Comparison of different clinical criteria (DSM-III, ADDTC, ICD-10, NINDS-AIREN, DSM-IV) for the diagnosis of vascular dementia. National Institute of Neurological Disorders and Stroke-Association Internationale pour la Recherche et l'Enseignement en Neurosciences

Study protocol: EXERcise and cognition in sedentary adults with early-ONset dementia (EXERCISE-ON)

Background

Although the development of early-onset dementia is a radical and invalidating experience for both patient and family there are hardly any non-pharmacological studies that focus on this group of patients. One type of a non-pharmacological intervention that appears to have a beneficial effect on cognition in older persons without dementia and older persons at risk for dementia is exercise. In view of their younger age early-onset dementia patients may be well able to participate in an exercise program. The main aim of the EXERCISE-ON study is to assess whether exercise slows down the progressive course of the symptoms of dementia.

Methods/Design

One hundred and fifty patients with early-onset dementia are recruited. After completion of the baseline measurements, participants living within a 50 kilometre radius to one of the rehabilitation centres are randomly assigned to either an aerobic exercise program in a rehabilitation centre or a flexibility and relaxation program in a rehabilitation centre. Both programs are applied three times a week during 3 months. Participants living outside the 50 kilometre radius are included in a feasibility study where participants join in a daily physical activity program set at home making use of pedometers. Measurements take place at baseline (entry of the study), after three months (end of the exercise program) and after six months (follow-up). Primary outcomes are cognitive functioning; psychomotor speed and executive functioning; (instrumental) activities of daily living, and quality of life. Secondary outcomes include physical, neuropsychological, and rest-activity rhythm measures.

Discussion

The EXERCISE-ON study is the first study to offer exercise programs to patients with early-onset dementia. We expect this study to supply evidence regarding the effects of exercise on the symptoms of early-onset dementia, influencing quality of life.

Trial registration

The present study is registered within The Netherlands National Trial Register (ref: NTR2124)

Disturbed oscillatory brain dynamics in subcortical ischemic vascular dementia

Background

White matter hyperintensities (WMH) can lead to dementia but the underlying physiological mechanisms are unclear. We compared relative oscillatory power from electroencephalographic studies (EEGs) of 17 patients with subcortical ischemic vascular dementia, based on extensive white matter hyperintensities (SIVD-WMH) with 17 controls to investigate physiological changes underlying this diagnosis.

Results

Differences between the groups were large, with a decrease of relative power of fast activity in patients (alpha power 0.25 ± 0.12 versus 0.38 ± 0.13, p = 0.01; beta power 0.08 ± 0.04 versus 0.19 ± 0.07; p<0.001) and an increase in relative powers of slow activity in patients (theta power 0.32 ± 0.11 versus 0.14 ± 0.09; p<0.001 and delta power 0.31 ± 0.14 versus 0.23 ± 0.09; p<0.05). Lower relative beta power was related to worse cognitive performance in a linear regression analysis (standardized beta = 0.67, p<0.01).

Conclusions

This pattern of disturbance in oscillatory brain activity indicate loss of connections between neurons, providing a first step in the understanding of cognitive dysfunction in SIVD-WMH.

Neuropsychological performance in patients with subcortical stroke

Vascular cognitive impairment (VCI) is characterized by cognitive compromise predominantly of executive dysfunction. OBJECTIVES: To assess cognitive functions in VCI, focusing on executive functions, to observe functional losses in relation to activities of daily living (ADLs) and to detect early symptoms prior to the onset of dementia. METHODS: We evaluated healthy subjects matched for gender, education and age to patients with diagnosis of subcortical vascular disease who had a stroke classified into three groups: 1) vascular lesions and no impairment; 2) vascular cognitive impairment with no dementia (VCIND); 3) vascular dementia (VaD). RESULTS AND DISCUSSION: The performance on neuropsychological tests differed among groups, worsening with increased impairment level. The probable VaD group demonstrated impaired performance in memory, processing speed and verbal production, while the VCIND group showed attention deficits. CONCLUSION: Impairment in executive functions and difficulties in ADLs allow us to differentiate levels of impairment in groups of subcortical vascular disease.

The VAS-COG clinic: an out-patient service for patients with cognitive and behavioral consequences of cerebrovascular diseases

Services dedicated to patients with cognitive and behavioral consequences of cerebrovascular diseases (CVD) are not established. We started an out-patient clinic (the "VAS-COG clinic") to assess patients with psycho-cognitive disturbances related to CVD. The work-up includes a clinical-neuroimaging diagnostic process and the individuation of the best therapeutic strategies as done in patients with neurodegenerative cognitive impairment. We report the results of the first 5 years of activity. Reasons for patient referral were not only cognitive, language, gait, and psychiatric disturbances related to stroke or chronic CVD, but also neuroimaging evidence of vascular encephalopathy and screening for familial microangiopathies. The patients were evaluated with uniformed protocols. From January 2006 to November 2010, we evaluated 403 patients. Of these, 374 (93%; mean age 69.7 years ± 15.0) were considered appropriate for the VAS-COG clinic. The following diagnoses were made: vascular dementia (8.6%), Alzheimer disease (2.1%), mixed dementia (vascular plus degenerative) (4.8%), vascular mild cognitive impairment (MCI) (9.1%), amnesic-MCI (8.0%), mixed-MCI (4.8%), post-stroke depression (2.7%), post-stroke language disturbances (4.5%), subjective memory complaint (1.3%), familiar microangiopathy (31.3%), vascular encephalopathy evidenced by neuroimaging not associated with specific clinical disturbances (15.3%), and other conditions (7.5%). Psycho-cognitive disturbances associated with CVD are heterogeneous. In addition to acute stroke care strategies, long-term assessment of patients with CVD is required. The VAS-COG clinic may represent a model in this regard and might be important for improving the care of patients and offering counseling to their families. The efficacy of this service needs, however, to be proved by successive work.

Vascular dementia: Diagnostic criteria and supplementary exams. Recommendations of the Scientific Department of Cognitive Neurology and Aging of the Brazilian Academy of Neurology. Part I

Vascular dementia (VaD) is the most prevalent form of secondary dementia and the second most common of all dementias. The present paper aims to define guidelines on the basic principles for treating patients with suspected VaD (and vascular cognitive impairment - no dementia) using an evidence-based, systematized approach. The knowledge used to define these guidelines was retrieved from searches of several databases (Medline, Scielo, Lilacs) containing scientific articles, systematic reviews, meta-analyses, largely published within the last 15 years or earlier when pertinent. Information retrieved and selected for relevance was used to analyze diagnostic criteria and to propose a diagnostic system encompassing diagnostic criteria, anamnesis, as well as supplementary and clinical exams (neuroimaging and laboratory). Wherever possible, instruments were selected that had versions previously adapted and validated for use in Brazil that take into account both schooling and age. This task led to proposed protocols for supplementary exams based on degree of priority, for application in clinical practice and research settings.

The potential for estrogens in preventing Alzheimer's disease and vascular dementia

Estrogens are the best-studied class of drugs for potential use in the prevention of Alzheimer's disease (AD). These steroids have been shown to be potent neuroprotectants both in vitro and in vivo, and to exert effects that are consistent with their potential use in prevention of AD. These include the prevention of the processing of amyloid precursor protein (APP) into beta-amyloid (Aß), the reduction in tau hyperphosphorylation, and the elimination of catastrophic attempts at neuronal mitosis. Further, epidemiological data support the efficacy of early postmenopausal use of estrogens for the delay or prevention of AD. Collectively, this evidence supports the further development of estrogen-like compounds for prevention of AD. Several approaches to enhance brain specificity of estrogen action are now underway in an attempt to reduce the side effects of chronic estrogen therapy in AD.

What are the differences between younger and older patients with symptomatic small vessel disease?

OBJECTIVE

Although typically linked to aging, small vessel disease (SVD) is also observed in younger adult patients, with common vascular risk factors (RF). We aimed to investigate features of SVD occurrence at an early adult age.

PATIENTS AND METHODS

Vascular RF, functional and cognitive status and severity of lesions on MRI expressed as total score on Age-Related White Matter Changes (ARWMC) scale were analyzed in 200 consecutive patients with cerebral SVD admitted to a tertiary neurological hospital. Variables were compared between younger (35-55 years) and older (>56 years) patients.

RESULTS

In this study, 63 (31.5%) of patients were 55 years or younger. Both age groups had comparable RF profiles, but smoking emerged as an independent predictor for SVD at a younger age (OR 2.9; 95% CI 1.5-5.5; p=0.002). Younger patients had better functional (OR 1.8; 95% CI 1.3-2.5; p=0.0001) and cognitive (χ(2) 13.94; p=0.0009) status compared to older patients. However, two thirds of younger patients had some degree of cognitive deficit. Total score on ARWMC scale was lower in younger patients (mean 12.3 in younger versus 15.2 in older, OR 1.11; 95% CI 1.0-1.18; p=0.001). There was a strong correlation in both groups between functional score, cognitive status and ARWMC score (p<0.0001).

CONCLUSION

In our dataset, younger patients with SVD shared common vascular RF with older patients. In the group aged ≤55, better functional and cognitive status and less severe MRI changes were noted. However, a substantial number of younger SVD patients presenting with TIA or ischemic stroke had various deficits.

Structural MRI

Clinical neuroimaging is increasingly being used in the diagnosis of neurodegenerative diseases and has become one of the most important paraclinical tools in the diagnosis of dementia. According to current guidelines, neuroimaging, preferably magnetic resonance imaging (MRI), should be performed at least once during the diagnostic work-up of patients with suspected or definite dementia. MRI is helpful in identifying or excluding potentially treatable causes of dementia; however, these account only for a small proportion of dementias. In addition, MRI is able to support the clinical diagnosis in a memory clinic setting by identifying certain patterns of atrophy and vascular damage. Visual rating scales are well-established methods in the clinical routine for the assessment and quantification of regional/global cortical atrophy, hippocampal atrophy and vascular damage. In addition, MRI is able to detect certain aspects of pathology associated with dementia, such as cerebral microbleeds which are related to cerebral amyloid angiopathy and Alzheimer pathology. This review paper aims to give an overview of the application of structural MRI in the diagnostic procedure for memory clinic patients in terms of excluding and supporting the diagnosis of various diseases associated with dementia.

Vascular dementia

Cerebrovascular disease is the second leading cause of cognitive impairment in the elderly, either alone or in combination with Alzheimer's disease (AD). Vascular dementia (VaD) is heterogeneous in terms of both clinical phenotype and pathogenetic mechanisms. It may result from multiple cortical infarctions due to cerebral large vessel pathologies or to subcortical ischemic changes such as leukoaraiosis or lacunar infarction due to cerebral small artery disease. Clinical symptoms and signs vary depending on the location and size of the stroke lesion, and no single neuropsychological profile characteristic of VaD has been defined, although dysexecutive function is common. A slightly higher mortality rate and slower progression are reported in VaD compared with AD. VaD is potentially preventable by rigorous identification and treatment of cardiovascular disease risk factors, and modest symptomatic improvement with cholinesterase inhibitors has been reported.

Neurobiology of vascular dementia

Vascular dementia is, in its current conceptual form, a distinct type of dementia with a spectrum of specific clinical and pathophysiological features. However, in a very large majority of cases, these alterations occur in an already aged brain, characterized by a milieu of cellular and molecular events common for different neurodegenerative diseases. The cell signaling defects and molecular dyshomeostasis might lead to neuronal malfunction prior to the death of neurons and the alteration of neuronal networks. In the present paper, we explore some of the molecular mechanisms underlying brain malfunction triggered by cerebrovascular disease and risk factors. We suggest that, in the age of genetic investigation and molecular diagnosis, the concept of vascular dementia needs a new approach.

C-reactive protein expression in a rodent model of chronic cerebral hypoperfusion

White matter lesions (WML) are a clinically significant, common feature of the aging brain and have been associated with cognitive decline and depression. They are a manifestation of cerebral small vessel disease, which is associated with the progression of vascular dementia. Recent research has been focused on identifying biomarkers which may have a correlation with WML. Previous population based studies have indicated a relation between the serum level of the acute phase protein, C-reactive protein (CRP), and WML. However no previous studies have demonstrated its expression and relation to WML in brain tissue itself. Here we use the rodent model of permanent bilateral common carotid artery ligation (BCCAL) to assess CRP expression during chronic cerebral hypoperfusion (CCH). Our results show that CRP is up-regulated at the mRNA and protein levels in brain tissue from BCCAL animals. The expression of CRP mRNA was upregulated on day 3 following surgery. Because previous studies, as well as the present study, have shown that microglial activity is prominent after the third day of CCH, we sought to determine the role of microglia in CRP expression. Results indicate that cultured microglia express mRNA and protein for CRP and this expression is increased when cells are treated with interleukin-1β (IL-1β), interleukin-6 (IL-6) or a combination of the two.. This finding could indicate a possible role for CRP in the progression of small vessel disease in the brain and provide a therapeutic target.

A voxel-based morphometric analysis of cerebral gray matter in subcortical ischemic vascular dementia patients and normal aged controls

BACKGROUND AND PURPOSE

The present study was designed to detect the abnormalities of the cerebral grey-matter density in subcortical ischemic vascular dementia patients by FSL-VBM method to promote the early diagnosis of it.

METHODS

Nine subcortical ischemic vascular dementia patients and nine age-matched normal controls underwent MRI brain structure scanning that was performed on a SIEMENS AVANTO 1.5 Tesla scanner and standard T1-weighted high-resolution anatomic scans of MPRAGE sequence were obtained. The 3-demensional MPRAGE images were processed with FSL-VBM package and the cerebral gray matter density was compared between the subcortical ischemic vascular dementia patients and normal controls.

RESULTS

Compared with the normal control group, the cerebral gray matter density of subcortical ischemic vascular dementia patients was found significantly decreasing, including brain regions of thalamus, parietal lobe, frontal lobe and temporal lobe (P<0.05).

CONCLUSIONS

The cerebral gray matter density alterations have closed correlation with cognitive dysfunction in subcortical ischemic vascular dementia patient and can be detected by MRI. MRI has some potential value in the diagnosis of them.

The neuropsychological characteristics and regional cerebral blood flow of vascular cognitive impairment-no dementia

OBJECTIVE

To investigate the neuropsychological characteristics of VCI-ND and to analyze the relationship between deficit pattern and regional cerebral blood flow (rCBF) in various VCI-ND subtypes defined by cognitive features.

METHODS

69 subjects diagnosed with VCI-ND were recruited, then further classified into four subtypes: amnestic VCI-ND with single memory impairment (subtype I, n = 19), amnestic VCI-ND with multi-domain impairment (subtype II, n = 27), non-amnestic VCI-ND with single domain impairment (subtype III, n = 16), and non-amnestic VCI-ND with multi-domain impairment (subtype IV, n = 7) according to their cognitive profile. Xenon-CT scan was administered to 31 VCI-ND patients (11 of subtype I, 12 of subtype II and 8 of subtype III) and 10 normal controls (NC) to evaluate rCBF.

RESULTS

The rate of different cognitive domains impairment in VCI-ND group ranged from 17 to 66%, lowest in clock drawing test and highest in time of modified version of trails making test A and maze tracing compared with NC, significant reduced rCBF was found in bilateral temporal lobe and thalamus, left periventricular white matter and caudate of subtype I, and in left temporal lobe and lenticular nucleus, bilateral periventricular white matter, white matter adjacent to left posterior horn of lateral ventricular and right caudate of subtype III, while significant reduced rCBF of subtype II was found in left subfrontal white matter, bilateral subtemporoparietal white matter, right lenticular nucleus, and in both regions of subtype I and III.

CONCLUSIONS

The manifestation of rCBF in VCI-ND subtypes was consistent with performance of neuropsychological assessment.

Vascular risk factors: imaging and neuropathologic correlates

Cerebrovascular disease plays an important role in cognitive disorders in the elderly. Cerebrovascular disease and Alzheimer's disease interact on several levels, with one important level being the overlap in risk factors. The major vascular risk factors such as diabetes and impaired glycemic control, hypertension, obesity, and hyper- or dyslipidemia have been associated both with Alzheimer's disease and vascular dementia. The purpose of this review is to consider the context in which vascular dementia is diagnosed, place the pathophysiological consequences of cerebrovascular disease on cognition in the context of clinical and pathological Alzheimer's disease, and then to consider the evidence for the role of major vascular risk factors in late-life cognitive impairment, changes in brain imaging and neuropathological changes. Midlife diabetes mellitus, hypertension, and obesity are established risk factors for clinically defined Alzheimer's disease as well as vascular dementia. The basis for these relationships could either be that the risk factors lead to microvascular brain disease, promote Alzheimer pathology or both. The associations of late-life onset diabetes mellitus, hypertension, and obesity with cognitive impairment are either attenuated or reversed. The role of vascular risk factors in midlife should be the focus of public health efforts to reduce the burden of late-life cognitive impairment.

Invited commentary: Albuminuria and microvascular disease of the brain--a shared pathophysiology

This commentary considers the implications of the association between albuminuria and cognitive decline described by Jassal et al. in this issue of the Journal (Am J Epidemiol. 2010;171(3):290-291). The authors report that men with albuminuria had a greater likelihood than men without albuminuria of experiencing declines in cognitive function over a 6.6-year period. Albuminuria is the result of endothelial damage in the kidney, which, in turn, is the result of microvascular disease. If one of the key mechanisms of brain microvascular disease is leakage of serum proteins into the brain extracellular space, in a fashion parallel to albuminuria that occurs in nephrosclerosis, several facets of cerebrovascular disease and cognitive decline are explained. First, brain microvascular disease would not be recognized by traditional clinical features of cerebrovascular disease because brain microvascular disease occurs gradually and insidiously. Second, the extravasation of serum proteins as a result of brain microvascular disease would account for the perivascular distribution of white matter hyperintensities on magnetic resonance imaging. Albuminuria might be a useful screening test for generalized microvascular disease and, if detected, might reasonably prompt brain imaging and more intensive therapeutic efforts to forestall further endothelial dysfunction in the kidney, brain, and elsewhere.

Harmonisation of ICD-11 and DSM-V: opportunities and challenges

BACKGROUND

Differences in the ICD-10 and DSM-IV definitions for the same disorder impede international communication and research efforts. The forthcoming parallel development of DSM-V and ICD-11 offers an opportunity to harmonise the two classifications.

AIMS

This paper aims to facilitate the harmonisation process by identifying diagnostic differences between the two systems.

METHOD

DSM-IV-TR criteria sets and the ICD-10 Diagnostic Criteria for Research were compared and categorised into those with identical definitions, those with conceptually based differences and those in which differences are not conceptually based and appear to be unintentional.

RESULTS

Of the 176 criteria sets in both systems, only one, transient tic disorder, is identical. Twenty-one per cent had conceptually based differences and 78% had non-conceptually based differences.

CONCLUSIONS

Harmonisation of criteria sets, especially those with non-conceptually based differences, should be prioritised in the DSM-V and ICD-11 development process. Prior experience with the DSM-IV and ICD-10 harmonisation effort suggests that for the process to be successful steps should be taken as early as possible.

Mild cognitive impairment in stroke patients with ischemic cerebral small-vessel disease: a forerunner of vascular dementia?

Ischemic cerebral small-vessel disease accounts for a third of acute cerebral ischemic events and contributes to the development of cognitive decline and dementia. Cerebral small-vessel disease can be visualized on MRI studies as lacunar infarcts, white matter lesions and cerebral microbleeds. In general, the short-term prognosis of ischemic cerebral small-vessel disease compared with other stroke subtypes is more favorable, with almost negligible early mortality, absence of neuropsychological impairment and excellent neurological recovery. However, it has been shown recently that the proportion of dementia caused by small-vessel disease ranges from 36 to 67%. On the other hand, patients with a first-ever lacunar infarction present with cognitive impairment (mainly executive dysfunction) in more than half of cases and more than 55% of patients fulfil the criteria of mild cognitive impairment of the vascular type. Moreover, patients with small-vessel disease have an increase in the mid- and long-term risk of death, stroke recurrence and dementia. Neuropsychological abnormalities in small-vessel disease occurred more frequently than previously recognized. Ischemic cerebral small-vessel disease should be regarded as a potentially severe condition prodrome of subcortical vascular dementia rather than a relatively benign disorder.

Leukoaraiosis severity and list-learning in dementia

In patients with dementia, leukoaraiosis (LA) was hypothesized to result in differential patterns of impairment on a verbal serial list-learning test. Using a visual rating scale, 144 dementia patients with ischemic scores <4 were re-categorized as having mild (n = 73), moderate (n = 44), or severe LA (n = 27). Mild LA was predicted to be associated with an amnestic list-learning profile, while severe LA was predicted to be associated with a dysexecutive profile. List-learning performances were standardized to a group of healthy older adults (n = 24). Analyses were conducted on a set of four factors derived from the list-learning paradigm, as well as error scores. Data indicate that LA severity is an important marker for understanding list learning in dementia.

Current Concepts in Vascular Cognitive Impairment and Pharmacotherapeutic Implications

Objective:

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

Data Sources:

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

Study Selection and Data Extraction:

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

Data Synthesis:

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

Conclusions:

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

Statins, ACE inhibitors and ARBs in cardiovascular disease

Atherosclerotic cardiovascular disease (CVD) is the main cause of death in developed and developing countries. It is well accepted that several diseases - including hypertension, dyslipidemia and diabetes mellitus - increase CVD. More recently also chronic inflammatory diseases, such as rheumatoid arthritis, have been shown to accelerate CVD. This association further supports a responsible role for inflammatory processes in all stages of CVD pathophysiology. Clinically, CVD ranges through different acute and chronic syndromes with ischemic symptoms in distal tissues, including heart, cerebral region or peripheral arteries. Several treatments for reducing CVD are under investigation. In this review we focus on statins, angiotensin-converting-enzyme (ACE) inhibitors, and angiotensin-II receptor blockers (ARBs), updating therapeutic evidence from the last clinical trials with particular relevance to diabetic patients.

Blood–brain barrier: Ageing and microvascular disease – systematic review and meta-analysis

Cerebral "microvascular" disease occurs in lacunar stroke, leukoaraiosis, vascular dementia and Alzheimer's disease. It may arise from or contribute to insidious damage to the blood-brain barrier (BBB). We systematically reviewed the literature for evidence that BBB permeability is altered in patients with manifestations of cerebral microvascular disease. We found 31 BBB permeability studies (1953 individuals) of normal ageing or cerebral microvascular disease. In healthy humans, increasing age (10 comparisons, controls(C):subjects(S)=357:336) was associated with increased BBB permeability (standardised mean difference (S.M.D.) 1.21, 95% confidence interval (CI) 0.60, 1.81, p<0.01). BBB permeability was increased further in patients with either vascular or Alzheimer's dementia compared with age-matched controls (26 comparisons, C:S=510:547, S.M.D. 0.81, 99% CI 0.37, 1.26, p<0.01); in vascular compared with Alzheimer's dementia (10 comparisons, C:S=291:165, S.M.D. 0.71, 99% CI 0.12, 1.29, p<0.01); and with worsening leukoaraiosis (5 comparisons, C:S=122:88, S.M.D. 0.60, 99% CI 0.30, 0.89, p<0.01). BBB permeability increases with normal ageing and may be an important mechanism in the initiation or worsening of cerebral microvascular disease. Further studies on the role of BBB permeability are urgently needed.

Rapid screening of cognitive change in patients with questionable dementia using the Memory Impairment Screen and the Isaacs Set Test

OBJECTIVES

To assess the efficacy of combining the Memory Impairment Screen (MIS) and the Isaacs Set Test (IST) in predicting short-term development of dementia in a group of people with questionable dementia (QD) at baseline.

DESIGN

Performances of the weighted sum of MIS and IST and the <<or>> rule were compared with each other and with the Mini-Mental State Examination.

SETTING

Database of the Regional Network for Diagnostic Aid and Management of Patients with Cognitive Impairment in the Franche-Comté geographical area in France.

PARTICIPANTS

A cohort of 106 patients aged 65 and older with QD were followed up for a mean of 14.9 months (range 6-24 months).

MEASUREMENTS

Sensitivity, specificity, positive predictive value, and negative predictive value were calculated for the combination of these two tests.

RESULTS

The weighted sum had a sensitivity of 0.74 and a specificity of 0.84. The <<or>> rule (MIS<6 or IST<25) had a sensitivity of 0.74 and a specificity of 0.81. When range values were applied, low scores on the MIS and the IST (MIS<6 and IST<25) led to a high probability of dementia, whereas high scores (MIS>7 and IST>29) suggested a high probability of remaining dementia-free in the study follow-up.

CONCLUSION

This quickly performed tool (5 minutes) is simple to use and score. When including cutscores (MIS<6 or IST<25) or range values, this test could be considered a useful screening procedure for all types of dementias.

Cognitive impairment after cerebrovascular stroke: Relationship to vascular risk factors

BACKGROUND

Cognitive decline after cerebrovascular stroke has adverse outcome consequences. Since some vascular causes can be prevented and treated, the identification of stroke-related cognitive impairment is a challenge. Patients with cognitive impairment and vascular diseases exhibit higher homocysteine (Hcy) concentrations. Whether Hcy is an independent risk factor for cognitive impairment after stoke is still in question. The objectives of this study were to determine: 1) the relative frequency of first-ever post-stroke dementia (PSD) (three months after onset) in a consecutive sample of our population, 2) the risk factors associated with PSD, and 3) the relationship between Hcy levels and PSD.

METHODS

Eighty-one inpatients with first-ever stroke were prospectively evaluated with a neuropsychological battery and event-related evoked potentials (P300) at onset and then after three months. A wide range of demographic, clinical, radiological and laboratory variables were examined. PSD was diagnosed if the clinical presentation fulfilled DSM-IV criteria of vascular dementia, the patient scored </=21 on Mini Mental State Examination (MMSE) and </=67 points on Cognitive Abilities Screening Instruments (CASI).

RESULTS

PSD was diagnosed in 21%. PSD was significantly associated with increasing age, low levels of education, large sized and lacunar infarctions, severity of stroke, prolonged P300 latency, smoking, hypertension, and elevated Hcy levels. High Hcy levels increased the odds ratio of PSD after adjustment of significantly relevant variables including age, smoking, size of infarction, and carotid stenosis.

CONCLUSIONS

Cognitive decline is common after stroke. The results of this study indicate that PSD may result from stroke and its related risk factors including possible direct association with high Hcy levels. Better knowledge of the risk factors for PSD should increase the effectiveness of preventive strategies in patients with this condition.

Neuroimaging in dementia

Although dementia is a clinical diagnosis, neuroimaging often is crucial for proper assessment. Magnetic resonance imaging (MRI) and computed tomography (CT) may identify nondegenerative and potentially treatable causes of dementia. Recent neuroimaging advances, such as the Pittsburgh Compound-B (PIB) ligand for positron emission tomography imaging in Alzheimer's disease, will improve our ability to differentiate among the neurodegenerative dementias. High-resolution volumetric MRI has increased the capacity to identify the various forms of the frontotemporal lobar degeneration spectrum and some forms of parkinsonism or cerebellar neurodegenerative disorders, such as corticobasal degeneration, progressive supranuclear palsy, multiple system atrophy, and spinocerebellar ataxias. In many cases, the specific pattern of cortical and subcortical abnormalities on MRI has diagnostic utility. Finally, among the new MRI methods, diffusion-weighted MRI can help in the early diagnosis of Creutzfeldt-Jakob disease. Although only clinical assessment can lead to a diagnosis of dementia, neuroimaging is clearly an invaluable tool for the clinician in the differential diagnosis.

Small vessel versus large vessel vascular dementia: risk factors and MRI findings

OBJECTIVE

The aim of this study was a cross-sectional comparison of clinical and MRI characteristics and risk factor profiles between patients with small vessel disease (lacunae and white matter hyperintensities) and large vessel disease (large territorial or strategical infarcts) in a large cohort of VaD patients.

METHODS

Patients with VaD (NINDS-AIREN) were included in a large multicenter treatment trial (the VantagE study). All patients were examined by a neurologist and interviewed about their medical history. Based on MRI, patients were classified as having large vessel VaD, small vessel VaD, or a combination. Other MRI characteristics included white matter hyperintensities (WMH), medial temporal lobe atrophy (MTA) and general cortical atrophy.

RESULTS

Of the 706 patients, 522 (74 %) had small vessel disease, 126 (18 %) had large vessel disease and 58 (8 %) had both. Patients with small vessel disease were older and less educated, and showed more cortical and medial temporal lobe atrophy than patients with large vessel disease. The most prevalent vascular risk factors (hypertension, diabetes and smoking) were equally distributed between the different types of VaD. However, patients with large vessel disease had more hypercholesterolemia and cardiac risk factors compared to patients with small vessel disease.

CONCLUSION

Cerebrovascular disease underlying VaD consists in the majority of small vessel disease and in about one fifth of large vessel disease. This study demonstrates heterogeneity between these two groups with regard to risk factor profile and atrophy scores on MRI.

Strategies for molecular imaging dementia and neurodegenerative diseases

Dementia represents a heterogeneous term that has evolved to describe the behavioral syndromes associated with a variety of clinical and neuropathological changes during continuing degenerative disease of the brain. As such, there lacks a clear consensus regarding the neuropsychological and other constituent characteristics associated with various cerebrovascular changes in this disease process. But increasing this knowledge has given more insights into memory deterioration in patients suffering from Alzheimer's disease and other subtypes of dementia. The author reviews current knowledge of the physiological coupling between cerebral blood flow and metabolism in the light of state-of-the-art-imaging methods and its changes in dementia with special reference to Alzheimer's disease. Different imaging techniques are discussed with respect to their visualizing effect of biochemical, cellular, and/or structural changes in dementia. The pathophysiology of dementia in advanced age is becoming increasingly understood by revealing the underlying basis of neuropsychological changes with current imaging techniques, genetic and pathological features, which suggests that alterations of (neuro) vascular regulatory mechanisms may lead to brain dysfunction and disease. The current view is that cerebrovascular deregulation is seen as a contributor to cerebrovascular pathologies, such as stroke, but also to neurodegenerative conditions, such as Alzheimer's disease. The better understanding of these (patho) physiological mechanisms may open an approach to new interventional strategies in dementia to enhance neurovascular repair and to protect neurovascular coupling.

Vascular cognitive impairment: current concepts and clinical developments

Vascular cognitive impairment (VCI) comprises a range of cognitive disorders related to cerebral vessel disease and has generally replaced the term multi-infarct dementia. Despite the heterogeneity of the VCI construct, some clinical patterns can be discerned, which enable subtypes, such as mixed dementia and VCI-no dementia, to be recognised. Diagnostic criteria for vascular dementia do not encompass the full range of the VCI construct, and clinical investigators now recognise the need for harmonised standards to study the many manifestations of VCI seen in daily practice and to inform the development of diagnostic criteria. Although executive dysfunction is a recognised feature of VCI, some data suggest a less exclusive role than was previously proposed. VCI might be preventable, although the evidence for this is not as complete as it is for the prevention of stroke. Future studies into specific therapies for VCI will need to consider the clinical features and outcomes carefully.

Diagnosis and management of vascular cognitive impairment

Accurate diagnosis of vascular cognitive impairment (VCI) is important but may be difficult. VCI diagnoses depend on determinations of the presence of both cognitive impairment and cerebrovascular disease (CVD), temporal causal links between cognitive impairment and CVD, and the presence or absence of other potential contributors to cognitive impairment, such as Alzheimer's disease (AD). Diagnostic criteria differ across currently utilized systems, resulting in widely differing VCI prevalence rates. Also, current systems may not be able to differentiate "pure" VCI from "mixed" AD and CVD. National Institute of Neurological Disorders and Stroke harmonization criteria for VCI have been developed for study and validation to help bridge gaps in our understanding of VCI diagnosis. VCI management begins with atherogenic risk factor control. Current VCI treatment options demonstrate statistical improvement but not consistent global clinical efficacy. Future clinical trials should concentrate on both primary risk factor control and development of new therapeutic agents to treat patients already diagnosed with VCI.

The role of higher-level cognitive function in gait: executive dysfunction contributes to fall risk in Alzheimer's disease

Alzheimer's disease (AD) is generally understood as primarily affecting cognition while sparing motor function, at least until the later stages of the disease. Studies reported over the past 10 years, however, have documented a prevalence of falls in AD patients significantly higher than in age-matched normal elders; also persons with AD have been observed to have different walking patterns with characteristics that increase gait instability. Recent work in cognitive neuroscience has begun to demonstrate the necessity of intact cognition, particularly executive function, for competent motor control. We put the pieces of this puzzle together and review the current state of knowledge about gait and cognition in general along with an exploration of the association between dementia, gait impairment and falls in AD. We also briefly examine the current treatment of gait instability in AD, mainly exercise, and propose a new approach targeting cognition.

Combining the Memory Impairment Screen and the Isaacs Set Test: A Practical Tool for Screening Dementias

OBJECTIVES

To assess the accuracy of combining the Memory Impairment Screen (MIS) with the Isaacs Set Test (IST) in distinguishing subjects with dementia from controls without dementia.

DESIGN

The weighted sum of MIS and IST scores was calculated, and the logical "or" rule combination was performed using two different patient and control samples. Combination results were compared with each test used alone and with Mini-Mental State Examination to detect all types of dementias.

SETTING

Database of the Regional Network for Diagnostic Aid and Management of Patients with Cognitive Impairment in the Franche-Comté, France, geographical area.

PARTICIPANTS

A cohort of 444 patients with Alzheimer's disease, non-Alzheimer's dementia, and reversible dementia and 311 controls.

MEASUREMENTS

Sensitivity, specificity, positive predictive value, and negative predictive value were calculated for the combination of these two tests.

RESULTS

The weighted sum had overall sensitivities of 0.92 and 0.84 for mild cases, with a specificity of 0.92. The "or" rule had overall sensitivities of 0.92 and 0.89 for mild cases, with a specificity of 0.90. This pairing requires no more than 5 minutes. Its scoring is simple with the "or" rule combination.

CONCLUSIONS

The combination of MIS and IST could be a useful tool for screening dementias. The "or" rule combination seems particularly adapted to medical practice.

Arterial stiffness as an independent predictor of longitudinal changes in cognitive function in the older individual

BACKGROUND

Cognitive decline significantly contributes to disability in older individuals. We previously demonstrated cross-sectionally that arterial stiffness [pulse wave velocity (PWV)] was associated with memory loss independently of traditional cardiovascular risk factors and of neuroimaging findings in older individuals without prior stroke. The present study aimed to evaluate PWV as a predictor of longitudinal changes in cognitive function in older individuals reporting memory problems.

PARTICIPANTS AND METHODS

We studied 102 older individuals (mean age 79 +/- 6 years; 31 men, 71 women) reporting memory problems. PWV was measured noninvasively by Complior. Traditional cardiovascular risk factor levels were measured. Global cognitive function was measured by the Mini-Mental State Examination (MMSE) (maximum score = 30) at baseline and at follow-up visit. Cerebral computed tomography evaluated the presence of microvascular damage or cortical atrophy. Individuals with prior stroke or atrial fibrillation were excluded.

RESULTS

The baseline MMSE was 22.9 +/- 5.5; 61% were hypertensive, 26.8% diabetic, 9.4% smokers, 10.5% taking statins, and 21.1% taking nitrates. The average PWV was 13.5 +/- 2.2 m/s. After a median follow-up of 12 months, the average per-year decline in MMSE was 2.9 points or 12.1%. Multiple regression models showed that PWV independently predicted cognitive decline (model R2 = 0.50). PWV was the single strongest predictor of cognitive decline, explaining 15.2% of the total variance (each 1 m/s increase in PWV was associated with an average 0.74 per-year decrease in MMSE score, P < 0.001).

CONCLUSION

In older individuals, arterial stiffness (PWV) is a strong predictor of loss in cognitive function, independent of age, sex, education, and traditional cardiovascular risk factors.

Incidence of dementia and associated risk factors in Japan: The Osaki-Tajiri Project

The incidence of dementia and risk factors has not been fully investigated in Japan. Following a prevalence study in 1998, we investigated the incidence and associated factors in the same population in 2003 and 2005. Randomly selected 771 residents in Tajiri were targeted. The final participants included 204 (65.2%) healthy older adults (Clinical Dementia Rating, CDR 0) and 335 (73.1%) people with questionable dementia (CDR 0.5). We analyzed the incidence of dementia and dementing diseases, and possible risk factors. The risk factors included demographics, lifestyle-related factors, vascular risk factors, cognitive functions, and MRI findings. Overall, 3.9% of the CDR 0 and 37.0% of the CDR 0.5 participants developed dementia during the 5-year period, whereas 40.2% of the CDR 0.5 participants developed dementia during the 7-year period. Older adults had a higher incidence. Higher CDR Box scores had a higher incidence. Of the dementing diseases, 60.8% of participants developed Alzheimer' disease (AD), followed by vascular dementia (VaD), 17.9%. Logistic regression analyses showed that age, MMSE, cognitive functions such as recent memory, and generalized atrophy were significant predictors of progression to AD. Similarly, predictive factors for progression to VaD were age, MMSE, cognitive functions such as frontal function, and white matter lesions and cerebrovascular diseases. A comprehensive system including CDR, cognitive tests, and MRI, is recommended in community-based health policy planning.

Validation of clinical criteria for possible vascular dementia in the oldest-old

Although vascular dementia (VaD) is a main pathology in nonagenarians and centenarians, the validity of clinical criteria for this diagnosis is unknown. We analyzed 110 autopsy cases and reported sensitivities and specificities of the State of California Alzheimer's Disease Diagnostic and Treatment Centers (ADDTC) and National Institute for Neurological Disorders and Stroke (NINDS-AIREN) criteria for possible VaD as well as Hachinski ischemic score (HIS). Among them, there were 36 neuropathologically confirmed VaD cases. All criteria displayed comparable sensitivities (0.56-0.58). Specificities values were 0.74, 0.73 and 0.66, respectively. There was an age-related decrease on ADDTC criteria sensitivity due to the fact that 42% of pure VaD cases did not present with stroke. Thirty percent of mixed dementia (MD) cases were diagnosed as VaD by both NINDS-AIREN and ADDTC criteria. This proportion reached 45.9% for the HIS. These data demonstrate that the new diagnostic criteria for possible VaD do not provide a substantial gain of sensitivity compared to the HIS. Although their specificity was significantly lower in this age group compared to younger cohorts, all of them successfully exclude AD cases.

The enigma of vascular cognitive disorder and vascular dementia

The prevalence, morphology and pathogenesis of vascular dementia (VaD), recently termed vascular cognitive impairment, are a matter of discussion, and currently used clinical diagnostic criteria show moderate sensitivity (average 50%) and variable specificity (range 64-98%). In Western clinic-based series, VaD is suggested in 8-10% of cognitively impaired aged subjects. Its prevalence in autopsy series varies from 0.03 to 58%, with reasonable values of 8-15%, while in Japan it is seen in 22-35%. Neuropathologic changes associated with cognitive impairment include multifocal and/or diffuse disease and focal lesions: multi-infarct encephalopathy, white matter lesions or arteriosclerotic subcortical (leuko)encephalopathy, multilacunar state, mixed cortico-subcortical type, borderline/watershed lesions, rare granular cortical atrophy, post-ischemic encephalopathy and hippocampal sclerosis. They result from systemic, cardiac and local large or small vessel disease. Recent data indicate that cognitive decline is commonly associated with widespread small ischemic/vascular lesions (microinfarcts, lacunes) throughout the brain with predominant involvement of subcortical and functionally important brain areas. Their pathogenesis is multifactorial, and their pathophysiology affects neuronal networks involved in cognition, memory, behavior and executive functioning. Vascular lesions often coexist with Alzheimer disease (AD) and other pathologies. Minor cerebrovascular lesions, except for severe amyloid angiopathy, appear not essential for cognitive decline in full-blown AD, while both mild Alzheimer pathology and small vessel disease may interact synergistically. The lesion pattern of "pure" VaD, related to arteriosclerosis and microangiopathies, differs from that in mixed-type dementia (AD with vascular encephalopathy), more often showing large infarcts, which suggests different pathogenesis of both types of lesions. Due to the high variability of cerebrovascular pathology and its causative factors, no validated neuropathologic criteria for VaD are available, and a large variability across laboratories still exists in the procedures for morphologic examination and histology techniques.

Dementia syndromes: evaluation and treatment

As our population ages, diseases affecting memory and daily functioning will affect an increasing number of individuals, their families and the healthcare system. The social, financial and economic impacts will be profound. This article provides an overview of current dementia syndromes to assist clinicians in evaluating, educating and treating these patients.