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- Inguanzo, A, et al.
(author)
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MRI data-driven clustering reveals different subtypes of Dementia with Lewy bodies
- 2023
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In: NPJ Parkinson's disease. - : Springer Science and Business Media LLC. - 2373-8057. ; 9:1, s. 5-
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Journal article (peer-reviewed)abstract
- Dementia with Lewy bodies (DLB) is a neurodegenerative disorder with a wide heterogeneity of symptoms, which suggests the existence of different subtypes. We used data-driven analysis of magnetic resonance imaging (MRI) data to investigate DLB subtypes. We included 165 DLB from the Mayo Clinic and 3 centers from the European DLB consortium and performed a hierarchical cluster analysis to identify subtypes based on gray matter (GM) volumes. To characterize the subtypes, we used demographic and clinical data, as well as β-amyloid, tau, and cerebrovascular biomarkers at baseline, and cognitive decline over three years. We identified 3 subtypes: an older subtype with reduced cortical GM volumes, worse cognition, and faster cognitive decline (n = 49, 30%); a subtype with low GM volumes in fronto-occipital regions (n = 76, 46%); and a subtype of younger patients with the highest cortical GM volumes, proportionally lower GM volumes in basal ganglia and the highest frequency of cognitive fluctuations (n = 40, 24%). This study shows the existence of MRI subtypes in DLB, which may have implications for clinical workout, research, and therapeutic decisions.
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- Jaramillo-Jimenez, A, et al.
(author)
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Association Between Amygdala Volume and Trajectories of Neuropsychiatric Symptoms in Alzheimer's Disease and Dementia With Lewy Bodies
- 2021
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In: Frontiers in neurology. - : Frontiers Media SA. - 1664-2295. ; 12, s. 679984-
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Journal article (peer-reviewed)abstract
- Introduction: The amygdala is implicated in psychiatric illness. Even as the amygdala undergoes significant atrophy in mild dementia, amygdala volume is underexplored as a risk factor for neuropsychiatric symptoms (NPS).Objective: To analyze the association between baseline amygdala volume and the longitudinal trajectories of NPS and cognitive decline in Alzheimer's disease (AD) and dementia with Lewy bodies (DLB) over 5 years.Methods: Eighty-nine patients with mild dementia were included (AD = 55; DLB = 34). Amygdala volume was segmented from structural magnetic resonance images (sMRI) using a semi-automatic method (Freesurfer 6.0) and normalized by intracranial volumes. The intracranial volume-normalized amygdala was used as a predictor of the Neuropsychiatric Inventory (NPI) total score, ordinal NPI item scores (0 = absence of symptoms, 1–3 = mild symptoms, ≥4 = clinically relevant symptoms), and Mini-Mental State Examination (MMSE) as measured annually over 5 years using gamma, ordinal, and linear mixed-effects models, respectively. The models were adjusted for demographic variables, diagnosis, center of sMRI acquisition, and cognitive performance. Multiple testing-corrected p-values (q-values) are reported.Results: Larger intracranial volume-normalized amygdala was associated with less agitation/aggression (odds ratio (OR) = 0.62 [0.43, 0.90], p = 0.011, q = 0.038) and less MMSE decline per year (fixed effect = 0.70, [0.29, 1.03], p = 0.001, q = 0.010) but more depression (OR = 1.49 [1.09, 2.04], p = 0.013, q = 0.040).Conclusions: Greater amygdala volume in mild dementia is associated with lower odds of developing agitation/aggression, but higher odds of developing depression symptoms during the 5-year study period.
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- Juang, Linda P., et al.
(author)
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Ethnic-racial identity in Europe: Adapting the identity project intervention in five countries
- 2023
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In: European Journal of Developmental Psychology. - : Informa UK Limited. - 1740-5629 .- 1740-5610. ; 20:6, s. 978-1006
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Journal article (peer-reviewed)abstract
- A global challenge for developmental psychology is to better understand how young people around the world make sense of their identities growing up in pluralistic societies. The study of ethnic-racial identity provides an important lens for this process. This paper describes how five European countries (Germany, Greece, Italy, Norway, and Sweden) adapted the Identity Project, an 8-week school-based intervention originally developed in the United States to promote adolescents’ ethnic-racial identity exploration and resolution. Across the five countries, deep structure adaptations included revised or added content regarding key terminology used, a focus on migration and foreignness rather than ‘race,’ and discussions regarding national and regional identities, in addition to ethnic-racial identities, and how they may relate to one another. The process and content of adaptation we describe addresses two fundamental issues relevant to a globalized developmental psychology: 1) contributing to theoretical advances on key aspects of development by taking sociohistorical context seriously, and 2) moving between etic and emic perspectives to arrive at psychological constructs that can be appropriately studied across diverse cultural contexts.
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- Oppedal, K, et al.
(author)
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Classifying dementia using local binary patterns from different regions in magnetic resonance images
- 2015
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In: International journal of biomedical imaging. - : Hindawi Limited. - 1687-4188 .- 1687-4196. ; 2015, s. 572567-
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Journal article (peer-reviewed)abstract
- Dementia is an evolving challenge in society, and no disease-modifying treatment exists. Diagnosis can be demanding and MR imaging may aid as a noninvasive method to increase prediction accuracy. We explored the use of 2D local binary pattern (LBP) extracted from FLAIR and T1 MR images of the brain combined with a Random Forest classifier in an attempt to discern patients with Alzheimer's disease (AD), Lewy body dementia (LBD), and normal controls (NC). Analysis was conducted in areas with white matter lesions (WML) and all of white matter (WM). Results from 10-fold nested cross validation are reported as mean accuracy, precision, and recall with standard deviation in brackets. The best result we achieved was in the two-class problem NC versus AD + LBD with total accuracy of 0.98 (0.04). In the three-class problem AD versus LBD versus NC and the two-class problem AD versus LBD, we achieved 0.87 (0.08) and 0.74 (0.16), respectively. The performance using 3DT1 images was notably better than when using FLAIR images. The results from the WM region gave similar results as in the WML region. Our study demonstrates that LBP texture analysis in brain MR images can be successfully used for computer based dementia diagnosis.
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- Borda, MG, et al.
(author)
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Hippocampal subfields and decline in activities of daily living in Alzheimer's disease and dementia with Lewy bodies
- 2020
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In: Neurodegenerative disease management. - : Future Medicine Ltd. - 1758-2032 .- 1758-2024. ; 10:6, s. 357-367
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Journal article (peer-reviewed)abstract
- Background: Hippocampal atrophy is presented in Alzheimer’s disease (AD) and dementia with Lewy bodies (DLB). Cognition, dual-tasks, muscular function, goal-related behaviors and neuropsychiatric symptoms are linked to hippocampal volumes and may lead to functional decline in activities of daily living. We examined the association between baseline hippocampal subfield volumes (HSv) in mild AD and DLB, and functional decline. Materials & methods: 12 HSv were computed from structural magnetic resonance images using Freesurfer 6.0 segmentation. Functional decline was assessed using the rapid disability rating scale score. Linear regressions were conducted. Results: In AD, HSv were smaller bilaterally. However, HSv were not associated with functional decline. Conclusion: Functional decline does not depend on HSv in mild AD and DLB.
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| 19. |
- Borda, MG, et al.
(author)
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Timed Up and Go in People with Subjective Cognitive Decline Is Associated with Faster Cognitive Deterioration and Cortical Thickness
- 2022
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In: Dementia and geriatric cognitive disorders. - : S. Karger AG. - 1421-9824 .- 1420-8008. ; 51:1, s. 63-72
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Journal article (peer-reviewed)abstract
- <b><i>Introduction:</i></b> Early markers of neurodegeneration provide an opportunity to detect, monitor, and initiate interventions in individuals who have an increased risk of developing dementia. Here, we investigated whether the Timed Up and Go (TUG) test is associated with early brain neurodegeneration and whether the TUG test could be a marker of cognitive decline in people with subjective cognitive decline (SCD). <b><i>Methods:</i></b> This is a longitudinal analysis of the Dementia Disease Initiation Study, a prospective, community-based, cohort study from Norway, designed to investigate early markers of cognitive impairment and dementia. Participants were classified as SCD and healthy controls (HC). The main studied variables were the TUG test and cognition as measured by the Mini-Mental State Examination and the Consortium to Establish a Registry for Alzheimer’s Disease memory composite score. Additionally, we investigated the cross-sectional association of brain morphology with the TUG using 1.5T-MRI. <b><i>Results:</i></b> The sample included 45 participants (SCD = 21, HC = 24) followed during a mean time of 1.50 ± 0.70 years. At baseline, the cognitive performance did not differ between the groups, but TUG was longer in SCD. Slower baseline TUG was associated with a faster cognitive decline in both groups and it was also associated with reduced cortical thickness especially in motor, executive, associative, and somatosensory cortical regions in people with SCD. <b><i>Discussion/Conclusion:</i></b> TUG predicted cognitive change in individuals with SCD, and there was a negative association between TUG and cortical thickness. TUG is a promising cheap and noninvasive marker of early cognitive decline and may help initiate interventions in individuals who have an increased risk of dementia.
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| 20. |
- Damangir, Soheil, et al.
(author)
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Multispectral MRI segmentation of age related white matter changes using a cascade of support vector machines
- 2012
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In: Journal of the Neurological Sciences. - : Elsevier BV. - 0022-510X .- 1878-5883. ; 322:1-2, s. 211-216
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Journal article (peer-reviewed)abstract
- White matter changes (WMC) are the focus of intensive research and have been linked to cognitive impairment and depression in the elderly. Cumbersome manual outlining procedures make research on WMC labor intensive and prone to subjective bias. We present a fast, fully automated method for WMC segmentation using a cascade of reduced support vector machines (SVMs) with active learning. Data of 102 subjects was used in this study. Two MRI sequences (T1-weighted and FLAIR) and masks of manually outlined WMC from each subject were used for the image analysis. The segmentation framework comprises pre-processing, classification (training and core segmentation) and post-processing. After pre-processing, the model was trained on two subjects and tested on the remaining 100 subjects. The effectiveness and robustness of the classification was assessed using the receiver operating curve technique. The cascade of SVMs segmentation framework outputted accurate results with high sensitivity (90%) and specificity (99.5%) values, with the manually outlined WMC as reference. An algorithm for the segmentation of WMC is proposed. This is a completely competitive and fast automatic segmentation framework, capable of using different input sequences, without changes or restrictions of the image analysis algorithm.
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| 23. |
- Oppedal, K, et al.
(author)
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White matter hyperintensities in mild lewy body dementia
- 2012
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In: Dementia and geriatric cognitive disorders extra. - : S. Karger AG. - 1664-5464. ; 2:1, s. 481-95
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Journal article (peer-reviewed)abstract
- <b><i>Background:</i></b> The objective of this study was to explore the load of white matter hyperintensities (WMH) in patients with Lewy body dementia (LBD) and compare to Alzheimer’s disease (AD) and normal controls (NC). <b><i>Methods:</i></b> Diagnosis of LBD and AD was made according to consensus criteria and cognitive tests were administered. MRI scans for 77 (61 AD and 16 LBD) patients and 37 healthy elderly control subjects were available for analysis. We segmented WMH from FLAIR images using an automatic thresholding technique and calculated the volume of WMH in several regions of the brain, using non-parametric tests to compare groups. Multivariate regression was applied. <b><i>Results:</i></b> There were no significant differences in WMH between AD and LBD. We found a significant correlation between total and frontal WMH and Mini-Mental State Examination (MMSE) and verbal fluency scores in the AD group, but not in the LBD group. <b><i>Conclusion:</i></b> The WMH load in LBD was similar to that of AD. A correlation between WMH load and cognition was found in the AD group, but not in the LBD group, suggesting that vascular disease contributes to cognitive impairment in AD but not LBD.
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| 25. |
- Soennesyn, H, et al.
(author)
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White matter hyperintensities and the course of depressive symptoms in elderly people with mild dementia
- 2012
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In: Dementia and geriatric cognitive disorders extra. - : S. Karger AG. - 1664-5464. ; 2, s. 97-111
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Journal article (peer-reviewed)abstract
- <i>Objectives:</i> To explore the relationship between white matter hyperintensities (WMH) and the prevalence and course of depressive symptoms in mild Alzheimer’s disease (AD) and Lewy body dementia. <i>Design:</i> This is a prospective cohort study conducted in secondary care outpatient clinics in western Norway. <i>Subjects:</i> The study population consisted of 77 elderly people with mild dementia diagnosed according to standardised criteria. <i>Methods:</i> Structured clinical interviews and physical, neurological, psychiatric, and neuropsychological examinations were performed and routine blood tests were taken. Depression was assessed using the depression subitem of the Neuropsychiatric Inventory and the Montgomery-Åsberg Depression Rating Scale (MADRS). A standardised protocol for magnetic resonance imaging scan was used, and the volumes of WMH were quantified using an automated method, followed by manual editing. <i>Results:</i> The volumes of total and frontal deep WMH were significantly and positively correlated with baseline severity of depressive symptoms, and depressed patients had significantly higher volumes of total and frontal deep WMH than non-depressed patients. Higher volumes of WMH were also associated with having a high MADRS score and incident and persistent depression at follow-up. After adjustment for potential confounders, frontal deep WMH, in addition to prior depression and non-AD dementia, were still significantly associated with baseline depressive symptoms (p = 0.015, OR 3.703, 95% CI 1.294–10.593). Similar results emerged for total WMH. <i>Conclusion:</i> In elderly people with mild dementia, volumes of WMH, in particular frontal deep WMH, were positively correlated with baseline severity of depressive symptoms, and seemed to be associated with persistent and incident depression at follow-up. Further studies of the mechanisms that determine the course of depression in mild dementia are needed.
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