Wee Shiong Lim

Utility of the clinical dementia rating in Asian populations.

Consistent with the worldwide demographic trend of population aging, dementia is expected to become a burgeoning public health problem in Asian populations. Thus, there is a pressing need for reliable and valid methods of dementia diagnosis and staging that are applicable in heterogeneous Asian populations. The Clinical Dementia Rating (CDR) is an informant-based global assessment scale with established reliability and validity that has been widely utilized as a severity-ranking scale in many studies of Asian populations. From a diagnostic standpoint, the CDR is congruent with the Diagnostic and Statistical Manual of Mental Disorders approach of dementia diagnosis. It exhibits excellent discriminatory ability in the very mild stages of dementia, a useful property that is germane to the surging interest in mild cognitive impairment and related concepts. Limitations of the CDR include its length of administration, reliance on clinical judgment and collateral source information, and relative insensitivity as a measure of change in interventional studies. Since the exercise of clinical judgment is inherent in scoring, CDR raters should be mindful of the influence of cultural factors on premorbid lifestyle, informant reliability and performance in certain CDR test items (especially those pertaining to the categories of judgment and problem solving, community, and home and hobbies). Thus, in future studies that involve the nascent use of the CDR in Asian populations, it is recommended that any transcultural adaptation of CDR items be described in detail and appropriate validation studies be carried out before adopting the CDR as a yardstick measure of assessment. The potential of adapted versions of the CDR in chronic care settings and advanced cases should be explored. An integrative approach, combining brief informant interview in conjunction with brief objective cognitive testing, could be a viable strategy for dementia screening in the clinical and research setting that warrants further evaluation in Asian populations.

Early-stage Alzheimer disease represents increased suicidal risk in relation to later stages.

The level of risk for suicide in individuals with Alzheimer disease (AD) generally is considered to be low. It is important to recognize, however, that suicide can occur in early-stage Alzheimer disease on the background of a distinct high-risk profile. The objective of this report is to describe the clinical profiles of individuals with very mild Alzheimer disease who either attempted or completed suicide. We describe two participants in a longitudinal study of early-stage Alzheimer disease who were in the ninth decade of life and had very mild Alzheimer disease. Consistent with earlier cases reported in the literature, both displayed the following high-risk phenotype predisposing to suicidal risk: male gender, highly educated professional, preserved insight, dysthymic symptoms that did not meet criteria for major depression and postdated the onset of cognitive decline, and suicidal ideation. Neuropathological examination confirmed histologic Alzheimer disease in both cases. These cases, taken together, emphasize the need for awareness that early-stage Alzheimer disease may present a unique suicidal risk compared with later stages.

Clinical dementia rating: experience of a multi-racial Asian population.

In this study, the authors describe how the Clinical Dementia Rating (CDR) scale fits into the overall evaluation process in an outpatient memory clinic. Based on a retrospective review of 329 patients attending the clinic from 1994 to 1999, the evidence for the validity of the Clinical Dementia Ratings overall ability to stage dementia severity is presented. The Clinical Dementia Rating showed convergent validity when compared against clinical features, mental status, and psychometric test scores, and DSM III-R measures of dementia severity, thus underscoring the trans-cultural feasibility of the Clinical Dementia Rating instrument. The Clinical Dementia Rating is also congruent with the DSM-IV approach of identifying dementia, and demonstrates better discriminatory ability in the milder dementia stages compared with DSM III-R. Future research should focus on addressing the limitations of the Clinical Dementia Rating in other social settings, advanced cases, as well as detecting clinically significant change.

Stage-Independent and Stage-Specific Phenotypic Differences between Vascular Dementia and Alzheimer’s Disease

Aims: We examined the effect of stratification by dementia severity on clinical and neuropsychological differences observed between vascular dementia (VaD) and Alzheimer’s disease (AD) to ascertain whether any observed phenotypic differences would differ between the early and late stages. Methods: The phenotypic features at presentation of 219 newly diagnosed VaD (n = 103) and AD (n = 116) patients were analyzed. All patients underwent clinical, neuropsychological and neuroimaging evaluation. Severity of dementia was staged using the Clinical Dementia Rating (CDR) scale. Results: VaD can be clinically distinguished from AD by criterion-related features that span across all stages of dementia. We also identified non-criterion-related features that differed according to dementia severity. In the CDR 0.5–1 stage, VaD patients demonstrated increased reading difficulty, loss of insight, apathy, and greater impairment in executive function compared with delayed and recognition memory. Unique distinguishing features for VaD in the CDR 2–3 stage included higher Geriatric Depression Scale scores, lower Barthel scores, gait apraxia and parkinsonism. Conclusions: Phenotypic differences between VaD and AD can be conceptualized as either criterion-related stage-independent features, or stage-specific features (comprising cognitive and neuropsychological elements in the mild stages, and physical, affective and functional components in the later stages).

Caregiver Burden: Looking Beyond the Unidimensional Total Score.

The Zarit Burden Interview allows caregiver burden to be interpreted from a total score. However, recent studies propose a multidimensional Zarit Burden Interview model. This study aims to determine the agreement between unidimensional (UD) and multidimensional (MD) classification of burden, and differences in predictors among identified groups. We studied 165 dyads of dementia patients and primary caregivers. Caregivers were dichotomized into low-burden and high-burden groups based upon: (1) UD score using quartile cutoffs; and (2) MD model via exploratory cluster analysis. We compared UD versus MD 2×2 classification of burden using &kgr; statistics. Caregivers not showing agreement by either definition were classified as “intermediate” burden. We performed binary logistic regression to ascertain differences in predictive factors. The 2 models showed moderate agreement (&kgr;=0.72, P<0.01), yielding 104 low, 20 intermediate (UD “low burden”/MD “high burden”), and 41 high-burden caregivers. Neuropsychiatric symptoms [odds ratio (OR)=1.27, P=0.003], coresidence (OR=6.32, P=0.040), and decreased caregiving hours (OR=0.99, P=0.018) were associated with intermediate burden, whereas neuropsychiatric symptoms (OR=1.21, P=0.001) and adult children caregivers (OR=2.80, P=0.055) were associated with high burden. Our results highlight the differences between UD and MD classification of caregiver burden. Future studies should explore the significance of the noncongruent intermediate group and its predictors.

A Combined Cognitive Stimulation and Physical Exercise Programme (MINDVital) in Early Dementia: Differential Effects on Single- and Dual-Task Gait Performance

Background: Gait disorders are common in early dementia, with particularly pronounced dual-task deficits, contributing to the increased fall risk and mobility decline associated with cognitive impairment. Objective: This study examines the effects of a combined cognitive stimulation and physical exercise programme (MINDVital) on gait performance under single- and dual-task conditions in older adults with mild dementia. Methods: Thirty-nine patients with early dementia participated in a multi-disciplinary rehabilitation programme comprising both physical exercise and cognitive stimulation. The programme was conducted in 8-week cycles with participants attending once weekly, and all participants completed 2 successive cycles. Cognitive, functional performance and behavioural symptoms were assessed at baseline and at the end of each 8-week cycle. Gait speed was examined under both single- (Timed Up and Go and 6-metre walk tests) and dual-task (animal category and serial counting) conditions. A random effects model was performed for the independent effect of MINDVital on the primary outcome variable of gait speed under dual-task conditions. Results: The mean age of patients enroled in the rehabilitation programme was 79 ± 6.2 years; 25 (64.1%) had a diagnosis of Alzheimers dementia, and 26 (66.7%) were receiving a cognitive enhancer therapy. There was a significant improvement in cognitive performance [random effects coefficient (standard error) = 0.90 (0.31), p = 0.003] and gait speed under both dual-task situations [animal category: random effects coefficient = 0.04 (0.02), p = 0.039; serial counting: random effects coefficient = 0.05 (0.02), p = 0.013], with reduced dual-task cost for gait speed [serial counting: random effects coefficient = -4.05 (2.35), p = 0.086] following successive MINDVital cycles. No significant improvement in single-task gait speed was observed. Improved cognitive performance over time was a significant determinant of changes in dual-task gait speed [random effects coefficients = 0.01 (0.005), p = 0.048, and 0.02 (0.005), p = 0.003 for category fluency and counting backwards, respectively]. Conclusion: A combined physical and cognitive rehabilitation programme leads to significant improvements in dual-task walking in early dementia, which may be contributed by improvement in cognitive performance, as single-task gait performance remained stable.

Contents Vol. 62, 2016

Clinical Section D. Aarsland, Stockholm J. Attems, Newcastle upon Tyne M. Burtscher, Innsbruck G. Del Giudice, Siena V.C. Emery, Guildford J.D. Erusalimsky, Cardiff L. Fontana, St. Louis, Mo. J.J. Goronzy, Stanford, Calif. U. Granacher, Potsdam K. Hauer, Heidelberg F. Kronenberg, Innsbruck T.F. Lue, San Francisco, Calif. A.B. Maier, Parkville, Vic. J. Olshansky, Chicago, Ill. A. Stuck, Bern T.M. Stulnig, Vienna J. Tao, Guangzhou D.C. Willcox, Ginowan D. Ziegler, Düsseldorf

Contents Vol. 26, 2008

S 6th International Conference on Frontotemporal Dementias September 3–5, 2008, Rotterdam, The Netherlands Guest Editors: van Swieten, J.C. (Rotterdam); Heutink, P. (Amsterdam); Scheltens, P. (Amsterdam)