Laura H. Lacritz

Normative data for the Montreal Cognitive Assessment (MoCA) in a population-based sample

Objective: To provide normative and descriptive data for the Montreal Cognitive Assessment (MoCA) in a large, ethnically diverse sample. Methods: The MoCA was administered to 2,653 ethnically diverse subjects as part of a population-based study of cardiovascular disease (mean age 50.30 years, range 18–85; Caucasian 34%, African American 52%, Hispanic 11%, other 2%). Normative data were generated by age and education. Pearson correlations and analysis of variance were used to examine relationship to demographic variables. Frequency of missed items was also reviewed. Results: Total scores were lower than previously published normative data (mean 23.4, SD 4.0), with 66% falling below the suggested cutoff (<26) for impairment. Most frequently missed items included the cube drawing (59%), delayed free recall (56%; <4/5 words), sentence repetition (55%), placement of clock hands (43%), abstraction items (40%), and verbal fluency (38%; <11 words in 1 minute). Normative data stratified by age and education were derived. Conclusion: These findings highlight the need for population-based norms for the MoCA and use of caution when applying established cut scores, particularly given the high failure rate on certain items. Demographic factors must be considered when interpreting this measure.

Staging Dementia Using Clinical Dementia Rating Scale Sum of Boxes Scores: A Texas Alzheimer's Research Consortium Study

BACKGROUND The Clinical Dementia Rating Scale Sum of Boxes (CDR-SOB) score is commonly used, although the utility regarding this score in staging dementia severity is not well established. OBJECTIVE To investigate the effectiveness of CDR-SOB scores in staging dementia severity compared with the global CDR score. DESIGN Retrospective study. SETTING Texas Alzheimers Research Consortium minimum data set cohort. PARTICIPANTS A total of 1577 participants (110 controls, 202 patients with mild cognitive impairment, and 1265 patients with probable Alzheimer disease) were available for analysis. MAIN OUTCOME MEASURES Receiver operating characteristic curves were generated from a derivation sample to determine optimal cutoff scores and ranges, which were then applied to the validation sample. RESULTS Optimal ranges of CDR-SOB scores corresponding to the global CDR scores were 0.5 to 4.0 for a global score of 0.5, 4.5 to 9.0 for a global score of 1.0, 9.5 to 15.5 for a global score of 2.0, and 16.0 to 18.0 for a global score of 3.0. When applied to the validation sample, kappa scores ranged from 0.86 to 0.94 (P < .001 for all), with 93.0% of the participants falling within the new staging categories. CONCLUSIONS The CDR-SOB score compares well with the global CDR score for dementia staging. Owing to the increased range of values, the CDR-SOB score offers several advantages over the global score, including increased utility in tracking changes within and between stages of dementia severity. Interpretive guidelines for CDR-SOB scores are provided.

A total score for the CERAD neuropsychological battery

Objective: To develop a total or composite score for the Consortium to Establish a Registry for Alzheimer’s Disease (CERAD) neuropsychological battery. Method: CERAD total scores were obtained by summing scores from the individual CERAD subtests (excluding the Mini-Mental State Examination [MMSE]) into a total composite (maximum score = 100). The method of tabulating the total score was constructed using normal controls (NCs; n = 424) and patients with AD (n = 835) from the CERAD registry database. The utility of the total score was further tested in independent samples of mild AD (n = 95), mild cognitive impairment (MCI; n = 60), and NC (n = 95) subjects. Results: The CERAD total score was highly accurate in differentiating NC and AD subjects in the CERAD registry. Age, gender, and education effects were observed, and demographic correction scores were derived through multiple regression analysis. Demographically corrected CERAD total scores showed excellent test-retest reliability across samples (r = 0.95) and were highly correlated with the MMSE (r = 0.89) and Clinical Dementia Rating Scale (r = −0.83) in mixed AD and NC samples and with the Blessed Dementia Rating Scale in an AD sample (r = −0.40). The CERAD total score was highly accurate in differentiating independent samples of NC, MCI, and AD subjects. Conclusion: Results provide support for the validity of a Consortium to Establish a Registry for Alzheimer’s Disease (CERAD) total score that can be used along with the normative data to provide an index of overall level of cognitive functioning from the CERAD neuropsychological battery.

Patterns of verbal memory performance in mild cognitive impairment, Alzheimer disease, and normal aging.

ObjectiveIndividuals with mild cognitive impairment (MCI) typically demonstrate memory loss that falls between normal aging (NA) and Alzheimer disease (AD), but little is known about the pattern of memory dysfunction in MCI. MethodTo explore this issue, California Verbal Learning Test (CVLT) performance was examined across groups of MCI, AD, and NA. ResultsMCI subjects displayed a pattern of deficits closely resembling that of AD, characterized by reduced learning, rapid forgetting, increased recency recall, elevated intrusion errors, and poor recognition discriminability with increased false-positives. MCI performance was significantly worse than that of controls and better than that of AD patients across memory indices. Although qualitative analysis of CVLT profiles may be useful in individual cases, discriminant function analysis revealed that delayed recall and total learning were the best aspects of learning/memory on the CVLT in differentiating MCI, AD, and NA. ConclusionsThese findings support the position that amnestic MCI represents an early point of decline on the continuum of AD that is different from normal aging.

Dyadic short forms of the Wechsler Adult Intelligence Scale-III.

Various short forms of the Wechsler Adult Intelligence Scale (WAIS)/WAIS-R have been developed to obtain estimates of overall intellectual level, although little research of WAIS-III short forms has been published to date. Full Scale IQ (FSIQ) estimates from four WAIS-III dyadic short forms were obtained by entering selected subtest scores from a mixed neurologic/psychiatric sample (n = 196) into regression equations. Results were cross validated on a second sample (n = 57). Within both samples, WAIS-III FSIQ scores were highly correlated (r = .90-.92, p < .001) with estimated FSIQ scores. Estimated FSIQ fell within 5 points of actual FSIQ in 49% to 74% of cross-validation cases and within 10 points of actual FSIQ in 81% to 93% of the sample. Comparable to findings from previous short-form investigations, actual and estimated FSIQ classification levels agreed in 46% to 67% of cases in the cross-validation sample. These dyadic WAIS-III forms appear appropriate for obtaining gross estimates of FSIQ in similar populations, although caution is recommended in interpreting estimated IQ scores.

Validation of the new interpretive guidelines for the clinical dementia rating scale sum of boxes score in the national Alzheimer's coordinating center database.

BACKGROUND It was recently demonstrated that the Clinical Dementia Rating scale Sum of Boxes (CDR-SB) score can be used to accurately stage severity of Alzheimer dementia and mild cognitive impairment (MCI). However, to our knowledge, the utility of those interpretive guidelines has not been cross-validated or applied to a heterogeneous sample of dementia cases. OBJECTIVE To cross-validate the staging guidelines proposed in a previous study using the National Alzheimers Coordinating Center (NACC) database. DESIGN The previously published cut scores were applied to the NACC sample and diagnostic accuracy estimates obtained. Next, analyses were restricted to NACC participants with a CDR global score (CDR-GS) of 0.5 and receiver operating characteristic curves generated to determine optimal CDR-SB cut scores for distinguishing MCI from very early dementia. SETTING The 2008 NACC uniform data set. PARTICIPANTS There were 12 462 participants (5115 controls; 2551 patients with MCI; 4796 patients with dementia, all etiologies) in the NACC data set used for the current analysis. Main Outcome Measure Accurate prediction of diagnoses (MCI or dementia) using the CDR-SB score. RESULTS The previously proposed CDR-SB ranges successfully classified the vast majority of patients across all impairment ranges with a kappa of 0.91 and 94% overall correct classification rate. Additionally, the CDR-SB score discriminated between patients diagnosed with MCI and dementia when CDR-GS was restricted to 0.5 (overall area under the curve = 0.83). CONCLUSIONS These findings cross-validate the previously published CDR-SB interpretative guidelines for staging dementia severity and extend those findings to a large heterogeneous sample of patients with dementia. Additionally, the CDR-SB scores distinguished MCI from dementia in patients with reasonable accuracy when CDR-GS was restricted to 0.5.

Cognitive functioning in individuals with "benign" essential tremor.

Essential tremor (ET) is the most common type of movement disorder, although its etiology and neurophysiological substrates remain unclear. While thought to be a benign condition, it has yet to be studied from a neuropsychological perspective. We examined the neurocognitive functioning of 13 nondemented subjects with severe ET, including aspects of memory, cognitive flexibility, and attention. Results revealed that 12/13 subjects demonstrated impairment on 1 or more cognitive measures in comparison with published normative data. The pattern of findings was suggestive of relative dysfunction of frontal-mediated processes not unlike that seen in Parkinsons disease. These deficits were found in subjects irrespective of the presence of cognitive complaints, depression, or the existence of other potential neurocognitive risk factors. These findings suggest that mild cognitive deficits are not uncommon in association with severe ET and may be related to subcortical systems.

Subscores of the FAB differentiate frontotemporal lobar degeneration from AD

Objective: To determine the clinical utility of the Frontal Assessment Battery (FAB), a short test of frontal lobe functions, in differentiating frontotemporal lobar degeneration (FTLD) from Alzheimer disease (AD). Methods: FAB total scores and subscores for 23 subjects with FTLD and 31 subjects with AD were compared for sensitivity, specificity, and positive predictive value. Concurrent validity of the FAB with the Mini-Mental State Examination (MMSE) and other scales was also assessed. Results: The FAB did not have positive predictive value for FTLD. Total FAB scores did not differ between the FTLD and AD groups. However, three subtests of the FAB (mental flexibility, motor programming, and environmental autonomy) demonstrated significant differences between the two groups. Total FAB scores correlated with scores on the MMSE, a more general test of cognition. Conclusion: The Frontal Assessment Battery did not discriminate subjects with frontotemporal lobar degeneration from those with Alzheimer disease, though certain subtests may be helpful in differential diagnosis.

Category fluency in mild cognitive impairment: reduced effect of practice in test-retest conditions.

Verbal fluency tests are commonly used in neurocognitive and mental status examinations in patients with suspected dementia. Inflation of test scores as a result of practice effects may yield false-negative results in test-retest and multidisciplinary settings, particularly among patients with mild cognitive deficits. To address this issue, animal naming was administered twice within a 1-week period to a group of individuals referred for suspected dementia who were ultimately diagnosed with mild cognitive impairment (MCI; amnestic form), probable Alzheimer disease (AD), or no dementia. A 2 × 3 repeated-measures analysis of variance revealed a statistically significant interaction between administration time and group. Post hoc analyses indicated that nondemented controls were the only group to demonstrate a significant practice effect, producing an average of approximately three more animal names at time two. Like patients with a diagnosis of AD, subjects with amnestic MCI failed to benefit from repeated exposure to the animal naming test, and only controls showed an average improvement upon retest. This underscores the cognitive similarity between individuals diagnosed with amnestic MCI and AD and suggests that improvement upon retest may be a diagnostically useful finding.

Comparison of the Hopkins Verbal Learning Test-Revised to the California Verbal Learning Test in Alzheimer's Disease

We examined the validity of the revised Hopkins Verbal Learning Test (HVLT-R) by comparing performances on the HVLT-R and the California Verbal Learning Test (CVLT) in participants with Alzheimers disease (AD). Total learning, delayed recall, intrusion errors, and recognition performance were significantly related across tests, but the number of perseverative responses showed no linear association. Despite similar results across measures, some of the variables were only modestly correlated, which may reflect differences in test procedures and the limited range of scores for some variables. Furthermore, the HVLT-R may not be challenging enough to elicit some of the types of recall errors commonly seen in AD to the same extent as the CVLT. Nonetheless, the HVLT-R shows promise for providing a multidimensional assessment of verbal learning and memory and may be ideal in cases where brief assessment of memory and/or serial evaluations are needed.