Victor Whitehead

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.

Validity of a novel computerized cognitive battery for mild cognitive impairment.

BackgroundThe NeuroTrax Mindstreams computerized cognitive assessment system was designed for widespread clinical and research use in detecting mild cognitive impairment (MCI). However, the capability of Mindstreams tests to discriminate elderly with MCI from those who are cognitively healthy has yet to be evaluated. Moreover, the comparability between these tests and traditional neuropsychological tests in detecting MCI has not been examined.MethodsA 2-center study was designed to assess discriminant validity of tests in the Mindstreams Mild Impairment Battery. Participants were 30 individuals diagnosed with MCI, 29 with mild Alzheimers disease (AD), and 39 healthy elderly. Testing was with the Mindstreams battery and traditional neuropsychological tests. Receiver operating characteristic (ROC) analysis was used to examine the ability of Mindstreams and traditional measures to discriminate those with MCI from cognitively healthy elderly. Between-group comparisons were made (Mann-Whitney U test) between MCI and healthy elderly and between MCI and mild AD groups.ResultsMindstreams outcome parameters across multiple cognitive domains significantly discriminated among MCI and healthy elderly with considerable effect sizes (p < 0.05). Measures of memory, executive function, visual spatial skills, and verbal fluency discriminated best, and discriminability was at least comparable to that of traditional neuropsychological tests in these domains.ConclusionsMindstreams tests are effective in detecting MCI, providing a comprehensive profile of cognitive function. Further, the enhanced precision and ease of use of these computerized tests make the NeuroTrax system a valuable clinical tool in the identification of elderly at high risk for dementia.

Multilingualism (But Not Always Bilingualism) Delays the Onset of Alzheimer Disease: Evidence From a Bilingual Community

A recent paper by Bialystok et al in Neuropsychologia (vol. 45, pgs. 459 to 464) suggested that early bilingualism produced a statistically significant 4.1-year delay in onset of memory loss symptoms in older individuals with Alzheimer disease, possibly reflecting an increase in the cognitive reserve of these individuals. That study focused on multilingual elderly patients of whom 90% were immigrants. Our memory clinic, in Montreal Canada, has the advantage of having a large set of individuals who are either multilingual immigrants to Canada, or who are nonimmigrants but raised in both official languages of Canada—French and English. We thus attempted to replicate the above findings using a larger cohort in a different setting. We examined age at diagnosis of Alzheimer disease and age at symptom onset for all unilingual versus multilingual participants, and then for those who were nonimmigrant English/French bilinguals. Overall, we found a small but significant protective effect of more than 2 languages spoken, but we found no significant benefit in bilinguals overall in relation to age at diagnosis or age at symptom onset. However, in the immigrant group, the results mirrored those of Bialystok et al with 2 or more languages delaying the diagnosis of Alzheimer disease by almost 5 years. A trend toward the same effect was also seen in nonimmigrants whose first language was French. In contrast, in nonimmigrants whose first language was English, no such effect was found. These results are discussed in relation to the earlier findings and the theory of cognitive reserve.

Validity of the Mindstreams Computerized Cognitive Battery for Mild Cognitive Impairment

This article, published as an invited review in the special ISOA issue of the journal, was first published as an original article in BMC Geriatrics: Dwolatzky T, Whitehead V, Doniger GM, Simon ES, Schweiger A, Jaffe D, Chertkow H. Validity of a novel computerized cognitive battery for mild cognitive impairment. BMC Geriatrics, 3, 4–16, 2003. J Mol Neurosci (2008) 35:251 DOI 10.1007/s12031-007-9031-9

The spectrum of category effects in object and action knowledge in dementia of the Alzheimer's type.

The validity and origin of category effects in the anomia demonstrated by individuals with dementia of the Alzheimers type (DAT) remains controversial. Twenty DAT subjects were tested with picture naming and semantic association judgment tests. Picture and word stimuli were drawn from biological, nonbiological, and actions-verbs categories, all of equal difficulty and previously normed on elderly controls. DAT subjects made significantly more naming and semantic judgment errors in the biological category than in the nonbiological category. They were relatively more accurate in naming and making judgments for actions-verbs when presented as words or as 5-s animations. When line drawings of actions were shown for naming, performance deteriorated significantly. Converging results from these 2 tasks provide strong evidence for a semantic memory impairment preferentially affecting biological items to a greater extent than nonbiological items or action verbs in DAT.

Can an 18-point clock-drawing scoring system predict dementia in elderly individuals with mild cognitive impairment?

The purpose of this study was to develop a clock-drawing scoring system better suited to detecting possible early markers of dementia in individuals with mild cognitive impairment (MCI). We modified the scoring system of Freedman et al. (1994), in which the major components are integrity of the circle, placement and size of the hands, and placement and sequence of the numbers. We rescored the clock-drawing test using a novel 18-point scoring system, which emphasizes hand elements—number of hands, direction indicated, and size differences. We retrospectively assessed 123 individuals (ages 58–88 years) selected from the Memory Clinic at the Jewish General Hospital in Montreal. These consisted of 21 normal elderly individuals (NORM group), 41 participants with mild cognitive impairment who did not develop dementia on follow-up visits (MCI-NP), 41 participants with mild cognitive impairment who became demented after a 48-month follow-up (MCI-D), and 20 participants diagnosed with Alzheimers disease (AD). On the 18-point system, the MCI-NP and the MCI-D did not show any difference on overall total score (p = .166), However, using Pearson chi-squares to examine the within-categories effects comparing the mildly cognitively impaired groups (MCI-NP and MCI-D), there were three significant hand items that appear to be possible early markers of progression to dementia. The clock has two hands (p = .043), hour hand is towards correct number (p = .023), and size difference of the hands is respected (p = .004), all showed significant differences between progressors and nonprogressors. The 18-point clock-drawing scoring system may have advantages in better indicating MCI individuals more likely to progress to dementia.

A predictive depression pattern in mild cognitive impairment.

To evaluate the prognostic utility of the presence, persistence, and patterns of depression in subjects with amnestic Mild Cognitive Impairment (MCI).

HM-PAO (CERETEC) SPECT brain scanning in the diagnosis of Alzheimer's disease

OBJECTIVE: To evaluate the accuracy of Single Photon Emission Computed Tomography (SPECT) scanning in the diagnosis of Alzheimers Disease (AD) and its capacity to improve the diagnostic accuracy of conventional clinical evaluation.

Cognitive Predictors of Donepezil Therapy Response in Alzheimer Disease

Objectives: To examine whether the presence of domain-specific cognitive impairments would predict a response to donepezil medication in patients with mild-to-moderate Alzheimer disease (AD). Methods: The protocol was an open-label study of 30 AD subjects (mean age 74 years; education 11 years; Mini-Mental State Exam (MMSE) 23 of 30) beginning a 6-month course of treatment with donepezil. Global response to treatment was determined using a combination algorithm based on changes over 6 months in the ADAS-cog, MMSE and CIBIC. In addition, a set of neuropsychological and experimental cognitive tests designed to test five domains of cognition were administered before beginning therapy in order to determine which domain of testing would be predictive to response to treatment. The tests examined attention, short-term and working memory, learning and memory, visuo-spatial motor skills, and lexical-semantic knowledge. Results: Eighteen of the thirty subjects were rated as having responded (stable or improved scores on the combination algorithm) to the therapy. Responders were significantly less impaired prior to treatment on the following tests: the Clock Drawing Test, a Visual-Spatial Motor Tracking Test, and the Boston Picture Naming Test. No significant initial group differences were noted on the other neuropsychological or experimental cognitive measures. Conclusion: The tests that most reliably predicted response to donepezil in AD subjects were in the domains of visual-spatial motor abilities and lexical-semantic functioning.

Effects of anosognosia on perceived stress and cortisol levels in Alzheimer's disease.

Anosognosia, or unawareness of ones own cognitive deficits, may cause issues when measuring perceived stress and cortisol levels in Alzheimers disease (AD) and Mild Cognitive Impairment (MCI). The goal of this study was to examine the effects of anosognosia on perceived stress and salivary cortisol levels in normal elderly (NE) adults, MCI individuals, newly diagnosed AD patients, and long-lasting AD patients, suspected to show more anosognosia. An anosognosia index for perceived stress was computed by subtracting the score on the Perceived Stress Scale measured in the participants and their relative. Cortisol levels were measured four times a day over two nonconsecutive days. Greater anosognosia for dementia correlated with greater anosognosia for perceived stress in the group as a whole. However, no correlation between cortisol levels and either anosognosia for dementia or perceived stress was observed. Our results suggest that measuring perceived stress in AD patients may be influenced by anosognosia.