Defining dementia: clinical criteria for the diagnosis of vascular dementia

The recognition of cerebrovascular disease (CVD) as a contributing factor and a cause of dementia has led to the development of clinical criteria for vascular dementia (VaD). Due to high specificity, the consensus criteria developed by the National Institute for Neurological and Communicative Disorders and Stroke (NINDS)–Association Internationale pour la Recherche et l'Enseignement en Neurosciences (AIREN) have been used in controlled clinical trials to select patients with pure VaD. VaD is predominantly a subcortical frontal form of dementia with prominent executive dysfunction. In contrast, the criteria of the NINCDS–Alzheimer's Disease and Related Disorders Association (ADRDA) emphasize memory loss as the main feature to distinguish Alzheimer's disease (AD) from VaD and from other forms of dementia. Moreover, CVD may precipitate the clinical expression of AD. Although no criteria have been created specifically for patients having AD with CVD, the ischemic score, the Informant Questionnaire on Cognitive Decline in the Elderly and a history of prestroke mild cognitive impairment (MCI) may be useful for identifying patients with this mixed form of dementia.     

The validity and reliability of 6 sets of clinical criteria to classify Alzheimer's disease and vascular dementia in cases confirmed post-mortem: added value of a decision tree approach

Data from 204 participants from the Oxford Project to Investigate Memory and Ageing, who were diagnosed post-mortem using the histopathological criteria of the Consortium to Establish a Registry for Alzheimer's Disease (CERAD), were used to assess the validity of the clinical criteria for Alzheimer's disease (AD) of the 'National Institute of Neurological and Communicative Disorders and Stroke/the Alzheimer's Disease and Related Disorders Association' (NINCDS/ADRDA). Cases who had been diagnosed as NINCDS/ADRDA 'probable AD' in life were usually confirmed at autopsy, but half of the NINCDS/ADRDA 'negative' cases were not (low specificity). It was hypothesized that the overall clinical impression may have taken precedence over the use of the actual criteria. We therefore investigated the validity and reliability of the clinical criteria using a computerized 'dementia diagnosis system' for each of 6 sets of criteria [Diagnostic and Statistical Manual of Mental Disorders (DSM-IV), NINCDS/ADRDA and three sets of criteria specifically for vascular dementia (VaD): NINCDS-AIREN, State of California Alzheimer's Disease Diagnostic and Treatment Centers (ADDTC), and Vascular Cognitive Impairment (VCI)] to classify a subset (n = 96) of the cases confirmed post-mortem. The use of the computerized system significantly (p = 0.01) increased the specificity (81%, similar to sensitivity) of the NINCDS/ADRDA diagnoses, which were shown to have 'moderate' inter-rater reliability. The DSM-IV criteria had good validity for AD when compared with post-mortem confirmation and showed 'substantial' inter-rater reliability. The ADDTC and VCI criteria for VaD had good specificity (88%) and sensitivity (75%), but only for one rater. The DSM-IV and NINCDS-AIREN criteria for VaD showed poor validity and inter-rater reliability. We conclude that the forced use of decision trees through a computerized system enhances the accuracy of the clinical diagnoses of dementia.     

Medial temporal lobe atrophy on MRI in dementia with Lewy bodies

OBJECTIVE: To investigate whether medial temporal lobe atrophy (MTA) on MRI is less frequent in dementia with Lewy bodies (DLB) compared with AD and vascular dementia (VaD), and to determine the diagnostic utility of MTA in the differential diagnosis of dementia. METHOD: Coronal T1-weighted 1.0-T MR images were acquired in patients with DLB (consensus criteria; n = 26; mean age, 75.9 years), AD (National Institute of Neurological and Communicative Disorders and Stroke-Alzheimer's Disease and Related Disorders Association; n = 28; mean age, 77.4 years), VaD (National Institute of Neurological Disorders and Stroke-Association Internationale pour la Recherche et l'Enseignement en Neurosciences; n = 24; mean age, 76.9 years), and normal control subjects (n = 26; mean age, 76.2 years). Cognitive function was assessed using the Cambridge Cognitive Examination (CAMCOG), and MTA was rated visually using a standardized scale. RESULTS: MTA was more frequent and severe in all dementia groups compared with control subjects (AD, 100%; VaD, 88%; DLB, 62%; control subjects, 4%; p < 0.001). Comparing dementia groups, MTA scores were significantly lower in DLB than AD (p = 0.002), with a trend toward less atrophy in DLB compared with VaD (p = 0.07). The absence of MTA had a specificity of 100% and 88% for separating DLB from AD and VaD respectively, and a sensitivity of 38%. In patients with DLB, MTA increased with age (r = 0.58, p = 0.002), and in all dementia patients MTA correlated with memory impairment (combined memory score, r = -0.34, p = 0.003) but not total CAMCOG score or other subscales. CONCLUSION: Patients with DLB have significantly greater MTA than control subjects but significantly less than those with AD. The authors confirmed that the presence of MTA is useful in detecting AD but less useful in differentiating between dementias. However, in the differentiation of DLB from AD and VaD, the absence of MTA is highly suggestive of a diagnosis of DLB.     

Preclinical cognitive trajectories differ for Alzheimer's disease and vascular dementia

We investigated differences between Alzheimer's disease (AD) and vascular dementia (VaD) from the appearance of the first cognitive symptoms, focusing on both time of onset and rate of accelerated decline for different cognitive functions before dementia diagnosis. Data from a longitudinal population-based study were used, including 914 participants (mean age = 82.0 years, SD = 5.0) tested with a cognitive battery (word recall and recognition, Block Design, category fluency, clock reading) on up to four occasions spanning 10 years. We fit a series of linear mixed effects models with a change point to the cognitive data, contrasting each dementia group to a control group. Significant age-related decline was observed for all five cognitive tasks. Relative to time of diagnosis, the preclinical AD persons deviated from the normal aging curve earlier (up to 9 years) compared to the preclinical VaD persons (up to 6 years). However, once the preclinical VaD persons started to decline, they deteriorated at a faster rate than the preclinical AD persons. The results have important implications for identifying the two dementia disorders at an early stage and for selecting cognitive tasks to evaluate treatment effects for persons at risk of developing AD and VaD.     

Cognitive and functional decline in African Americans with VaD, AD, and stroke without dementia.

OBJECTIVE: To compare the rates of cognitive and functional decline in African American patients diagnosed at baseline with vascular dementia (VaD) (n = 79), AD (n = 113), or stroke without dementia (SWD) (n = 56) and followed for up to 7 years with annual neuropsychological and other examinations. METHODS: Study patients were diagnosed using established criteria for dementia and were administered cognitive screening, functional screening, and neuropsychological measures. Baseline dementia severity was rated using the Clinical Dementia Rating Scale. Random effects modeling was used to examine rates of decline and to compare the rates of decline in the three groups. RESULTS: Both patients with VaD and those with AD showed significant cognitive and functional decline during follow-up; patients with VaD declined at a slower rate than patients with AD; and patients diagnosed with SWD at baseline did not show cognitive or functional decline during follow-up. CONCLUSIONS: Patients with VaD decline at a slower rate than patients with AD. Patients who do not meet criteria for dementia soon after stroke may not be at high risk for developing dementia. Future studies are needed to follow VaD patients with longitudinal, specialized MR protocols, concurrent neuropsychological examinations, and neuropathologic examination to determine possible neuroimaging predictors of progressive cognitive and functional decline and to assess the contribution of Alzheimer's pathology to decline in patients diagnosed with VaD.     

Neuropsychiatric profiles in patients with Alzheimer's disease and vascular dementia

Background/Aims:

The aim of the following study is to compare the behavioral and psychological symptoms of dementia (BPSD) in patients of Alzheimer disease (AD) and vascular dementia (VaD).

Materials and Methods:

We used National Institute of Neurological and Communicative Disorders and Stroke-Alzheimer''s Disease and Related Disorders Association criteria for diagnosing AD and National Institute of Neurological Disorders and Stroke-Association International pour la Recherche et l’Enseignement en Neurosciences Criteria for diagnosing VaD. VaD cohort was further subcategorized into small vessel and large vessel disease. The severity of cognitive impairment and the BPSD were studied by means of the Clinical Dementia Rating Scale (CDR) and the Neuropsychiatric Inventory respectively.

Results:

We studied 50 AD and 50 VaD patients of whom 38 were small vessels and 12 were large vessels VaD. The severity of dementia was comparable in both groups. The agitation/aggression, depression/dysphoria, anxiety, apathy/indifference, irritability, aberrant motor behavior, appetite and eating behavior and night-time behaviors occurred significantly more frequently in patients with VaD than AD. We found a weak positive correlation between the CDR score and the number of neuropsychiatric symptoms per patient in both cohorts. Elation/euphoria, agitation/aggression was significantly more frequent in patients with large vessel in comparison to small vessel VaD.

Conclusions:

BPSD are common in both types of dementia and they are more severe in VaD than AD when the groups have similar levels of cognitive impairment.     

The progression of cognitive impairment in dementia with Lewy bodies, vascular dementia and Alzheimer's disease

BACKGROUND: Little is known about the rate of progression or associations of cognitive impairment in dementia with Lewy bodies (DLB), or the associations of accelerated decline. METHOD: Dementia patients from a case register were evaluated at baseline and 1 year follow-up using the Cambridge Assessment for Mental Disorders in the Elderly, section B (CAMCOG) and the Mini-Mental State Examination (MMSE) to determine the rate of cognitive decline. Operationalized clinical diagnoses were applied (NINCDS ADRDA for Alzheimer's disease (AD), NINCDS AIRENS for vascular dementia (VaD) and consensus criteria for DLB). RESULTS: One hundred and ninety-three patients completed annual MMSE schedules (AD, 101; DLB, 64; VaD, 38), of whom 154 completed the CAMCOG. The magnitude of cognitive decline (MMSE, 4-5 points; CAMCOG, 12-14 points) was similar in each of the dementias. The strongest predictor of accelerated cognitive decline in DLB was the apolipoprotein E4 allele (17.5 vs 8.3 points decline on the CAMCOG). CONCLUSION: Over 1 year, DLB, VaD and AD patients had similar rates of cognitive decline overall. Apolipoprotein E4 may be an important predictor of more rapid decline in DLB.     

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.     

Clinical impact of updated diagnostic and research criteria for Alzheimer's disease

Almost 30 years ago, the National Institute of Neurological and Communicative Disorders and Stroke and the Alzheimer's Disease and Related Disorders Association (more commonly known as the Alzheimer's Association) developed the original clinical diagnostic criteria for Alzheimer's disease (AD). Recently, the National Institute on Aging and the Alzheimer's Association released updated research and diagnostic criteria for AD. The new criteria establish that AD exists on a continuum and is comprised of not only dementia but also a preclinical phase and a phase of mild cognitive impairment due to AD. The new criteria also describe advancements in biomarker evidence, which is still being researched and is not yet ready for clinical settings. Additionally, the American Psychiatric Association is currently revising the Diagnostic and Statistical Manual of Mental Disorders, which will include updated diagnostic criteria for AD and other neurocognitive disorders.     

Clinical diagnosis of dementia

This paper presents recommendations deriving from the Third Canadian Consensus Conference on the Diagnosis and Treatment of Dementia, concerning the clinical diagnosis of dementia. There are currently no universally accepted biological or radiological markers of dementia. In the absence of these, the diagnosis of dementia remains a clinical exercise aiming to integrate all available clinical and laboratory information. It is proposed that the currently used National Institute of Neurological and Communicative Disorders and Stroke/Alzheimer’s Disease and Related Disorders Association (NINCDS/ADRA) criteria for diagnosis of Alzheimer’s disease (AD) be retained. The currently available vascular dementia (VaD) diagnostic criteria have variable accuracy. An integrative approach to VaD diagnosis based on all the available evidence (history, vascular risk factors, physical exam, clinical course, neuroimaging, cognitive impairment pattern) is recommended. The separation of Lewy body dementia (DLB) from Parkinson’s disease dementia (PDD) is based on the dominant clinical presenting feature of each syndrome, and relies on the duration of this feature: long duration of parkinsonian “motor” syndrome preceding dementia for PDD versus early/initial dementia accompanied by extrapyramidal symptoms for DLB. It is recognized that it is impossible clinically to characterize DLB with (pathologically) coexisting AD changes. The Frontotemporal group of dementia syndromes are discussed in regards to their typical clinical pictures, recognizing that their neuropathological substrate are not predictable from their mode of presentation. Finally, the particular rapid time sequence of evolution of the dementias due to prior disease is recognized as the clinically most useful distinguishing feature of these syndromes.     

Dementia subtypes in China: prevalence in Beijing, Xian, Shanghai, and Chengdu

BACKGROUND: Prevalences of Alzheimer disease (AD) and vascular dementia (VaD) in China reportedly differ from those in Western countries. OBJECTIVE: To estimate prevalence of AD and VaD in 4 regions of China. DESIGN: Cross-sectional, population-based prevalence survey with a stratified, multistage cluster sampling design. SETTING: Rural (n = 99) and urbanized (n = 71) communities of Beijing, Xian, Shanghai, and Chengdu. PARTICIPANTS: A sample of 34 807 community residents (94% of those eligible) 55 years or older. MAIN OUTCOME MEASURES: Participants were screened with the Chinese Mini-Mental State Examination. Those who screened positive (n = 3950) underwent a standardized diagnostic workup. Screening sensitivity was assessed in a 3.3% random sample (n = 1008 of the 30 857 who passed the screening). Diagnoses of AD and VaD were made according to National Institute of Neurological and Communicative Diseases and Stroke-Alzheimer Disease and Related Disorders Association and National Institute of Neurological Disorders and Stroke-Association Internationale pour la Recherche et l'Enseignement en Neurosciences criteria, respectively. Final diagnoses were made after a 6-month confirmation interval. RESULTS: We identified 732 AD cases and 295 VaD cases. Prevalence in persons 65 years or older was 3.5% (95% confidence interval, 3.0%-3.9%) for AD and 1.1% (95% confidence interval, 0.9%-1.1%) for VaD. After post hoc correction for negative screening errors, prevalence increased to 4.8% for AD and remained at 1.1% for VaD. CONCLUSION: Prevalence of dementia subtypes in China is comparable with that in Western countries.     

Impaired attention function based on the Montréal Cognitive Assessment in vascular dementia patients with frontal hypoperfusion: The Osaki-Tajiri project

We previously reported that the Montréal Cognitive Assessment (MoCA) was effective in the evaluation of cerebrovascular diseases. We also demonstrated that the test was effective for screening for very mild vascular dementia (VaD) in the community. Herein, we examined the effectiveness of MoCA in the assessment of patients with VaD in an outpatient clinic. Forty-four patients with VaD (National Institute of Neurological Disorders and Stroke–Association Internationale pour la Recherche et l’Enseignement en Neurosciences [NINDS-AIREN] criteria) and 58 patients with Alzheimer’s disease (AD) (National Institute of Neurological and Communicative Disorders and Stroke–Alzheimer’s Disease and Related Disorders Association [NINCDS-ADRDA] criteria) were compared with 67 non-demented control subjects. All were outpatients at the Tajiri Memory Clinic, Osaki-Tajiri, northern Japan. All underwent 1.5 Tesla MRI and ethyl cysteinate dimer (ECD) single photon emission computed tomography (SPECT) examinations. The SPECT images were used to classify the VaD patients into two subgroups, those with frontal hypoperfusion (F-VaD) and those without frontal hypoperfusion. The frontal hypoperfusion pattern was defined as the “P2” pattern of the Sliverman classification, with or without focal hypometabolism in other areas, based on the agreement of three neurologists who were blinded to the results of the neuropsychological examinations. Total scores and attention subscores on the MoCA were lower in the F-VaD group compared with other groups. Our results suggest that the MoCA attention subscale can detect VaD participants, particularly those with frontal hypoperfusion.     

Classification and subtypes of vascular dementia

Vascular dementia (VaD) is a heterogeneous entity with a large clinicopathological spectrum. It has been classified and subclassified in many different ways. The difficulty in identifying the various subtypes is a problem in the diagnostic process. For clinical purposes, it is desirable to find subtypes of VaD that are homogeneous enough to allow meaningful comparisons across studies. This article presents candidates for such subtypes: poststroke dementia, subcortical VaD, and combined Alzheimer's disease and VaD (AD + VaD). The first two candidates are easy to identify. Poststroke dementia occurs with cognitive decline in close temporal relation to a transient ischemic attack. Subcortical VaD has a relatively homogeneous clinical picture for which detailed criteria are suggested. AD + VaD is more difficult to identify but is possible, sometimes with the aid of neuroimaging and/or biological markers.     

Apolipoprotein E phenotypes in demented and cognitively impaired patients with and without cerebrovascular disease

Controversy exists regarding the apolipoprotein E (ApoE) epsilon4 allele association with vascular dementia (VaD), ranging from increased epsilon4 frequency, similar to that found for Alzheimer's disease (AD), to no association between the epsilon4 allele and VaD. To clarify further the relationship between ApoE alleles polymorphism and cerebrovascular disease (CVD) in demented and cognitively impaired patients, we examined the ApoE phenotypes in a sample of 280 patients: 155 with AD, 21 with VaD, 32 with mixed dementia (MD), 45 with mild cognitive impairment (MCI) but without CVD, and 27 in which vascular disease was the most probable cause of cognitive decline [vascular mild cognitive impairment (VMCI)]. Our results show that the frequency of the ApoE epsilon4 allele in patients over 70 years old with clinically diagnosed VaD and VMCI does not differ significantly from that of controls. In contrast, ApoE epsilon4 allele-bearing individuals had greater risk of having late-onset AD (OR = 8.8; 95% CI 3.7-21.0), or non-vascular cognitive impairment (OR = 7.0; 95% CI 2.5-19.0).     

Prevalence of dementia and dementing diseases in Japan: the Tajiri project

BACKGROUND: Vascular dementia (VaD) has been considered to be more prevalent than Alzheimer disease in Japan. However, this might be the result of overdiagnosis stemming from some problematic diagnosis of VaD or of the frequent use of magnetic resonance imaging to detect cerebrovascular disease in older adults. OBJECTIVES: We investigated the prevalence of dementia and the ratios of dementing diseases. The effects of different criteria for VaD (DSM-IV, Alzheimer's Disease Diagnostic and Treatment Centers [ADDTC], and National Institute of Neurological Disorders and Stroke and the Association Internationale pour la Recherche et l'Enseignement en Neurosciences [NINDS-AIREN]) were considered. Hippocampal atrophy and vascular contribution to dementia were evaluated using magnetic resonance imaging findings. METHODS: We targeted all residents 65 years and older (n = 3207) in Tajiri, Japan, and examined 1654 (participant group 1). Of these, 564 (participant group 2) were randomly selected, and 497 underwent magnetic resonance imaging and diagnosis of dementing diseases. RESULTS: We found the overall prevalence of dementia to be 8.5% (141/1654) in participant group 1. Of these, 21 (14.9%) had a history of stroke. Of the 113 participants who had a history of stroke independent of dementia, 18.6% (21/113) were demented. For participant group 2 (n = 497), 32 were demented. The ratio among the dementia for probable VaD based on the NINDS-AIREN criteria was 18.8% (6/32), whereas that for ischemic vascular dementia was 31.3% (10/32) according to the ADDTC criteria. CONCLUSION: We confirmed the overall prevalence of dementia in adults 65 years and older to be 8.5%. We found that VaD was not a common disorder according to the NINDS-AIREN criteria. Rather, the condition of possible Alzheimer disease with cerebrovascular disease was more common.     

Clinical criteria for the diagnosis of vascular dementia: a multicenter study of comparability and interrater reliability

BACKGROUND: Several clinical criteria have been developed to standardize the diagnosis of vascular dementia (VaD). Significant differences in patient classification have been reported, depending on the criteria used. Few studies have examined interrater reliability. OBJECTIVE: To assess the concordance in classification and interrater reliability for the following 4 clinical definitions of VaD: the Hachinski Ischemic Score (HIS), the Alzheimer Disease Diagnostic and Treatment Centers (ADDTC), National Institute of Neurological Disorders and Stroke-Association Internationale pour la Recherche et l'Enseignement en Neurosciences (NINDS-AIREN), and Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV). METHODS: Structured diagnostic checklists were developed for 4 criteria for VaD, 2 criteria for Alzheimer disease (AD), and 4 criteria for dementia. Twenty-five case vignettes, representing a spectrum of cognitive impairment and subtypes of dementia, were prepared in a standardized clinical format. Concordance in case classification using different criteria and interrater reliability among 7 ADDTCs given a specific set of criteria was assessed using the kappa statistic. RESULTS: The frequency of a diagnosis of VaD was highest using the modified HIS or DSM-IV criteria, intermediate using the original HIS and ADDTC criteria, and lowest using the NINDS-AIREN criteria. Scores for interrater reliability ranged from kappa = 0.30 (ADDTC) to kappa = 0.61 (original HIS). CONCLUSIONS: Clinical criteria for VaD are not interchangeable. Depending on the criteria selected, the reported prevalence of VaD will vary significantly. The traditional HIS has higher interrater reliability than the newer criteria for VaD. Prospective longitudinal studies with clinical-pathological correlation are needed to compare validity.     

Neuronal repair and replacement in spinal cord injury

OBJECTIVE: To assess age-, gender, and subtype-specific incidence rates of dementia in three populations in central Spain using data from the Neurological Disorders in Central Spain (NEDICES), a population-based survey of elderly participants. METHODS: Individuals were evaluated at baseline (1994-1995) and at follow-up (a median of 3.2 years later in 1997-1998). The evaluation included a screening questionnaire for dementia and a neurological assessment, when possible. RESULTS: Of 5278 participants evaluated at baseline, there were 306 prevalent dementia cases. One hundred and sixty-one incident dementia cases were identified among 3,891 individuals assessed at follow-up. The large majority had Alzheimer's disease (AD): 115 (71.4%) AD, 18 (11.2%) vascular dementia (VaD), 11 (6.8%) dementia associated with parkinsonism, 11 (6.8%) undetermined etiology, and 6 (3.7%) secondary dementia. Average annual incidence rates (per 1,000 person-years) in the population aged 65 to 90 and over years, adjusted to the standard European population, were 10.6 (95% CI, 8.9 to 12.3) for dementia, 7.4 (95% CI=6.0 to 8.8) for AD, and 1.4 (95% CI=0.6 to 2.3) for VaD. Age-specific incidence rates of dementia and AD increased exponentially with advancing age. Age, stroke and illiteracy were independent risk factors for dementia and AD. Aggregation of vascular risk factors was related to a higher risk of both VaD and AD. CONCLUSIONS: In the NEDICES study, incidence of dementia increased with age beyond age 85 and AD was the most frequent type of dementia. The risk of AD and VaD increased with the number of vascular risk factors.     

Normal aging and executive functions in "old-old" community dwellers: poor performance is not an inevitable outcome

BACKGROUND: Studies on normal aging and cognitive functioning commonly describe early and more pronounced age-related changes in executive functions (EFs) compared to other cognitive abilities. Two of the three most common neurodegenerative disorders associated with aging (vascular dementia [VaD] and extrapyramidal [EP]-related dementia) show executive dysfunctions in their clinical presentation; and these cognitive deficits are not uncommon in the third one: Alzheimer's disease (AD). METHODS: Nine EF tests (yielding 12 measures) were administered to 123 randomly selected community dwellers, aged 81 years and over, with the view to determine the effect of age on performance. Markers of AD, VaD, and EP-related dementia, as well as sociodemographic and psychological variables, were selected and their contribution to EF performance was investigated. RESULTS: Multiple linear regression analyses revealed the greatest contribution to EF scores from the markers of AD and estimated IQ but not from the markers of VaD and EP-related dementia or from age. CONCLUSIONS: These findings suggest that chronological age acts as a proxy variable mediating the impact of other factors such as subclinical signs of neurodegenerative disorders and that it has little independent contribution to make. They also indicate the importance of cognitive abilities supported by posterior cortical circuits in EF problem resolution. This study demonstrates that cognitive decline is not an ineluctable process that is associated with "normal" aging but rather represents, in many cases, a byproduct of neurodegenerative disorders, albeit themselves highly age-related.     

Galantamine in the treatment of vascular dementia

Vascular dementia (VaD) is a disorder with no cure and limited treatment options. Similarities between VaD and Alzheimer's disease (AD) arise on a number of levels. Both involve progressive decline in cognition, functional ability, and behavior, and there is evidence for a central role of reduced cholinergic neurotransmission in the two illnesses. Treatment strategies in VaD have historically focused on prevention, although evidence of cognitive benefits with preventative treatment is scarce. Acetylcholinesterase inhibitors represent a rational treatment possibility for symptomatic therapy of patients with VaD. A recent large-scale trial of galantamine in patients with VaD or AD with cerebrovascular disease (AD + CVD) represents the first placebo-controlled trial showing clinically relevant benefits in these important patient populations.     

Ten-year incidence of dementia in a rural elderly US community population: the MoVIES Project

OBJECTIVE: To determine incidence rates by age, sex, and education of overall dementia and probable/ possible AD in a largely rural community. METHODS: Ten-year prospective study of a randomly selected community sample aged 65+; biennial cognitive screening followed by standardized clinical evaluation. Incidence rates were estimated for overall dementia (Diagnostic and Statistical Manual of Mental Disorders, 3rd ed., revised, criteria and Clinical Dementia Rating [CDR]) and for probable/possible AD (National Institute of Neurological and Communicative Disorders and Stroke-Alzheimer's Disease and Related Disorders Association criteria). RESULTS: The cohort consisted of 1,298 individuals free of dementia at study entry. Among these, 199 incident (new) cases of overall (all-cause) dementia with CDR stage > or = 0.5, including 110 with CDR > or = 1, were detected during follow-up. Among the incident cases, 153 (76.9%) had probable/ possible AD. Age-specific incidence rates are reported for all dementia and for probable/possible AD, by sex and CDR stage. Among all-cause dementias with CDR = 0.5, controlling for age and education, men had a higher incidence rate than women. In the same group, those with less than high school education had significantly higher incidence rates than those with more education. Rates did not vary significantly by sex or education for probable/possible AD or for dementia with CDR > or = 1. CONCLUSIONS: Incidence rates of all dementias and of AD increased with age; men and those with lesser education had higher rates of possible/incipient dementia (CDR = 0.5) in this community. Potential explanations for these sex and education effects are discussed.