An audit of the Addenbrooke's Cognitive Examination (ACE) in clinical practice

Prevalence and Factors Associated with Subjective Memory Complaint in a Semi-Rural Community in Chile

BACKGROUND

Subjective memory complaints (SMC) are commonly studied in older adults and have been identified as potentially prodromal to dementia and Alzheimer's disease. Studies among younger adults from South America are lacking.

OBJECTIVE

To estimate the prevalence of SMC and the factors associated with it among Maule Cohort (MAUCO) participants.

METHODS

We performed a cross-sectional analysis to estimate the prevalence of SMC and investigated its associated factors from MAUCO baseline data (N = 6,687). Within groups defined by age (38-59, 60-74) and global cognition (Mini-Mental State Examination: ≥26, 25-22, ≤21), multinomial logistic regression models evaluated risk factors for SMC (Yes, Sometimes, No).

RESULTS

Overall, SMC prevalence was 16.4%; 15.9% (95% CI 14.9-16.9%) among younger and 17.6% (15.8-19.4%) among older participants. Female sex, comorbidities, and bad/fair self-reported health status (SRHS) were generally associated with higher odds of SMC.

CONCLUSION

Overall prevalence of SMC was 16%. Different factors were associated with the odds of SMC depending on age and global cognitive status. Future SMC studies should include sex-specific assessments, evaluate SRHS as a moderator of SMC reporting, and the influence of the SARS-CoV-2 pandemic on SMC reporting.

The revised Addenbrooke's Cognitive Examination can facilitate differentiation of dementia with Lewy bodies from Alzheimer's disease

OBJECTIVES

Dementia with Lewy bodies (DLB) is a major cause of degenerative dementia, yet the diagnosis is often missed or mistaken for Alzheimer's disease (AD). We assessed whether the revised Addenbrooke's Cognitive Examination (ACE-R), a brief test for dementia, differentiates DLB from AD.

METHODS

We first compared baseline ACE-R performance in 76 individuals with DLB, 40 individuals with AD and 66 healthy controls. We then investigated the diagnostic accuracy of a simple standardised 'memory/visuospatial' ratio calculated from the ACE-R subscores. Finally, as a comparison a logistic regression machine learning algorithm was trained to classify between DLB and AD.

RESULTS

Individuals with AD had poorer memory (p = 0.001) and individuals with DLB had poorer visuospatial function (p = 0.005). Receiver operating characteristics curves confirmed that the ACE-R total score could differentiate dementia from non-dementia cases with 98% accuracy, but could not discriminate between dementia types (50%, or chance-level accuracy). However, a 'memory/visuospatial' ratio ≥1.1 differentiated DLB from AD with 82% sensitivity, 68% specificity and 77% mean accuracy. The machine learning classifier did not improve the overall diagnostic accuracy (74%) of the simple ACE-R subscores ratio.

CONCLUSIONS

The ACE-R-based 'memory/visuospatial' ratio, but not total score, demonstrates good clinical utility for the differential diagnosis of DLB from AD.

Mini-Mental State Examination (MMSE) for the detection of dementia in clinically unevaluated people aged 65 and over in community and primary care populations

BACKGROUND

The Mini Mental State Examination (MMSE) is a cognitive test that is commonly used as part of the evaluation for possible dementia.

OBJECTIVES

To determine the diagnostic accuracy of the Mini-Mental State Examination (MMSE) at various cut points for dementia in people aged 65 years and over in community and primary care settings who had not undergone prior testing for dementia.

SEARCH METHODS

We searched the specialised register of the Cochrane Dementia and Cognitive Improvement Group, MEDLINE (OvidSP), EMBASE (OvidSP), PsycINFO (OvidSP), LILACS (BIREME), ALOIS, BIOSIS previews (Thomson Reuters Web of Science), and Web of Science Core Collection, including the Science Citation Index and the Conference Proceedings Citation Index (Thomson Reuters Web of Science). We also searched specialised sources of diagnostic test accuracy studies and reviews: MEDION (Universities of Maastricht and Leuven, www.mediondatabase.nl), DARE (Database of Abstracts of Reviews of Effects, via the Cochrane Library), HTA Database (Health Technology Assessment Database, via the Cochrane Library), and ARIF (University of Birmingham, UK, www.arif.bham.ac.uk). We attempted to locate possibly relevant but unpublished data by contacting researchers in this field. We first performed the searches in November 2012 and then fully updated them in May 2014. We did not apply any language or date restrictions to the electronic searches, and we did not use any methodological filters as a method to restrict the search overall.

SELECTION CRITERIA

We included studies that compared the 11-item (maximum score 30) MMSE test (at any cut point) in people who had not undergone prior testing versus a commonly accepted clinical reference standard for all-cause dementia and subtypes (Alzheimer disease dementia, Lewy body dementia, vascular dementia, frontotemporal dementia). Clinical diagnosis included all-cause (unspecified) dementia, as defined by any version of the Diagnostic and Statistical Manual of Mental Disorders (DSM); International Classification of Diseases (ICD) and the Clinical Dementia Rating.

DATA COLLECTION AND ANALYSIS

At least three authors screened all citations.Two authors handled data extraction and quality assessment. We performed meta-analysis using the hierarchical summary receiver-operator curves (HSROC) method and the bivariate method.

MAIN RESULTS

We retrieved 24,310 citations after removal of duplicates. We reviewed the full text of 317 full-text articles and finally included 70 records, referring to 48 studies, in our synthesis. We were able to perform meta-analysis on 28 studies in the community setting (44 articles) and on 6 studies in primary care (8 articles), but we could not extract usable 2 x 2 data for the remaining 14 community studies, which we did not include in the meta-analysis. All of the studies in the community were in asymptomatic people, whereas two of the six studies in primary care were conducted in people who had symptoms of possible dementia. We judged two studies to be at high risk of bias in the patient selection domain, three studies to be at high risk of bias in the index test domain and nine studies to be at high risk of bias regarding flow and timing. We assessed most studies as being applicable to the review question though we had concerns about selection of participants in six studies and target condition in one study.The accuracy of the MMSE for diagnosing dementia was reported at 18 cut points in the community (MMSE score 10, 14-30 inclusive) and 10 cut points in primary care (MMSE score 17-26 inclusive). The total number of participants in studies included in the meta-analyses ranged from 37 to 2727, median 314 (interquartile range (IQR) 160 to 647). In the community, the pooled accuracy at a cut point of 24 (15 studies) was sensitivity 0.85 (95% confidence interval (CI) 0.74 to 0.92), specificity 0.90 (95% CI 0.82 to 0.95); at a cut point of 25 (10 studies), sensitivity 0.87 (95% CI 0.78 to 0.93), specificity 0.82 (95% CI 0.65 to 0.92); and in seven studies that adjusted accuracy estimates for level of education, sensitivity 0.97 (95% CI 0.83 to 1.00), specificity 0.70 (95% CI 0.50 to 0.85). There was insufficient data to evaluate the accuracy of the MMSE for diagnosing dementia subtypes.We could not estimate summary diagnostic accuracy in primary care due to insufficient data.

AUTHORS' CONCLUSIONS

The MMSE contributes to a diagnosis of dementia in low prevalence settings, but should not be used in isolation to confirm or exclude disease. We recommend that future work evaluates the diagnostic accuracy of tests in the context of the diagnostic pathway experienced by the patient and that investigators report how undergoing the MMSE changes patient-relevant outcomes.

The Addenbrooke's Cognitive Examination Revised (ACE-R) and its sub-scores: normative values in an Italian population sample

The Addenbrooke's Cognitive Examination Revised (ACE-R) is a rapid screening battery, including five sub-scales to explore different cognitive domains: attention/orientation, memory, fluency, language and visuospatial. ACE-R is considered useful in discriminating cognitively normal subjects from patients with mild dementia. The aim of present study was to provide normative values for ACE-R total score and sub-scale scores in a large sample of Italian healthy subjects. Five hundred twenty-six Italian healthy subjects (282 women and 246 men) of different ages (age range 20-93 years) and educational level (from primary school to university) underwent ACE-R and Montreal Cognitive Assessment (MoCA). Multiple linear regression analysis revealed that age and education significantly influenced performance on ACE-R total score and sub-scale scores. A significant effect of gender was found only in sub-scale attention/orientation. From the derived linear equation, a correction grid for raw scores was built. Inferential cut-offs score were estimated using a non-parametric technique and equivalent scores (ES) were computed. Correlation analysis showed a good significant correlation between ACE-R adjusted scores with MoCA adjusted scores (r = 0.612, p < 0.001). The present study provided normative data for the ACE-R in an Italian population useful for both clinical and research purposes.

The use of the Addenbrooke's Cognitive Examination in a community memory clinic

Early diagnosis of dementia enables early intervention and gives people the opportunity to make choices and plan for their future. Such an early diagnosis requires accurate assessment. A clinical assessment in people with suspected dementia in a memory clinic setting should include a clinical interview of the patient and their next of kin, a physical and neurological examination, cognitive assessment with appropriate cognitive tests, blood investigations, ECG (electrocardiography), and brain imaging.

Addenbrooke's Cognitive Examination-Revised is accurate for detecting dementia in Parkinson's disease patients with low educational level

Diagnosis of Parkinson's disease dementia is a challenge in clinical settings. A comprehensive neuropsychological evaluation is time-consuming and expensive; brief instruments for cognitive evaluation must be easier to administer and provide a reliable classification.

OBJECTIVE

To study the validity of the Brazilian version of Addenbrooke's Cognitive Examination-Revised (ACE-R) for the cognitive assessment of Parkinson's disease (PD) patients with heterogeneous educational level.

METHODS

Patients were evaluated according to the diagnostic procedures recommended by the Movement Disorder Society (MDS) as the gold standard for the diagnosis of dementia in PD.

RESULTS

We studied 70 idiopathic PD patients, with a mean (SD) age of 64.1 (9.3) years and mean disease duration of 7.7 (5.3) years and educational level of 5.9 years, matched for education and age to controls. Twenty-seven patients fulfilled MDS clinical criteria for PD dementia. Mean scores on the ACE-R were 54.7 (12.8) points for patients with PD dementia, 76 (9.9) for PD patients without dementia and 79.7 (1.8) points for healthy controls. The area under the receiver operating curve, taking the MDS diagnostic procedures as a reference, was 0.93 [95% CI, 0.87-0.98; p<0.001] for ACE-R. The optimal cut-off value for ACE-R was ≤72 points [sensitivity 90%; specificity 85%; Kappa concordance (K) 0.79].

CONCLUSION

ACE-R appears to be a valid tool for dementia evaluation in PD patients with heterogeneous educational level, displaying good correlation with clinical criteria and diagnostic procedures of the MDS.

Utility and limitations of Addenbrooke's Cognitive Examination-Revised for detecting mild cognitive impairment in Parkinson's disease

BACKGROUND/AIMS

To evaluate the utility of the Addenbrooke's Cognitive Examination-Revised (ACE-R) as a screening tool for mild cognitive impairment in Parkinson's disease (PD-MCI).

METHODS

PD patients underwent comprehensive neuropsychological and neurological evaluations and ACE-R assessment.

RESULTS

The ACE-R was superior to the Mini-Mental State Exam (MMSE) in detecting PD-MCI, with a cutoff score of ≤93 offering a sensitivity of 61% and a specificity of 64%. The utility of the ACE-R in detecting PD-MCI is largely influenced by the fluency sub-domain score, and has optimal discriminability when utilized in patients with lower levels of education (≤12 years of formal schooling).

CONCLUSION

The ACE-R must be used cautiously as a screening tool for PD-MCI, with results being most influenced by its fluency sub-domain score and patient education levels.

The diagnostic accuracy of dementia-screening instruments with an administration time of 10 to 45 minutes for use in secondary care: a systematic review

Early screening for dementia is crucial for identifying reversible causes as well as managing, counseling, and other therapeutic interventions. Many reviews have compared the suitability of very brief screening instruments for use in primary care, but reviews on more extensive instruments in secondary care are scarce. In addition, results on diagnostic accuracy are often biased due to methodological shortcomings, differences in the spectrum of patients or reporting. This systematic review reports the diagnostic accuracy of dementia-screening instruments with an administration time of 10 to 45 minutes, validated in secondary care, restricted to mild dementia and validation studies of ''high quality.'' Characteristics such as cognitive domains and reliability figures are also highlighted.

Addenbrooke's Cognitive Examination validation in Parkinson's disease

BACKGROUND

There is a clear need for brief, sensitive and specific cognitive screening instruments in Parkinson's disease (PD).

OBJECTIVES

To study Addenbrooke's Cognitive Examination (ACE) validity for cognitive assessment of PD patient's using the Mattis Dementia Rating Scale (MDRS) as reference method. A specific scale for cognitive evaluation in PD, in this instance the Scales for Outcomes of Parkinson's disease-Cognition (SCOPA-COG), as well as a general use scale the Mini-mental state examination (MMSE) were also studied for further correlation.

METHODS

Forty-four PD patients were studied, of these 27 were males (61%), with a mean (SD) age of 69.5 (11.8) years, mean (SD) disease duration of 7.6 (6.4) years (range 1-25), mean (SD) total Unified Parkinson's Disease Rating Scale (UPDRS) score 37 (24) points, UPDRS III 16.5 (11.3) points. MDRS, ACE and SCOPA-COG scales were administered in random order. All patients remained in on-state during the study.

RESULTS

Addenbrooke's Cognitive Examination correlated with SCOPA-COG (r = 0.93, P < 0.0001), and MDRS (r = 0.91 P < 0.0001) and also with MMSE (r = 0.84, P < 0.001). Area under the receiver-operating curve, taking MDRS as the reference test, was 0.97 [95% confidence interval (CI): 0.92-1.00] for ACE, 0.92 (95% CI: 0.83-1.00) for SCOPA-COG and 0.91 (95% CI: 0.83-1.00) for MMSE. Best cut-off value for ACE was 83 points [Sensitivity (Se) = 92%; Specificity (Sp) = 91%; Kappa concordance (K) = 0.79], 20 points for the SCOPA-COG (Se = 92%; Sp = 87%; K = 0.74) and 26 points for MMSE (Se = 61%; Sp = 100%; K = 0.69).

CONCLUSION

Addenbrooke's Cognitive Examination appears to be a valid tool for dementia evaluation in PD, with a cut-off point which should probably be set at 83 points, displaying good correlation with both the scale specifically designed for cognitive deficits in PD namely SCOPA-COG, as well as with less specific tests such as MMSE.

Differentiation of semantic dementia and Alzheimer's disease using the Addenbrooke's Cognitive Examination (ACE)

BACKGROUND

The Addenbrooke's Cognitive Examination (ACE) is a simple diagnostic tool bridging the gap between the very brief Mini Mental State Exam (MMSE) and much longer test batteries used by neuropsychologists which has proven extremely popular internationally.

OBJECTIVE

We aimed to assess the ability of the ACE to differentiate semantic dementia (SD) from Alzheimer's disease (AD).

METHODS

The ACE was administered to three groups: SD patients (n = 40) and two separate groups of AD patients (n = 40 in each), matched for overall ACE or MMSE score.

RESULTS

Significant differences were found between SD and both AD groups for the ACE sub-scores of naming, reading and orientation in time. Discriminant analysis (SD versus AD) led to the formulation of a 'semantic index' (naming plus reading minus scores for serial-7s, orientation in time and drawing). Application of the semantic index to the patient data found values of less than zero to be predictive of SD rather than AD with 88% sensitivity and 90% specificity. Validation analysis in an independent sample of 24 SD and AD patients proved even more favourable.

CONCLUSIONS

The overall ACE score is known to be a sensitive, and specific, indicator of early neurodegenerative dementia; this study shows that the ACE can also be used to detect SD through application of the semantic index.

The diagnosis of dementia: diagnostic accuracy of an instrument measuring activities of daily living in a clinic-based population

BACKGROUND/AIMS

Since widely accepted definitions of dementia encompass impairments in social and occupational, as well as cognitive, function, we investigated the diagnostic accuracy of Lawton and Brody's Instrumental Activities of Daily Living (IADL) Scale as an independent test for the diagnosis of dementia.

METHODS

The IADL Scale was administered to consecutive referrals to 2 memory clinics over a 2-year period, independent of other tests (interview, neuropsychology, imaging) which were used to establish diagnoses according to standard diagnostic criteria, and the results were compared.

RESULTS

In a cohort of 296 patients, 52% adjudged to have dementia, IADL Scale scores and subscores showed low sensitivity, specificity, and positive and negative predictive values for the diagnosis of dementia. The likelihood ratios, a measure of diagnostic gain, were generally small to unimportant, and diagnostic accuracy as measured by area under the receiver operating characteristic curve was no better than 0.75.

CONCLUSION

IADL Scale scores are not very helpful in making a diagnosis of dementia. More sensitive scales may be required to detect dementia-related functional decline, although it is also possible that dementia syndromes may be present in the absence of functional decline, challenging accepted definitions of dementia.

Transient global amnesia in the district general hospital

Cases of transient global amnesia (TGA) seen by one consultant neurologist over a 4-year period (2002-2005 inclusive) were identified. Of 10 possible cases, eight fulfilled suggested diagnostic criteria. Five cases were seen as ward consultations, three in outpatient clinics; seven were seen in district general hospitals. Six of the eight cases had already been seen by hospital physicians, whose working diagnoses included stroke/TIA and epilepsy. In some cases, this had resulted in inappropriate investigation, treatment and advice. Although rare, TGA is a diagnosis both hospital physicians and general practitioners need to be aware of in order to avoid potential pitfalls. The critical importance of collateral history in reaching the diagnosis is emphasised.

The Addenbrooke's Cognitive Examination Revised (ACE-R): a brief cognitive test battery for dementia screening

There is a clear need for brief, but sensitive and specific, cognitive screening instruments as evidenced by the popularity of the Addenbrooke's Cognitive Examination (ACE).

OBJECTIVES

We aimed to validate an improved revision (the ACE-R) which incorporates five sub-domain scores (orientation/attention, memory, verbal fluency, language and visuo-spatial).

METHODS

Standard tests for evaluating dementia screening tests were applied. A total of 241 subjects participated in this study (Alzheimer's disease=67, frontotemporal dementia=55, dementia of Lewy Bodies=20; mild cognitive impairment-MCI=36; controls=63).

RESULTS

Reliability of the ACE-R was very good (alpha coefficient=0.8). Correlation with the Clinical Dementia Scale was significant (r=-0.321, p<0.001). Two cut-offs were defined (88: sensitivity=0.94, specificity=0.89; 82: sensitivity=0.84, specificity=1.0). Likelihood ratios of dementia were generated for scores between 88 and 82: at a cut-off of 82 the likelihood of dementia is 100:1. A comparison of individual age and education matched groups of MCI, AD and controls placed the MCI group performance between controls and AD and revealed MCI patients to be impaired in areas other than memory (attention/orientation, verbal fluency and language).

CONCLUSIONS

The ACE-R accomplishes standards of a valid dementia screening test, sensitive to early cognitive dysfunction.

"Frontal variant Alzheimer's disease": a reappraisal

Two cases of clinically diagnosed sporadic Alzheimer's disease with early and prominent behavioural features (social disinhibition, emotional blunting, stereotyped verbal utterances) sufficient to prompt an initial diagnosis of frontotemporal dementia are presented. It is suggested that the term "frontal variant AD" be used for this clinically defined phenotype, which has also been described in cases of inherited AD associated with certain presenilin-1 gene mutations. This differs from previous usage of the term "frontal variant AD" to describe AD with predominant frontal lobe neuropathological change (although the clinical phenotype may reflect regional distribution of pathology), but parallels the clinical definition of visual agnosic, aphasic and apraxic presentations of AD. The proposed usage would also emphasise differential diagnosis.