Baycrest Center

Toronto, Canada

Baycrest Center

Toronto, Canada

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Described here are systems and methods for estimating a quantitative measure of cerebrovascular reactivity (CVR) from data acquired using resting-state functional magnetic resonance imaging (fMRI).

Mariani M.,Sudbury Regional Hospital | Shammi P.,Baycrest Center
Clinical Neuropsychologist | Year: 2010

We present a case study of an individual diagnosed with isolated neurosarcoidosis, a rare granulomatous condition of unknown aetiology. Although the extant medical literature on this disease is adequate, no study has focused on the neuropsychological sequelae involved with such an inflammatory disorder. The case described herein is of a 57-year-old woman who participated in a neuropsychological evaluation following complaints of recurring cognitive difficulties. Results of the assessment revealed moderate difficulties in effortful word retrieval and recall of unstructured verbal information, as well as some mild mental rigidity, slowing, and subtle difficulties with attention. Her neuropsychological profile is discussed in terms of neuroanatomic lesion localization and clinical diagnostic implications.

Shatenstein B.,University of Montréal | Ferland G.,University of Montréal | Belleville S.,University of Montréal | Gray-Donald K.,McGill University | And 5 more authors.
Experimental Gerontology | Year: 2012

Background and objectives: A healthy diet may prevent cognitive decline either directly, or by decreasing risk of nutrition-related chronic diseases associated with cognitive decline. This study examined the relationships between diet quality (DQ) and cognition for over 3. years among 1488 older adults (52.6% female) from the NuAge study, aged 67 to 84. years at recruitment. Methods: Cognition was assessed at four annual visits using the modified mini-mental status examination (3MS); rate of cognitive decline was computed for each participant over the 3. years of follow-up using mixed model analyses and the individual-specific number of months between 3MS assessments. Dietary data were collected at recruitment using a validated 78-item, semi-quantitative food frequency questionnaire (FFQ). DQ was characterized as the Canadian Healthy Eating Index (C-HEI), a 9-component global DQ index (maximum score. =. 100) computed from the FFQ output. Other variables were collected by questionnaire or direct measurement. Multivariate analyses were carried out to assess the association of DQ controlled for confounders on cognition. Results: Total C-HEI was better in females (78.7. ±. 9.1 vs 75.7. ±. 9.4, p. <. .0001) as were C-HEI component subscores. Males, the less educated, smokers, those with poor social engagement, symptoms of depression, a higher waist:hip ratio and who reported financial insecurity had a poor quality diet that could contribute to chronic diseases associated with cognition. Along with functional autonomy, most of these variables emerged as covariates of baseline 3MS and predictors of cognitive decline. While certain C-HEI subscores and total C-HEI were positive univariate correlates of 3MS at recruitment, total DQ was not associated with cognition in multivariate analyses, either at baseline or over 3. years of follow-up. Conclusions: DQ was not independently associated with cognition. However, the study demonstrates relationships between diet quality and risk factors for chronic diseases associated with cognition. Consequently, older adults might benefit from a healthy diet to decrease risk of nutrition-related chronic diseases established as risk factors for cognitive decline. Further work in diverse older populations, use of dietary data collected earlier in life, finer cognitive measures and longer follow-up are necessary to better elucidate relationships between diet quality, chronic diseases and cognition. © 2012 Elsevier Inc.

Troyer A.K.,Baycrest Center | D'Souza N.A.,University of Toronto | D'Souza N.A.,McGill University | Vandermorris S.,Rotman Research Institute | And 2 more authors.
Aging, Neuropsychology, and Cognition | Year: 2011

Building on well-established findings of age-related decline in associative memory, we examined whether the magnitude of age differences depends on the types of associations that are formed. Specifically, because of predominant age-related changes in the hippocampus, we expected to find larger age differences in recognition of between-domain than within-domain associations. Twenty younger and 20 older healthy adults were given two associative recognition tests, using face-name and word-word pairs, that were matched for difficulty level. As hypothesized, a three-way interaction indicated that, relative to item recognition, age differences in associative recognition were greater for between-domain face-name associations than for within-domain word-word associations. This dissociation is consistent with the idea that the hippocampus plays a prominent role in binding information received from distal neocortical regions. The discussion focuses on the roles of recollection and familiarity in supporting associative memory as well as implications for the remediation of age-related memory decline. © 2011 Psychology Press.

Fujioka T.,Rotman Research Institute | Ween J.E.,Baycrest Center | Ween J.E.,Rockwood Deaconess Medical Center | Jamali S.,University of Toronto | And 3 more authors.
Annals of the New York Academy of Sciences | Year: 2012

Precise timing of sound is crucial in music for both performing and listening. Indeed, listening to rhythmic sound sequences activates not only the auditory system but also the sensorimotor system. Previously, we showed the significance of neural beta-band oscillations (15-30 Hz) for the timing processing that involves such auditory-motor coordination. Thus, we hypothesized that motor rehabilitation training incorporating music playing will stimulate and enhance auditory-motor interaction in stroke patients. We examined three chronic patients who received Music-Supported Therapy following the protocols practiced by Schneider. Neuromagnetic beta-band activity was remarkably alike during passive listening to a metronome and during finger tapping, with or without the metronome, for either the paretic or nonparetic hand, suggesting a shared mechanism of the beta modulation. In the listening task, the magnitude of the beta decrease after the tone onset was more pronounced at the posttraining time point and was accompanied by improved arm and hand skills. The present case data give insight into the neural underpinnings of rehabilitation with music making and rhythmic auditory stimulation. © 2012 New York Academy of Sciences.

Seitz D.,Baycrest Center | Seitz D.,Kunin Lunenfeld Applied Research Unit | Seitz D.,Womens College Research Institute | Purandare N.,Manchester Academic Health Science Center | Conn D.,Baycrest Center
International Psychogeriatrics | Year: 2010

Background: The population of older adults in long-term care (LTC) is expected to increase considerably in the near future. An understanding of the prevalence of psychiatric disorders in LTC will help in planning mental health services for this population. This study reviews the prevalence of common psychiatric disorders in LTC populations. Methods: We searched electronic databases for studies on the prevalence of major psychiatric disorders in LTC using medical subject headings and key words. We only included studies using validated measures for diagnosing psychiatric disorders or psychiatric symptoms. Our review focused on the following psychiatric disorders: dementia, behavioral and psychological symptoms of dementia (BPSD), major depression, depressive symptoms, bipolar disorder, anxiety disorders, schizophrenia, and alcohol use disorders. We also determined the prevalence of psychiatric disorders in the U.S. LTC population using data from the 2004 National Nursing Home Survey (NNHS). Results: A total of 74 studies examining the prevalence of psychiatric disorders and psychological symptoms in LTC populations were identified including 30 studies on the prevalence of dementia, 9 studies on behavioral symptoms in dementia, and 26 studies on depression. Most studies involved few LTC facilities and were conducted in developed countries. Dementia had a median prevalence (58%) in studies while the prevalence of BPSD was 78% among individuals with dementia. The median prevalence of major depressive disorder was 10% while the median prevalence of depressive symptoms was 29% among LTC residents. There were few studies on other psychiatric disorders. Results from the 2004 NNHS were consistent with those in the published literature. Conclusions: Dementia, depression and anxiety disorders are the most common psychiatric disorders among older adults in LTC. Many psychiatric disorders appear to be more prevalent in LTC settings when compared to those observed in community-dwelling older adults. Policy-makers and clinicians should be aware of the common psychiatric disorders in LTC and further research into effective prevention and treatments are required for this growing population. © 2010 International Psychogeriatric Association.

Clements-Cortes A.,Baycrest Center
Journal of Music, Technology and Education | Year: 2014

This study investigated the utilization of an original sing-a-long DVD and activity package titled ‘Sing-A-Long of the 1930s’ to engage older adults’ participation in singing and therapeutic recreation activities. Participants (n=693) included a combination of persons residing and/or working at 25 long-term care facilities, retirement homes and adult day care centres across Canada engaging in a DVD sing-a-long and activity programme for five weeks. Following this experience, participants were individually interviewed or took part in one of 25 focus groups. The results focused on participant, caregiver and DVD facilitator’s perceived benefits and indicate the DVD was successful in engaging older adults with cognitive impairment in singing, social interaction and discussion, participation in meaningful activity, reminiscence, sensory stimulation, and quality of life in aging. © 2014 Intellect Ltd Article.

Winocur G.,Rotman Research Institute | Winocur G.,Trent University | Winocur G.,University of Toronto | Moscovitch M.,Rotman Research Institute | And 3 more authors.
Neurobiology of Learning and Memory | Year: 2013

This review evaluates three current theories - Standard Consolidation (Squire & Wixted, 2011), Overshadowing (Sutherland, Sparks, & Lehmann, 2010), and Multiple Trace-Transformation (Winocur, Moscovitch, & Bontempi, 2010) - in terms of their ability to account for the role of the hippocampus in recent and remote memory in animals. Evidence, based on consistent findings from tests of spatial memory and memory for acquired food preferences, favours the transformation account, but this conclusion is undermined by inconsistent results from studies that measured contextual fear memory, probably the most commonly used test of hippocampal involvement in anterograde and retrograde memory. Resolution of this issue may depend on exercising greater control over critical factors (e.g., contextual environment, amount of pre-exposure to the conditioning chamber, the number and distribution of foot-shocks) that can affect the representation of the memory shortly after learning and over the long-term. Research strategies aimed at characterizing the neural basis of long-term consolidation/transformation, as well as other outstanding issues are discussed. © 2013 Elsevier Inc.

Winocur G.,Rotman Research Institute | Winocur G.,University of Toronto | Winocur G.,Trent University | Moscovitch M.,Rotman Research Institute | And 2 more authors.
Journal of the International Neuropsychological Society | Year: 2011

With time and experience, memories undergo a process of reorganization that involves different neuronal networks, known as systems consolidation. The traditional view, as articulated in standard consolidation theory (SCT), is that (episodic and semantic) memories initially depend on the hippocampus, but eventually become consolidated in their original forms in other brain regions. In this study, we review the main principles of SCT and report evidence from the neuropsychological literature that would not be predicted by this theory. By comparison, the evidence supports an alternative account, the transformation hypothesis, whose central premise is that changes in neural representation in systems consolidation are accompanied by corresponding changes in the nature of the memory. According to this view, hippocampally dependent, episodic, or context-specific memories transform into semantic or gist-like versions that are represented in extra-hippocampal structures. To the extent that episodic memories are retained, they will continue to require the hippocampus, but the hippocampus is not needed for the retrieval of semantic memories. The transformation hypothesis emphasizes the dynamic nature of memory, as well as the underlying functional and neural interactions that must be taken into account in a comprehensive theory of memory. © 2011 The International Neuropsychological Society.

Seitz D.P.,Baycrest Center | Gill S.S.,Queen's University | Conn D.K.,Baycrest Center
International Journal of Geriatric Psychiatry | Year: 2010

Objective: To determine the efficacy and tolerability of citalopram when compared to other antidepressants for late-life depression (LLD). Methods We searched electronic databases and trial registries to identify randomized controlled trials comparing citalopram to other antidepressants for LLD. Study quality was assessed using the Cochrane collaboration risk of bias tool. We summarized the efficacy of citalopram compared to other antidepressants by examining rates of depression remission, depression response and change in depression symptom scores. Medication tolerability was assessed through trial withdrawals due adverse events and withdrawals due to any cause. We used meta-analysis to determine the odds ratios (OR) of efficacy and tolerability outcomes for citalopram compared to other antidepressants. Results Seven studies comparing citalopram (N = 647) to other antidepressants (N = 641) for LLD were identified including four studies with tricyclic comparators and three studies with non-tricyclic comparators. Most of the studies had methodological limitations that placed them at risk for potential bias. The majority of studies reported no significant differences between citalopram and comparator medications for depression efficacy or tolerability outcomes. Meta-analysis did not find any significant differences between citalopram and other antidepressants for depression remission [OR = 0.84; 95%CI: 0.56-1.28] or for trial withdrawals due to adverse effects [OR = 0.70; 95%CI: 0.48-1.02]. Conclusions Currently there are few studies directly comparing citalopram to other antidepressants for LLD. The small number of studies and methodological issues in many studies limit any conclusions about the relative efficacy and tolerability of citalopram compared to other antidepressants. Well-designed studies comparing citalopram to other antidepressants for LLD are required. Copyright © 2010 John Wiley & Sons, Ltd.

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