Comparisons of cognitive deterioration rates by dementia subtype

Pathophysiological aspects of dementia and its rate of cognitive deterioration could be dependent on disease subtype, Alzheimer's dementia (AD), vascular dementia (VaD), and Parkinson's disease with dementia (PDD). 150 patients diagnosed at the Chungnam National University Hospital (87 women and 63 men) memory clinic. The participants consisted of 68 patients with AD, 23 patients with VaD, and 59 patients with PDD, who were diagnosed by the individual criteria, respectively. Cognitive screening was evaluated using the Korean version of the mini-mental state examination (MMSE). Repeated evaluations were conducted at 6-month, 1 year, and 2 years after initial baseline assessment. Rates of cognitive decline were calculated by dividing MMSE score differences by the number of months lapsed. No difference was found between the three dementia subtypes with respect to baseline MMSE scores. Cognitive decline was not obvious up to 6-month of the follow-up, but by 12-month of follow-ups was significant regardless of the dementia subtype. Furthermore, the rate of cognitive decline in the AD group was significantly faster than in the PDD or VaD groups. This study suggests that rate of cognitive deterioration in dementia is not linear over time and that dementia subtypes have different rates of cognitive deterioration.     

帕金森病痴呆与阿尔茨海默病认知障碍特点分析

目的 分析帕金森病痴呆(PDD)与阿尔茨海默病(AD)患者的认知障碍特点.方法 采用语义流畅性、语音流畅性、动作流畅性测验与物品和动作命名测验评定PDD组(30例)、AD组(30例)与对照组(60例)患者临床情况.结果 PDD组语义流畅性测验总分(9.33±2.78)分、语音流畅性测验总分(6.17±1.67)分、动作流畅性测验总分(7.03±2.34)分,AD组分别为(6.90±2.47)分、(7.87±2.01)分、(8.30±3.17)分;PDD组物件命名测验总分(36.33±3.39)分、动作命名测验总分(17.63±2.17)分,AD组分别为(33.23±3.56)分与(22.33±2.37)分.与对照组比较,PDD与AD患者三项言语流畅性与物品和动作命名均受损(P＜0.01).其中,PDD患者以语音流畅性、动作流畅性与动作命名损害为重,而AD患者以语义流畅性与物件损害为重(P＜0.01).结论 PDD与AD患者均存在执行功能障碍与命名损害,PDD是一种伴有皮质功能损害以额叶皮质下功能障碍为主要特点的认知损害性疾病,而AD亦存在皮质下功能障碍.

Abstract：

Objective To analyze the characterization of cognitive function in Parkinson's disease with dementia and Alzheimer's disease. Methods Cognitive function was examined in Parkinson's disease with dementia (PDD) patients ( n = 30) , Alzheimer's disease (AD) patients ( n = 30) and healthy elderly control subjects ( n = 60) . Neuropsychological evaluation contained semantic fluency test, phonemic fluency test, action fluency test, objective and action naming tests. Results In PDD group , the score of semantic fluency test is 9. 33 ±2. 78, 6. 17 ± 1.67 of phonemic fluency test and 7.03 ±2. 34 of action fluency test,it is 6.90 ±2.47, 7.87±2.01,8.30±3. 17 of AD group. The score of objective and action naming tests is 36.33 ±3.39, 17.63 ±2. 17 in PDD group,while AD patients is 33.23 ±3.56 and 22.33 ±2.37. The verbal fluency tests and naming tests were impaired in PDD and AD patients compared with the healthy elderly control group (P ＜ 0. 01 ), phonemic fluency, action fluency and action naming were more impaired in PDD patients compared with the AD group , while semantic fluency and objective naming were more impaired in AD patients (P ＜ 0. 01 ). Conclusions Executive function deficit and naming impairment are found in PDD and AD patients, it shows that PDD is characterized by the addition of cortical dysfunction upon a predominant and progressive fronto-subcortical impairment. There is subcortical dysfunction in AD patients.     

Awareness of memory deficits in patients with dementias: a study with the Everyday Memory Checklist

AIM: We examined the level of awareness of memory deficits in 63 patients with Alzheimer's disease (AD), 17 patients with dementia with Lewy bodies (DLB), 14 patients with vascular dementia (VaD), and 56 patients with amnestic mild cognitive impairment (MCI). METHODS: The unawareness of memory impairment was evaluated with a standardized memory questionnaire system based on the Everyday Memory Checklist (EMC). The EMC scores for the patient's own rating, the caregivers' rating and the unawareness score, defined as the discrepancy between these (caregiver rating-patient rating), were analyzed. RESULTS: Although the EMC self-rating scores were comparable among the four groups, the EMC scores in caregivers were significantly higher in the AD group than in the DLB, VaD, and MCI groups. Therefore, the unawareness scores were significantly higher in the AD groups than in other groups. When an unawareness score of 9 or more was defined as significant, impaired awareness was found in 41 (65%) patients with AD, 1 (6%) patient with DLB, 5 (36%) patients with VaD, and in 19 (34%) patients with MCI. CONCLUSION: We found that impaired awareness was found in two-thirds of patients with mild AD and even in one-third of patients with MCI. However, other dementias, in particular DLB, had less severe and less frequent unawareness of memory deficits than AD, suggesting the difference in the pathophysiology between them.     

Toll样受体4在阿尔茨海默病及血管性痴呆患者外周血单核细胞表达的初步研究

目的:检测Toll样受体4(TLR4)在阿尔茨海默病(AD)及血管性痴呆(VaD)患者外周血单核细胞的表达情况,探讨TLR4在老年期痴呆发病机制中的可能作用。方法:选择临床确诊的AD患者(n=26)、VaD患者(n=31)和正常对照组(n=29)共86例,采用流式细胞术检测3组外周血单核细胞膜上TLR4蛋白阳性表达率及平均荧光强度(MFI)并进行比较分析。结果:外周血单核细胞膜表达TLR4的阳性表达率和MFI AD组和VaD组较对照组明显增高(P0.05)。结论:TLR4作为免疫炎性机制信号通路的关键蛋白,在AD、VaD的发病中均表现为增高,提示炎性机制在AD和VaD的发病中均发挥了作用,TLR4可能不能作为鉴别诊断的潜在生物标志物。     

Comparisons of cognitive deterioration rates by dementia subtype

Pathophysiological aspects of dementia and its rate of cognitive deterioration could be dependent on disease subtype, Alzheimer's dementia (AD), vascular dementia (VaD), and Parkinson's disease with dementia (PDD). 150 patients diagnosed at the Chungnam National University Hospital (87 women and 63 men) memory clinic. The participants consisted of 68 patients with AD, 23 patients with VaD, and 59 patients with PDD, who were diagnosed by the individual criteria, respectively. Cognitive screening was evaluated using the Korean version of the mini-mental state examination (MMSE). Repeated evaluations were conducted at 6-month, 1 year, and 2 years after initial baseline assessment. Rates of cognitive decline were calculated by dividing MMSE score differences by the number of months lapsed. No difference was found between the three dementia subtypes with respect to baseline MMSE scores. Cognitive decline was not obvious up to 6-month of the follow-up, but by 12-month of follow-ups was significant regardless of the dementia subtype. Furthermore, the rate of cognitive decline in the AD group was significantly faster than in the PDD or VaD groups. This study suggests that rate of cognitive deterioration in dementia is not linear over time and that dementia subtypes have different rates of cognitive deterioration.     

Serum uric acid level and association with cognitive impairment and dementia: systematic review and meta-analysis

Serum uric acid (sUA) level may be associated with cognitive impairment/dementia. It is possible this relationship varies with dementia subtype, particularly between vascular dementias (VaD) and Alzheimer’s (AD) or Parkinson’s disease (PDD)-related dementia. We aimed to present a synthesis of all published data on sUA and relationship with dementia/cognition through systematic review and meta-analysis. We included studies that assessed the association between sUA and any measure of cognitive function or a clinical diagnosis of dementia. We pre-defined subgroup analyses for patients with AD, VaD, PDD, mild cognitive impairment (MCI), and mixed or undifferentiated. We assessed risk of bias/generalizability, and where data allowed, we performed meta-analysis to describe pooled measures of association across studies. From 4811 titles, 46 papers (n?=?16,688 participants) met our selection criteria. Compared to controls, sUA was lower in dementia (SDM ?0.33 (95%CI)). There were differences in association by dementia type with apparent association for AD (SDM ?0.33 (95%CI)) and PDD (SDM ?0.67 (95%CI)) but not in cases of mixed dementia (SDM 0.19 (95%CI)) or VaD (SDM ?0.05 (95%CI)). There was no correlation between scores on Mini-Mental State Examination and sUA level (summary r 0.08, p?=?0.27), except in patients with PDD (r 0.16, p?=?0.003). Our conclusions are limited by clinical heterogeneity and risk of bias in studies. Accepting this caveat, the relationship between sUA and dementia/cognitive impairment is not consistent across all dementia groups and in particular may differ in patients with VaD compared to other dementia subtypes.     

Cerebrospinal fluid amyloid beta42/phosphorylated tau ratio discriminates between Alzheimer's disease and vascular dementia

BACKGROUND: The differentiation of Alzheimer's disease (AD) from vascular dementia (VaD) is hampered by clinical diagnostic criteria with disappointing sensitivity and specificity. The objective of this study was to investigate whether cerebrospinal fluid (CSF) levels of total tau protein (t-tau), amyloid beta42 protein (Abeta42), and tau phosphorylated at threonine 181 (p-tau181) are useful biomarkers to distinguish AD patients from VaD patients. METHODS: We measured CSF levels of p-tau181, Abeta42, and t-tau in 86 patients with a clinical diagnosis of AD or VaD and in 30 control participants. RESULTS: Optimal differentiation between AD and VaD was achieved by using the ratio of the CSF levels of Abeta42 and p-tau181 (Q Abeta42/p-tau) with sensitivity, specificity, positive and negative predictive values all > or = 85%. CONCLUSIONS: Our results support further efforts to prospectively validate the use of Q Abeta42/p-tau as a biomarker to discriminate between AD and VaD.     

Incidence of dementia,Alzheimer's disease,and vascular dementia in Italy. The ILSA Study

OBJECTIVES: To estimate the incidence of dementia, Alzheimer's disease (AD), and vascular dementia (VaD) in older Italians and evaluate the relationship of age, gender, and education to developing dementia. DESIGN: Cohort incidence study in the context of the Italian Longitudinal Study on Aging. SETTING: Population sample from eight Italian municipalities. PARTICIPANTS: A dementia-free cohort of 3,208 individuals (aged 65-84), individuated after a baseline evaluation performed in 1992 / 93, aimed at detecting prevalent cases. MEASUREMENTS: The dementia-free cohort was reexamined in 1995 to identify incident cases. The Mini-Mental State Examination (cutoff 23 / 24) was employed to screen for dementia. Trained neurologists evaluated the individuals who screened positive. Final diagnoses had to meet Diagnostic and Statistical Manual of Mental Disorders, Third Edition, Revised criteria for dementia, National Institute of Neurological and Communicative Disorders and Stroke-Alzheimer's Disease and Related Disorders Association criteria for AD, and International Classification of Diseases, Tenth Revision criteria for VaD. RESULTS: Before the follow-up examination, 382 individuals had died (232 had reliable information). Of the 2,826 survivors, 2,266 completed the study. Overall, 127 new dementia cases were identified. Average incidence rates per 1,000 person-years were 12.47 (95% confidence interval (CI)=10.23-14.72) for dementia, 6.55 (95% CI=4.92-8.17) for AD, and 3.30 (95% CI=2.14-4.45) for VaD. Both AD and VaD showed age-dependent patterns. Education was protective against dementia and AD. Women carried a significantly higher risk of developing AD (hazard ratio=1.67, 95% CI=1.02-2.75), and men of developing VaD (hazard ratio=2.23, 95% CI=1.06-4.71). CONCLUSIONS: Incidence of dementia in Italy paralleled that in most industrialized countries. About 150,000 new cases per year are expected. A significant gender effect was evidenced for major dementia subtypes. The burden of VaD, especially in men, offers opportunities for prevention.     

Physical performance across the cognitive spectrum and between dementia subtypes in a population-based sample of older adults: The HUNT study

BackgroundLiterature on physical performance in older adults across the cognitive spectrum remains inconclusive, and knowledge on differences between dementia subtypes is lacking. We aim to identify distinct physical-performance deficits across the cognitive spectrum and between dementia subtypes.Methods11,466 persons were included from the 70-year-and-older cohort in the fourth wave of the Trøndelag Health Study (HUNT4 70+). Physical performance was assessed with the Short Physical Performance Battery (SPPB), 4-meter gait speed, five-times-sit-to-stand (FTSS), grip strength and one-leg-standing (OLS). Clinical experts diagnosed dementia per DSM-5 criteria. Multiple linear and logistic regression were performed to analyze differences between groups. Age, sex, education, somatic comorbidity, physical activity and smoking status were used as covariates.ResultsGait speed declined across the cognitive spectrum, beginning in people with subjective cognitive decline (SCD). Participants with mild cognitive impairment (MCI) additionally showed reduced lower-limb muscle strength, balance and grip strength. Those with dementia scored lowest on all physical-performance measures. Participants with Alzheimer's disease (AD) had a higher SPPB sum score and faster gait speed than participants with vascular dementia (VaD) and Lewy body dementia (LBD); participants with VaD and LBD had lower odds of being able to perform FTSS and OLS than participants with AD.ConclusionsPhysical performance declined across the spectrum from cognitively healthy to SCD to MCI and to dementia. Participants with AD performed better on all assessments except grip strength than participants with VaD and LBD. Stage of cognitive impairment and dementia subtype should guide exercise interventions to prevent mobility decline and dependency.     

Characteristics of clock drawing test (CDT) errors by the dementia type: quantitative and qualitative analyses

We wanted to define the characteristics of errors on the clock drawing test (CDT) and we also wanted to determine their value for making the early diagnosis of dementia, so the performance of patients with three types of dementia on the four CDT was evaluated. The patients with subcortical vascular dementia (VaD) and patients with Parkinson's disease with dementia (PDD) had more stimulus bound responses. Patients with Alzheimer disease (AD) made significantly more conceptual deficit (CD) errors. The CD correlated with the severity of dementia and it could be detected in the early and mild stage of dementia. Qualitative and quantitative analyses of the errors on the CDT might be useful for making the early differential diagnosis of dementia types.     

Endogenous sex hormones as risk factors for dementia in elderly men and women

BACKGROUND: The associations of endogenous sex hormones with risk of dementia in the elderly population are not well known. METHODS: The relationship of baseline serum total estradiol (E2) and free testosterone (FT) to 4-year risk of all-cause dementia, Alzheimer's disease (AD), and vascular dementia (VaD) was examined in a dementia-free, population-based cohort of 433 women (mean age 74 years) and 376 men (mean age 73 years). Multivariable proportional hazards regression was used to adjust for sociodemographic and lifestyle variables, body mass index, apolipoprotein E genotype, cardiovascular conditions, and homocysteinemia. RESULTS: Dementia developed in 71 women (46 AD, 21 VaD) and 39 men (23 AD, 12 VaD). In women with high E2 (serum E2 >or= 10 pg/mL), the multivariable-adjusted hazard ratio (HR) for dementia was 1.75 (95% confidence interval [CI], 1.06-2.89). The corresponding multivariable-adjusted HR for AD was 1.94 (95% CI, 1.04-3.61), whereas no association was found for VaD. No association with dementia was found for serum FT in women and for either serum E2 or FT in men. CONCLUSION: High serum E2 is an independent predictor for dementia and AD in elderly women.     

Usefulness of [123I]metaiodobenzylguanidine ([123I]MIBG) myocardial scintigraphy in differentiating between Alzheimer's disease and dementia with Lewy bodies

OBJECTIVE: To confirm the clinical usefulness of [123I] metaiodobenzylguanidine ([123I]MIBG) myocardial scintigraphy in the antemortem differential diagnosis between patients with Alzheimer's disease (AD) and those with dementia with Lewy bodies (DLB). PATIENTS AND METHODS: We compared cardiac [123I] MIBG uptake in 10 patients with AD with that in 10 patients with DLB. We selected the patients with AD or DLB by using stringent diagnostic criteria that combined commonly used clinical criteria with tau protein levels in cerebrospinal fluid and radiographical examinations. RESULTS: The heart to mediastinum ratio of [123I]MIBG uptake in all the patients with DLB was significantly lower than that in the patients with AD (p<0.01). CONCLUSION: This study confirms that [123I]MIBG myocardial scintigraphy is useful in the antemortem differential diagnosis of AD and DLB.     

Systematic review of quantitative clinical gait analysis in patients with dementia

INTRODUCTION: Diminished mobility often accompanies dementia and has a great impact on independence and quality of life. New treatment strategies for dementia are emerging, but the effects on gait remains to be studied objectively. In this review we address the general effects of dementia on gait as revealed by quantitative gait analysis. METHODS: A systematic literature search with the (MESH) terms: 'dementia' and 'gait disorders' in Medline, CC, Psychlit and CinaHL between 1980-2002. Main inclusion criteria: controlled studies; patients with dementia; quantitative gait data. RESULTS: Seven publications met the inclusion criteria. All compared gait in Alzheimer's Disease (AD) with healthy elderly controls; one also assessed gait in Vascular Dementia (VaD). The methodology used was inconsistent and often had many shortcomings. However, there were several consistent findings: walking velocity decreased in dementia compared to healthy controls and decreased further with progressing severity of dementia. VaD was associated with a significant decrease in walking velocity compared to AD subjects. Dementia was associated with a shortened step length, an increased double support time and step to step variability. DISCUSSION: Gait in dementia is hardly analyzed in a well-designed manner. Despite this, the literature suggests that quantitative gait analysis can be sufficiently reliable and responsive to measure decline in walking velocity between subjects with and without dementia. More research is required to assess, both on an individual and a group level, how the minimal clinically relevant changes in gait in elderly demented patients should be defined and what would be the most responsive method to measure these changes.     

Metabolic Syndrome and Risk of Dementia in Older Adults

OBJECTIVES: To investigate the association between metabolic syndrome (MetS; a clustering of cardiovascular risk factors including abdominal obesity, hypertension, dyslipidemia, and hyperglycemia, each of which has been individually associated with dementia) and incident dementia, Alzheimer's disease (AD), and vascular dementia (VaD) in older adults before and after the age of 75. DESIGN: Prospective population‐based cohort. SETTING: An Italian municipality. PARTICIPANTS: A community‐based sample of 749 subjects aged 65 and older who, in 1999/2000, were free of cognitive impairment and, in 2003/04, underwent follow‐up for incident dementia. MEASUREMENTS: The relationship between incident overall dementia, AD, and VaD and MetS. Dementia was defined according to the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition. MetS was defined according to the National Cholesterol Education Program criteria. RESULTS: Risk of overall dementia and its subtypes was not associated with MetS or any MetS component in participants younger than 75. In participants aged 75 and older, MetS was associated with a lower risk of AD (hazard ratio (HR)=0.33, 95% confidence interval (CI)=0.12–0.94) but not of VaD, and abdominal obesity was associated with a lower risk of overall dementia (HR=0.53, 95% CI=0.28–0.98). CONCLUSION: MetS measured in late life is not associated with risk of dementia. After age 75, persons with MetS may even be at lower risk for AD.     

帕金森病痴呆危险因素的研究进展

原发性帕金森病（Parkinson's disease,PD）是一种好发于中老年人的常见中枢神经系统变性疾病。痴呆是PD患者的一种常见非运动症状,表现为痴呆的患者被称为帕金森病痴呆（PD dementia,PDD）。PDD严重影响了PD患者的社会功能及生活质量,对PD患者的预后造成不良影响。目前的研究发现,PDD危险因素包括人口学特征、生活习惯、运动症状、非运动症状、生物学标志物、基因、影像学类标志等各种因素,本文旨在对这些因素的相关研究结果进行综述。     

Distinguishing dementia with Lewy bodies from dementia occurring in Parkinson's disease: A literature review

There has been considerable debate as to whether dementia with Lewy bodies (DLB) represents a distinct diagnosis or lies on a spectrum with Parkinson's disease dementia (PDD). The objective of this review was to identify whether conceptualising these dementias as distinct diagnostic entities is meaningful, or indeed possible. A literature review was conducted using the databases MEDLINE and PSYCHINFO. DLB and PDD share many clinical features including the pattern of cognitive deficits and Lewy‐body pathology. However, they may be usefully distinguished by their clinical course and differential response to treatment. Some patients with DLB have a rapidly progressive dementia and may be particularly sensitive to neuroleptic medication, resulting in considerable morbidity and mortality.     

Axon pathology in Parkinson's disease and Lewy body dementia hippocampus contains alpha-, beta-, and gamma-synuclein

Pathogenic alpha-synuclein (alphaS) gene mutations occur in rare familial Parkinson's disease (PD) kindreds, and wild-type alphaS is a major component of Lewy bodies (LBs) in sporadic PD, dementia with LBs (DLB), and the LB variant of Alzheimer's disease, but beta-synuclein (betaS) and gamma-synuclein (gammaS) have not yet been implicated in neurological disorders. Here we show that in PD and DLB, but not normal brains, antibodies to alphaS and betaS reveal novel presynaptic axon terminal pathology in the hippocampal dentate, hilar, and CA2/3 regions, whereas antibodies to gammaS detect previously unrecognized axonal spheroid-like lesions in the hippocampal dentate molecular layer. The aggregation of other synaptic proteins and synaptic vesicle-like structures in the alphaS- and betaS-labeled hilar dystrophic neurites suggests that synaptic dysfunction may result from these lesions. Our findings broaden the concept of neurodegenerative "synucleinopathies" by implicating betaS and gammaS, in addition to alphaS, in the onset/progression of PD and DLB.     

Prevalence of dementia subtypes: a 30-year retrospective survey of neuropathological reports

We investigated the distribution of neuropathologically defined dementia subtypes among individuals with dementia disorder. The neuropathological reports were studied on all patients (n=524; 55.3% females; median age 80, range 39-102 years) with clinically diagnosed dementia disorder who underwent complete autopsy including neuropathological examination within the Department of Pathology at the University Hospital in Lund, Sweden, during the years 1974-2004. The neuropathological diagnosis was Alzheimer's disease (AD) in 42.0% of the cases, vascular dementia (VaD) in 23.7%, dementia of combined Alzheimer and vascular pathology in 21.6%, and frontotemporal dementia in 4.0% of the patients. The remaining 8.8% of the patients had other dementia disorders, including combinations other than combined Alzheimer and vascular pathology. The registered prevalence of dementia subtypes depends on many variables, including referral habits, clinical and neuropathological judgments and diagnostic traditions, all of these variables potentially changing over time. This, however, does not seem to obscure the delineation of the major dementia subgroups. In this material of 30 years from Lund in the south of Sweden, AD by far dominated among dementia subtypes, while cerebrovascular pathology corresponded with the dementia disorder, either entirely or partly, in almost half of the demented patients.     

Lipids' peroxidation markers in Alzheimer's disease and vascular dementia

Aim: Although a large body of evidence supports a role of oxidative stress in the etiopathogenesis of dementia, there is still a substantial lack of data regarding the biomarkers of oxidative stress characteristic of Alzheimer's disease (AD) as opposed to different types of dementia. In this study, the level of various oxidative stress parameters were measured in AD, vascular dementia (VaD), and age‐ and sex‐matched control patients. The AD and VaD patients all had similar levels of cognitive impairment as measured by the Mini‐Mental State Examination. Methods: Thirty AD, 19 VaD and 29 controls patients were recruited to the study. Plasma levels of malondialdehyde (MDA), total sulfhydryl (T‐SH), calcium (Ca⁺⁺) and magnesium (Mg⁺⁺) were measured. Results: In both AD and VaD groups, the levels of oxidative stress parameters were higher compared with controls. Further, the VaD patients expressed significantly higher levels of plasma parameters of oxidative stress than AD. The difference was noted in MDA, the marker of lipid peroxidation, whereas in VaD the level of MDA was more than 2.8‐fold higher than that registered in AD patients. Conclusion: Vascular dementia in patients is characteristic of increased levels of oxidative stress, especially lipid peroxidation markers. This finding is relevant to determining the pathophysiology of dementia, particularly in the light of the recently suggested importance of the vascular component in dementia development, in addition to aiding in the diagnosis of VaD following clinical presentation. The study will be continued to compare the character and level of decline in both groups.     

Mild cognitive impairment: epidemiology and dementia risk in an elderly Italian population

OBJECTIVES: To investigate prevalence and incidence of mild cognitive impairment (MCI) and its risk of progression to dementia in an elderly Italian population.
DESIGN: Longitudinal.
SETTING: Population-based cohort aged 65 and older resident in an Italian municipality.
PARTICIPANTS: A total of 1,016 subjects underwent baseline evaluation in 1999/2000. In 2003/04, information about cognitive outcome was collected for 745 participants who were free of dementia at baseline.
MEASUREMENTS: MCI (classified as with or without impairment of the memory domain), dementia, Alzheimer's dementia (AD), and vascular dementia (VaD) diagnosed according to current international criteria.
RESULTS: Overall prevalence of MCI was 7.7% (95% confidence interval (CI)=6.1–9.7 %) and was greater with older age and poor education. During 4 years of follow-up, 155 incident MCI cases were diagnosed, with an incidence rate of 76.8 (95% CI=66.8–88.4) per 1,000 person-years. Approximately half of prevalent and incident MCI cases had memory impairment. Compared with normal cognition, multivariable-adjusted risk for progression from MCI with memory impairment to dementia was 4.78 (95% CI=2.78–8.07) for any dementia, 5.92 (95% CI=3.20–10.91) for AD, and 1.61 (95% CI=0.37–7.00) for VaD. No association with dementia risk was found for MCI without memory impairment. Approximately one-third of MCI cases with memory impairment did not progress to dementia.
CONCLUSION: MCI occurs often in this elderly Italian cohort and is associated with greater risk of AD, but only when the impairment involves the memory domain. However, a substantial proportion of MCI cases with memory impairment do not progress to dementia.