Clinical application of the Polish adaptation of the Montreal Cognitive Assessment (MoCA) test in screening for cognitive impairment

Background and purposeThe Montreal Cognitive Assessment (MoCA) test is a brief cognitive screening tool with high sensitivity and specificity for detecting mild cognitive impairment (MCI). The aim of this study was to evaluate the usefulness of MoCA and compare it with the Mini-Mental State Examination (MMSE) in the early detection of cognitive decline in MCI.Material and methodsA group of 115 subjects (36 meeting DSM-IV criteria for Alzheimer disease (AD) [Clinical Dementia Rating (CDR) = 1], 42 meeting Petersen's criteria for MCI [CDR = 0.5], and 37 cognitively intact controls [CDR = 0]) was recruited for the study in the university-based Alzheimer out-patient clinic. All participants underwent general medical, neurological, and psychiatric examinations. The MoCA, the MMSE, CDR and the short (15-item) version of the Geriatric Depression Scale were also applied.ResultsBoth MCI and AD groups exhibited impaired performance on MoCA compared to controls. Polish versions of the MMSE and MoCA tests were comparable in discriminating mild dementia from both MCI and control groups. The Polish version of the MoCA test performed marginally better than MMSE in discriminating MCI from controls. We propose to use the MoCA test to screen for MCI using an optimal cut-off score of 24 and to screen for dementia using a cut-off score of 19.ConclusionsThe Polish version of the MoCA seems effective in the detection of deteriorated cognitive performance and appropriate for differentiating impaired from preserved cognitive function in a Polish population.     

Clinical correlates of functional performance in community-dwelling Chinese older persons with mild cognitive impairment

ABSTRACTBackground: Increasing evidence suggests that functional impairment can be detected in older persons with mild cognitive impairment (MCI). This study explores the functional profiles and the clinical correlates of a population-based sample of Chinese older persons with MCI in Hong Kong.Methods: A random sample of 765 Chinese elderly subjects without dementia was recruited, of which 389 were elderly normal controls (Clinical Dementia Rating = 0), and 376 had questionable dementia (CDR = 0.5). The latter were categorized into an MCI group (n = 291) and a very mild dementia (VMD) group (n = 85). Their functional performances were measured and compared with the normal controls (NC). Multiple regression analyses investigated the associations between functional scores (Disability Assessment in Dementia) and clinical correlates (cognitive test scores, neuropsychiatric symptoms and motor signs) in the NC subjects and cognitively impaired subjects.Results: Subjects with MCI had intermediate functional performance between the NC and those with VMD. Regression analyses revealed that lower scores of cognitive tests (delayed recall and categorical verbal fluency tests), apathy, aberrant motor symptoms and parkinsonism features were associated with lower functional scores in clinically non-demented subjects. Functional scores had no correlation with age, education and medical illness burden.Conclusion: Neuropsychiatric symptoms and parkinsonism features were associated with functional impairment in the clinically non-demented elderly in the community. Assessment of these should be incorporated in the evaluation of older persons for early cognitive impairment.     

Subjective memory complaints in Chinese subjects with mild cognitive impairment and early Alzheimer's disease

BACKGROUND: Mild cognitive impairment (MCI) represents a transitional state between normal aging and dementia. However, there is inconsistent opinion as to the validity of subjective memory complaints as a criterion for diagnosis. OBJECTIVE: This study aimed to examine the potential significance of applying a short memory questionnaire in the assessment of Chinese subjects with MCI and early dementia. METHODS: Three hundred and six ambulatory Chinese subjects were recruited. Each participant completed a short memory questionnaire. They were also assessed with the Chinese versions of the mini-mental state examination (CMMSE), Alzheimer's disease assessment scale-cognitive subscale (ADAS-Cog), category verbal fluency test (CVFT) and span tests. Severity of cognitive impairment was evaluated using the Clinical Dementia Rating (CDR); subjects with CDR 0.5 were further classified into MCI not demented (MCIND) and MCI possible incipient dementia (MCIID) depending on the subscale scores of CDR. RESULTS: An increasing frequency of memory complaints with increasing CDR was observed (Kruskal Wallis test, chi square = 21.29, df 3, p < 0.001). With a cutoff of 3 or more memory complaints, the memory questionnaire demonstrated a sensitivity of 65.3% and 70.4% in identifying subjects with incipient and early dementia respectively. Significant associations between memory complaints and most cognitive test performance were found (Spearman's correlations, p < 0.01). Logistic regression analysis revealed that educational level, the memory questionnaire, ADAS-Cog total and delayed recall scores were significant predictors of MCIID status. CONCLUSIONS: The findings suggested that a short memory questionnaire is useful in the screening of MCI, particularly in subjects who already present with subtle functioning disturbances. Subjective memory complaints were significant correlated with objective performance of memory functions, reflecting the usefulness of memory complaints in the assessment of MCI.     

Clinical correlates of Parkinsonian signs in community- dwelling Chinese older persons: a population based study

BACKGROUND AND OBJECTIVE: This study examined the clinical correlates of parkinsonian signs including neuropsychiatric symptoms, cognitive impairment and medical illness burden in the community-dwelling non-demented Chinese elderly. METHODS: A random sample of 765 Chinese elderly subjects from a thematic household survey was recruited. There were 389 normal elderly controls (Clinical Dementia Rating [CDR] 0) (NC) and 376 subjects with questionable dementia (CDR 0.5). The subjects with questionable dementia (CDR 0.5) were categorized into two groups: a MCI group (n = 291) and a very mild dementia (VMD) group (n = 85). Parkinsonian signs were measured by Unified Parkinson Disease Rating Scale- motor scale (UPDRS). The clinical correlates were investigated in each group. RESULTS: UPDRS motor score was associated with age, cumulative medical illness burden and cerebrovascular accidents in the normal control and MCI groups. It correlated negatively with MMSE scores in the NC group. It was associated with presence of soft signs in the NC and MCI groups; and apathy in the VMD group. CONCLUSION: Neuropsychiatric symptoms, cognitive impairment and vascular risk factors had different patterns of associations with parkinsonian signs in the older persons with different degree of cognitive impairment.     

Neuropsychiatric symptoms in mild cognitive impairment: a population‐based study

Introduction: Few studies have examined neuropsychiatric symptoms in community dwelling older adults with mild cognitive impairment (MCI). In the present study, we compared the prevalence of neuropsychiatric symptoms in older adults with normal cognition, MCI, and dementia in a population‐based sample. Methods: Subjects were selected from the Singapore Longitudinal Ageing study. Normal cognitive function was defined as Clinical Dementia Rating (CDR) global score=0 and Mini‐Mental State Examination (MMSE) total score ≥24. MCI was defined as CDR global score=0.5, and dementia was defined as CDR global score ≥1. Neuropsychiatric Inventory (NPI) was administered on reliable informants for 293 subjects (136 normal, 133 MCI, and 24 dementia). Results: The prevalence of neuropsychiatric symptoms (at lest one symptom) was 5.9% for normal cognition, 12.8% for MCI, and 50% for dementia. The most common neuropsychiatric symptoms in subjects with MCI were depression/dysphoria (6.8%), irritability/lability (3.8%), apathy/indifference (2.3%), and agitation/aggression (2.3%). NPI total score increased with increasing CDR global score (P<0.001). The adjusted mean NPI total score was 0.07 (SEM=0.49) for normal cognition, 0.86 (SEM=0.46) for MCI, and 4.50 (SEM=0.82) for dementia. Discussion: In community dwelling Asian older adults, we found an increasing prevalence of neuropsychiatric symptoms in subjects with normal cognition, MCI and dementia. Further studies with larger samples and strict criteria for MCI in an Asian population should be conducted.     

Subjective complaints and self-evaluation of memory test performance in Questionable dementia

BACKGROUND: The clinical significance of subjective memory complaints in elderly subjects has been an area of active research. In this study, we evaluated subjective complaints and self-evaluation of memory test performance in subjects with Questionable dementia (QD) and mild Alzheimer's disease (AD). METHODS: Ninety-two subjects (35 cognitively intact normal controls NC, 33 QD, and 24 mild AD) were assessed. Subjective memory complaints were evaluated using a memory inventory for the Chinese (MIC); objective assessment of awareness was assessed by the self-evaluation of own memory test performance. Cognitive function was assessed with the Alzheimer's Disease Assessment Scale-Cognitive subscale (ADAS-Cog), Category Verbal Fluency Test (CVFT) and Executive Interview (EXIT-25). Depressive symptoms were evaluated with the Cornell Scale for Depression in Dementia (CSDD). RESULTS: The total number of subjective memory complaints (MI-tol) were significantly different between different subject groups (Kruskal Wallis test, chi2 = 13.19, p = 0.001). Significant correlations between scores of the MI-tol and CSDD (r = 0.33, p < 0.001), CMMSE (r = -0.33, p < 0.001), CDR (r = 0.36, p < 0.001) were found. In self-evaluation of memory test performance, the NC group tended to under-estimate while the AD subjects tended to over-estimate their performance. Group differences in the discrepancies of self-evaluation of memory performance were significant for both the immediate (Kruskal Wallis test, chi2 = 9.86, p = 0.007) and delayed recall (Kruskal Wallis test, chi2 = 10.55, p < 0.001) trials. CONCLUSIONS: Subjects with QD and mild AD showed higher frequency of subjective memory complaints, reflecting that the subjects still retain some ability to appreciate own memory function. However, the trend for over-estimation of performance in AD subjects suggests that the precision of estimation may be suboptimal. Moreover, depressive symptoms may affect the presentation of memory complaints and this factor should be carefully considered in future prospective studies.     

Hippocampal size may contribute to prospective diagnosis of age-related dementia

Background: The hippocampus is a center of cognitive function and therefore hippocampal atrophy is the major factor in cognitive decline. Analysis of hippocampal size may make it possible to predict progression in cognitive impairment. To address this point, the present study investigated the relationship between hippocampal atrophy and dementia using magnetic resonance (MR) images and the Hasegawa Dementia Scale‐Revised (HDS‐R). Methods: The present study was performed on 274 subjects (14–97 years old; average, 66 years; 106 male and 168 female) who had no focal neurological deficit. Hippocampal area and whole brain area were measured in three series of coronal MR images taken from a 5‐mm slice rostrally along dorsal edge of the pons, and hippocampal size normalized by calculating summated hippocampal areas as percentages of summated whole brain areas. Dementia was screened for using HDS‐R. Results: Hippocampal size decreased and HDS‐R reduced with age. Hippocampal atrophy was highly correlated with cognitive deterioration; a critical normalized hippocampal size for HDS‐R of less than 20, which corresponds with mild cognitive impairment and dementia, was found in 65% of over 60‐years old subjects and 98% of subjects with HDS‐R of less than 20 were over 60 years old. Conclusion: There is a high probability that over 60‐year‐old people with a normalized hippocampal size of less than 1.0 would develop dementia in the future, even though their HDS‐R might presently be over 20. Measurement of hippocampal size with coronal MR imaging may therefore contribute to prospective diagnoses of age‐related dementia.     

Yamaguchi fox–pigeon imitation test (YFPIT) for dementia in clinical practice

Background: In out‐patient clinics, having simple procedures to check for signs of dementia is invaluable. In the present study, we evaluated the imitation of hand gestures to detect visuomotor deficits in dementia in clinical practice. Methods: In all, 1219 subjects were enrolled in the present study, including 497 with Alzheimer's disease (AD), 98 with dementia with Lewy bodies (DLB), 71 with other types of dementia diseases, 175 with a Clinical Dementia Rating (CDR) of 0.5, and 378 normal controls. All subjects were aged 65 years or older. Subjects were recruited from 10 clinics and two communities. Visuomotor function was evaluated by the Yamaguchi fox–pigeon imitation test (YFPIT), which consists of a simple one‐handed sign for ‘fox’ and a complex two‐handed sign for ‘pigeon’, a rapid, game‐like test with low psychological burden. Results: The success rate (successful/total) for imitating the ‘pigeon’ hand gesture was reduced as the severity of the dementia increased: 85.7% in normal controls, 60.6% in CDR 0.5 (mild cognitive impairment), 39.2% in CDR 1 (mild dementia), 21.2% in CDR 2 (moderate dementia), and 5.7% in CDR 3 (severe dementia). The success rate for imitating the ‘pigeon’ hand gesture was higher in patients with DLB than AD within the CDR 1 group (51.2% vs 35.4%, respectively), but lower for patients with DLB than AD within the CDR 2 group (12.5% vs 24.4%, respectively). The success of imitating the hand gesture for ‘fox’ was similar for patients with AD and DLB. Of those subjects who failed to imitate the hand gesture for ‘pigeon’, 49.5% of those with AD showed the palm–palm pattern (both palms facing outward), suggesting deficits of perspective conversion from the first‐person to the third‐person. Conversely, 52.8% of patients with DLB showed a dorsum–dorsum pattern (both dorsa facing outwards), suggesting deterioration of visual attention and recognition. Conclusion: In conclusion, the YFPIT is a useful test to detect visuomotor deficits in dementia that can differentiate between AD and DLB.     

Prevalence of mild cognitive impairment: a population-based study in elderly subjects

OBJECTIVES: Mild cognitive impairment (MCI) has been suggested as a term for a boundary area between normal aging and dementia, especially Alzheimer's disease (AD). In follow-up studies, more than 50% of MCI subjects have been converted to dementia in 3-4 years. However, the epidemiology of MCI is not well known. This study was designed to determine the prevalence of MCI in an elderly population. METHODS: A total of 806 subjects (60-76 years of age) from a population-based random sample of 1150 subjects living in the city of Kuopio in eastern Finland were evaluated. Neuropsychological tests and a structured interview including the modified Clinical Dementia Rating (CDR) were used to apply the diagnostic criteria of MCI as proposed by Mayo Clinic Alzheimer's Disease Research Centre. Thus, subjects having a test score more than 1.5 SDs below the age appropriate mean in memory tests and a CDR score of 0.5 but no dementia, were diagnosed as having MCI. RESULTS: A total of 43 subjects, 5.3%, met the MCI criteria. MCI was more prevalent in older and less-educated subjects, but no difference was found between men and women. The CDR appeared to be the most important part of the criteria. The memory tests had less impact on prevalence variables. CONCLUSIONS: The low prevalence of MCI indicate that in a population-based study design its criteria may identify a more homogeneous group of subjects at the lower end of the cognitive continuum as contrasted with various other criteria of cognitive impairment in the elderly population. This is compatible with follow-up studies showing a high probability of dementia in the MCI group. Thus, probable candidates for trials of preventive intervention for dementia can be screened from the elderly population using these diagnostic criteria.     

Diagnostic differentiation of mild cognitive impairment due to Alzheimer's disease using a hippocampus‐dependent test of spatial memory

The hippocampus is one of the earliest brain regions affected in Alzheimer's disease (AD) and tests of hippocampal function have the potential to detect AD in its earliest stages. Given that the hippocampus is critically involved in allocentric spatial memory, this study applied a short test of spatial memory, the 4 Mountains Test (4MT), to determine whether test performance can differentiate mild cognitive impairment (MCI) patients with and without CSF biomarker evidence of underlying AD and whether the test can distinguish patients with MCI and mild AD dementia when applied in different cultural settings. Healthy controls (HC), patients with MCI, and mild AD dementia were recruited from study sites in UK and Italy. Study numbers were: HC (UK 20, Italy 10), MCI (UK 21, Italy 14), and AD (UK 11, Italy 9). Nineteen UK MCI patients were grouped into CSF biomarker‐positive (MCI+, n = 10) and biomarker‐negative (MCI–, n = 9) subgroups. Behavioral data were correlated with hippocampal volume and cortical thickness of the precuneus and posterior cingulate gyrus. Spatial memory was impaired in both UK and Italy MCI and AD patients. Test performance additionally differentiated between MCI+ and MCI– subgroups (P = 0.001). A 4MT score of ≤8/15 was associated with 100% sensitivity and 90% specificity for detection of early AD (MCI+ and mild AD dementia) in the UK population, and with 100% sensitivity and 50% specificity for detection of MCI and AD in the Italy sample. 4MT performance correlated with hippocampal volume in the UK population and cortical thickness of the precuneus in both study populations. In conclusion, performance on a hippocampus‐sensitive test of spatial memory differentiates MCI due to AD with high diagnostic sensitivity and specificity. The observation that similar diagnostic sensitivity was obtained in two separate study populations, allied to the scalability and usability of the test in community memory clinics, supports future application of the 4MT in the diagnosis of pre‐dementia due to AD. © 2015 Wiley Periodicals, Inc.     

Reduced semantic fluency as an additional screening tool for subjects with questionable dementia

BACKGROUND: Subjective memory complaints in subjects with mild cognitive impairment may represent a genuine decline in episodic memory. This paper evaluates the neuropsychological correlates of the semantic fluency test in subjects with questionable dementia (QD). METHODS: A total of 331 Chinese subjects (118 normal controls, NC, 150 with QD and 63 with mild Alzheimer's disease, AD) were assessed with the Category Verbal Fluency Test (CVFT), the AD Assessment Scale-cognitive subscale (ADAS-Cog), and digit and verbal span tests. CVFT performance was evaluated in each Clinical Dementia Rating (CDR) group. The total number of exemplars, the subcategory and the category size generated were evaluated. Neuropsychological correlates of CVFT scores were computed. RESULTS: Significant differences in CVFT performance were found between the different CDR groups. The subjects with QD had intermediate scores compared to the NC and AD subjects (1-way ANOVA, p < 0.001, post-hoc Bonferroni comparisons). In NC the CVFT scores were significantly associated with ADAS-Cog total, and immediate and delayed recall scores (partial correlations controlled for age and education, p < 0.005). In the QD group the CVFT scores were correlated with ADAS-Cog total, and immediate recall and object naming scores (partial correlation controlled for age and education, p < 0.005). Regression analysis revealed that age and delayed recall were significant predictors of CVFT performance in NCs. In the QD group, age, ADAS-Cog immediate recall and object naming scores predicted the CVFT performance. CONCLUSIONS: The CVFT was impaired in the subjects with QD. Apart from episodic memory, semantic memory deficits also occur early in AD. The different cognitive predictors of CVFT scores in the NC and QD groups suggest that the test is associated with specific psychological functions at different stages of cognitive impairment.     

Prevalence and cognitive performances of clinical dementia rating 0.5 and mild cognitive impairment in Japan. The Tajiri project

The borderline zone condition between normal aging and dementia is a major issue of concern. Although the term mild cognitive impairment (MCI) is popular, its prevalence and neuropsychological features have not been fully investigated. We investigated the prevalence and neuropsychological features for Clinical Dementia Rating (CDR) 0.5 and MCI. For normal aging, the effects of age and educational level on cognitive performance were examined. We examined 1501 older residents (46.8%) in Tajiri 65 years of age and older. They performed the Cognitive Abilities Screening Instrument (CASI). Depressive scores and subjective memory complaints were also evaluated. There was no age effect but an educational effect on cognitive performance in healthy adults. We found the overall prevalence of CDR 0.5 to be 30.2%, whereas that of MCI was only 4.9%. All CASI domains were deteriorated except for long-term memory and visual construction in the CDR 0.5 participants compared with healthy adults, suggesting that CDR 0.5 is similar to very mild Alzheimer disease. Memory complaints' data suggested that it would be better to exclude memory complaints from the MCI criteria. We considered that the concept of CDR 0.5 would be more applicable to community residents rather than that of the MCI.     

Brief screening for mild cognitive impairment in elderly outpatient clinic: validation of the Korean version of the Montreal Cognitive Assessment

The Montreal Cognitive Assessment (MoCA) is a brief cognitive screening tool with high sensitivity for screening patients with mild cognitive impairment (MCI). The authors examined the validity and reliability of the Korean version of the MoCA (MoCA-K) in elderly outpatients. The MoCA-K, a Korean version of the Mini-Mental State Examination (MMSE), Clinical Dementia Rating (CDR) scale, and neuropsychological batteries were administered to 196 elderly persons (mild Alzheimer's disease [AD] = 44, MCI = 37, normal controls [NC] = 115). MoCA-K scores were highly correlated with those of MMSE and CDR. Using a cutoff score of 22/23, the MoCA-K had an excellent sensitivity of 89% and a good specificity of 84% for screening MCI. Internal consistency and test-retest reliability were good. The results obtained show that the MoCA-K is brief, reliable, and suitable for use as a screening tool to screen MCI patients in elderly outpatient clinic settings.     

Comparing 3 T and 1.5 T MRI for tracking Alzheimer's disease progression with tensor‐based morphometry

A key question in designing MRI‐based clinical trials is how the main magnetic field strength of the scanner affects the power to detect disease effects. In 110 subjects scanned longitudinally at both 3.0 and 1.5 T, including 24 patients with Alzheimer's Disease (AD) [74.8 ± 9.2 years, MMSE: 22.6 ± 2.0 at baseline], 51 individuals with mild cognitive impairment (MCI) [74.1 ± 8.0 years, MMSE: 26.6 ± 2.0], and 35 controls [75.9 ± 4.6 years, MMSE: 29.3 ± 0.8], we assessed whether higher‐field MR imaging offers higher or lower power to detect longitudinal changes in the brain, using tensor‐based morphometry (TBM) to reveal the location of progressive atrophy. As expected, at both field strengths, progressive atrophy was widespread in AD and more spatially restricted in MCI. Power analysis revealed that, to detect a 25% slowing of atrophy (with 80% power), 37 AD and 108 MCI subjects would be needed at 1.5 T versus 49 AD and 166 MCI subjects at 3 T; however, the increased power at 1.5 T was not statistically significant (α = 0.05) either for TBM, or for SIENA, a related method for computing volume loss rates. Analysis of cumulative distribution functions and false discovery rates showed that, at both field strengths, temporal lobe atrophy rates were correlated with interval decline in Alzheimer's Disease Assessment Scale‐cognitive subscale (ADAS‐cog), mini‐mental status exam (MMSE), and Clinical Dementia Rating sum‐of‐boxes (CDR‐SB) scores. Overall, 1.5 and 3 T scans did not significantly differ in their power to detect neurodegenerative changes over a year. Hum Brain Mapp, 2010. © 2009 Wiley‐Liss, Inc.     

Brief informant screening test for mild cognitive impairment and early Alzheimer's disease

BACKGROUND/AIMS: Recent research has attempted combinations of instruments to improve screening accuracy for mild cognitive impairment (MCI) and early Alzheimer's disease (AD). We compared Mini-Mental State Examination (MMSE), Immediate and Delayed Recall (Logical Memory I and II; LM-I and LM-II, respectively), a single-item informant report of memory problem (IRMP), and a four-item Instrumental Activities of Daily Living (4IADL) scale, and combinations of these tests. METHOD: The tests were administered together with Clinical Dementia Rating (CDR) to subjects who were cognitively intact (CDR = 0, n = 88), and with diagnoses of MCI (CDR = 0.5, n = 37) and early AD (CDR = 1-2, n = 19). RESULTS: Screening accuracy (receiver operating characteristic area under curve, AUC) for identifying MCI or MCI-AD was lowest for MMSE (AUC 67.6% for MCI or 77.9% for MCI-AD), and better for IRMP (79.5 or 83.2%), 4IADL (76.9 or 84.7%), LM-I (81.2 or 87.1%) and LM-II (86.1 or 90.8%). Combining IRMP, 4IADL and LM-II was most accurate (AUC 91.7% for MCI or 94.5% for MCI-AD); sensitivity: 86.5 or 89.3%; specificity: 86.4 or 88.6%. However, combining IRMP and 4IADL gave nearly as good accuracy (AUC 87.2 or 91.6%); sensitivity: 86.5 or 85.7%; specificity: 79.5 or 85.2%. CONCLUSION: A brief instrument combining an IRMP and 4IADL items is potentially useful in screening for MCI and early AD.     

Identification of high‐risk dementia cohorts in a community sample of Japanese elderly

Aim: The aim of this study was to develop a simple diagnostic procedure for subjects at high risk of developing dementia using the Clinical Dementia Rating (CDR), which is applicable to community‐based activities. Methods: This study divided 252 community‐dwelling elderly with a CDR score of 0.5 into two groups based on the presence or absence of cognitive decline within the previous one year of the baseline, as assessed by a semi‐structured interview. One hundred subjects were in the ‘previously progressive group’ (PP group) and 152 subjects were in the ‘previously stable group’ (PS group). After 6 years of observation, a total of 111 subjects were assessed in the follow‐up investigation. Results: Among the 39 subjects from the PP group (82.9 ± 6.8 years old, 11 male, 28 female), 34 developed dementia (87%). Among the 72 subjects from the PS group (84.4 ± 6.0 years old, 22 male, 50 female), 44 developed dementia (61%). The relative risk of developing dementia for the PP group versus the PS group was 1.43. The rate of conversion to dementia was 12.9% per 100 person‐years in the PP group, and 9.8% in the PS group. In the PP group, the Mini‐Mental State Examination score was significantly lower and the CDR score was significantly higher than in the PS group. Conclusion: Although there have been many attempts to identify subjects with high risk of dementia, this preliminary study suggests that information about temporal changes in cognitive function is useful when performing community‐based surveys.     

Evolution of cognitive deficits and conversion to dementia in patients with mild cognitive impairment: a very-long-term follow-up study

Ten patients with mild cognitive impairment (MCI) underwent extensive neuropsychological evaluation at 12-monthly intervals for a minimum of 6 years. All 10 patients declined and 5 have now died. The onset of dementia, as defined by a fall in global cognitive function (MMSE <24) or activities of daily living (Clinical Dementia Rating Scale; CDR) ranged from 1 to 8 years with generally good concordance between these measures. The rate of decline on the MMSE was highly variable ranging from 0.86 to 2.83 points per year. Other than a consistent impairment on tests of episodic memory and category fluency (8 out of 10), other early cognitive deficits were difficult to define and tended to be unstable in the early stages. Impairment of semantic memory, visuo-spatial and attentional abilities eventually developed but the sequence of deficit acquisition was heterogeneous. These findings are discussed in the light of current views of MCI. Amnestic MCI may not be an accurate concept unless semantic memory impairment is also considered as an integral core deficit. Full-blown dementia may take many years to develop in patients with MCI but was a universal feature in this study.     

Mild cognitive impairment represents early-stage Alzheimer disease

BACKGROUND: Mild cognitive impairment (MCI) is considered to be a transitional stage between aging and Alzheimer disease (AD). OBJECTIVE: To determine whether MCI represents early-stage AD by examining its natural history and neuropathologic basis. DESIGN: A prospective clinical and psychometric study of community-living elderly volunteers, both nondemented and minimally cognitively impaired, followed up for up to 9.5 years. Neuropathologic examinations were performed on participants who had undergone autopsy. SETTING: An AD research center. PARTICIPANTS: All participants enrolled between July 1990 and June 1997 with Clinical Dementia Rating (CDR) scores of 0 (cognitively healthy; n = 177; mean age, 78.9 years) or 0.5 (equivalent to MCI; n = 277; mean age, 76.9 years). Based on the degree of clinical confidence that MCI represented dementia of the Alzheimer type (DAT), 3 subgroups of individuals with CDR scores of 0.5 were identified: CDR 0.5/DAT, CDR 0.5/incipient DAT, and CDR 0.5/uncertain dementia. MAIN OUTCOME MEASURE: Progression to the stage of CDR 1, which characterizes mild definite DAT. RESULTS: Survival analysis showed that 100% of CDR 0.5/DAT participants progressed to greater dementia severity over a 9.5-year period. At 5 years, rates of progression to a score of CDR 1 (or greater) for DAT were 60.5% (95% confidence interval [CI], 50.2%-70.8%) for the CDR 0.5/DAT group, 35.7% (95% CI, 21.0%-50.3%) for the CDR 0.5/incipient DAT group, 19.9% (95% CI, 8.0%-31.8%) for the CDR 0.5/uncertain dementia group, and 6.8% (95% CI, 2.2%-11.3%) for CDR 0/controls. Progression to greater dementia severity correlated with degree of cognitive impairment at baseline. Twenty-four of the 25 participants with scores of CDR 0.5 had a neuropathologic dementing disorder, which was AD in 21 (84%). CONCLUSIONS: Individuals currently characterized as having MCI progress steadily to greater stages of dementia severity at rates dependent on the level of cognitive impairment at entry and they almost always have the neuropathologic features of AD. We conclude that MCI generally represents early-stage AD.     

PDD‐Short Screen: A brief cognitive test for screening dementia in Parkinson's disease

The diagnosis of Parkinson's disease with dementia (PDD) is currently based on clinical criteria (DSM‐IV, MDS–Task Force). In daily practice and research studies, these criteria still depend on the subjective impression of the examiner. Brief screening tests (BST) are helpful in identifying patients with PD with dementia, which can be difficult in patients with advanced PD. We aimed to develop a BST for PD, the PDD‐Short Screen (PDD‐SS), to accurately and quickly screen for PDD. In this prospective study, 70 patients with nondemented (age 73.8 ± 4.4) and 32 demented (age 73.8 ± 4.4) PD regularly attending a Movement Disorders Clinic were included. Diagnosis of dementia was based on DSM‐IV criteria, CDR score ≥1, and PD‐CRS total score ≤64. The PDD‐SS, Mattis Dementia Rating Scale (MDRS), and Mini‐Mental State Examination (MMSE) were administered to all participants. Validity, reliability, and discriminative power of the PDD‐SS were examined. The final version of the scale included the items immediate and delayed verbal memory, clock drawing, alternating verbal fluency, and a questionnaire covering cognitive and psychiatric (hallucinations, apathy) symptoms common in PDD. A cutoff score ≤11 on the PDD‐SS yielded high sensitivity (89.8%) and specificity (88.5%) for diagnosing PDD. The MDRS displayed similar accuracy, but the PDD‐SS administration time was significantly shorter (4.8–6.9 vs. 17.5–25.2 minutes). Diagnosis of dementia using the PDD‐SS was not influenced by age, education, or motor function. The PDD‐SS appears as the first BST for diagnosing PDD, displays an excellent diagnostic accuracy, and takes 5 to 7 minutes to be administered. © 2010 Movement Disorder Society