Since 1989, four Canadian Consensus Conferences on the Diagnosis and Treatment of Dementia (CCCDTD) have provided evidence‐based dementia guidelines for Canadian clinicians and researchers. We ...present the results of the 5th CCCDTD, which convened in October 2019, to address topics chosen by the steering committee to reflect advances in the field, and build on previous guidelines. Topics included: (1) utility of the National Institute on Aging research framework for clinical Alzheimer's disease (AD) diagnosis; (2) updating diagnostic criteria for vascular cognitive impairment, and its management; (3) dementia case finding and detection; (4) neuroimaging and fluid biomarkers in diagnosis; (5) use of non‐cognitive markers of dementia for better dementia detection; (6) risk reduction/prevention; (7) psychosocial and non‐pharmacological interventions; and (8) deprescription of medications used to treat dementia. We hope the guidelines are useful for clinicians, researchers, policy makers, and the lay public, to inform a current and evidence‐based approach to dementia.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Molecular imaging techniques using 18F-fluorodeoxyglucose, amyloid tracers, and, more recently, tau ligands have taken dementia research by storm and undoubtedly improved our understanding of ...neurodegenerative diseases. The ability to image in vivo the pathological substrates of degenerative diseases and visualize their downstream impact has led to improved models of pathogenesis, better differential diagnosis of atypical conditions, as well as focused subject selection and monitoring of treatment in clinical trials aimed at delaying or preventing the symptomatic phase of Alzheimer's disease. In this article, we present the main molecular imaging techniques used in research and practice. We further summarize the key findings brought about by each technique individually and more recently, as adjuncts to each other. Specific limitations of each imaging modality are discussed, as well as recommendations to overcome them. A nonvalidated clinical algorithm is proposed for earlier and more accurate identification of complex/atypical neurodegenerative diseases.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
When walking on a split-belt treadmill, where each leg is driven at a different speed, a temporary change is made to the typical steady-state walking pattern. The exact ways in which the brain ...controls these temporary changes to walking are still unknown. Ten young adults (23±3y) walked on a split-belt treadmill for 30 min on 2 separate occasions: tied-belt control with both belts at comfortable walking speed, and continuous adjustment where speed ratio between belts changed every 15 seconds. 18F-fluorodeoxyglucose (18FDG) positron emission tomography (PET) imaging measured whole brain glucose metabolism distribution, or activation, during each treadmill walking condition. The continuous adjustment condition, compared to the tied-belt control, was associated with increased activity of supplementary motor areas (SMA), posterior parietal cortex (PPC), anterior cingulate cortex and anterior lateral cerebellum, and decreased activity of posterior cingulate and medial prefrontal cortex. In addition, peak activation of the PPC, SMA and PFC were correlated with cadence and temporal gait variability. We propose that a “fine-tuning” network for human locomotion exists which includes brain areas for sensorimotor integration, motor planning and goal directed attention. These findings suggest that distinct regions govern the inherent flexibility of the human locomotor plan to maintain a successful and adjustable walking pattern.
•18FDG PET imaging measured brain activation during split-belt treadmill walking.•A “fine-tuning” network increased activity: SMA, PPC, ACC and Cerebellar Lobule VI.•Aspects of the DMN (PCC, mPFC) decreased activity compared to typical walking.•Unplanned locomotor plan updates require a widespread network of brain areas.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
OBJECTIVE:To determine whether the Parkinson disease–related covariance pattern (PDRP) expression is abnormally increased in idiopathic REM sleep behavior disorder (RBD) and whether increased ...baseline activity is associated with greater individual risk of subsequent phenoconversion.
METHODS:For this cohort study, we recruited 2 groups of RBD and control subjects. Cohort 1 comprised 10 subjects with RBD (63.5 ± 9.4 years old) and 10 healthy volunteers (62.7 ± 8.6 years old) who underwent resting-state metabolic brain imaging with F-fluorodeoxyglucose PET. Cohort 2 comprised 17 subjects with RBD (68.9 ± 4.8 years old) and 17 healthy volunteers (66.6 ± 6.0 years old) who underwent resting brain perfusion imaging with ethylcysteinate dimer SPECT. The latter group was followed clinically for 4.6 ± 2.5 years by investigators blinded to the imaging results. PDRP expression was measured in both RBD groups and compared with corresponding control values.
RESULTS:PDRP expression was elevated in both groups of subjects with RBD (cohort 1p < 0.04; cohort 2p < 0.005). Of the 17 subjects with long-term follow-up, 8 were diagnosed with Parkinson disease or dementia with Lewy bodies; the others did not phenoconvert. For individual subjects with RBD, final phenoconversion status was predicted using a logistical regression model based on PDRP expression and subject age at the time of imaging (r = 0.64, p < 0.0001).
CONCLUSIONS:Latent network abnormalities in subjects with idiopathic RBD are associated with a greater likelihood of subsequent phenoconversion to a progressive neurodegenerative syndrome.
Abstract
Background
Suicide is among the top 10 leading causes of premature morality in the United States and its rates continue to increase. Thus, its prevention has become a salient public health ...responsibility. Risk factors of suicide transcend the individual and societal level as risk can increase based on climatic variables. The purpose of the present study is to evaluate the association between average temperature and suicide rates in the five most populous counties in California using mortality data from 1999 to 2019.
Methods
Monthly counts of death by suicide for the five counties of interest were obtained from CDC WONDER. Monthly average, maximum, and minimum temperature were obtained from nCLIMDIV for the same time period. We modelled the association of each temperature variable with suicide rate using negative binomial generalized additive models accounting for the county-specific annual trend and monthly seasonality.
Results
There were over 38,000 deaths by suicide in California’s five most populous counties between 1999 and 2019. An increase in average temperature of 1 °C corresponded to a 0.82% increase in suicide rate (IRR = 1.0082 per °C; 95% CI = 1.0025–1.0140). Estimated coefficients for maximum temperature (IRR = 1.0069 per °C; 95% CI = 1.0021–1.0117) and minimum temperature (IRR = 1.0088 per °C; 95% CI = 1.0023–1.0153) were similar.
Conclusion
This study adds to a growing body of evidence supporting a causal effect of elevated temperature on suicide. Further investigation into environmental causes of suicide, as well as the biological and societal contexts mediating these relationships, is critical for the development and implementation of new public health interventions to reduce the incidence of suicide, particularly in the face increasing temperatures due to climate change.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Introduction
Mild behavioral impairment (MBI) is characterized by the emergence of neuropsychiatric symptoms in elderly persons. Here, we examine the associations between MBI and Alzheimer's disease ...(AD) biomarkers in asymptomatic elderly individuals.
Methods
Ninety‐six cognitively normal elderly individuals underwent MRI, 18FAZD4694 β‐amyloid‐PET, and 18FMK6240 tau‐PET. MBI was assessed using the MBI Checklist (MBI‐C). Pearson's correlations and voxel‐based regressions were used to evaluate the relationship between MBI‐C score and 18FAZD4694 retention, 18FMK6240 retention, and gray matter (GM) volume.
Results
Pearson correlations revealed a positive relationship between MBI‐C score and global and striatal 18FAZD4694 standardized uptake value ratios (SUVRs). Voxel‐based regression analyses revealed a positive correlation between MBI‐C score and 18FAZD4694 retention. No significant correlations were found between MBI‐C score and 18FMK6240 retention or GM volume.
Conclusion
We demonstrate for the first time a link between MBI and early AD pathology in a cognitively intact elderly population, supporting the use of the MBI‐C as a metric to enhance clinical trial enrolment.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Abstract
Urinary tract infections caused by the bacterium Escherichia coli are among the most frequently encountered infections and are a common reason for antimicrobial prescriptions. Resistance to ...fluoroquinolone antimicrobial agents, particularly ciprofloxacin, has increased in recent decades. It is intuitive that variation in fluoroquinolone resistance is driven by changes in antimicrobial use, but careful study of this association requires the use of time-series methods. Between April 2010 and December 2014, we studied seasonal variation in resistance to ciprofloxacin, trimethoprim-sulfamethoxazole, and ampicillin in community-acquired urinary E. coli isolates in Montreal, Quebec, Canada. Using dynamic linear models, we investigated whether seasonal variation in resistance could be explained by seasonal variation in community antimicrobial use. We found a positive association between total fluoroquinolone use lagged by 1 and 2 months and the proportion of isolates resistant to ciprofloxacin. Our results suggest that resistance to ciprofloxacin is responsive to short-term variation in antimicrobial use. Thus, antimicrobial stewardship campaigns to reduce fluoroquinolone use, particularly in the winter when use is highest, are likely to be a valuable tool in the struggle against antimicrobial resistance.
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