Sleep quality in older adults should receive particular attention by clinicians because poor sleep quality can be an early sign of cognitive decline.
HighlightsWe present a robust and simple bias-adjustment scheme for neuroimaging-based brain age frameworks.The efficiency of proposed bias-adjustment scheme was assessed in the context of cognitively healthy aging and Alzheimer's disease.The proposed bias-adjustment scheme was shown efficient and statistically improved results, making it a necessary part for future brain age frameworks.
Normative data for volumetric estimates of brain structures are necessary to adequately assess brain volume alterations in individuals with suspected neurological or psychiatric conditions. Although many studies have described age and sex effects in healthy individuals for brain morphometry assessed via magnetic resonance imaging, proper normative values allowing to quantify potential brain abnormalities are needed. We developed norms for volumetric estimates of subcortical brain regions based on cross-sectional magnetic resonance scans from 2790 healthy individuals aged 18 to 94 years using 23 samples provided by 21 independent research groups. The segmentation was conducted using FreeSurfer, a widely used and freely available automated segmentation software. Models predicting subcortical regional volumes of each hemisphere were produced including age, sex, estimated total intracranial volume (eTIV), scanner manufacturer, magnetic field strength, and interactions as predictors. The mean explained variance by the models was 48%. For most regions, age, sex and eTIV predicted most of the explained variance while manufacturer, magnetic field strength and interactions predicted a limited amount. Estimates of the expected volumes of an individual based on its characteristics and the scanner characteristics can be obtained using derived formulas. For a new individual, significance test for volume abnormality, effect size and estimated percentage of the normative population with a smaller volume can be obtained. Normative values were validated in independent samples of healthy adults and in adults with Alzheimer's disease and schizophrenia.
Objectives-Subthreshold anxiety refers to a condition where individuals do not meet the full symptom criteria (i.e., the number of symptoms required for a formal diagnosis is not reached) and/or do not report significant impairment or distress in functioning (i.e., the clinical significance criterion is not met). The purpose of this study was to examine how the symptom and the clinical significance criteria may affect the prevalence estimates of anxiety problems in the older adult population and whether applying these criteria results in an identifiable older group showing more severe anxiety.Setting and Participants-Data came from a large representative sample of communitydwelling older adults age 65 years and older (N = 2,784). Results-Resultsshowed that the 12-month prevalence rate of any anxiety problem varied from 5.6% when DSM-IV criteria for anxiety disorders were used to 26.2% when all subthreshold manifestations of anxiety were considered. Findings also indicated that when compared with respondents without anxiety, older adults presenting different manifestations of subthreshold or threshold anxiety appear to be more similar than different in their health and health behavior characteristics.Conclusions-Subthreshold anxiety has a high prevalence and may cause significant impairment. Both symptom and clinical significance criteria do not perfectly discriminate between older adults with or without a severe anxiety problem presenting comorbid disorders and needing psychiatric help. Anxiety disorders fulfilling DSM-IV criteria are common in community-dwelling older adults with prevalence estimates hovering between 0.1% and 15%, depending on the time period considered. 1-5 Studies suggest that late-life sub-threshold anxiety is even more prevalent 6-8 and could significantly interfere with functioning as much as disorders meeting full DSM criteria. 9-11 Subthreshold anxiety usually refers to a condition where individuals do not meet the full symptom criteria (i.e., the number of symptoms required for a formal diagnosis is not reached) and/or do not report significant impairment or distress in functioning (i.e., the clinical significance criterion is not met). [6][7][8] Despite its relevance in older adults, manifestations of subthreshold anxiety are nevertheless not considered as disorders according to the DSM-IV, particularly when the clinical significance criterion is not met. The rationale behind the introduction of the clinical significance criterion was to help identify a group of people presenting a more severe condition needing psychiatric help. 12 One of the major problems with this criterion is that no operational definition exists for measuring impairment or distress. 13 The evidence for impairment is often not clear-cut; clinicians have to rely on their own judgment to determine whether reported symptoms significantly interfere with daily functioning. Studies with younger adults suggest that the inclusion of the clinical significance criterion substantially decreases the prevalence rate of ...
for the CIMA-Q group and the CCNA group Background: Harmonized protocols to collect imaging data must be devised, employed, and maintained in multicentric studies to reduce interscanner variability in subsequent analyses. Purpose: To present a standardized protocol for multicentric research on dementia linked to neurodegeneration in aging, harmonized on all three major vendor platforms. The protocol includes a common procedure for qualification, quality control, and quality assurance and feasibility in large-scale studies. Study Type: Prospective. Subjects: The study involved a geometric phantom, a single individual volunteer, and 143 cognitively healthy, mild cognitively impaired, and Alzheimer's disease participants in a large-scale, multicentric study. Field Strength/Sequences: MRI was perform with 3T scanners (GE, Philips, Siemens) and included 3D T 1 w, PD/T 2 w, T Ã 2 , T 2 w-FLAIR, diffusion, and BOLD resting state acquisitions. Assessment: Measures included signal-and contrast-to-noise ratios (SNR and CNR, respectively), total brain volumes, and total scan time. Statistical Tests: SNR, CNR, and scan time were compared between scanner vendors using analysis of variance (ANOVA) and Tukey tests, while brain volumes were tested using linear mixed models. Results: Geometric phantom T 1 w SNR was significantly (P < 0.001) higher in Philips (mean: 71.4) than Siemens (29.5), while no significant difference was observed between vendors for T 2 w (32.0 and 37.2, respectively, P 5 0.243). Single individual volunteer T 1 w CNR was higher in subcortical regions for Siemens (P < 0.001), while Philips had higher cortical CNR (P 5 0.044). No significant difference in brain volumes was observed between vendors (P 5 0.310/0.582/0.055). The average scan time was 41.0 minutes (SD: 2.8) and was not significantly different between sites (P 5 0.071) and cognitive groups (P 5 0.853). Data Conclusion: The harmonized Canadian Dementia Imaging Protocol suits the needs of studies that need to ensure quality MRI data acquisition for the measurement of brain changes across adulthood, due to aging, neurodegeneration, and other etiologies. A detailed description, exam cards, and operators' manual are freely available at the following site: www.cdip-pcid.ca. Level of Evidence: 2 Technical Efficacy: Stage 2
Proper normative data of anatomical measurements of cortical regions, allowing to quantify brain abnormalities, are lacking. We developed norms for regional cortical surface areas, thicknesses, and volumes based on cross-sectional MRI scans from 2713 healthy individuals aged 18 to 94 years using 23 samples provided by 21 independent research groups. The segmentation was conducted using FreeSurfer, a widely used and freely available automated segmentation software. Models predicting regional cortical estimates of each hemisphere were produced using age, sex, estimated total intracranial volume (eTIV), scanner manufacturer, magnetic field strength, and interactions as predictors. The explained variance for the left/right cortex was 76%/76% for surface area, 43%/42% for thickness, and 80%/80% for volume. The mean explained variance for all regions was 41% for surface areas, 27% for thicknesses, and 46% for volumes. Age, sex and eTIV predicted most of the explained variance for surface areas and volumes while age was the main predictors for thicknesses. Scanner characteristics generally predicted a limited amount of variance, but this effect was stronger for thicknesses than surface areas and volumes. For new individuals, estimates of their expected surface area, thickness and volume based on their characteristics and the scanner characteristics can be obtained using the derived formulas, as well as Z score effect sizes denoting the extent of the deviation from the normative sample. Models predicting normative values were validated in independent samples of healthy adults, showing satisfactory validation R. Deviations from the normative sample were measured in individuals with mild Alzheimer's disease and schizophrenia and expected patterns of deviations were observed.
Objective: Given that aging is associated with higher risk of cognitive decline and dementia, improving early detection of cognitive impairment has become a research and clinical priority. The Montreal Cognitive Assessment (MoCA) is a screening instrument used to assess different aspects of cognition. Despite its widespread use, norms adjusted to the sociodemographics of Quebec-French people are not yet available. Such norms are however important because performance on neuropsychological tests varies according to sociodemographic variables including age, sex, and education. As such, the present study aimed to establish normative data for the MoCA in middle-aged and elderly Quebec-French population. Method: For that purpose, 1,019 community-dwelling older adults aged between 41 and 98 were recruited. Participants from 12 recruiting sites completed the MoCA. Regression-based normative data were produced and cross-validated with a validation sample (n = 200). Results: Regression analyses indicated that older age, lower education level, and male sex were associated with poorer MoCA scores. The best predictive model included age (p < .001), education (p < .001), sex (p < .001), and a quadratic term for education (education X education; p < .001). This model explained a significant amount of variance of the MoCA score (p < .001, R 2 = 0.26). A regression equation to calculate Z scores is presented. Conclusions: This study provides normative data for the MoCA test in the middle-aged and elderly French-Quebec people. These data will facilitate more accurate detection and follow-up of the risk of cognitive impairment in this population, taking into account culture, age, education, and sex.
Anxiety and depression appear to have different relationships with incident cognitive impairment according to sex and the nature of cognitive impairment. Clinicians should pay particular attention to anxiety in older adults because it may shortly be followed by incident cognitive treatment.
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