doppler (TCD) were used to observe changes of cognitive ability and cerebral blood flow in VCIND patients before and after treatment in both groups. Then the clinical data were analyzed so as to compare the efficacy in two groups.

RESULTS

After 3 month-treatment in combined treatment group, the scores of executive ability, attention, abstract, delayed memory, orientation in the MoCA were significantly increased compared with those before treatment and those in control group after treatment. Besides, blood flow velocity of anterior cerebral artery increased significantly than that before treatment and that in control group after treatment.

CONCLUSIONS

GBT tablet can improve the therapeutic efficacy as well improve cognitive ability and cerebral blood flow supply of patients with VCIND.

Cardiovascular risk factors, cortisol, and amyloid-β deposition in Alzheimer's Disease Neuroimaging Initiative

BACKGROUND

There is epidemiological evidence that cardiovascular risk factors (CVRF) also are risk factors for Alzheimer's disease, but there is limited information on this from neuropathological studies, and even less from in vivo studies. Therefore, we examined the relationship between CVRF and amyloid-β (Aβ) brain burden measured by Pittsburgh Compound B-positron emission tomography (PiB-PET) studies in the Alzheimer's Disease Neuroimaging Initiative.

METHODS

Ninety-nine subjects from the Alzheimer's Disease Neuroimaging Initiative cohort who had a PiB-PET study measure, apolipoprotein E genotyping data, and information available on CVRF (body mass index [BMI], systolic blood pressure, diastolic blood pressure [DBP], and cholesterol and fasting glucose test results) were included. Eighty-one subjects also had plasma cortisol, C-reactive protein, and superoxide dismutase 1 measurements. Stepwise regression models were used to assess the relation between the CVRF and the composite PiB-PET score.

RESULTS

The first model included the following as baseline variables: age, clinical diagnosis, number of apolipoprotein ɛ4 alleles, BMI (P = .023), and DBP (P = .012). BMI showed an inverse relation with PiB-PET score, and DBP had a positive relation with PiB-PET score. In the second adjusted model, cortisol plasma levels were also associated with PiB-PET score (P = .004). Systolic blood pressure, cholesterol, or impaired fasting glucose were not found to be associated with PiB-PET values.

CONCLUSION

In this cross-sectional study, we found an association between Aβ brain burden measured in vivo and DBP and cortisol, indicating a possible link between these CVRF and Aβ burden measured by PiB-PET. These findings highlight the utility of biomarkers to explore potential pathways linking diverse Alzheimer's disease risk factors.

Effects of exercise intervention on vascular risk factors in older adults with mild cognitive impairment: a randomized controlled trial

Aims

The purpose of this study is to clarify the effects of exercise intervention on vascular risk factors in older adults with mild cognitive impairment (MCI).

Methods

Community-dwelling older adults who met the definition of MCI using the Petersen criteria (n = 100; mean age = 75.3 years) were randomly allocated to the exercise (n = 50) or education control group (n = 50). Participants in the exercise group exercised under the supervision of physiotherapists for 90 min/day, 2 days/week, 80 times for 12 months. Anthropometric profiles, blood markers, blood pressure, and physical fitness (the 6-min walking test) were measured. Total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), and TC/HDL-C risk ratio measurements were taken from blood samples.

Results

The exercise group showed significantly reduced TC and TC/HDL-C risk ratio after training compared with baseline levels (p < 0.001, p = 0.004). However, no significant reduction was found for the control group (p = 0.09, p = 0.09). Physical fitness also significantly improved after exercise intervention compared with the control group (p < 0.0001).

Conclusion

Exercise intervention was associated with positive changes in important vascular risk factors related to cognitive decline and vascular disease in older adults with MCI.

Assessment of dementia risk in aging adults using both FDG-PET and FDDNP-PET imaging

BACKGROUND

In a previous study, positron emission tomography (PET) with 2-(1-{6-[(2-[F-18]fluoroethyl)(methyl)amino]-2-naphthyl}ethylidene)malononitrile (FDDNP), a molecule that binds to plaques and tangles in vitro, identified three subgroups of non-demented subjects according to FDDNP binding patterns: low global (LG) binding; high frontal, parietal, medial temporal binding (HF/PA); and high medial and lateral temporal and posterior cingulate (HT/PC) binding. In this follow-up investigation, we compared 2-deoxy-2-[F-18]fluoro- d-glucose (FDG)-PET cerebral metabolic patterns in the three FDDNP-PET binding subgroups.

METHODS

Fifty-four subjects with normal aging (N = 28) or amnestic forms of mild cognitive impairment (N = 26) underwent FDDNP-PET and FDG-PET scanning. Subjects in the LG, HF/PA, and HT/PC FDDNP subgroups were compared according to visual ratings, statistical parametric mapping, and automated region of interest analyses of their FDG-PET data.

RESULTS

The FDDNP-PET subgroups demonstrated different glucose metabolic patterns according to visual ratings, region of interest, and statistical parametric mapping analyses of FDG-PET data. The LG FDDNP subgroup showed no areas of significant hypometabolism relative to the other subgroups and had low Alzheimer's disease risk by FDG-PET standards. The HF/PA FDDNP subgroup demonstrated hypometabolism in bilateral inferior parietal/parietotemporal, bilateral posterior cingulate, perisylvian, mid-temporal gyrus, and dorsolateral prefrontal regions, which is a pattern suggestive of high Alzheimer's disease risk. The HT/PC FDDNP subgroup demonstrated heterogeneous FDG-PET patterns with predominant anterior frontal and anterior temporal hypometabolism, suggestive of mixed etiologies, including fronto-temporal dementia risk.

CONCLUSIONS

The FDG-PET data provided independent validation that different patterns of FDDNP-PET binding in non-demented individuals may be associated with differential dementia risk.

Metabolomics: a novel approach to identify potential diagnostic biomarkers and pathogenesis in Alzheimer's disease

Although the pathogenesis of Alzheimer's disease (AD) is still not fully understood, it is acknowledged that intervention should be made at the early stage. Therefore, identifying biomarkers for the clinical diagnosis is critical. Metabolomics, a novel "omics", uses methods based on low-molecular-weight molecules, with high-throughput evaluation of a large number of metabolites that may lead to the identification of new disease-specific biomarkers and the elucidation of pathophysiological mechanisms. This review discusses metabolomics investigations of AD and potential future developments in this field.

Benzodiazepine use and risk of dementia: prospective population based study

OBJECTIVE

To evaluate the association between use of benzodiazepines and incident dementia.

DESIGN

Prospective, population based study.

SETTING

PAQUID study, France.

PARTICIPANTS

1063 men and women (mean age 78.2 years) who were free of dementia and did not start taking benzodiazepines until at least the third year of follow-up.

MAIN OUTCOME MEASURES

Incident dementia, confirmed by a neurologist.

RESULTS

During a 15 year follow-up, 253 incident cases of dementia were confirmed. New use of benzodiazepines was associated with an increased risk of dementia (multivariable adjusted hazard ratio 1.60, 95% confidence interval 1.08 to 2.38). Sensitivity analysis considering the existence of depressive symptoms showed a similar association (hazard ratio 1.62, 1.08 to 2.43). A secondary analysis pooled cohorts of participants who started benzodiazepines during follow-up and evaluated the association with incident dementia. The pooled hazard ratio across the five cohorts of new benzodiazepine users was 1.46 (1.10 to 1.94). Results of a complementary nested case-control study showed that ever use of benzodiazepines was associated with an approximately 50% increase in the risk of dementia (adjusted odds ratio 1.55, 1.24 to 1.95) compared with never users. The results were similar in past users (odds ratio 1.56, 1.23 to 1.98) and recent users (1.48, 0.83 to 2.63) but reached significance only for past users.

CONCLUSIONS

In this prospective population based study, new use of benzodiazepines was associated with increased risk of dementia. The result was robust in pooled analyses across cohorts of new users of benzodiazepines throughout the study and in a complementary case-control study. Considering the extent to which benzodiazepines are prescribed and the number of potential adverse effects of this drug class in the general population, indiscriminate widespread use should be cautioned against.

Benefits in cognitive function, blood pressure, and insulin resistance through cocoa flavanol consumption in elderly subjects with mild cognitive impairment: the Cocoa, Cognition, and Aging (CoCoA) study

Flavanol consumption is favorably associated with cognitive function. We tested the hypothesis that dietary flavanols might improve cognitive function in subjects with mild cognitive impairment. We conducted a double-blind, parallel arm study in 90 elderly individuals with mild cognitive impairment randomized to consume once daily for 8 weeks a drink containing ≈990 mg (high flavanols), ≈520 mg (intermediate flavanols), or ≈45 mg (low flavanols) of cocoa flavanols per day. Cognitive function was assessed by Mini Mental State Examination, Trail Making Test A and B, and verbal fluency test. At the end of the follow-up period, Mini Mental State Examination was similar in the 3 treatment groups (P=0.13). The time required to complete Trail Making Test A and Trail Making Test B was significantly (P<0.05) lower in subjects assigned to high flavanols (38.10±10.94 and 104.10±28.73 seconds, respectively) and intermediate flavanols (40.20±11.35 and 115.97±28.35 seconds, respectively) in comparison with those assigned to low flavanols (52.60±17.97 and 139.23±43.02 seconds, respectively). Similarly, verbal fluency test score was significantly (P<0.05) better in subjects assigned to high flavanols in comparison with those assigned to low flavanols (27.50±6.75 versus 22.30±8.09 words per 60 seconds). Insulin resistance, blood pressure, and lipid peroxidation also decreased among subjects in the high-flavanol and intermediate-flavanol groups. Changes of insulin resistance explained ≈40% of composite z score variability through the study period (partial r(2)=0.4013; P<0.0001). To the best of our knowledge, this is the first dietary intervention study demonstrating that the regular consumption of cocoa flavanols might be effective in improving cognitive function in elderly subjects with mild cognitive impairment. This effect appears mediated in part by an improvement in insulin sensitivity.

Cerebral white matter lesions and lacunar infarcts contribute to the presence of mild parkinsonian signs

BACKGROUND AND PURPOSE

Mild parkinsonian signs (MPS) are common in elderly people and may be an early stage of parkinson(ism). They might be related to cerebral small-vessel disease, although this association remains incompletely understood. To identify subjects at early stages of the disease, we investigated whether the presence of MPS was dependent on the severity and location of small-vessel disease, including white matter lesions and lacunar infarcts.

METHODS

Four hundred thirty individuals, with small-vessel disease, aged between 50 and 85 years, without dementia or parkinsonism, were included in this analysis and underwent MRI scanning. The number and location of lacunar infarcts were rated. White matter lesion volume was assessed by manual segmentation with automated delineating of different regions. Presence of MPS was based on the motor section of the Unified Parkinson's Disease Rating Scale. Associations were determined using logistic regression analysis adjusted for age, sex, and total brain volume.

RESULTS

Severe white matter lesions and the presence of lacunar infarcts were independently associated with the presence of MPS (OR, 2.6; 95% CI, 1.3-4.9 and OR, 1.8; 95% CI, 1.0-3.0). Frontal and parietal white matter lesions and, to a lesser extent, lacunar infarcts in the thalamus were associated with a higher risk of MPS. The presence of lacunar infarcts was independently related to the bradykinesia category of parkinsonian signs.

CONCLUSIONS

This study shows that severe small-vessel disease, especially at certain locations, is associated with MPS signs in older adults. Our findings suggest that small-vessel disease interrupts basal ganglia-thalamocortical circuits involving both the frontal and parietal lobes and hence may result in MPS.

Cognitive assessment protocol design in the ISSYS (Investigating Silent Strokes in hYpertensives: a magnetic resonance imaging Study)

Hypertension and silent cerebrovascular lesions (SCL) detected by brain magnetic resonance imaging (MRI) are associated with an increased risk of cognitive decline. In a prospective observational study in 1000 hypertensive patients, aged 50-70 years, with no prior history of stroke or dementia, we will study the presence of mild cognitive impairment (MCI) and the relationship between SCL and cognition. All participants will be assessed by means of the Dementia Rating Scale-2 (DRS-2) and will undergo a brain MRI. In order to better characterize MCI and future dementia risk in our cohort, those patients that are suspected to be cognitively impaired according to the DRS-2 results will have a further neurological evaluation and complete neuropsychological testing. Follow-up for the entire cohort is planned to last for at least 3 years.

Baseline cardiovascular risk predicts subsequent changes in resting brain function

BACKGROUND AND PURPOSE

The Framingham Heart Study group cardiovascular disease risk profile (FCRP) score was used to assess the relationship between baseline cardiovascular risk and subsequent changes in resting state cerebral blood flow (CBF) in cognitively normal older participants from the Baltimore Longitudinal Study of Aging.

METHODS

Ninty-seven cognitively normal participants underwent annual resting-state positron emission tomography scans at baseline and over a period of up to 8 years (mean interval, 7.4 years). Images quantifying voxel-wise longitudinal rates of CBF change were calculated and used to examine the relationship between baseline FCRP score and changes over time in regional CBF. Individual components of the FCRP score (age, cholesterol, blood pressure, smoking status, and type 2 diabetes) were also correlated with changes in regional CBF to examine the independent contributions of each component to the overall pattern of change.

RESULTS

Higher baseline FCRP scores were associated with accelerated longitudinal decline in CBF in orbitofrontal, medial frontal/anterior cingulate, insular, precuneus, and brain stem regions. Of the components that comprise the FCRP score, higher diastolic blood pressure and diabetes were associated independently with greater decline in the medial frontal/anterior cingulate and insular regions, respectively.

CONCLUSIONS

Baseline cardiovascular risk factors are associated with greater rates of decline in resting state regional brain function. The regions showing accelerated decline participate in higher-order cognitive processes and are also vulnerable to age-related neuropathology. These results, in conjunction with other studies, encourage early treatment of cardiovascular risk factors in older individuals.

Increased Aβ production prompts the onset of glucose intolerance and insulin resistance

Type 2 diabetes (T2D) mellitus and Alzheimer's disease (AD) are two prevalent diseases with comparable pathophysiological features and genetic predisposition. Patients with AD are more susceptible to develop T2D. However, the molecular mechanism linking AD and T2D remains elusive. In this study, we have generated a new mouse model to test the hypothesis that AD would prompt the onset of T2D in mice. To test our hypothesis, we crossed Alzheimer APPswe/PS1dE9 (APP/PS1) transgenic mice with mice partially deficient in leptin signaling (db/+). Body weight, plasma glucose, and insulin levels were monitored. Phenotypic characterization of glucose metabolism was performed using glucose and insulin tolerance tests. β-Cell mass, islet volume, and islet number were analyzed by histomorphometry. APP/PS1 coexpression in mice with intact leptin receptor signaling did not show any metabolic perturbations in glucose metabolism or insulin sensitivity. In contrast, APP/PS1 coexpression in db/+ mice resulted in nonfasting hyperglycemia, hyperinsulinemia, and hypercholesterolemia without changes in body weight. Conversely, fasting blood glucose and cholesterol levels remained unchanged. Coinciding with altered glucose metabolism, APP/PS1 coexpression in db/+ mice resulted in glucose intolerance, insulin resistance, and impaired insulin signaling. In addition, histomorphometric analysis of pancreata revealed augmented β-cell mass. Taken together, these findings provide experimental evidence to support the notion that aberrant Aβ production might be a mechanistic link underlying the pathology of insulin resistance and T2D in AD.

Cognitive profiles in heart failure: a cluster analytic approach

Cognitive impairment is common among individuals with heart failure (HF), but the exact nature of these impairments remains unclear. The current study examined 140 older adults with heart failure and sought to determine whether there are distinct cognitive profiles using a cluster analytic approach. Results indicated three unique profiles comprising individuals who were cognitively intact, memory impaired, and globally impaired. Clusters differed on several important demographic and clinical characteristics. These findings suggest that cognitive impairment in persons with HF is more heterogeneous than commonly believed and has important implications for treatment recommendations.

A turning point for Alzheimer's disease?

Despite an archive of over 73,000 research papers published in the last two decades on the subject of Alzheimer's disease (AD), little clinical progress has been made relative to how people get sporadic AD and what can be done to help them avoid it. This review spotlights strategic steps that could be a turning point in the dramatic lowering of Alzheimer prevalence. The main strategy includes application of four pillars of prevention: 1) early identification of AD vascular risk factors; 2) early detection of AD vascular risk factors; 3) early intervention of AD vascular risk factors based on evidence-based medical decisions; 4) patient follow-up to assess and modify interventions as needed. Tandem to these four pillars of prevention, a proactive lifestyle consisting of a healthy diet coupled to physical and mental activity should be applied as part of any therapeutic intervention. We are persuaded by mounting and compelling evidence that AD is a multifactorial disorder kindled by vascular risk factors that generate chronic brain hypoperfusion (CBH) during advanced aging. A pathobiological cascade of biochemical events in the presence of CBH that leads to oxidative stress and neurodegeneration appears to involve multiple biofactors including micronutrients, trace metals, lipids, and pro-oxidants, as reviewed in this special issue of BioFactors. Modulation of these biofactors may help prevent or control incipient AD. © 2012 International Union of Biochemistry and Molecular Biology, Inc.

Suitability of the Montreal cognitive assessment versus the mini-mental state examination in detecting vascular cognitive impairment

The Mini-Mental State Examination (MMSE) has been criticized as being an insufficient screening test for patients with vascular cognitive impairment because of its insensitivity to visuospatial and executive functional deficits. The Montreal Cognitive Assessment (MoCA) was designed to be more sensitive to such deficits, and thus may be a superior screening instrument for vascular cognitive impairment. Twelve patients with extensive leukoaraiosis detected on magnetic resonance imaging (average age, 76.0 ± 8.7 years) underwent neurologic and cognitive testing, including MMSE and the Japanese version of the MoCA (MoCA-J). Accepted cutoff scores of <27 for the MMSE and <26 for the MoCA-J were taken to indicate cognitive impairment. Z-scores were calculated to evaluate the discriminating ability of individual MMSE and MoCA-J subtest scores. Although there was a strong correlation between the total MMSE and total MoCA-J scores (r = 0.90; P < .0001), MMSE scores were skewed toward the higher end of the range (range, 18-30; median, 28), whereas MoCA-J scores were normally distributed (range, 9-28; median, 21). Of the 7 patients with an unimpaired MMSE score, 6 (86%) had an impaired MoCA-J score. Z-scores were >5 for 4 MMSE subtests (orientation, registration, naming, and language) but for only 1 MoCA-J subtest (naming). The MoCA-J better discriminated cognitive status in subjects with extensive leukoaraiosis. Our findings suggest that the MoCA-J is more sensitive than the MMSE in screening for cognitive impairment in patients with subcortical vascular cognitive impairment.