Screening for Alzheimer's disease: the memory impairment screen versus the conventional three-word memory test

OBJECTIVES: To improve screening for Alzheimer's disease (AD) with the Memory Impairment Screen (MIS), a 4-minute, four-item delayed free and cued recall memory test with controlled learning and high discriminative validity. To assess the discriminative validity of the MIS for AD and to compare it with the conventional three-word memory test, a delayed free recall task, widely recommended as a dementia-screening test in clinical practice. DESIGN: Cross-sectional validation study nested within a longitudinal study of aging and dementia. The MIS and the standard three-word memory task were administered as part of a comprehensive neurological and neuropsychological evaluation. SETTING: Einstein Aging Study at the Albert Einstein College of Medicine, Bronx, New York. PARTICIPANTS: Two hundred forty community-dwelling older adults. MEASUREMENTS: Sensitivity, specificity, and positive predictive value (PPV) were calculated for the MIS and three-word memory test as screening tests for AD. RESULTS: In comparison with the three-word memory task, the MIS had higher sensitivity (.86 vs.65), higher specificity (.97 vs.85), and greater PPV (.80 vs.37) as a screen for AD. CONCLUSIONS: The MIS had high discriminative validity as a screening test for AD and substantially outperformed the three-word memory task. Given its validity and brevity, the MIS has important advantages as an AD screen for use in primary care.     

Validity of the telephone interview for cognitive status (TICS) and modified TICS (TICSm) for mild cognitive imparment (MCI) and dementia screening

This study aimed to validate the TICS and modified TICS (TICSm) in Korean elderly population and to compare MCI and dementia screening ability between TICS and TICSm. TICS and TICSm were administered to 70 cognitively normal (CN), 75 MCI, and 85 dementia subjects, with mini-mental state examination (MMSE) and other cognitive and functional measures. TICS and TICSm scores were highly correlated with other global cognitive and functional scores. The CN vs. dementia discrimination ability of both instruments was as excellent as that of MMSE (sensitivity/specificity at optimal cutoff: 87.1/90.1 for TICS; 88.2/90.0 for TICSm). Although their CN vs. MCI discrimination performances were comparable to that of MMSE, they were far from perfect (sensitivity/specificity: 69.3/68.6 for TICS; 73.3/67.1 for TICSm). There was no significant difference in dementia or MCI screening accuracy between TICS and TICSm. Both of them also showed high test-retest reliability. Our findings indicate that TICS and TICSm are reliable and as valid as MMSE in regard of screening cognitively impaired elderly. In terms of the comparison between TICSm and TICS, however, TICSm has little advantage over TICS for screening dementia and even MCI, in spite of longer administration time and more efforts required.     

Computer-automated dementia screening using a touch-tone telephone.

BACKGROUND: This study investigated the sensitivity and specificity of a computer-automated telephone system to evaluate cognitive impairment in elderly callers to identify signs of early dementia. METHODS: The Clinical Dementia Rating Scale was used to assess 155 subjects aged 56 to 93 years (n = 74, 27, 42, and 12, with a Clinical Dementia Rating Scale score of 0, 0.5, 1, and 2, respectively). These subjects performed a battery of tests administered by an interactive voice response system using standard Touch-Tone telephones. Seventy-four collateral informants also completed an interactive voice response version of the Symptoms of Dementia Screener. RESULTS: Sixteen cognitively impaired subjects were unable to complete the telephone call. Performances on 6 of 8 tasks were significantly influenced by Clinical Dementia Rating Scale status. The mean (SD) call length was 12 minutes 27 seconds (2 minutes 32 seconds). A subsample (n = 116) was analyzed using machine-learning methods, producing a scoring algorithm that combined performances across 4 tasks. Results indicated a potential sensitivity of 82.0% and specificity of 85.5%. The scoring model generalized to a validation subsample (n = 39), producing 85.0% sensitivity and 78.9% specificity. The kappa agreement between predicted and actual group membership was 0.64 (P<.001). Of the 16 subjects unable to complete the call, 11 provided sufficient information to permit us to classify them as impaired. Standard scoring of the interactive voice response-administered Symptoms of Dementia Screener (completed by informants) produced a screening sensitivity of 63.5% and 100% specificity. A lower criterion found a 90.4% sensitivity, without lowering specificity. CONCLUSIONS: Computer-automated telephone screening for early dementia using either informant or direct assessment is feasible. Such systems could provide wide-scale, cost-effective screening, education, and referral services to patients and caregivers.     

Korean Addenbrooke's Cognitive Examination Revised (K‐ACER) for differential diagnosis of Alzheimer's disease and subcortical ischemic vascular dementia

Aim: Sensitive, specific neuropsychological screening tests, such as the Addenbrooke's Cognitive Examination Revised (ACE‐R), are essential for dementia diagnosis. We aimed to validate the use of the Korean version of ACE‐R (K‐ACER) to differentiate Alzheimer's disease (AD) from subcortical ischemic vascular dementia (SIVD). Methods: Standard tests for dementia screening were applied to 156 subjects (84 controls, 30 AD, 42 SIVD), and total and sub‐domain scores on the K‐ACER, as well as the sub‐domain ratio (VLOM), were compared. Results: The reliability of the K‐ACER was very good (α‐coefficient 0.84), and cut‐off score for dementia was determined (cut‐off value 78, sensitivity 0.93, specificity 0.95). The likelihood ratio for dementia was calculated as between 78 and 82. At a cut‐off of 78, the likelihood of dementia was 18.6:1. Although a comparison of K‐ACER scores between AD and SIVD patients revealed significant differences in verbal fluency, language domain and VLOM ratio, sensitivity and specificity for differential diagnosis between AD and SVID proved less accurate. Conclusion: The K‐ACER is a rapid, sensitive and specific dementia screening test. Though sub‐domains of items may be useful for differentiating between AD and SIVD, sensitivity and specificity is less accurate than dementia screening itself. Geriatr Gerontol Int 2010; 10: 295–301.     

The Validation of a Mailed Health Survey for Screening of Dementia of the Alzheimer''s Type

OBJECTIVE: To test the efficacy of a mailed health survey, which included the Clock Completion Test (CCT), to screen previously undiagnosed older adults for dementia of the Alzheimer's type (DAT) in a community-dwelling population, and to determine whether the addition of selected risk factors for Alzheimer's disease (AD) would enhance the screening instrument's operating characteristics. DESIGN: Comparison of the results of a self-administered screen for DAT with the diagnosis of DAT by clinician evaluation or telephone interviews. SETTING: A geriatric assessment clinic. PARTICIPANTS: Three hundred and five women age 65 and older from St. Louis, Missouri. MEASUREMENTS: The sensitivity and specificity of the CCT and the CCT plus risk factors for AD were evaluated using two standards: The Short Blessed Test (SBT) and the physician diagnosis of probable AD using National Institute of Neurological and Communicative Disorders and Stroke-Alzheimer's Disease and Related Disorders Association criteria. RESULTS: Sensitivity and specificity for the CCT by SBT criteria were 63% and 79%, respectively. Using the physician's assessment as a criterion, the CCT had better sensitivity (67%) but poorer specificity (69%). Adding two or more risk factors for AD improved sensitivity and specificity to 71% and 89% and, in the physician assessment subgroup, to 75% and 87%, primarily by halving the false-positive rate. CONCLUSION: The combination of the simple, self-administered CCT and two or more AD risk factors is a more effective screening instrument for DAT and potentially preclinical DAT than the CCT alone. However, the instrument may be better suited for use in an office setting because of a poor response rate by subjects with dementia.     

Demenzscreening per Telefon

Background

To assess cognitive impairment or dementia in epidemiologic studies using telephone interviews for data acquisition, valid, reliable and short instruments suitable for telephone administration are required. For the Telephone Interview for Cognitive Status (TICS) in its modified German version, the only instrument used in Germany so far, more data on reliability and practicability are needed.

Material and methods

Participants were recruited in the offices of nine primary care physicians. Data from 197?participants (115?females, mean age 78.5±4.1?years) who were tested by telephone and in the office by means of the Mini-Mental State Examination (MMSE) were used for the evaluation. For assessing reliability, a group of 91?participants (55?females, mean age 78.1±4.1?years) was contacted twice during 30?days to be tested during a telephone interview by means of the TICS in its modified German version.

Results

The intraclass correlation coefficient (ICC), a measure of reliability, was 0.67 [95% confidence interval (CI): 0.53; 0.77]. The Bland–Altman plot did not reveal any relationship between the variability of the difference between repeated measures and the total amount of the measure. For the overall TICS score, no differences were found between repeated measurements. However, the tasks recall of the word list and counting backwards showed some improvement in the repeated tests. TICS and MMSE showed only moderate correlation, with a correlation coefficient of 0.48 (95% CI: 0.36; 0.58). TICS values were dependent on age and educational level of the person tested.

Conclusions

The TICS in its modified German version appears to be of acceptable reliability for the assessment of cognitive impairment during a telephone interview. TICS values depend on age and educational level of the person tested. TICS and MMSE correlate only moderately.     

The Montreal Cognitive Assessment, MoCA: a brief screening tool for mild cognitive impairment

OBJECTIVES: To develop a 10-minute cognitive screening tool (Montreal Cognitive Assessment, MoCA) to assist first-line physicians in detection of mild cognitive impairment (MCI), a clinical state that often progresses to dementia. DESIGN: Validation study. SETTING: A community clinic and an academic center. PARTICIPANTS: Ninety-four patients meeting MCI clinical criteria supported by psychometric measures, 93 patients with mild Alzheimer's disease (AD) (Mini-Mental State Examination (MMSE) score > or =17), and 90 healthy elderly controls (NC). MEASUREMENTS: The MoCA and MMSE were administered to all participants, and sensitivity and specificity of both measures were assessed for detection of MCI and mild AD. RESULTS: Using a cutoff score 26, the MMSE had a sensitivity of 18% to detect MCI, whereas the MoCA detected 90% of MCI subjects. In the mild AD group, the MMSE had a sensitivity of 78%, whereas the MoCA detected 100%. Specificity was excellent for both MMSE and MoCA (100% and 87%, respectively). CONCLUSION: MCI as an entity is evolving and somewhat controversial. The MoCA is a brief cognitive screening tool with high sensitivity and specificity for detecting MCI as currently conceptualized in patients performing in the normal range on the MMSE.     

The Mini-Cog as a screen for dementia: validation in a population-based sample

OBJECTIVES: To test the Mini-Cog, a brief cognitive screening test, in an epidemiological study of dementia in older Americans. DESIGN: A population-based post hoc examination of the sensitivity and specificity of the Mini-Cog for detecting dementia in an existing data set. SETTING: The Monongahela Valley in Western Pennsylvania. PARTICIPANTS: A random sample of 1,119 older adults enrolled in the Monongahela Valley Independent Elders Survey (MoVIES). MEASUREMENTS: The effectiveness of the Mini-Cog in detecting independently diagnosed dementia was compared with that of the Mini-Mental State Examination (MMSE) and a standardized neuropsychological battery. RESULTS: The Mini-Cog, scored by an algorithm as "possibly impaired" or "probably normal," and the MMSE, at a cutpoint of 25, had similar sensitivity (76% vs 79%) and specificity (89% vs 88%) for dementia, comparable with that achieved using a conventional neuropsychological battery (75% sensitivity, 90% specificity). CONCLUSION: When applied post hoc to an existing population, the Mini-Cog was as effective in detecting dementia as longer screening and assessment instruments. Its brevity is a distinct advantage when the goal is to improve identification of older adults in a population who may be cognitively impaired. Prior evidence of good performance in a multiethnic community-based sample further supports its validity in the ethnolinguistically diverse populations of the United States in which widely used cognitive screens often fail.     

A comparison of the MMSE and the TICS‐m in hearing‐impaired older adults

Objective: The efficacy of telephone‐administered cognitive screening instruments used with hearing‐impaired populations is as yet unknown. Method: In a pilot study, performance of hearing‐impaired veterans (N = 46) was compared on telephone‐administered (Telephone Interview for Cognitive Status – modified; TICS‐m) and face‐to‐face administered (Mini‐Mental State Examination; MMSE) instruments. Results: Correlations between the MMSE and the TICS‐m (r = 0.39) are lower than previously reported in the literature. Participants had difficulty perceiving words from the TICS‐m on registration and thus also on later recall, regardless of whether hearing aids were worn. Further analyses revealed that when these items were removed from the TICS‐m scores, correlations with the MMSE improved significantly. Conclusions: Hearing‐impaired participants may have difficulties with telephone‐administered instruments requiring accurate hearing of words in the absence of any context. Participants’ hearing should be taken into account when administering and interpreting cognitive screens over the telephone.     

Is telephone screening feasible? Accuracy and cost-effectiveness of identifying people medically eligible for home- and community-based services

PURPOSE: To determine the accuracy of a telephone-screening system to identify persons eligible for home- and community-based long-term care. DESIGN AND METHODS: Data from Michigan telephone screens were compared to data from in-person assessments using the Minimum Data Set for Home Care (MDS-HC). Weighted kappa statistics measured the level of agreement between the two assessments. RESULTS: Overall, recommendations based on the telephone screen produced a marginal match compared to recommendations based on in-person assessment. "False positives" (individuals scoring as more impaired on the telephone screen than in person) occurred in 27% of all cases, while "false negatives" (individuals scoring as less impaired on the telephone screen) only occurred among 6% of the callers. Neither individual screen questions, source of information, location of the individual, timing between screen and assessment, nor temporal changes accounted for mismatches. Telephone screens resulted in an 11% savings over the cost of providing in-person assessments to all program seekers. IMPLICATIONS: The telephone screen has utility as a broad targeting mechanism that allows agencies to avoid costly in-person assessments for all program seekers. Evidence does not support use of the telephone screen alone to determine either medical eligibility or a specific level of care.     

西安地区中老年人的痴呆患病率调查

目的：了解西安载我中老年人痴呆的流行现状。方法：E要用多分层,多级,随机、整群抽样、以简易智能状态量表（MMSE）为筛查工具,对西安地区4850例5及以上中老年人进行了痴呆患病率调查。结果：符合美国精神疾病诊断和统计手册第4版（DSM－Ⅳ）和美国国立神经病学、语言交流障碍和卒中－老年性痴呆 关疾病学会（NINCDS－ADRDA）痴呆诊断标准者171例,痴呆患病率3．53％。其中Alzheimer痴呆（AD）100例,患病率2．06％,占58．48％,血管性痴呆（VD）54例,患病率1．11％,占31．58％,痴呆及VD患病率男女间差异无显著性P＞0．05）,而AD患病率女性明显高于男性（P＜0．01）。痴呆及AD、VD、患病率均随增龄而显著增高（P＜0．01）,年龄每增长5岁,患病率约增高1倍。文盲组痴呆及AD患病率高于小学和初中以上组（P＜0．01）。各职业之间痴呆及AD、VD患病率用年龄分层后差异均无显著性（P＞005）。城市和农村痴呆、AD、VD患病率差异亦无显著性（P＞0．05）。结论：我国痴呆患病率并不低,基本与欧美国家持平,高龄、女性、低文化水平,能是AD的危险因素。     

Prevalence and severity of gait disorders in Alzheimer's and non-Alzheimer's dementias

OBJECTIVES: To compare the prevalence, severity, and type of gait and balance disorders in Alzheimer's disease (AD), vascular dementia (VaD), Parkinson's disease with dementia (PDD), dementia with Lewy bodies (DLB), Parkinson's disease without dementia (PD), and age-matched controls. DESIGN: Cross-sectional. SETTING: Secondary care clinics in geriatric psychiatry, neurology, and geriatrics. PARTICIPANTS: Two hundred forty-five participants aged 65 and older (AD, n=40; VaD, n=39; PDD, n=46; DLB, n=32; PD, n=46; and controls, n=42). MEASUREMENTS: Prevalence and severity of gait and balance disorders were assessed using the Tinetti gait and balance scale. The types of gait disorders in each diagnostic group were classified using the Nutt et al. classification. RESULTS: Gait and balance disorders were more common with PDD (93%), VaD (79%), and DLB (75%) than with PD (43%) and AD (25%) and in controls (7%). The risk of gait and balance disorder was higher in the non-Alzheimer's dementia groups (VaD, PDD, and DLB) than in the AD group (odds ratio=15 (95% confidence interval=6-37). If a gait disorder was present in mild dementia (Cambridge Examination for Mental Disorders of the Elderly cognitive subsection score >65), this was diagnostic of non-Alzheimer's dementia, with sensitivity of 78% and specificity of 100%. Non-Alzheimer's dementia groups had worse Tinetti gait and balance scores than the AD group (all P<.001). The types of gait disorders discriminated between non-Alzheimer's dementias. CONCLUSION: The findings support the idea that gait and balance assessment may augment the diagnostic evaluation of dementia.     

Instrumental activities of daily living as a screening tool for cognitive impairment and dementia in elderly community dwellers.

OBJECTIVE: To identify which Instrumental Activities of Daily Living (IADL) are related to cognitive impairment, independent of age, sex, and education; to assess the performance of an IADL score using these items in screening for cognitive impairment and dementia in elderly community dwellers. DESIGN: Survey based on the baseline interview of the PAQUID study on functional and cerebral aging. SETTING: Community survey in 37 randomly selected parishes in Gironde, France. SUBJECTS: Random sample of 2,792 community dwellers aged 65 and over (participation rate: 69%). MEASUREMENTS: Two-phase screening: (1) functional assessment, Mini-Mental State Examination (MMSE) and DSM-III criteria for dementia; (2) in DSM-III-positive patients, NINCDS-ADRDA criteria applied by a neurologist. Functional assessment: IADL scale of Lawton and Brody. Criterion standards: cognitive impairment: MMSE score lower than 24; dementia: DSM-III and NINCDS-ADRDA criteria. RESULTS: Four IADL items are correlated with cognitive impairment independent of age, sex, and education: telephone use, use of means of transportation, responsibility for medication intake, and handling finances. A score adding the number of IADL dependencies has a sensitivity of 0.62 and a specificity of 0.80 at the lowest cut-off point (score > 0) for the diagnosis of cognitive impairment. The same score at the same cut-off has a sensitivity of 0.94 and a specificity of 0.71 for the diagnosis of dementia. The prevalence of dementia (2.4%) is reduced by a factor of 12 in subjects independent for the four IADL. CONCLUSION: The four IADL score could be incorporated into the screening procedure for dementia in elderly community dwellers.     

Development of a short neuropsychological battery to screen early dementia in the elderly

Background:   The purpose of the present study was to develop a short screening neuropsychological battery for patients with very mild and mild dementia.
Methods:   The participants involved in the present study consisted of 162 persons who were 65 years and older. Fifty-four of the patients had very mild or mild dementia and had a mini-mental state examination (MMSE) score of 19 or above. Normal control samples were community-dwelling volunteers, or persons recruited from outpatients who did not suffer from any cognitive problems. Mini-mental state examination, the category cued memory test (CCMT) – a modified brief memory test in which category cues were given for both acquisition and retrieval – verbal fluency test (VFT) and clock drawing test (CDT) were carried out. Using logistic regression models, the best battery was selected. The validity and reliability of the battery were also assessed.
Results:   The combination of CCMT, VFT and CDT was the best screening battery and could be accomplished in about 10 min. The battery had a high degree of sensitivity (94.4%), specificity (99.1%), positive and negative predictive values. Test-retest, interrater and alternate forms reliabilities were substantial using the intraclass correlation coefficient, and all of the P -values analyzed by the Pearson correlation coefficient were below 0.005.
Conclusions:   This short battery has enough validity, reliability and efficiency to detect early dementia especially in an elderly primary care setting. The CCMT is also a useful memory test even if used alone.     

Sensitivity and specificity of cognitive and functional screening instruments for dementia: the Indo-U.S. Dementia Epidemiology Study

There is a shortage of adequate screening instruments for dementia in poorly educated populations and non-English-speaking groups. An epidemiological survey was conducted in a population-based, largely illiterate, sample of 5,126 individuals aged 55 and older in 28 villages in the rural community of Ballabgarh in northern India. All participants were administered a general mental status test, the Hindi Mental State Examination (HMSE), and a brief battery of neuropsychological tests. Their informants answered a questionnaire assessing functional ability, the Everyday Abilities Scale for India (EASI). Six hundred thirty-two participants underwent clinical diagnostic evaluation for dementia. We investigated whether the sensitivity, specificity, and predictive value for dementia of the mental status test could be improved by the addition of the brief neuropsychological test battery or the functional questionnaire, comparing the instruments alone and in combination. In participants who could be tested cognitively, the HMSE, the neuropsychological battery, and EASI had sensitivities of 81.3%, 81.3%, and 62.5%, respectively, with specificities of 60.2%, 74.5%, and 89.7%, respectively. The combination of all three was 93.8% sensitive and 41.8% specific. The sensitivity of the HMSE alone was nonsignificantly improved by the addition of either the EASI or the neuropsychological battery, whereas its specificity was significantly decreased by either addition. An advantage of the EASI was that it could also be administered to informants of subjects who were cognitively untestable. In this largely illiterate community, with a low prevalence of dementia, the combination of cognitive tests and a functional ability questionnaire had substantial value for population screening.     

扩瞳试验在Alzheimer病诊断中的意义

目的　探讨扩瞳试验在Alzheimer病 (AD)诊断中的意义。　方法　在滴入 0 0 1%托吡卡胺 7～ 10min后 ,用双侧瞳孔红外线同步记录分析仪自动记录并分析滴药眼的瞳孔直径扩大程度(按对照侧校正 )。共测定AD 5 2例 ,血管性痴呆 (VD) 33例和健康对照 (HC) 5 8例。利用受试者工作特性曲线 (ROC)确定最能明显区别AD与HC的分界线 ,计算敏感度、特异度和Kappa值 ,评估扩瞳试验的诊断价值。　结果　 ,AD患者滴药眼的瞳孔明显扩大 ,与VD或HC差异有极显著性 (P <0 0 1) ,其中以第 18min时的差别最为显著。如以瞳孔扩大 15 %作为分界线 ,敏感度均为 0 81,特异度分别为 0 82和 0 79,Kappa值分别为 0 6 7和 0 6 0。　结论　扩瞳试验可以作为筛选早期AD的一个手段 ,也可在鉴别AD与VD时作参考。     

简易认知量表和8条目痴呆筛查问卷在高龄老年人群早期认知功能下降筛查中的应用

目的探讨简易认知量表（Mini-Cog）和8条目痴呆筛查问卷（8-item ascertain dementia, AD8）对80岁以上老年人群早期轻度认知功能障碍（mild cognitive impairment, MCI）的筛查价值。 方法选取杭州市某福利中心的2014年10月前已入住的908名高龄老年人进行Mini-Cog和AD8筛查,随访5年后对仍然健在且能配合完成检查者进行二次认知功能评估。计算Mini-Cog和AD8初筛的敏感度和特异度,并分析随访5年后AD8的ROC曲线结果以及两种量表的一致性检验结果。 结果908例高龄老年人中523例确诊为痴呆（不计入后续筛查及随访调查）,余385例筛查结果显示：Mini-Cog、AD8诊断MCI的敏感度分别为54.88%、57.32%,特异度分别为85.52%、86.43%。随访5年后仍健在且接受二次评估的老年人共167名,其中认知功能正常106例（54例出现认知功能下降）,MCI 61例（36例出现认知功能进一步下降）。对于随访5年的认知功能正常者及MCI者,AD8诊断的AUC分别为0.572（95%CI=0.486-0.658）、0.723（95%CI=0.611-0.835）,Mini-Cog和AD8（以得分>3为分界线）诊断的一致性Kappa值分别为0.105、0.018和0.225、0.524。 结论AD8和Mini-Cog均具有一定的MCI评估效能,尤其适用于养老机构及社区高龄老年群体的认知功能筛查。     

The Clock Drawing Test: utility for dementia detection in multiethnic elders

BACKGROUND: Disproportionate increases in dementia morbidity in ethnic minorities challenge established screening methodologies because of language and culture barriers, varying access to health services, and a relative paucity of cross-cultural data validating their use. Simple screening techniques adapted to a range of health and social service settings would accelerate dementia detection and social and health services planning for demented minority elders. METHODS: The effectiveness of the Clock Drawing Test (CDT) for dementia detection was compared with that of the Mini-Mental State Examination (MMSE) and the Cognitive Abilities Screening Instrument (CASI) in community-dwelling elders of diverse linguistic, ethnic, and educational backgrounds. Subjects (N = 295) were tested at home in their native languages (English, n = 141; another language, n = 154). An informant-based clinical dementia history and functional severity index derived from the Consortium to Establish a Registry for Alzheimer's Disease (CERAD) protocols were used to classify subjects as probably demented (n = 170), and probably not demented (n = 125). RESULTS: All tests were significantly affected by education (p < .001) but not by primary language (p > .05). Sensitivities and specificities for probable dementia were 82% and 92%, respectively, for the CDT; 92% and 92% for the MMSE; and 93% and 97% for the CASI for subjects completing each test. However, in poorly educated non-English speakers, the CDT detected demented subjects with higher sensitivity than the two longer instruments (sensitivity and specificity 85% and 94% for the CDT, 46% and 100% for the MMSE, and 75% and 95% for the CASI). Moreover less information was lost due to noncompletion of the CDT than the MMSE or CASI (severe dementia or refusal: CDT 8%, MMSE 12%, and CASI 16%). CONCLUSIONS: Overall, the CDT may be as effective as the MMSE or CASI as a first-level dementia screen for clinical use in multiethnic, multilingual samples of older adults. Its brevity (1-5 minutes), minimal language requirements, high acceptability, and lack of dependence on specialized testing materials are well adapted for screening of non-English-speaking elderly persons in settings where bilingual interpreters are not readily available and screening time is at a premium.     

The role of routine laboratory studies and neuroimaging in the diagnosis of dementia: a clinicopathological study

OBJECTIVE: To determine the neuropathological diagnoses of longitudinally followed patients with potentially reversible causes of dementia and to examine the results of the "dementia work-up," especially neuroimaging, by comparison with the pathological diagnosis. DESIGN: A neuropathologic series of 61 consecutive patients, with review of clinical, laboratory, neuroimaging, and pathological results. RESULTS: Of the 61 patients, forty-eight (79%) had a clinical diagnosis of probable or possible Alzheimer's disease (AD). Compared with the pathological diagnosis, the sensitivity and specificity of the clinical diagnosis of AD were 96% and 79%, respectively. Of the 61 patients, 9 had abnormal laboratory tests, the correction of which did not improve the subsequent course. These patients were found to have AD8 and frontotemporal dementia on pathology. In two patients, neuroimaging was helpful in the clinical diagnoses of frontotemporal dementia and progressive supranuclear palsy (PSP). Neuroimaging revealed cerebrovascular disease in 18 patients, only two of whom were suspected clinically. Pathology confirmed AD in 17 and PSP in 1 of these patients. Sensitivity and specificity for the clinical diagnosis of cerebrovascular disease in comparison with pathology were 6% and 98%, respectively. With the added information from neuroimaging, that sensitivity increased to 59% and specificity decreased to 81%. CONCLUSIONS: All cases with abnormal laboratory or neuroimaging results had AD or some other neurodegenerative disease on pathology. The "dementia work-up" did not reveal any reversible causes for dementia in this group of patients. Neuroimaging may have a role, especially in the diagnosis of possible AD with concomitant cerebrovascular disease.