Prevalence Rates of Dementia and Mild Cognitive Impairment Are Affected by the Diagnostic Parameter Changes for Neurocognitive Disorders in the DSM-5 in a Korean Population.

AIM: To examine the impact of the revised diagnostic criteria for neurocognitive disorders (NCDs) in the Diagnostic and Statistical Manual of Mental Disorders, 5th edition (DSM-5) on the prevalence of dementia and mild cognitive impairment (MCI). METHODS: A total of 755 participants aged 65 years or older in the Nationwide Survey on Dementia Epidemiology in Korea 2012 were rediagnosed according to the DSM-5 criteria. RESULTS: The estimated age-, gender-, education-, and urbanicity-standardized prevalence rates of major and mild NCDs were 8.35 and 11.10%, respectively, and those of dementia and MCI were 8.74 and 31.85%, respectively. Cohen's κ for dementia and major NCD was 0.988, and that for MCI and mild NCD was 0.273. CONCLUSION: Diagnostic discrepancies between major/mild NCDs and dementia/MCI might depend on the operationalization of neuropsychological performance criteria.

Amyloid-Independent Amnestic Mild Cognitive Impairment and Serum Apolipoprotein A1 Levels.

OBJECTIVES: The present study investigated the characteristics of amnestic mild cognitive impairment (aMCI) in subjects with low brain amyloid-beta (Aß) burden. Furthermore, the relationships between amyloid-independent cognitive decline and serum lipid profiles, particularly apolipoprotein A1 (APOA1), were evaluated. DESIGN: Cross-sectional and longitudinal follow-up study. SETTING: University hospital dementia clinic. PARTICIPANTS: 28 aMCI and 35 cognitive normal (CN) elderly. MEASUREMENTS: The study measures included baseline assessments of the subjects' clinical characteristics, lipid profiles, and magnetic resonance imaging and (11)C-labelled Pittsburgh Compound B (PiB) positron emission tomography scans. Based on PiB retention at baseline, the aMCI subjects were divided into low Aß (aMCI-) and high Aß (aMCI+) subgroups. All aMCI subjects were followed up over a 1-year period. RESULTS: The aMCI- group had a longer duration of illness than did the aMCI+ group. None of the aMCI- subjects were diagnosed with Alzheimer disease (AD) dementia during the 1-year follow-up period, whereas 26.7% of aMCI+ subjects developed AD dementia. The aMCI- group also exhibited lower serum APOA1 levels compared with both the aMCI+ and CN groups. Additionally, lower serum APOA1 levels were associated with cognitive decline and brain atrophy independent of Aß deposition and vascular burden. CONCLUSIONS: Patients with aMCI- likely exhibit different clinical and pathophysiological characteristics than patients with aMCI+. Additionally, APOA1 may be an important contributor underlying amyloid-independent neurodegeneration.

Association Between Serum Triglycerides and Cerebral Amyloidosis in Cognitively Normal Elderly.

OBJECTIVES: Although many preclinical studies have suggested the possible linkage between dyslipidemia and cerebral amyloid deposition, the association between serum lipid measures and cerebral amyloid-beta (Aß) deposition in human brain is still poorly known. We aimed to investigate the association in cognitively normal (CN) elderly individuals. DESIGN: Cross-sectional study. SETTING: University hospital dementia clinic. PARTICIPANTS: 59 CN elderly. MEASUREMENTS: The study measures included comprehensive clinical and neuropsychological assessment based on the CERAD protocol, magnetic resonance imaging and (11)C-labelled Pittsburgh Compound B positron emission tomography scans, and quantification for serum lipid biomarkers. RESULTS: Multiple linear regression analyses showed that a higher serum triglycerides level was associated with heavier global cerebral Aß deposition even after controlling age, sex, and apolipoprotein E ε4 genotype. Serum apolipoprotein B also showed significant positive association with global cerebral Aß deposition, but the significance disappeared after controlling serum triglycerides level. No association was found between other lipid measures and global cerebral Aß deposition. CONCLUSIONS: The findings suggest that serum triglycerides are closely associated with cerebral amyloidosis, although population-based prospective studies are needed to provide further evidence of the causative effect of triglycerides on cerebral amyloidosis.

Frequency of Depressive Syndromes in Elderly Individuals with No Cognitive Impairment, Mild Cognitive Impairment, and Alzheimer's Disease Dementia in a Memory Clinic Setting.

AIMS: The aims of this study were to investigate the frequency of various depressive syndromes in elderly individuals with no cognitive impairment (NC), mild cognitive impairment (MCI), and Alzheimer's disease dementia (AD) in a memory clinic setting, and then to test whether severe and milder forms of depressive syndromes are differentially associated with the cognitive groups. METHODS: For 216 NC, 478 MCI, and 316 AD subjects, we investigated the frequency of depressive syndromes, defined by three different categories: major and minor depressive disorder (MaDD and MiDD) according to the Diagnostic and Statistical Manual of Mental Disorders, 4th edition, as well as depression according to the National Institute of Mental Health provisional diagnostic criteria for depression in Alzheimer's disease (NIMH-dAD). RESULTS: The frequency of MaDD did not show any significant difference among NC, MCI, and AD. In contrast, the frequencies of MiDD and NIMH-dAD were higher than those of MaDD and showed significant group differences with a gradual increase from NC to AD. CONCLUSION: The findings suggest that the degenerative process of Alzheimer's disease contributes to the occurrence of mild depressive conditions, but not to severe depression.

Multicenter, randomized, placebo-controlled, double-blind clinical trial of escitalopram on the progression-delaying effects in Alzheimer's disease.

OBJECTIVES: A series of preclinical studies have suggested that selective serotonin reuptake inhibitor antidepressants not only stimulate neurogenesis but also have neuroprotective effects. The present study primarily aimed to investigate whether escitalopram would decelerate the brain atrophy of patients with mild-to-moderate Alzheimer's disease (AD). We also assessed the effects of escitalopram on the cognitive function and neuropsychiatric symptoms of these participants. METHODS: Seventy-four probable AD patients without major depression were recruited from four dementia clinics of university hospitals and randomly assigned in a 1:1 ratio. Each group received 20 mg/day of escitalopram or placebo for 52 weeks. The primary outcome measures were the change rates of hippocampal and whole brain volume on magnetic resonance imaging for 52 weeks. The Alzheimer's Disease Assessment Scale-cognitive subscale, Mini-Mental State Examination, Neuropsychiatric Inventory, and Cornell Scale for Depression in Dementia (CSDD) were also applied. RESULTS: We did not find any significant differences in the changes of hippocampal or whole brain volume between the groups. Escitalopram showed significant beneficial effects on the CSDD score at 28 weeks compared with placebo (t = -2.17, df = 50.42, p = 0.035), but this finding did not persist throughout the study. CONCLUSION: The findings of the present study do not support the role of escitalopram as a progression-delaying treatment for AD. However, the negative results of the present trial should be interpreted cautiously because of the relatively small sample size. Further large-scale escitalopram trials targeting the earlier stages of AD, even prodromal AD, are still needed. Copyright © 2015 John Wiley & Sons, Ltd.

Functional Neuroanatomical Correlates of The Frontal Assessment Battery Performance in Alzheimer Disease: A FDG-PET Study.

BACKGROUND/OBJECTIVES: We aimed to elucidate the functional neuroanatomical correlates of Frontal Assessment Battery (FAB) performances by applying [(18)F]fluorodeoxyglucose positron emission tomography (FDG-PET) to a large population of patients with Alzheimer disease (AD). METHODS: The FAB was administered to 177 patients with AD, and regional cerebral glucose metabolism (rCMglc) was measured by FDG-PET scan. Correlations between FAB scores and rCMglc were explored using both region-of-interest-based (ROI-based) and voxel-based approaches. RESULTS: The ROI-based analysis showed that FAB scores correlated with the rCMglc of the dorsolateral prefrontal cortices. Voxel-based approach revealed significant positive correlations between FAB scores and rCMglc which were in various cortical regions including the temporal and parietal cortices as well as frontal regions, independent of age, gender, and education. After controlling the effect of global disease severity with Mini-Mental State Examination score, significant positive correlation was found only in the bilateral prefrontal regions. CONCLUSIONS: Although FAB scores are influenced by temporoparietal dysfunction due to the overall progression of AD, it likely reflects prefrontal dysfunction specifically regardless of global cognitive state or disease severity in patients with AD.

Comparison of regional gray matter atrophy, white matter alteration, and glucose metabolism as a predictor of the conversion to Alzheimer's disease in mild cognitive impairment.

We compared the predictive ability of the various neuroimaging tools and determined the most cost-effective, non-invasive Alzheimer's disease (AD) prediction model in mild cognitive impairment (MCI) individuals. Thirty-two MCI subjects were evaluated at baseline with [(18)F]-fluorodeoxyglucose positron emission tomography (FDG-PET), MRI, diffusion tensor imaging (DTI), and neuropsychological tests, and then followed up for 2 yr. After a follow up period, 12 MCI subjects converted to AD (MCIc) and 20 did not (MCInc). Of the voxel-based statistical comparisons of baseline neuroimaging data, the MCIc showed reduced cerebral glucose metabolism (CMgl) in the temporo-parietal, posterior cingulate, precuneus, and frontal regions, and gray matter (GM) density in multiple cortical areas including the frontal, temporal and parietal regions compared to the MCInc, whereas regional fractional anisotropy derived from DTI were not significantly different between the two groups. The MCIc also had lower Mini-Mental State Examination (MMSE) score than the MCInc. Through a series of model selection steps, the MMSE combined with CMgl model was selected as a final model (classification accuracy 93.8%). In conclusion, the combination of MMSE with regional CMgl measurement based on FDG-PET is probably the most efficient, non-invasive method to predict AD in MCI individuals after a two-year follow-up period.

A normative study of total scores of the CERAD neuropsychological assessment battery in an educationally diverse elderly population.

BACKGROUND: This study aimed to investigate the influences of age, education, and gender on the two total scores (TS-I and TS-II) of the Consortium to Establish a Registry for Alzheimer's Disease Neuropsychological assessment battery (CERAD-NP) and to provide normative information based on an analysis for a large number of elderly persons with a wide range of educational levels. METHODS: In the study, 1,987 community-dwelling healthy volunteers (620 males and 1,367 females; 50-90 years of age; and zero to 25 years of education) were included. People with serious neurological, medical, and psychiatric disorders (including dementia) were excluded. All participants underwent the CERAD-NP assessment. TS-I was generated by summing raw scores from the CERAD-NP subtests, excluding Mini-Mental State Examination and Constructional Praxis (CP) recall subtests. TS-II was calculated by adding CP recall score to TS-I. RESULTS: Both TS-I and TS-II were significantly influenced by demographic variables. Education accounted for the greatest proportion of score variance. Interaction effect between age and gender was found. Based on the results obtained, normative data of the CERAD-NP total scores were stratified by age (six overlapping tables), education (four strata), and gender. CONCLUSIONS: The normative information will be very useful for better interpretation of the CERAD-NP total scores in various clinical and research settings and for comparing individuals' performance of the battery across countries.

Improvement of dementia screening accuracy of mini-mental state examination by education-adjustment and supplementation of frontal assessment battery performance.

This study aimed to investigate whether the demographic variable-adjustment and supplementation of Frontal Assessment Battery (FAB) score can improve the screening ability of Mini-Mental State Examination (MMSE) for dementia and its subtypes. Five hundred forty-one non-demented comparison (NC) and 474 dementia (320 Alzheimer's disease [AD]; 139 non-Alzheimer's disease dementia [NAD]; and 15 mixed AD-NAD dementia) individuals living in the community were included. Education-adjusted MMSE (MMSE-edu) score showed significantly better screening accuracy for overall dementia, AD, and NAD than MMSE raw score. FAB-supplemented MMSE (MMSE-FAB) score had significantly better screening ability for NAD, but not for overall dementia and AD, than MMSE raw score alone. Additional supplementation of FAB to MMSE-edu further increased the ability for overall dementia or NAD screening, but not for AD screening. Further education adjustment of MMSE-FAB also improved its ability for overall dementia, AD, and NAD screening. These results strongly support the usefulness of education-adjustment and supplementation of frontal function assessment to improve screening performance of MMSE for dementia and its subtypes, NAD in particular.

Choline acetyltransferase 2384G>a polymorphism and the risk of Alzheimer disease.

The potential association between choline acetyltransferase (CHAT) polymorphism and the risk of Alzheimer disease (AD) has been controversial. We examined the main effect of CHAT polymorphism and its interaction with apolipoprotein E (APOE) polymorphism in the development of AD in a well-powered elderly Korean sample. We analyzed CHAT 2384G>A polymorphism and APOE polymorphism among 736 Korean patients with probable AD and 1386 nondemented Korean controls. We tested the association between AD and CHAT genotype using a logistic regression model. In addition, we used generalized multifactor dimensionality reduction to investigate the interaction between CHAT and APOE with regard to the risk of AD. The CHAT A allele was associated with AD risk in a dose-dependent manner (odds ratio=1.40, 95% confidence interval=1.06-1.85, P=0.018 for heterozygotes; and odds ratio=3.92, 95% confidence interval=1.78-8.58, P=0.001 for homozygotes). The generalized multifactor dimensionality reduction approach identified a significant gene-gene interaction between CHAT and APOE (Balanced accuracy score=0.647, P=0.001). The CHAT A/A genotype was associated with earlier onset of AD (F=5.070, df=2, P=0.007). The CHAT A allele was associated with AD risk in a dose-dependent manner, and its interaction with the APOE ε4 allele was significant with regard to the development of AD. The CHAT A allele was also associated with earlier onset and possibly accelerated progression of AD.

Interactive influences of demographics on the Mini-Mental State Examination (MMSE) and the demographics-adjusted norms for MMSE in elderly Koreans.

BACKGROUND: The influences of demographics, culture, language, and environmental changes on Mini-Mental State Examination (MMSE) scores are considerable. METHODS: Using a sample of 7452 healthy, community-dwelling elderly Koreans, aged 55 to 94 years, who participated in the four ongoing geriatric cohorts in Korea, we investigated demographic influences on MMSE scores and derived normative data for this population. Geropsychiatrists strictly excluded subjects with cognitive disorders according to the protocol of the Korean version of the Consortium to Establish a Registry for Alzheimer's Disease Assessment Packet (CERAD-K) Clinical Assessment Battery (CERAD-K-C). RESULTS: Education (standardized ß = 0.463), age (standardized ß = -0.303), and gender (standardized ß = -0.057) had significant effects on MMSE scores (p < 0.001). The score of MMSE increase 0.379 point per 1-year education, decrease 0.188 per 1-year older, and decrease 0.491 in women compared to men. Education explained 30.4% of the scores' total variance, which was much larger than the variances explained by age (8.4%) or gender (0.3%). Accordingly, we present normative data for the MMSE stratified by education (0, 1-3, 4-6, 7-9, 10-12, and ≥ 13 years), age (60-69, 70-79, and 80-89 years), and gender. CONCLUSIONS: We provide contemporary education-, age-, and gender-stratified norms for the MMSE, derived from a large, community-dwelling elderly Korean population sample, which could be useful in evaluating individual MMSE scores.

Neurocognitive dysfunction associated with sleep quality and sleep apnea in patients with mild cognitive impairment.

OBJECTIVES: Sleep apnea syndrome (SAS) is considered a risk factor for cognitive decline in the elderly. The specific neurocognitive decline has been suggested as a predictive factor for dementia in patients with mild cognitive impairment (MCI). The authors aim to illustrate the sleep characteristics related to the specific neurocognitive decline in the community-dwelling elderly including patients with MCI. DESIGN: Cross-sectional. SETTINGS: Center for sleep and chronobiology in Kangwon National University Hospital. PARTICIPANTS: Thirty patients with MCI and 30 age- and sex-matched normal elderly subjects were selected. MEASUREMENTS: The authors administered seven tests in the Korean version of the Consortium to Establish A Registry of Alzheimer's Disease Neuropsychological battery and conducted nocturnal polysomnography. A p value below 0.05 was considered a statistical significance. RESULTS: There was no significant difference in sleep parameters between the MCI and normal comparison (NC) groups. Sleep efficiency was positively correlated with Constructional Recall (CR) scores in both NC and MCI groups (r = 0.393 and 0.391, respectively). The amount of slow wave sleep (SWS) was also positively correlated with Boston naming test (BNT) scores in both groups (r = 0.392, 0.470, respectively). Stepwise multiple regression models showed that SWS and the apnea index were significant independent variables associated with the BNT score (Δß = 0.43 and -0.34, respectively; adjusted R = 0.298) in the MCI group, and the amount of rapid eye movement sleep was a significant independent variable associated with the CR score (Δß = 0.49; adjusted R = 0.217) in the NC group. CONCLUSIONS: Our results show that poor sleep quality and greater severity of SAS were associated with impaired language function reflecting frontal-subcortical pathology in patients with MCI. This suggests that vulnerability to a specific brain damage associated with SAS could increase the risk for dementia.

Microstructural alteration of the anterior cingulum is associated with apathy in Alzheimer disease.

OBJECTIVES: To identify regional alterations of white matter integrity associated with apathy in Alzheimer disease (AD). DESIGN: Cross-sectional study. SETTING: University Dementia Clinic. PARTICIPANTS: Fifty-one very mild or mild probable AD subjects. INTERVENTION: Volumetric magnetic resonance imaging with diffusion tensor imaging. MEASUREMENTS: Volume of interest analyses were performed to compare regional fractional anisotropy (FA) between apathy and apathy-free group, and to test linear relationship between regional FA and apathy severity. Apathy was assessed by the Neuropsychiatric Inventory. RESULTS: Apathy group showed significantly lower FA values than apathy-free group in the left anterior cingulum (A-C), regardless of concomitant depression and psychotropic medications. Left A-C FA values also had significant linear relationship with apathy-composite scores as a measure of apathy severity, even after controlling gray matter density of the ipsilateral anterior cingulate cortex. CONCLUSIONS: Our findings support that communication failure between the anterior cingulate cortex and other brain structures via the A-C contributes to the development and aggravation of apathy in AD, additionally supporting the general notion of disconnection syndrome for clinical manifestation of AD.

Relationship of amyloid-ß burden with age-at-onset in Alzheimer disease.

OBJECTIVE: To investigate the relationship between in vivo brain amyloid-beta (Aß) burden, measured by C-labeled Pittsburgh Compound B (C-PiB) retention, and age-at-onset in patients with Alzheimer disease (AD). DESIGN: Cross-sectional study. SETTING: University Dementia Clinic. PARTICIPANTS: Twenty-two AD patients including 11 early-onset AD (EOAD: onset <65 years) and 11 late-onset AD (LOAD: onset ≥65years) cases with matched dementia severity, duration of illness, and apolipoprotein E ε4 allele number. INTERVENTION: C-PiB positron emission tomography scans. MEASUREMENTS: Both region of interest and voxel-based analyses were performed to compare C-PiB retention between EOAD and LOAD groups, and to test linear relationship between age-at-onset and C-PiB retention. RESULTS: Both region of interest (ROI) and voxel-based analyses revealed that EOAD patients had significantly higher C-PIB retentions than LOAD patients in diffuse brain regions including frontal, lateral parietal, lateral temporal, and occipital cortex, and basal ganglia. Subgroup analyses showed that negative correlation between age-at-onset and C-PiB retention was significant in LOAD but not in EOAD. CONCLUSIONS: Our finding of a heavier Aß burden in the brain of living EOAD patients than LOAD patients is in agreement with those from postmortem studies. The inverse relationship between age-at-onset and Aß burden is possibly associated with aging-related decrease of brain or cognitive reserve and with aging-related increase of brain vulnerability.

Associations between Brain Reserve Proxies and Clinical Progression in Alzheimer's Disease Dementia.

The purpose of this study was to investigate whether brain and cognitive reserves were associated with the clinical progression of AD dementia. We included participants with AD dementia from the Alzheimer's Disease Neuroimaging Initiative, provided they were followed up at least once, and candidate proxies for cognitive (education for early-life reserve and Adult Reading Test for late-life reserve) or brain reserve (intracranial volume [ICV] for early-life reserve and the composite value of [18F] fluorodeoxyglucose positron emission tomography regions of interest (FDG-ROIs) for late-life reserve) were available. The final analysis included 120 participants. Cox proportional hazards model revealed that FDG-ROIs were the only significant predictor of clinical progression. Subgroup analysis revealed a significant association between FDG-ROIs and clinical progression only in the larger ICV group (HR = 0.388, p = 0.028, 95% CI 0.167-0.902). Our preliminary findings suggest that relatively preserved cerebral glucose metabolism might delay further clinical progression in AD dementia, particularly in the greater ICV group. In addition to ICV, cerebral glucose metabolism could play an important role as a late-life brain reserve in the process of neurodegeneration. Distinguishing between early- and late-life reserves, and considering both proxies simultaneously, would provide a wider range of factors associated with the prognosis of AD dementia.

Total scores of the CERAD neuropsychological assessment battery: validation for mild cognitive impairment and dementia patients with diverse etiologies.

OBJECTIVES: This study aimed to validate the two total scores (TS-I and TS-II) of the Consortium to Establish a Registry for Alzheimer Disease neuropsychological battery (CERAD-NP) for a large elderly population including mild cognitive impairment (MCI) and dementia patients with various etiologic backgrounds. The authors also investigated whether the addition of frontal-executive function score can improve the discrimination accuracy of the total scores for dementia and MCI. DESIGN, SETTING, AND PARTICIPANTS: One thousand three hundred thirty-six normal comparison (NC), 583 dementia (420 AD, 111 non-AD dementia, and 52 mixed AD with non-AD dementia), and 250 MCI (223 amnestic and 27 nonamnestic MCI) individuals living in the community were included (all aged 60 years and older). RESULTS: Both TS-I and TS-II were highly correlated with other global cognitive and functional scales. Both total scores showed, though modest, superior NC versus MCI discrimination ability to Mini-Mental State Examination (MMSE). Their discrimination ability for NC versus dementia was excellent and significantly better, especially in discriminating very mild dementia, than MMSE. The addition of frontal-executive test score to TS-I or TS-II did not make a significant improvement in dementia or MCI discrimination ability. Both of them also showed higher test-retest and interrater reliability than MMSE or any individual neuropsychological tests in the CERAD-NP. CONCLUSION: These results strongly support the validity and usefulness of CERAD total scores for early detection and progression monitoring of MCI and dementia in clinical and research settings.

Korean version of frontal assessment battery: psychometric properties and normative data.

BACKGROUND: We developed the Korean version of the Frontal Assessment Battery (FAB-K), evaluated its psychometric properties and constructed normative data for Korean elders. METHODS: FAB-K was administered to 300 Alzheimer's disease (AD) patients and 635 normal controls. Reliability of FAB-K was evaluated by testing its internal consistency, test-retest and inter-rater reliabilities. Validity of FAB-K was evaluated by testing discriminant validity for AD and concurrent validity with other frontal function tests. Age- and education-specific normative data of FAB-K were developed. RESULTS: Cronbach's alpha, inter-rater reliability and test-retest reliability of FAB-K were 0.802, 0.980 (p < 0.001) and 0.820 (p < 0.001), respectively. FAB-K exhibited significant correlations with the scores of MMSE and other frontal function tests (p < 0.01). Total and item scores of FAB-K were lower in AD patients than in controls and became worse as clinical dementia rating increased (F = 192.026, d.f. = 4, p < 0.001). The optimal cut-off score of FAB-K for AD was determined as 10/11, where sensitivity and specificity for AD were 0.717 and 0.827, respectively. Normative data were stratified by 3 age groups and 4 education groups. CONCLUSION: The FAB-K is a valid and reliable instrument for evaluating frontal dysfunction, and may be useful for screening AD.

Discrimination of normal aging, MCI and AD with multimodal imaging measures on the medial temporal lobe.

This study aimed to compare the discrimination accuracy of hippocampal volume (HC-Vol), parahippocampal cingulum fractional anisotropy (PHC-FA), hippocampal glucose metabolism (HC-Glu), and any combination of the three measurements among normal control (NC), mild cognitive impairment (MCI), and Alzheimer's disease (AD). Three-dimensional MRI, diffusion tensor imaging, and FDG-PET were applied to age- and gender-matched 17 NC, 17 MCI, and 17 mild AD patients. Subjects also underwent a neuropsychological test battery including three verbal episodic memory tests. Logistic regression analyses were systematically conducted to select the best model for between-group discrimination. PHC-FA plus HC-Vol model, HC-Glu only model, and the model combining all three modalities were finally chosen for NC vs. MCI (discrimination accuracy: 79.4%), MCI vs. AD (73.5%), and NC vs. AD discrimination (94.1%), respectively. All the three imaging measures also showed significant correlation with all three episodic memory tests. These findings support that each imaging measure, respectively, and their combination have a stage-specific potential as a useful neuroimaging marker for detection and progression monitoring of early stage of AD.

Development of the Subjective Memory Complaints Questionnaire.

AIM: We aimed to evaluate the psychometric properties of the Subjective Memory Complaints Questionnaire (SMCQ). METHODS: The reliability of the SMCQ was evaluated by testing its internal consistency and test-retest reliability. Pearson correlation analyses were performed to assess the concurrent validity. Confirmatory factor analysis was used to evaluate the construct validity. Diagnostic ability for dementia was tested with receiver operator characteristic curve analyses. RESULTS: Cronbach's alpha coefficient and intraclass correlation coefficients of the SMCQ were 0.864 and 0.828 (p < 0.001), respectively. The SMCQ scores were significantly correlated with the scores on Camdex Memory Complaint Questionnaire, Seoul Informant Report Questionnaire for Dementia and cognitive tests from the CERAD (Consortium to Establish a Registry for Alzheimer's Disease) neuropsychological test battery (p < 0.01). The results of confirmatory factor analyses confirmed that the SMCQ consisted of subjective memory complaints (SMC) for general memory and for everyday memory. The SMCQ score discriminated well between nondemented elderly without dementia and those with dementia (p < 0.01). The area under the curve value of the SMCQ was 0.84, indicating that it had high diagnostic ability. CONCLUSION: The SMCQ was found to be a brief, reliable and valid questionnaire for evaluating SMC. It might be useful for evaluating the cognition of elderly subjects when reliable informants are not available.

Prevalence of mild cognitive impairment and its subtypes are influenced by the application of diagnostic criteria: results from the Korean Longitudinal Study on Health and Aging (KLoSHA).

AIMS: We investigated the influence of varying applications of diagnostic criteria on the prevalence of mild cognitive impairment (MCI) in community-dwelling Korean elders. METHODS: A study population of 1,118 Korean elders was randomly sampled from the residents aged 65 years or older living in Seongnam, Korea. Standardized face-to-face interviews, with neurological and physical examinations, were conducted with 714 respondents. Cognitive function was evaluated using the Korean version of the CERAD Neuropsychological Assessment Battery, digit span test, and lexical fluency test. Activities of daily living were evaluated using the Blessed Dementia Scale in the CERAD Clinical Assessment Battery (Korean version). Using variable sets of operational diagnostic criteria, the prevalence of MCI was estimated. RESULTS: Age- and gender-standardized prevalence estimates according to the Petersen criteria were 28.6% (95% CI = 25.3-31.9) for overall MCI, 17.0% (95% CI = 14.3-19.8) for amnestic MCI, and 11.5% (95% CI = 9.2-13.9) for non-amnestic MCI. However, the estimated prevalence of MCI varied widely (8.3-27.6%) according to the applied operational diagnostic criteria. The proportion of MCI subtypes also varied considerably according to the number and types of applied neuropsychological tests. CONCLUSIONS: Variable implementation of MCI diagnostic criteria may significantly complicate the homogeneity of this condition.