The diagnosis of "mixed" dementia in the Consortium for the Investigation of Vascular Impairment of Cognition (CIVIC)

Neuroimaging in Vascular Cognitive Impairment and Dementia: A Systematic Review

Cerebrovascular diseases are well established causes of cognitive impairment. Different etiologic entities, such as vascular dementia (VaD), vascular cognitive impairment, subcortical (ischemic) VaD, and vascular cognitive disorder, are included in the umbrella definition of vascular cognitive impairment and dementia (VCID). Because of the variability of VCID clinical presentation, there is no agreement on criteria defining the neuropathological threshold of this disorder. In fact, VCID is characterized by cerebral hemodynamic alteration which ranges from decreased cerebral blood flow to small vessels disease and involves a multifactorial process that leads to demyelination and gliosis, including blood-brain barrier disruption, hypoxia, and hypoperfusion, oxidative stress, neuroinflammation and alteration on neurovascular unit coupling, cerebral microbleeds, or superficial siderosis. Numerous criteria for the definition of VaD have been described: the National Institute of Neurological Disorders and Stroke Association Internationale pour Recherche'-et-l'Enseignement en Neurosciences criteria, the State of California Alzheimer's Disease Diagnostic and Treatment Centers criteria, DSM-V criteria, the Diagnostic Criteria for Vascular Cognitive Disorders (a VASCOG Statement), and Vascular Impairment of Cognition Classification Consensus Study. Neuroimaging is fundamental for definition and diagnosis of VCID and should be used to assess the extent, location, and type of vascular lesions. MRI is the most sensible technique, especially if used according to standardized protocols, even if CT plays an important role in several conditions. Functional neuroimaging, in particular functional MRI and PET, may facilitate differential diagnosis among different forms of dementia. This systematic review aims to explore the state of the art and future perspective of non-invasive diagnostics of VCID.

Prevalence of Cognitive and Vestibular Impairment in Seniors Experiencing Falls

BACKGROUND

Falls are a growing concern in seniors (≥65 yrs). Cognitive impairment (CI) and vestibular impairment (VI) increase fall risk. The aim of this study is to assess the prevalence of CI and VI in seniors experiencing falls.

METHODS

Participants (≥65 yrs) with falls were recruited from Falls Prevention Programs (FPPs) and a Memory Clinic (MC). CI was assessed using the Montreal Cognitive Assessment at FPPs. VI was assessed at an MC and FFPs using the Head Impulse- (video + bedside), Headshake-, Dix-Hallpike test, and test of sensory interaction in balance. Questionnaires included Dizziness Handicap Inventory (DHI) and Activities-specific Balance Confidence Scale (ABC).

RESULTS

Of 41 participants (29 FPPs, 12 MC); mean age was 80.1 ± 7.1 years, and 58.5% were female. Overall, 82.9% had VI. At FPPs, 76.0% had CI, and 72.3% had CI + VI. Bilateral vestibular hypofunction (BVH) was more common than unilateral vestibular hypofunction (UVH) (70.6% vs. 29.4%); p = 0.016. Dizziness Handicap (DHI) was not different between those with a VI (23.5 ± 23.9) versus without VI [PVI + no impairment] (10.0 ± 15.4); p = 0.160. Balance confidence (ABC) was lowest in VI but not significantly different between those with a VI (63.4 ± 27.3) versus without VI [PVI + no impairment] (85.0 ± 16.5); p = 0.053.

CONCLUSIONS

VI and CI are prevalent in seniors experiencing falls. For seniors with history of falls, both cognitive and vestibular functions should be considered in the assessment and subsequent treatment. Screening enables earlier detection, targeted interventions, and prevention, reducing the clinical and financial impact.

A randomized controlled trial to evaluate the effectiveness and safety of electro acupuncture and transcranial direct current stimulation with computerized cognitive rehabilitation in patients with vascular cognitive impairment

BACKGROUND

Vascular cognitive impairment (VCI) refers to all cognitive disorders caused by cerebrovascular disorders. For the treatment, many types of pharmacologic and nonpharmacologic treatments are used but their underlying mechanisms and effects are unclear. Regarding nonpharmacologic treatment, electroacupuncture (EA), transcranial direct current stimulation (tDCS), and computerized cognitive rehabilitation treatment (CCRT) are effective. Here, we report the protocol for a randomized controlled trial of the effect and safety of combination therapy of EA or tDCS and CCRT in patients with VCI.

METHODS

This study will be a prospective, outcome assessor-blinded, parallel-arm, randomized controlled clinical trial. Participants with cognitive impairment caused by stroke after 3 months of onset (n = 45) will be randomly assigned to a CCRT, combination therapy with EA and computerized cognitive rehabilitation treatment, or combination therapy with tDCS and computerized cognitive rehabilitation treatment group. All groups will receive treatment 3 times per week for 8 weeks, giving a total of 24 treatments. The CCRT group will perform a training task like shopping, calculating, and others and involving computerized cognitive assessment and brain training system (RehaCom) for 30 minutes. The combination therapy with EA and computerized cognitive rehabilitation treatment group will receive EA using 8 acupuncture points - baekhoe, sinjeong, both sides of pungji, 4 sites of sishencong - and will be applied using an EA stimulator and receive CCRT for 30 minutes at the same time. The combination therapy with tDCS and computerized cognitive rehabilitation treatment group will receive tDCS treatment and receive CCRT for 30 minutes at the same time. The primary outcome will be evaluated using the Lowenstein occupational therapy cognitive assessment, while other scales assessing walking ability, activities of daily living, and quality of life are considered secondary outcome measures. Outcomes will be evaluated before intervention, at the end of intervention 8 weeks after the first intervention, and 4 weeks after completion of the intervention program.

DISCUSSION

This study aims to examine the effect and safety of combination therapy with EA or tDCS and CCRT in patients with VCI. This study can be useful in developing new treatment technologies using collaborative research with combined traditional Korean and conventional medicines.

TRIAL REGISTRATION

This trial has been registered with cris.nih.go.kr (registration number, KCT 0003644 Registered 01 April 2019, http://cris.nih.go.kr).

Exploratory study on immune phenotypes in Alzheimer's disease and vascular dementia

BACKGROUND AND PURPOSE

The differentiation of Alzheimer's disease (AD) dementia from vascular dementia (VaD) and mixed-type dementia (mixed dementia) requires stepwise analysis and usually occurs late in the disease process. Early diagnosis and therapy monitoring would benefit greatly from the identification of biomarkers of neurodegeneration, especially blood biomarkers. To this end, the aim of the present pilot study was to investigate differences in the distribution of peripheral T-cell populations in patients with AD compared to VaD and mixed dementia.

METHODS

Flow cytometry was performed on blood samples from 11 patients with AD, six with VaD and six with mixed dementia, as well as 17 healthy control subjects (HCs). CD4+ and CD8+ T cells were typed for expression of CD45, CD27, CD28, CD25, FoxP3, CCR4 and CCR6; the other leukocytes were also assessed. Functionally, immune cell uptake of the β-amyloid (Aβ) toxic fragment (Aβ_1-42 ) was also evaluated.

RESULTS

A higher proportion of CD4+CD28- memory T cells and a reciprocal reduction of CD4+CD28+CD27+ naïve T lymphocytes was detected in all patient groups relative to controls. Significantly fewer CD4+CD25+FoxP3 regulatory T cells were present in patients with VaD, and significantly more CCR6+ and CCR4+ CD4+ T cells in those with AD. Higher CCR6+ T-cell frequencies were also present in patients with mixed dementia, potentially due to the inflammation and immune cell chemoattraction triggered by Aβ.

CONCLUSIONS

The present study was a comprehensive investigation comparing different kinds of dementia, revealing differentially expressed peripheral markers that are potentially useful for early AD, VaD and mixed dementia diagnoses, and that would assist in proper treatments for these disparate diseases. Validation is now required.

Mixed dementia: Neglected clinical entity or nosographic artifice?

Clinical and pathological data show that Alzheimer's disease (AD) and vascular dementia (VaD) are the most prevalent types of dementia in the elderly. Medically speaking, mixed dementia (MxD) is a heterogenous disorder mostly referred to the coexistence of AD and VaD. The weight of vascular contribution to AD phenotype is nowadays matter of debate. Despite great efforts in the field of neurodegeneration and cerebrovascular disease, controversy over the exact nature of their relation still remains, hampering progress in the specialty and raising doubts about the MxD concept validity. Is MxD a neglected clinical entity or a nosographic artifice? Starting from the assumption that recent advances in dementia classification and diagnostic criteria make this a propitious time to set up preventive and therapeutic strategies, this narrative review and opinion paper summarizes the literature concerning the questioned etiopathogenic overlap between AD and VaD and challenges the traditional view of MxD as the mere co-occurrence of different pure forms of dementia.

Vestibular Exercises as a Fall Prevention Strategy in Patients with Cognitive Impairment

Vestibular impairment (VI) and cognitive impairment (CI) are risk factors for senior falls. We tested the feasibility of a self-directed 12-week vestibular rehabilitation (VR) program in Memory Clinic patients (65 years+) with a fall, CI and VI. We assessed recruitment, exercise adherence and ability to complete questionnaires/assessments. Twelve patients with CI and falls were screened and 8/12 (75% - prevalence) had VI. All patients completed the screening tests/questionnaires (100% - completeness); 7/8 patients were recruited (87.5% - recruitment); 1/7 (85.7% - attrition) patient attended follow-up. VI is prevalent in patients with CI experiencing falls but traditional VR is not feasible, so a novel delivery of VR must be explored.

Dementia

Dementia is a syndrome seen most commonly in older people and characterized by a decline in cognitive performance which impacts on the person's ability to function. There are approximately 47 million people worldwide with dementia and there are 10 million new cases every year. It is a major cause of disability and dependence and impacts on the physical, psychologic, and social well-being of families and carers. Alzheimer's disease is the most common form of dementia. Gait and balance impairments are common in people with dementia and contribute to the significantly elevated risk of falls. Older people with dementia are at increased risk of injury, institutionalization, hospitalization, morbidity, and death after a fall. There is preliminary evidence, predominantly from relatively small studies, that falls and disability can be prevented in this population. However, more good-quality research is needed, both to provide some certainty around the existing evidence base as well as to explore alternate approaches to prevention, including combined cognitive-motor training and cognitive pharmacotherapy.

Cellular and Molecular Mediators of Intestinal Fibrosis

Intestinal fibrosis is a major complication of the inflammatory bowel diseases (IBD) and although inflammation is necessary for its development, it would appear that it plays a minor role in its progression as anti-inflammatory treatments in IBD do not prevent fibrosis once it has started. The processes that regulate fibrosis would thus appear to be distinct from those regulating inflammation and, therefore, a detailed understanding of these pathways is vital to the development of anti-fibrogenic strategies. There have been several recent reviews exploring what is known, and what remains unknown, about the development of intestinal fibrosis. This review is designed to add to this literature but with a focus on the cellular components that are involved in the development of fibrogenesis and the major molecular mediators that impact on these cells. The aim is to heighten the understanding of the factors involved in intestinal fibrogenesis so that detailed research can be encouraged in order to advance the processes that could lead to effective treatments.

Centiloid method evaluation for amyloid PET of subcortical vascular dementia

Reference region selection is important for proper amyloid PET analysis, especially in subcortical vascular dementia (SVaD) patients. We investigated reference region differences between SVaD and Alzheimer's disease (AD) using Centiloid scores. In 57 [C-11] Pittsburgh compound B (PiB) positive (+) AD and 23 PiB (+) SVaD patients, we assessed standardized PiB uptake and Centiloid scores in disease-specific cortical regions, with several reference regions: cerebellar gray (CG), whole cerebellum (WC), WC with brainstem (WC + B), pons, and white matter (WM). We calculated disease group differences from young controls (YC) and YC variance according to reference region. SVaD patients showed large effect sizes (Cohen's d > 0.8) using all reference regions. WM and pons showed larger YC variances than other regions. Findings were similar for AD patients. CG, WC, and WC + B, but not WM or pons, are reliable reference regions for amyloid imaging analysis in SVaD.

Progress toward standardized diagnosis of vascular cognitive impairment: Guidelines from the Vascular Impairment of Cognition Classification Consensus Study

INTRODUCTION

Progress in understanding and management of vascular cognitive impairment (VCI) has been hampered by lack of consensus on diagnosis, reflecting the use of multiple different assessment protocols. A large multinational group of clinicians and researchers participated in a two-phase Vascular Impairment of Cognition Classification Consensus Study (VICCCS) to agree on principles (VICCCS-1) and protocols (VICCCS-2) for diagnosis of VCI. We present VICCCS-2.

METHODS

We used VICCCS-1 principles and published diagnostic guidelines as points of reference for an online Delphi survey aimed at achieving consensus on clinical diagnosis of VCI.

RESULTS

Six survey rounds comprising 65-79 participants agreed guidelines for diagnosis of VICCCS-revised mild and major forms of VCI and endorsed the National Institute of Neurological Disorders-Canadian Stroke Network neuropsychological assessment protocols and recommendations for imaging.

DISCUSSION

The VICCCS-2 suggests standardized use of the National Institute of Neurological Disorders-Canadian Stroke Network recommendations on neuropsychological and imaging assessment for diagnosis of VCI so as to promote research collaboration.

Associations between cerebral amyloid and changes in cognitive function and falls risk in subcortical ischemic vascular cognitive impairment

Background

To determine the association between amyloid-beta (Aβ) plaque deposition and changes in global cognition, executive functions, information processing speed, and falls risk over a 12-month period in older adults with a primary clinical diagnosis of subcortical ischemic vascular cognitive impairment (SIVCI).

Methods

This is a secondary analysis of data acquired from a subset of participants (N = 22) who were enrolled in a randomized controlled trial of aerobic exercise (NCT01027858). The subset of individuals completed an ¹¹C Pittsburgh compound B (PIB) scan. Cognitive function and falls risk were assessed at baseline, 6-months, and 12-months. Global cognition, executive functions, and information processing speed were measured using: 1) ADAS-Cog; 2) Trail Making Test; 3) Digit Span Test; 4) Stroop Test, and 5) Digit Symbol Substitution Test. Falls risk was measured using the Physiological Profile Assessment. Hierarchical multiple linear regression analyses determined the unique contribution of Aβ on changes in cognitive function and falls risk at 12-months after controlling for experimental group (i.e. aerobic exercise training or usual care control) and baseline performance. To correct for multiple comparisons, we applied the Benjamini-Hochberg procedure to obtain a false discovery rate corrected threshold using alpha = 0.05.

Results

Higher PIB retention was significantly associated with greater decrements in set shifting (Trail Making Test, adjusted R² = 35.3%, p = 0.002), attention and conflict resolution (Stroop Test, adjusted R² = 33.4%, p = 0.01), and information processing speed (Digit Symbol Substitution Test, adjusted R² = 24.4%, p = 0.001) over a 12-month period. Additionally, higher PIB retention was significantly associated with increased falls risk (Physiological Profile Assessment, adjusted R² = 49.1%, p = 0.04). PIB retention was not significantly associated with change in ADAS-Cog and Verbal Digit Span Test (p > 0.05).

Conclusions

Symptoms associated with SIVCI may be amplified by secondary Aβ pathology.

Trial registration

ClinicalTrials.gov, NCT01027858, December 7, 2009.

Neuropsychiatric Symptoms in Alzheimer Disease, Vascular Dementia, and Mixed Dementia

BACKGROUND/AIMS

Neuropsychiatric symptoms (NPS) are common in Alzheimer disease (AD) and vascular dementia (VaD), and are distressful to patients and caregivers. NPS are likely related to the underlying pathology. Previous studies suggest that frontal lobe lesions and vascular changes such as white matter hyperintensities (WMH) have a significant association with specific NPS. The current study aimed to compare NPS in patients with AD, VaD, and mixed AD/VaD, and to evaluate the differences in the prevalence of NPS in relation to frontal WMH volume.

METHODS

In total, 180 patients with NPS and MRI data (92 probable AD, 51%; 34 probable VaD, 19%; and 54 probable mixed AD/VaD, 30%) were included in the study. Regression analyses were performed to determine the relationships between NPS prevalence and diagnosis, and between NPS and frontal WMH.

RESULTS

VaD patients had significantly more agitation (p < 0.05; 40 vs. 14%) and sleep disturbances (p < 0.05; 57 vs. 32%) than AD patients, and significantly more depression (p < 0.05; 48 vs. 20%) and aberrant motor behaviors (p < 0.05; 31 vs. 13%) than mixed AD/VaD patients. AD patients with delusions had significantly greater right frontal WMH volumes than those without (p < 0.05; delusions 1/0 = 314.8/112.6 mm3).

CONCLUSION

Differences in NPS prevalence are likely related to the underlying pathology and warrant further study as they have implications for treatment.

Provision of dementia-related services in Canada: a comparative study

BACKGROUND

Dementia is common, particularly among older adults, and is one of the major causes of dependency later in life. We sought to provide an overview and comparison of key services related to dementia care as the disease progresses in three large Canadian healthcare centres.

METHODS

We identified family physicians, geriatric specialists, and dementia case managers from three major population centres in Canada with universal healthcare coverage. Using a standardized longitudinal dementia case vignette, participants were interviewed on services they would provide at each stage of the disease. We used principles of content analysis to generate codes and identify themes; appropriate time frames from the vignette fitting the necessary provision of services were derived from the Canadian consensus statement and determined in consultation with clinical experts. Proportions of participants that identified dementia-related care services were analyzed at each time point of the vignette using chi-square tests.

RESULTS

Thirty-four healthcare providers from Calgary (Alberta), Edmonton (Alberta), and Ottawa (Ontario) participated. Review of our data identified seven overarching themes of dementia-related care services. Services provided in the community setting include future planning and related services, educational and social support services, and home care and respite services. Although all providers consistently identified educational and social support services (e.g. the Alzheimer Society) within the appropriate time frame, the provision of other services was variable. The proportion of providers reporting potential access of future planning services was significantly different across the three sites (Calgary, 91.7 %; Edmonton; 58.3 %; and Ottawa, 30.0 %), p = 0.012. Also, the proportion of providers that identified day program services were significantly different across the three sites (Calgary, 100.0 %; Edmonton, 91.7 %; and Ottawa, 60.0 %), p = 0.023 according to a chi-square test.

CONCLUSIONS

We found important types of variability in service delivery among different regions in Canada for a typical patient with dementia and their family caregiver. Health systems can be calibrated by aligning services from different settings to appropriate time points in the vignette, which illustrates the dynamic course of service delivery and opportunities for improvement throughout the disease trajectory.

[A modern concept of mixed dementia]

Cognitive impairment is currently one of the most urgent problems. A number of newly registered cases of dementia in the world approaches to 7,7 millions that means that a new case of dementia arises every four seconds. According to WHO data, Western Europe is in the first place (appr. 7,0 millions of patients). In 2010, Russia was among 9 countries with the highest number of patients with dementia. Mixed dementia is characterized by the presence of one or several pathogenetic mechanisms of cognitive impairment. Its prevalence is about 45%. Neurodegenerative and vascular processes underlying dementia are mutually potentiated. An analysis of the majority of characteristics demonstrates that mixed dementia has characteristics of both Alzheimer's disease and vascular dementia. Disturbances of neurotransmitter systems are caused by cholinergic deficit. Galantamine (reminil) is the drug that has demonstrated its efficacy in the treatment of dementia of Alzheimer's type including dementia with chronic disturbances of cerebral blood circulation.

Exploring the effects of coexisting amyloid in subcortical vascular cognitive impairment

Background

Mixed pathology, particularly Alzheimer’s disease with cerebrovascular lesions, is reported as the second most common cause of dementia. Research on mixed dementia typically includes people with a primary AD diagnosis and hence, little is known about the effects of co-existing amyloid pathology in people with vascular cognitive impairment (VCI). The purpose of this study was to understand whether individual differences in amyloid pathology might explain variations in cognitive impairment among individuals with clinical subcortical VCI (SVCI).

Methods

Twenty-two participants with SVCI completed an ¹¹C Pittsburgh compound B (PIB) position emission tomography (PET) scan to quantify global amyloid deposition. Cognitive function was measured using: 1) MOCA; 2) ADAS-Cog; 3) EXIT-25; and 4) specific executive processes including a) Digits Forward and Backwards Test, b) Stroop-Colour Word Test, and c) Trail Making Test. To assess the effect of amyloid deposition on cognitive function we conducted Pearson bivariate correlations to determine which cognitive measures to include in our regression models. Cognitive variables that were significantly correlated with PIB retention values were entered in a hierarchical multiple linear regression analysis to determine the unique effect of amyloid on cognitive function. We controlled for age, education, and ApoE ε4 status.

Results

Bivariate correlation results showed that PIB binding was significantly correlated with ADAS-Cog (p < 0.01) and MOCA (p < 0.01); increased PIB binding was associated with worse cognitive function on both cognitive measures. PIB binding was not significantly correlated with the EXIT-25 or with specific executive processes (p > 0.05).

Regression analyses controlling for age, education, and ApoE ε4 status indicated an independent association between PIB retention and the ADAS-Cog (adjusted R-square change of 15.0 %, Sig F Change = 0.03). PIB retention was also independently associated with MOCA scores (adjusted R-Square Change of 27.0 %, Sig F Change = 0.02).

Conclusion

We found that increased global amyloid deposition was significantly associated with greater memory and executive dysfunctions as measured by the ADAS-Cog and MOCA. Our findings point to the important role of co-existing amyloid deposition for cognitive function in those with a primary SVCI diagnosis. As such, therapeutic approaches targeting SVCI must consider the potential role of amyloid for the optimal care of those with mixed dementia.

Trial registration

NCT01027858

Patients with dementia syndrome in public and private services in southern Brazil

Dementia is characterized by deficits in more than one cognitive domain, affecting language, praxis, gnosis, memory or executive functions. Despite the essential economic growth observed in many developing countries, especially over the last century, huge differences remain in health care, whether among nations themselves or across different regions of the same country.

Heart failure and dementia: survival in relation to types of heart failure and different dementia disorders

Aims

Heart failure (HF) and dementia frequently coexist, but little is known about their types, relationships to each other and prognosis. The aims were to (i) describe patients with HF and dementia, assess (ii) the proportion of specific dementia disorders in types of HF based on ejection fraction and (iii) the prognostic role of types of HF and dementia disorders.

Methods and results

The Swedish Heart Failure Registry (RiksSvikt) and The Swedish Dementia Registry (SveDem) were record-linked. Associations between dementia disorders and HF types were assessed with multinomial logistic regression and survival was investigated with Kaplan–Meier analysis and multivariable Cox regression. We studied 775 patients found in both registries (55% men, mean age 82 years). Ejection fraction was preserved in 38% of patients, reduced in 34%, and missing in 28%. The proportions of dementia disorders were similar across HF types. Vascular dementia was the most common dementia disorder (36%), followed by other dementias (28%), mixed dementia (20%), and Alzheimer disease (16%). Over a mean follow-up of 1.5 years, 76% of patients survived 1 year. We observed no significant differences in survival with regard to HF type (P = 0.2) or dementia disorder (P = 0.5). After adjustment for baseline covariates, neither HF types nor dementia disorders were independently associated with survival.

Conclusions

Heart failure with preserved ejection fraction was the most common HF type and vascular dementia was the most common dementia disorder. The proportions of dementia disorders were similar across HF types. Neither HF types nor specific dementia disorders were associated with survival.

Cardiovascular medication burden in dementia disorders: a nationwide study of 19,743 dementia patients in the Swedish Dementia Registry

Introduction

Administration of several cardiovascular drugs has an effect on dementia. We aimed to investigate whether there are differences in the use of cardiovascular medication between different dementia disorders.

Methods

We obtained information about dementia patients from the Swedish Dementia Registry. Patients were diagnosed with one of these dementia disorders: Alzheimer’s disease (n = 8,139), mixed dementia (n = 5,203), vascular dementia (n = 4,982), Lewy body dementia (n = 605), frontotemporal dementia (n = 409) and Parkinson’s disease dementia (n = 405). Multivariate logistic regression analysis was performed to investigate the association between use of cardiovascular medication and dementia disorders, after adjustment for age, gender, living alone, cognitive status and total number of drugs (a proxy for overall co-morbidity).

Results

Seventy percent of all the dementia patients used cardiovascular medication. Use of cardiovascular drugs is common in patients with vascular and mixed dementia. Male gender, higher age, slightly better cognitive status and living with another person was associated with use of cardiovascular medication.

Conclusions

Cardiovascular medication is used extensively across dementia disorders and particularly in vascular and mixed dementia. Future research should investigate the tolerability and effectiveness of these drugs in the different dementia disorders.

Developing predictive models of excellent and devastating outcome after stroke

BACKGROUND

models to predict functional status post-stroke have utility in balancing groups in randomised trials, for outcome comparison between stroke centres and may assist in outcome prediction. This study aimed to develop models of both excellent [modified Rankin score (mRS) 0-1] and devastating outcomes (mRS of 5-6).

METHODS

patients admitted with ischaemic or haemorrhagic stroke in 2001-02 to the Halifax Infirmary, Canada, were enrolled. Sixteen clinical variables from the first neurological assessment and six radiological variables from the acute CT scan were used to the model outcome at 6 months.

RESULTS

five hundred and thirty-eight stroke patients were enrolled. Thirty per cent had an excellent outcome and 30% had a devastating outcome. Three models of the excellent outcome were developed [area under the receiver operator curve (AUC) 0.866-882] including the variables age, pre-stroke functional status, stroke severity, ability to lift both arms, walk independently, normal verbal Glasgow Coma Scale and leukoaraiosis. Predictive models of the devastating outcome (AUC of 0.859-0.874) included additional variables living alone pre-stroke and total anterior circulation stroke. The simplest models of both outcomes were externally validated (AUC of 0.856-0.885).

CONCLUSION

this study demonstrates new externally validated predictive models of both excellent and devastating outcomes. Leukoaraiosis was the only independent radiological predictor of both outcomes. Living alone pre-stroke predicted devastating outcome post-stroke.

Prevalence and pathology of dementia with Lewy bodies in the oldest old: a comparison with other dementing disorders

BACKGROUND

While the prevalence of Alzheimer disease (AD) increases with age, little is known about the frequency of dementia with Lewy bodies (DLB) in the oldest old. A retrospective hospital-based study compared the relative prevalence of DLB among very old individuals.

METHODS

1,100 consecutive autopsy cases of demented patients aged over 70 years (mean age: 83.9 ± 5.4 years) were examined using standardized neuropathological methods and current diagnostic consensus criteria.

RESULTS

Evaluation of three age groups (8th-10th decade) showed a significant increase in the relative prevalence of AD with cerebrovascular lesions including mixed dementia, while AD with Lewy body (LB) pathology showed a mild but insignificant age-related increase. Both 'pure' AD and vascular dementia showed a mild but insignificant decline, while DLB (without severe AD pathology) decreased progressively. While the severity of Lewy pathology in DLB slightly decreased with age, concomitant Alzheimer-like pathology increased progressively.

CONCLUSION

Whether DLB in the oldest old represents a distinct group is a matter of discussion, but the relative prevalence of AD with LB in our sample remained fairly stable.

Management of mixed dementia

Alzheimer's disease (AD) and vascular dementia (VaD) are the most common causes of dementia in the elderly. Although AD can be diagnosed with a considerable degree of accuracy, the distinction between isolated AD, VaD and mixed dementia (MD) [when both pathologies coexist in the same patient] remains a controversial issue and one of the most difficult diagnostic challenges. MD represents a very common pathology, especially in the elderly, as reported in neuropathological studies. Accurate diagnosis of MD is of crucial significance for epidemiological purposes and for preventive and therapeutic strategies. Until recently, pharmacological studies have generally focused on pure disease, either AD or VaD, and have provided few data on the best therapeutic approach to MD. There is only one original randomized clinical trial on (acetyl)cholinesterase inhibitor therapy (GAL-INT-6, galantamine) for MD; the other studies are post hoc analyses of AD trial subgroups (AD2000, donepezil) or of VaD trial subgroups (VantagE, rivastigmine). Cholinesterase inhibitors have reproducible beneficial effects on cognitive and functional outcomes in patients with MD. These benefits are of a similar magnitude to those previously reported for the treatment of AD. It is likely that the beneficial effects of memantine (an NMDA receptor antagonist) in AD may also apply to MD, but randomized controlled trials are still lacking. Treatment of cardiovascular risk factors, especially hypertension, may protect brain function and should be included in prevention strategies for MD.

Predicting functional outcome after stroke by modelling baseline clinical and CT variables

BACKGROUND

we aimed to assess whether the performance of stroke outcome models comprising simple clinical variables could be improved by the addition of more complex clinical variables and information from the first computed tomography (CT) scan.

METHODS

538 consecutive acute ischaemic and haemorrhagic stroke patients were enrolled in a Stroke Outcome Study between 2001 and 2002. Independent survival (modified Rankin scale <or=2) was assessed at 6 months. Models based on clinical and radiological variables from the first assessment were developed using multivariate logistic regression analysis.

RESULTS

three models were developed (I-III). Model I included age, pre-stroke independence, arm power and a stroke severity score (area under a receiver operating characteristic curve, AUC = 0.882) but performed no better than Model II, which comprised age, pre-stroke independence, normal verbal component of the Glasgow coma score, arm power and being able to walk without assistance (AUC 0.876). Model III, including two radiological variables and clinical variables, was not statistically superior to model II (AUC 0.901, P = 0.12). Model II was externally validated in two independent datasets (AUCs of 0.773 and 0.787).

CONCLUSION

this study demonstrates an externally validated stroke outcome prediction model using simple clinical variables. Outcome prediction was not significantly improved with CT-derived radiological variables or more complex clinical variables.

Is sticky blood bad for the brain?: Hemostatic and inflammatory systems and dementia in the Caerphilly Prospective Study

OBJECTIVE

Hemostasis and inflammation have been implicated in dementia. This study investigates the role of specific hemostatic and inflammatory pathways with incident vascular and nonvascular dementia.

METHODS AND RESULTS

This was a prospective study of a population sample of men aged 65 to 84 years, with baseline assessment of hemostatic and inflammatory factors and cognition measured 17 years later. The sample included 865 men (59 had dementia and 112 had cognitive impairment, not dementia), free of vascular disease at baseline and for whom hemostatic and inflammatory marker data were available and cognitive status was known. A total of 15 hemostatic and 6 inflammatory markers were assessed. Factor analysis was used to identify hemostatic subsystems. The National Institute of Neurological Disorders and Stroke-Association Internationale pour la Recherche et l'Enseignement en Neurologie criteria were used to identify vascular dementia. By using standardized (z) scores for hemostatic and inflammatory markers, and after adjustment for age and risk factors, vascular dementia was associated with fibrinogen (hazard ratio [HR], 1.68; 95% confidence interval [CI], 1.02-2.76), factor VIII (HR, 1.79; 95% CI, 1.09-3.00), and plasminogen activator inhibitor 1 (HR, 3.13; 95% CI, 1.73-5.70). For vascular dementia, the HR risk from high levels of all three hemostatic variables (fibrinogen, factor VIII, and plasminogen activator inhibitor 1) was 2.97 (P<0.001). Inflammatory factors were not associated with vascular dementia.

CONCLUSIONS

The associations of these hemostatic markers with vascular dementia may implicate clot formation as the primary mechanism and are consistent with a microinfarct model of vascular dementia.

Beyond mild cognitive impairment: vascular cognitive impairment, no dementia (VCIND)

Identifying the causes of dementia is important in the search for effective preventative and treatment strategies. The concept of mild cognitive impairment (MCI), as prodromal dementia, has been useful but remains controversial since in population-based studies it appears to be a limited predictor of progression to dementia. Recognising the relative contribution of neurodegenerative and vascular causes, as well as their interrelationship, may enhance predictive accuracy. The concept of vascular cognitive impairment (VCI) has been introduced to describe the spectrum of cognitive change related to vascular causes from early cognitive decline to dementia. A recent review of this concept highlighted the need for diagnostic criteria that encompass the full range of the VCI construct. However, very little is known regarding the mildest stage of VCI, generally termed 'vascular cognitive impairment, no dementia' (VCIND). Whether mild cognitive change in the context of neurodegenerative pathologies is distinct from that in the context of cerebrovascular diseases is not known. This is key to the definition of VCIND and whether it is possible to identify this state. Distinguishing between vascular (that is, VCIND) and non-vascular (that is, MCI) cognitive disorders and determining how well each might predict dementia may not be possible due to the overlap in pathologies observed in the older population. Here, we review the concept of VCIND in an effort to identify recent developments and areas of controversy in nosology and the application of VCIND for screening individuals at increased risk of dementia secondary to vascular disease and its risk factors.

100 years after Alzheimer: contemporary neurology practice assessment of referrals for dementia

BACKGROUND

The prevalence of dementia is placing an increased burden on specialists.

METHODS

Canadian neurologists responded to a structured questionnaire to assess reasons for referral and services provided as well as to compare the neurologists' perceptions of their practice characteristics against cases seen over a 3-month period.

RESULTS

The audit confirmed the participants' perception that family practitioners are the main referral source (358/453, 79%). Sixty-two percent of patients had undergone clinical investigation for dementia prior to being seen by the neurologist; 39% (177/453) were on pharmacotherapy at the time of referral, 68% were initiated on pharmacotherapy by the neurologist. A fifth of the referrals did not meet clinical criteria for dementia, which may be directly related to the prevalence of prior workup that did not include mental status testing.

CONCLUSIONS

Neurologists currently treat patients referred for dementia who may already have been adequately evaluated and treated by primary care providers.

Prevalence and pattern of cognitive impairment in a community cohort of men in South Wales: methodology and findings from the Caerphilly Prospective Study

BACKGROUND/AIMS

The prevalence of dementia and cognitive impairment not dementia was investigated in the Caerphilly Prospective Study cohort (men currently aged 65-84 years).

METHODS

Of 1,633 men eligible for cognitive screening, 1,225 (75%) were seen, with those failing the screening criteria (CAMCOG <83 or decline in CAMCOG >9) being neurologically examined.

RESULTS

For dementia, diagnosed by DSM-IV criteria, the population prevalence was 5.2% rising to 6.1% in the screened population. For cognitive impairment not dementia, the prevalence in the screened population was 15.6% giving an overall prevalence of cognitive impairment of 21.8%. Prevalence rose fivefold between ages of 65 and 84 years to reach over 50%.

CONCLUSION

These figures are likely to underestimate actual prevalence in this population, and developing effective interventions should be a public health priority.

Differentiating Dementias in Long-Term Care Patients

Many long-term care residents are diagnosed with dementia, but dementia appears in many forms. Alzheimer's disease, the most common, is typified by a slow onset and relentless progression to complete incapacitation. Vascular dementia usually appears somewhat abruptly, is associated with vascular comorbidities, and has an unpredictable progression pattern. Lewy body dementia shares features of both Alzheimer's and Parkinson's disease; its hallmarks include fluctuating cognitive performance, visual hallucinations, and extrapyramidal motor symptoms. Frontotemporal dementias are associated less with memory disorders and more with behavioral and language aberrations. Mixed dementia covers those patients who do not have an apparent singular cause of dementia. Pseudodementia is a dementia resulting from underlying causes and is reversible, unlike the aforementioned dementias.

Behavioural measures in frontotemporal lobar dementia and other dementias: the utility of the frontal behavioural inventory and the neuropsychiatric inventory in a national cohort study

BACKGROUND

Distinguishing between patients with frontotemporal lobar dementia (FTLD) and other dementing illnesses remains a difficult task for many clinicians. In this study, we aimed to provide further evidence for the construct validity of the frontal behavioural inventory (FBI) and assess its utility in differentiating FTLD patients from other groups using data from the Canadian Collaborative Cohort of Related Dementias (ACCORD) study.

METHOD

Baseline scores on the FBI and neuropsychiatric inventory (NPI) were compared among several clinical groups (n = 177).

RESULTS

The FBI discriminated a higher percentage of FTLD patients (>75% correct classification) from Alzheimer's disease and other groups compared to the NPI (54.2%).

CONCLUSION

This study provides good evidence for convergent validity between the FBI and NPI (r = 0.72), indicating that both measures capture similar psychopathology in this nationwide cohort.

[Vascular dementia and mixed dementia]

The concept of vascular dementia has evolved over the past century to include multiple underlying pathophysiological mechanisms. Neuroimaging techniques offer new and better ways to identify the presence of cerebrovascular pathology, although they do not improve our ability to link these changes to the onset of clinical cognitive impairment. Clinical criteria for vascular dementia have also evolved but they remain imperfect. Most epidemiological studies define mixed dementia as the coexistence of Alzheimer's disease and vascular dementia. Clinicopathologic correlations show a clear association between the concomitant presence of vascular and Alzheimer lesions and the severity of cognitive impairment in mixed dementia and provide strong support for the validity of the mixed dementia concept. Mixed dementia is a very frequent disease that remains underdiagnosed, especially in the elderly. The diagnosis of vascular and mixed dementia remains a clinical challenge and cannot be improved without further studies of clinicopathological correlations and functional neuroimaging. Preventive therapeutic interventions include control of vascular risk factors and especially treatment of hypertension.

Distinguishing between Vascular Dementia and Alzheimer's Disease by Means of the WAIS: A Meta-analysis

This study was intended to, meta-analytically, review whether the subtests of the Wechsler Adult Intelligence Scale are useful in differentiating between vascular dementia and Alzheimer's disease. We expected the Alzheimer's disease group to outperform the vascular dementia group on those subtests that require executive functions, whereas inferior performance of the Alzheimer's disease patients was expected on memory tests. Two steps in the analysis were undertaken in an attempt to clarify this issue. The first step consisted of including all studies examining Wechsler Adult Intelligence Scale subtest performance in vascular dementia and Alzheimer's disease patients. Secondly, a subcortical vascular dementia subgroup was distinguished and performance of this subgroup was compared to that of the Alzheimer's disease group.Overall, the analyses showed that both the vascular dementia and, more strongly, the subcortical vascular dementia group revealed decreased executive functions on several subtests compared to the Alzheimer's disease group. The Alzheimer's disease group showed inferior performance on a single semantic memory test only compared to both the vascular dementia and the subcortical vascular dementia groups. These results indicate that several subtests of the Wechsler Adult Intelligence Scale can differentiate between these two clinical groups, and that most of these tests reveal more impaired performance in the vascular dementia group.

Comparison of provincial and territorial legislation governing substitute consent for research

In Canada, provincial and territorial laws address circumstances in which a substitute decision-maker may be appointed for an adult deemed legally incapable of making decisions in one or more areas of life. We searched for provincial and territorial laws that explicitly address substitute decision-making about research participation, and found significant differences among Canadian jurisdictions. In some provinces and territories there is no direct statutory guidance on the issue. Differences among jurisdictions that address substitute decision-making about research in legislation include whether judicial intervention is required to authorize the substitute decision-maker, whether any advance directive in place must explicitly authorize the decision about research in order for a proxy to consent, and how risk and benefit thresholds beyond which substitute consent to research is prohibited are articulated. It is imperative that government, researchers, and the Canadian public revisit the principles underpinning substitute decision-making about research in light of national and international norms, in order to lend clarity and consistency to this area of law and research practice.

[Alzheimer's disease: cardiovascular risk factors must be assessed]

BACKGROUND

Dementia is nowadays of major importance in public health. Alzheimer's disease and vascular cognitive impairments are its main aetiology in the elderly. The cause of Alzheimer's disease remains unknown. The factor initiating the physiopathology of this neurodegenerative disease is source of controversy.

CURRENT KNOWLEDGE AND KEY POINTS

The theory of a neurotoxicity initiated by amyloid deposition is questioned. A growing number of data suggest a central role of cardiovascular risk factors and alteration of arterial walls, inducing chronic brain hypoperfusion, as the primary trigger in the physiopathology of the disease. These data are based on epidemiological, physiopathological, neuroimaging, neuropathological and pharmacological studies. However, the exact link between arteriosclerosis, vascular cognitive impairment and Alzheimer's disease remains controversial.

FUTURE PROSPECTS AND PROJECTS

These debates point out the crucial importance of the assessment of cardiovascular risk factors, as a preventable cause, either of cognitive decline, morbidity and mortality. In this aim, major targets could be different when primary or secondary prevention are at stake. These controversies also suggest new research directions towards Alzheimer's disease physiopathology, and for pharmacological interventions aimed on the prevention of cognitive decline or the curative treatment for this disease.

APOE genotype, vascular risk factors, memory test performance and the five-year risk of vascular cognitive impairment or Alzheimer's disease

The APOE epsilon4 gene and poor memory test performance have each been associated with an increased risk of developing dementia, but the relationship between these risk factors in predicting dementia is unclear. We examined the multivariate effects of APOE genotype, memory test performance and vascular risk factors in predicting incident Alzheimer's disease (AD) and vascular cognitive impairment (VCI) in the Canadian Study of Health and Aging. Delayed free recall was measured by the Buschke Cued Recall Test (BCRT). The study sample included 223 people who were identified as having no cognitive impairment (NCI) and either APOE epsilon3/epsilon3 or epsilon3/epsilon4 genotypes at the baseline clinical assessment. After 5 years, 182 (82%) still had NCI, 21 developed VCI (9%) and 20 AD (9%). Multivariate analyses demonstrated that APOE epsilon4 increased the risk of AD (OR, 3.48; CI, 1.15-10.48) but not VCI (OR, 0.89; CI, 0.24-3.27). Vascular risk factors increased the risk of VCI (OR, 2.18; CI, 1.36-3.51) but not AD (OR, 0.68; CI, 0.38-1.20). Lower BCRT scores conferred an increased risk of both VCI (OR, 1.75; CI, 1.27-2.42) and AD (OR, 1.86; CI, 1.29-2.67) but attenuated the APOE epsilon4 effect in AD. VCI and AD have different risk profiles and outcomes, but subtle memory difficulties may be an early feature of both.

Sex, Hormones, and Alzheimer's Disease

More women than men have Alzheimer's disease (AD). Retrospective studies suggested that hormone replacement therapy (HRT) might counteract this disparity by reducing the risk of developing dementia. However, a recent, large, prospective study revealed the puzzling result that HRT increased dementia risk. A review of the literature was conducted to generate hypotheses that might explain why more women than men have AD, and how HRT may increase dementia risk. Longer life span of women than men may be the largest factor in the preponderance of women with AD. Longer duration of disease, less vascular dementia, and less testosterone in women than men may also contribute somewhat. HRT might increase dementia risk by several mechanisms: greater risk of strokes, leading to dementia; use of medroxyprogesterone acetate and estrone, which might have somewhat different possible effects on neuronal and cerebrovascular function than may progesterone and estradiol; decrease of free testosterone which might protect against AD; a dose or delivery method perhaps producing drug levels that might lie outside a hypothetical beneficial range; and down-regulation of estrogen receptors on cholinergic neurons, possibly reducing cholinergic activity. Further study is required to discern by which of several possible mechanisms HRT increases dementia risk.

Prolonged lymphopenia, lymphoid depletion, and hypoprolactinemia in children with nosocomial sepsis and multiple organ failure

Lymphopenia and lymphoid depletion occur in adults dying of sepsis. Prolactin increases Bcl-2 expression, suppresses stress-induced lymphocyte apoptosis, and improves survival from experimental sepsis. We hypothesized that prolonged lymphopenia, lymphoid depletion, and hypoprolactinemia occur in children dying with sepsis and multiple organ failure (MOF). Fifty-eight critically ill children with and 55 without MOF admitted to a university hospital pediatric intensive care unit were enrolled in a prospective, longitudinal, observational clinical study. Prolactin levels and absolute lymphocyte count were measured on days 1, 3, 7, 14, and 21. Lymph node, thymus, and spleen autopsy specimens were examined for lymphoid depletion, with immunohistochemical staining for CD4, CD20, and CD21 and for lymphoid apoptosis. Prolonged lymphopenia (absolute lymphocyte count < 1000 for >7 days) occurred only in children with MOF (29 vs 0%, p < 0.05) and was associated independently with nosocomial infection (odds ratio (OR), 5.5, 95% confidence interval (CI), 1.7-17, p < 0.05), death (OR, 6.8, 95% CI, 1.3-34, p < 0.05), and splenic and lymph node hypocellularity (OR, 42, 95% CI, 3.7-473, p < 0.05). Lymphocyte apoptosis and ante/postmortem infection were observed only in children with lymphoid depletion. Prolonged hypoprolactinemia (>7 days) was more common in children with MOF (17 vs 2%, p < 0.05) and was associated independently with prolonged lymphopenia (OR, 8.3, 95% CI, 2.1-33, p < 0.05) and lymphoid depletion (OR, 12.2, 95% CI, 2.2-65, p < 0.05). Prolonged lymphopenia and apoptosis-associated depletion of lymphoid organs play a role in nosocomial sepsis-related death in critically ill children. Prolonged hypoprolactinemia is a previously unrecognized risk factor for this syndrome.

Alzheimer's disease with and without cerebral infarcts

OBJECTIVE

To compare the clinical and pathological features of Alzheimer's disease (AD) patients with and without associated cerebral infarcts (CI).

METHODS

The consecutive records of 57 prospectively studied demented patients fulfilling the CERAD criteria for the pathological diagnosis of AD were reviewed. Cases with cortical Lewy bodies were excluded. CI were found in 22 cases (39%) (AD+CI group): large infarcts (5), lacunes (13) and/or hippocampal sclerosis (4), and were absent in 35 cases (AD group). Microscopic infarcts, cribiform change, amyloid angiopathy, and white matter rarefaction were not considered in this classification, but were quantified. Cortical atrophy, neurofibrillary tangle and senile plaque (diffuse and neuritic) load were also measured. Pathological evaluation was independent of clinical information. Clinical and pathological data were compared between both groups.

RESULTS

AD+CI cases were significantly older, more commonly female, less educated, and more often had blue collar occupations, sleep disturbances, frontal release signs, and EEG spikes than AD cases. Other differences found (acute/subacute onset, behavioral disturbances, and leukoaraiosis on CT scan) disappeared after controlling for age. The frequency of known vascular risk factors and focal motor and sensory signs did not differ between the groups, which showed remarkable clinical similarity overall. The only significant differences on pathological exam were hippocampal microinfarcts and white matter lesions, although there was a trend for lower neurodegenerative lesion load in the AD+CI group. The ischemic lesions were located in temporal lobe in 50% of AD+CI patients; these cases had a significantly lower neocortical neurodegenerative lesion load than those with CI in other sites.

CONCLUSIONS

The presence of CI in AD increases significantly with age, but has scarce influence on the clinical features, and cannot be predicted from common vascular risk factors. In spite of a trend, there are no major differences in neurodegenerative lesion load between AD and AD+CI groups, except when CI are located in the temporal lobe (including hippocampus), suggesting that this location may be important in the physiopathology of mixed vascular and AD dementia.

The Consortium to Investigate Vascular Impairment of Cognition: methods and first findings

BACKGROUND

The Consortium to Investigate Vascular Impairment of Cognition (CIVIC) is a Canadian, multi-centre, clinic-based prospective cohort study of patients with Vascular Cognitive Impairment (VCI). We report its organization and the impact of diagnostic criteria on the study of VCI.

METHODS

Nine memory disability clinics enrolled patients and recorded their usual investigations and care. A case report form included all vascular dementia (VaD) individual criteria for each of four sets (National Institute of Neurological Disorders and Stroke (NINDS-AIREN), Alzheimer's Disease Diagnostic Treatment Centers (ADDTC), the ICD-10 Classification of Mental and Behavioural Disorders (ICD-10), and the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV)) of consensus-based diagnostic criteria and for the Hachinski Ischemia Score (HIS). Investigators, having completed the case report form, were asked to make a clinical judgement about the cognitive diagnosis based on the best available information, including neuroimaging.

RESULTS

Of 1,347 patients (mean age 72 years; 56% women), 846 (63%) were diagnosed with dementia and 324 (24%) were diagnosed with VCI. The proportion of patients diagnosed with VaD by the diagnostic criteria was: 23.9% (n = 322) by DSM-IV, 10.2% (n = 137) by HIS, 4.3% (n = 58) by ICD-10, 3.8% (n = 51) by ADTCC, and 3.6% (n = 48) by NINDS-AIREN. Judged against a clinical diagnosis of VaD, the sensitivity/specificity of each was: DSM-IV (0.77/0.80); HIS (0.41/0.92); ICD-10 (0.29/0.98); ADTCC (0.24/0.98); NINDS-AIREN (0.42/0.995). Compared with a clinical diagnosis of VCI, sensitivities were lower for the diagnostic criteria, reflecting the exclusion of patients who did not have dementia.

CONCLUSIONS

Consensus-based criteria for VaD omit patients who do not meet dementia criteria that are modeled on Alzheimer's disease. Even for patients who do, the proportion identified with VaD varies widely. Criteria based on empirical analyses need to be developed and validated.

The role of neuroimaging in the diagnosis of vascular dementia

Vascular dementia (VaD) and Alzheimer's disease share many pathological and clinical characteristics. Whereas clinical criteria can help differentiate VaD from other types of dementia, neuroimaging is required for confirmation of vascular lesions. Neuroimaging also provides information about location and size of vascular lesions that can lead to a better understanding of symptoms and may help guide therapy.

Relevant clinical outcomes in probable vascular dementia and Alzheimer's disease with cerebrovascular disease

Two important prerequisites for assessing therapeutic benefits in patients with vascular dementia (VaD), or Alzheimer's disease (AD) with cerebrovascular disease (CVD), are the inclusion of appropriate patients and the use of relevant outcome measures. There is substantial overlap in the clinical symptomatology, risk factors, imaging changes, pathophysiology and neurochemical mechanisms between VaD, AD and AD with CVD. While validated and acceptable clinical criteria suitable for clinical trials have been developed for VaD, there is still debate as to how mixed cases (i.e. AD with CVD) are best conceptualized. As with AD, there is consensus that outcome measures in studies of patients with VaD, or AD with CVD, should include assessments of cognitive and global function, of ability to perform activities of daily living (ADL) and of behavioral symptoms. Other measures, e.g., caregiver burden, would be desirable. Care must be taken in extrapolating AD-specific evaluations to VaD, however, because different specific domains are affected and the disease course is different. In clinical trials, cognitive performance and global function decline steadily in patients with untreated AD compared with smaller changes in patients with untreated VaD, while behavior and ADL deteriorate over 6 months in patients with either untreated AD or untreated VaD. Such differences in untreated outcome need to be considered when interpreting trial results using outcome measures that were largely designed for studies of patients with AD.

Mixed dementia: epidemiology, diagnosis, and treatment

Alzheimer's disease (AD) and vascular dementia (VaD) are the most frequent causes of dementia in older people. Although AD can be diagnosed with a considerable degree of accuracy, the distinction between isolated AD, VaD, and mixed dementia (MD), where both pathologies coexist in the same patient, remains a controversial issue and one of the most difficult diagnostic challenges. Although MD represents a very frequent pathology, especially in older people, as reported in neuropathological studies, the respective importance of degenerative and vascular lesions, their interaction in the genesis of dementia, and the mere existence of MD are still debated. Accurate diagnosis of MD is of crucial significance for epidemiological purposes and for preventive and therapeutic strategies. Until recently, pharmacological studies have generally focused on pure disease, AD or VaD, and have provided little information on the best therapeutic approach to MD. This article provides an overview of MD in older people. A retrospective review of the recent literature on prevalence, incidence, course, risk factors, diagnosis, and treatment of MD was performed. The article also emphasizes the need for further studies, including neuropsychological and functional evaluations, and neuroimaging and clinicopathological correlations to develop a better understanding of MD, which appears to be one of the most common forms of dementia.

Prevalence of dementia in the older Japanese-Brazilian population

The prevalence of dementing disorders in Campo Grande of a community of Japanese-Brazilians who immigrated from Okinawa was studied. Previous reports showed that the dietary pattern in Japanese immigrants in Brazil, which characterized by a low fish and large meat intake, is possibly responsible for increased risk of cardiovascular diseases compared with Japanese in Okinawa. A total of 157 persons over 70-year-old were examined, and 19 cases were diagnosed as having dementia. The prevalence (cases/100 aged 70-year-older) was 12.1 for all types of dementia, 5.7 for Alzheimer's disease (AD), 0.6 for vascular dementia (VD), 4.5 for mixed dementia (AD/VD) and 1.3 for other types of dementia. There was no case of dementia with Lewy bodies or frontotemporal lobar degeneration. These results are similar to many previous studies in Western countries and some recent surveys in Japan, and clearly show that more AD than VD appears even in the Japanese-Brazilian population. The higher prevalence rate of dementia in Japanese-Brazilians compared with several studies in Japan may indicate the importance of dietary factors rather than genetic factors.

Disordered proteins in dementia

Aggregates of dysfunctional proteins and peptides in or between brain neurons are key neuropathological features of dementia and are believed to directly cause or substantially contribute to the development of these diseases. Fundamental parts of the mechanisms underlying the dysregulation of proteins in Alzheimer's disease, frontotemporal dementia, prion diseases and other dementing disorders are now well characterized, mainly due to the discovery of genes causing dominantly inherited disease forms (Table 1). As of today, no efficient pharmacotherapies are available, but new insights into the underlying molecular mechanisms are providing strategies to prevent or even cure these devastating disorders.

Mild cognitive impairment: clinical features and review of screening instruments

Clinical criteria to recognize subjects with cognitive impairment in the pre-dementia stage are becoming available. These are frail subjects, at risk of adverse outcomes, such as death, institutionalization, and functional and cognitive deterioration. Early identification of these subjects has a great importance in order to start rehabilitative or pharmacological interventions that could slow the progression of cognitive impairment, and the onset of disability. In this regard, cognitive screening tests might be helpful in different clinical settings (general practice, acute care, rehabilitation, and nursing home). We describe the most frequent clinical presentations of cognitive impairment in the pre-dementia stage, and review eleven screening tests to provide recommendations on which should be preferred in each setting.