Browsing by Subject "Dementia"

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  • Strandberg, Timo; Tienari, Pentti (2019)
    Amyloiditeoriaa on jouduttu katsomaan uudesta näkökulmasta.
  • Rantalainen, Ville; Lahti, Jari; Kajantie, Eero; Tienari, Pentti; Eriksson, Johan G.; Raikkonen, Katri (2019)
    We tested if the epsilon 4 major isoform of the APOE gene and rs405509 and rs440446 promoter and intron-1 polymorphisms predicted risk of any dementia or Alzheimer's disease with diagnoses derived from the Hospital Discharge and Causes of Death Registers in 1453 participants of the Helsinki Birth Cohort Study. We used Cox proportional hazard models adjusted for sex, year of birth, maximum lifetime occupational status and education, and diagnoses of stroke, coronary heart disease, mood disorders, and depressive symptoms. APOE epsilon 4 predicted higher risk of any dementia (hazard ratios >3.68; 95% confidence interval [CI] 1.76, 7.70) across all statistical models, and when adjusted for rs405509 and rs440446. The number of minor alleles in rs405509 or rs440446 was not associated with dementia risk (hazard ratios
  • Tynkkynen, Juho; Chouraki, Vincent; van der Lee, Sven J.; Hernesniemi, Jussi; Yang, Qiong; Li, Shuo; Beiser, Alexa; Larson, Martin G.; Sääksjärvi, Katri; Shipley, Martin J.; Singh-Manoux, Archana; Gerszten, Robert E.; Wang, Thomas J.; Havulinna, Aki S.; Würtz, Peter; Fischer, Krista; Demirkan, Ayse; Ikram, M. Arfan; Amin, Najaf; Lehtimäki, Terho; Kähönen, Mika; Perola, Markus; Metspalu, Andres; Kangas, Antti J.; Soininen, Pasi; Ala-Korpela, Mika; Vasan, Ramachandran S.; Kivimäki, Mika; van Duijn, Cornelia M.; Seshadri, Sudha; Salomaa, Veikko (2018)
    Introduction: Metabolite, lipid, and lipoprotein lipid profiling can provide novel insights into mechanisms underlying incident dementia and Alzheimer's disease. Methods: We studied eight prospective cohorts with 22,623 participants profiled by nuclear magnetic resonance or mass spectrometry metabolomics. Four cohorts were used for discovery with replication undertaken in the other four to avoid false positives. For metabolites that survived replication, combined association results are presented. Results: Over 246,698 person-years, 995 and 745 cases of incident dementia and Alzheimer's disease were detected, respectively. Three branched-chain amino acids (isoleucine, leucine, and valine), creatinine and two very low density lipoprotein (VLDL)-specific lipoprotein lipid subclasses were associated with lower dementia risk. One high density lipoprotein (HDL; the concentration of cholesterol esters relative to total lipids in large HDL) and one VLDL (total cholesterol to total lipids ratio in very large VLDL) lipoprotein lipid subclass was associated with increased dementia risk. Branched-chain amino acids were also associated with decreased Alzheimer's disease risk and the concentration of cholesterol esters relative to total lipids in large HDL with increased Alzheimer's disease risk. Discussion: Further studies can clarify whether these molecules play a causal role in dementia pathogenesis or are merely markers of early pathology. (C) 2018 The Authors. Published by Elsevier Inc. on behalf of the Alzheimer's Association.
  • Torniainen-Holm, Minna; Suvisaari, Jaana; Lindgren, Maija; Härkänen, Tommi; Dickerson, Faith; Yolken, Robert H. (2018)
    Background: Earlier studies have documented an association between cytomegalovirus and cognitive impairment, but results have been inconsistent. Few studies have investigated the association of cytomegalovirus and Epstein-Barr virus with cognitive decline longitudinally. Our aim was to examine whether cytomegalovirus and Epstein-Barr virus are associated with cognitive decline, in adults. Method: The study sample is from the Finnish Health 2000 Survey (BRIF8901, n = 7112), which is representative of the Finnish adult population. The sample was followed up after 11 years in the Health 2011 Survey. In addition, persons with dementia were identified from healthcare registers. Results: In the Finnish population aged 30 and over, the seroprevalence of cytomegalovirus was estimated to be 84% and the seroprevalence of Epstein-Barr virus 98%. Seropositivity of the viruses and antibody levels were mostly not associated with cognitive performance. In the middle-aged adult group, cytomegalovirus serointensity was associated with impaired performance in verbal learning. However, the association disappeared when corrected for multiple testing. No interactions between infection and time or between the two infections were significant when corrected for multiple testing. Seropositivity did not predict dementia diagnosis. Conclusions: The results suggest that adult levels of antibodies to cytomegalovirus and Epstein-Barr virus may not be associated with a significant decline in cognitive function or with dementia at population level. (C) 2018 Published by Elsevier Inc.
  • Nazu, Nazma Akter; Wikström, Katja; Lamidi, Marja-Leena; Lindström, Jaana; Tirkkonen, Hilkka; Rautiainen, Päivi; Laatikainen, Tiina (2020)
    Aims: To compare the quality of diabetes care among type 2 diabetes patients with and without mental disorders during six-year follow-up in North Karelia, Finland. Methods: All type 2 diabetes patients (n = 10190) were analysed using the electronic health records data from 2011-12 to 2015-16. The diabetes care was evaluated using the measurement activity and the achievement of the treatment targets for HbA1c and LDL. Results: Monitoring of HbA1c and LDL levels improved among all patient groups, except the dementia patients. The proportion of those achieving the HbA1c target declined and those achieving the LDL target improved in all patient groups. Differences in the changes of achievement of the target HbA1c level among patients with dementia and depression were observed when compared with those having only type 2 diabetes. Conclusions: This study highlights the challenge of glucose level management as the age and comorbidities of the patients related to the care and achievements of the treatment targets. Mental disorders that are likely to affect patients' adherence to medication and other treatments should be taken into account and more support for self-care should be provided to such patients. Improvement in the achievement of LDL target address the progress in the prevention of macrovascular complications. (C) 2020 The Authors. Published by Elsevier B.V.
  • Stephen, Ruth; Liu, Yawu; Ngandu, Tiia; Antikainen, Riitta; Hulkkonen, Juha; Koikkalainen, Juha; Kemppainen, Nina; Lötjönen, Jyrki; Levälahti, Esko; Parkkola, Riitta; Pippola, Pauliina; Rinne, Juha; Strandberg, Timo; Tuomilehto, Jaakko; Vanninen, Ritva; Kivipelto, Miia; Soininen, Hilkka; Solomon, Alina (BioMed Central, 2019)
    Abstract Background The Finnish Geriatric Intervention Study to Prevent Cognitive Impairment and Disability (FINGER) was a multicenter randomized controlled trial that reported beneficial effects on cognition for a 2-year multimodal intervention (diet, exercise, cognitive training, vascular risk monitoring) versus control (general health advice). This study reports exploratory analyses of brain MRI measures. Methods FINGER targeted 1260 older individuals from the general Finnish population. Participants were 60–77 years old, at increased risk for dementia but without dementia/substantial cognitive impairment. Brain MRI scans were available for 132 participants (68 intervention, 64 control) at baseline and 112 participants (59 intervention, 53 control) at 2 years. MRI measures included regional brain volumes, cortical thickness, and white matter lesion (WML) volume. Cognition was assessed at baseline and 1- and 2-year visits using a comprehensive neuropsychological test battery. We investigated the (1) differences between the intervention and control groups in change in MRI outcomes (FreeSurfer 5.3) and (2) post hoc sub-group analyses of intervention effects on cognition in participants with more versus less pronounced structural brain changes at baseline (mixed-effects regression models, Stata 12). Results No significant differences between the intervention and control groups were found on the changes in MRI measures. Beneficial intervention effects on processing speed were more pronounced in individuals with higher baseline cortical thickness in Alzheimer’s disease signature areas (composite measure of entorhinal, inferior and middle temporal, and fusiform regions). The randomization group × time × cortical thickness interaction coefficient was 0.198 (p = 0.021). A similar trend was observed for higher hippocampal volume (group × time × hippocampus volume interaction coefficient 0.1149, p = 0.085). Conclusions The FINGER MRI exploratory sub-study did not show significant differences between the intervention and control groups on changes in regional brain volumes, regional cortical thicknesses, or WML volume after 2 years in at-risk elderly without substantial impairment. The cognitive benefits on processing speed of the FINGER intervention may be more pronounced in individuals with fewer structural brain changes on MRI at baseline. This suggests that preventive strategies may be more effective if started early, before the occurrence of more pronounced structural brain changes. Trial registration ClinicalTrials.gov, NCT01041989 . Registered January 5, 2010.
  • FINGER Study Grp; Stephen, Ruth; Liu, Yawu; Ngandu, Tiia; Antikainen, Riitta; Hulkkonen, Juha; Koikkalainen, Juha; Levälahti, Esko; Parkkola, Riitta; Pippola, Pauliina; Rinne, Juha; Strandberg, Timo; Tuomilehto, Jaakko; Vanninen, Ritva; Kivipelto, Miia; Soininen, Hilkka; Solomon, Alina (2019)
    BackgroundThe Finnish Geriatric Intervention Study to Prevent Cognitive Impairment and Disability (FINGER) was a multicenter randomized controlled trial that reported beneficial effects on cognition for a 2-year multimodal intervention (diet, exercise, cognitive training, vascular risk monitoring) versus control (general health advice). This study reports exploratory analyses of brain MRI measures.MethodsFINGER targeted 1260 older individuals from the general Finnish population. Participants were 60-77years old, at increased risk for dementia but without dementia/substantial cognitive impairment. Brain MRI scans were available for 132 participants (68 intervention, 64 control) at baseline and 112 participants (59 intervention, 53 control) at 2years. MRI measures included regional brain volumes, cortical thickness, and white matter lesion (WML) volume. Cognition was assessed at baseline and 1- and 2-year visits using a comprehensive neuropsychological test battery. We investigated the (1) differences between the intervention and control groups in change in MRI outcomes (FreeSurfer 5.3) and (2) post hoc sub-group analyses of intervention effects on cognition in participants with more versus less pronounced structural brain changes at baseline (mixed-effects regression models, Stata 12).ResultsNo significant differences between the intervention and control groups were found on the changes in MRI measures. Beneficial intervention effects on processing speed were more pronounced in individuals with higher baseline cortical thickness in Alzheimer's disease signature areas (composite measure of entorhinal, inferior and middle temporal, and fusiform regions). The randomization groupxtimexcortical thickness interaction coefficient was 0.198 (p=0.021). A similar trend was observed for higher hippocampal volume (groupxtimexhippocampus volume interaction coefficient 0.1149, p=0.085).ConclusionsThe FINGER MRI exploratory sub-study did not show significant differences between the intervention and control groups on changes in regional brain volumes, regional cortical thicknesses, or WML volume after 2years in at-risk elderly without substantial impairment. The cognitive benefits on processing speed of the FINGER intervention may be more pronounced in individuals with fewer structural brain changes on MRI at baseline. This suggests that preventive strategies may be more effective if started early, before the occurrence of more pronounced structural brain changes.Trial registrationClinicalTrials.gov, NCT01041989. Registered January 5, 2010.
  • Kaivola, Karri; Kiviharju, Anna; Jansson, Lilja; Rantalainen, Ville; Eriksson, Johan G.; Strandberg, Timo E.; Laaksovirta, Hannu; Renton, Alan E; Traynor, Bryan J.; Myllykangas, Liisa; Tienari, Pentti (2019)
    The hexanucleotide repeat expansion in C9orf72 is a common cause of amyotrophic lateral sclerosis/frontotemporal dementia and also rarely found in other psychiatric and neurodegenerative conditions. Alleles with >30 repeats are often considered an expansion, but the pathogenic repeat length threshold is still unclear. It is also unclear whether intermediate repeat length alleles (often defined either as 7-30 or 20-30 repeats) have clinically significant effects. We determined the C9orf72 repeat length distribution in 3142 older Finns (aged 60-104 years). The longest nonexpanded allele was 45 repeats. We found 7-45 repeats in 1036/3142 (33%) individuals, 20-45 repeats in 56/3142 (1.8%), 30-45 repeats in 12/3142 (0.38%), and expansion (>45 repeats) in 6/3142 (0.19%). There was no apparent clustering of neurodegenerative or psychiatric diseases in individuals with 30-45 repeats indicating that 30-45 repeats are not pathogenic. None of the 6 expansion carriers had a diagnosis of amyotrophic lateral sclerosis/frontotemporal dementia but 4 had a diagnosis of a neurodegenerative or psychiatric disease. Intermediate length alleles (categorized as 7-45 and 20-45 repeats) did not associate with Alzheimer's disease or cognitive impairment. (C) 2019 The Author(s). Published by Elsevier Inc.
  • van der Lee, Sven J.; Teunissen, Charlotte E.; Pool, Rene; Shipley, Martin J.; Teumer, Alexander; Chouraki, Vincent; van Lent, Debora Melo; Tynkkynen, Juho; Fischer, Krista; Hernesniemi, Jussi; Haller, Toomas; Singh-Manoux, Archana; Verhoeven, Aswin; Willemsen, Gonneke; de Leeuw, Francisca A.; Wagner, Holger; van Dongen, Jenny; Hertel, Johannes; Budde, Kathrin; van Dijk, Ko Willems; Weinhold, Leonie; Ikram, M. Arfan; Pietzner, Maik; Perola, Markus; Wagner, Michael; Friedrich, Nele; Slagboom, P. Eline; Scheltens, Philip; Yang, Qiong; Gertzen, Robert E.; Egert, Sarah; Li, Shuo; Hankemeier, Thomas; van Beijsterveldt, Catharina E. M.; Vasan, Ramachandran S.; Maier, Wolfgang; Peeters, Carel F. W.; Grabe, Hans Joergen; Ramirez, Alfredo; Seshadri, Sudha; Metspalu, Andres; Kivimäki, Mika; Salomaa, Veikko; Demirkan, Ayse; Boomsma, Dorret I.; van der Flier, Wiesje M.; Amin, Najaf; van Duijn, Cornelia M. (2018)
    Introduction: Identifying circulating metabolites that are associated with cognition and dementia may improve our understanding of the pathogenesis of dementia and provide crucial readouts for preventive and therapeutic interventions. Methods: We studied 299 metabolites in relation to cognition (general cognitive ability) in two discovery cohorts (N total = 5658). Metabolites significantly associated with cognition after adjusting for multiple testing were replicated in four independent cohorts (N total = 6652), and the associations with dementia and Alzheimer's disease (N = 25,872) and lifestyle factors (N = 5168) were examined. Results: We discovered and replicated 15 metabolites associated with cognition including subfractions of high-density lipoprotein, docosahexaenoic acid, ornithine, glutamine, and glycoprotein acetyls. These associations were independent of classical risk factors including high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, triglycerides, glucose, and apolipoprotein E (APOE) genotypes. Six of the cognition-associated metabolites were related to the risk of dementia and lifestyle factors. Discussion: Circulating metabolites were consistently associated with cognition, dementia, and lifestyle factors, opening new avenues for prevention of cognitive decline and dementia. (C) 2018 The Authors. Published by Elsevier Inc. on behalf of the Alzheimer's Association.
  • Hale, Jo Mhairi; Schneider, Daniel C.; Mehta, Neil K.; Myrskylä, Mikko (2020)
    Prior studies have analyzed the burden of cognitive impairment, but often use potentially biased prevalence-based methods or measure only years lived with impairment, without estimating other relevant metrics. We use the Health and Retirement Study (1998–2014; n = 29,304) and the preferred incidence-based Markov-chain models to assess three key measures of the burden of cognitive impairment: lifetime risk, mean age at onset, and number of years lived impaired. We analyze both mild and severe cognitive impairment (dementia) and gender, racial/ethnic, and educational variation in impairment. Our results paint a multi-dimensional picture of cognitive health, presenting the first comprehensive analysis of the burden of cognitive impairment for the U.S. population age 50 and older. Approximately two out of three Americans experience some level of cognitive impairment at an average age of approximately 70 years. For dementia, lifetime risk for women (men) is 37% (24%) and mean age at onset 83 (79) years. Women can expect to live 4.2 years with mild impairment and 3.2 with dementia, men 3.5 and 1.8 years. A critical finding is that for the most advantaged groups (i.e., White and/or higher educated), cognitive impairment is both delayed and compressed toward the very end of life. In contrast, despite the shorter lives of disadvantaged subgroups (Black and/or lower educated), they experience a younger age of onset, higher lifetime risk, and more years cognitively impaired. For example, men with at least an Associate degree have 21% lifetime dementia risk, compared to 35% among men with less than high school education. White women have 6 years of cognitively-impaired life expectancy, compared to 12 and 13 years among Black women and Latinas. These educational and racial/ethnic gradients highlight the very uneven burden of cognitive impairment. Further research is required to identify the mechanisms driving these disparities in cognitive impairment.
  • Sarkamo, Teppo (2018)
    Music has the capacity to engage auditory, cognitive, motor, and emotional functions across cortical and subcortical brain regions and is relatively preserved in aging and dementia. Thus, music is a promising tool in the rehabilitation of aging-related neurological illnesses, such as stroke and Alzheimer disease. As the population ages and the incidence and prevalence of these illnesses rapidly increases, music-based interventions that are enjoyable and effective in the everyday care of the patients are needed. In addition to formal music therapy, musical leisure activities, such as music listening and singing, which patients can do on their own or with a caregiver, are a promising way to support psychological well-being during aging and in neurological rehabilitation. This review article provides an overview of current evidence on the cognitive, emotional, and neural effects of musical leisure activities both during normal aging and in the rehabilitation and care of stroke patients and people with dementia. (C) 2017 Elsevier Masson SAS. All rights reserved.
  • Könönen, Maija (2020)
    This essay explores the various ways of talking about senility and how the two competing (or, possibly, complementing) discourses-the biomedical dementia discourse and the discourse of senility as part of "normal" aging-affect our perception of and attitudes toward old age. Moreover, I explore the role of fiction in articulating senility. As my approach combines critical gerontology with narratological analysis, it belongs to the burgeoning domain of literary gerontology, a discipline that embraces various literary genres from fiction to nonfiction. This double perspective of literary studies and cultural gerontology makes it possible to examine senility as a historically and culturally specific concept and phenomenon. My aim is to demonstrate with two examples from contemporary Russian short prose (Nina Katerli's story "Na dva golosa" [In Two Voices] and Nina Sadur's story "Stul" [The Chair]) how a literary work can be related to prevailing cultural, sociological, and medical discourses on and norms of aging. With tools of narratology I shed light on the literary devices deployed in the stories to articulate the experience of senility from the viewpoint of the elderly protagonists themselves.
  • El-Khoury, Riyad; Kaulio, Eveliina; Lassila, Katariina A.; Crowther, Damian C.; Jacobs, Howard T.; Rustin, Pierre (2016)
    Mitochondrial dysfunction has been widely associated with the pathology of Alzheimer's disease, but there is no consensus on whether it is a cause or consequence of disease, nor on the precise mechanism(s). We addressed these issues by testing the effects of expressing the alternative oxidase AOX from Ciona intestinalis, in different models of AD pathology. AOX can restore respiratory electron flow when the cytochrome segment of the mitochondrial respiratory chain is inhibited, supporting ATP synthesis, maintaining cellular redox homeostasis and mitigating excess superoxide production at respiratory complexes I and III. In human HEK293-derived cells, AOX expression decreased the production of beta-amyloid peptide resulting from antimycin inhibition of respiratory complex III. Because hydrogen peroxide was neither a direct product nor substrate of AOX, the ability of AOX to mimic antioxidants in this assay must be indirect. In addition, AOX expression was able to partially alleviate the short lifespan of Drosophila models neuronally expressing human beta-amyloid peptides, whilst abrogating the induction of markers of oxidative stress. Our findings support the idea of respiratory chain dysfunction and excess ROS production as both an early step and as a pathologically meaningful target in Alzheimer's disease pathogenesis, supporting the concept of a mitochondrial vicious cycle underlying the disease. (C) 2016 The Authors. Published by Elsevier Inc.
  • Kallio, Eeva-Liisa; Ohman, H.; Carlson, S.; Kautiainen, H.; Hietanen, M.; Pitkala, K. H. (2017)
    Introduction: Evidence is unclear whether cognitive training (CT) has efficacy in patients with dementia. We present the recruitment and baseline findings of a carefully designed Finnish cognitive training (FINCOG) trial exploring the effectiveness of CT among community-dwelling older persons with mild-to-moderate dementia. Methods: Participants were recruited from adult day care centres in Helsinki, Finland, and randomised into two groups: (1) day care with systematic CT twice a week for 12 weeks (n = 76) and (2) day care as usual (n = 71). Demographics, diagnoses and drug use were retrieved from medical records, and baseline cognition, functioning, health-related quality of life (HRQoL) and psychological well-being were assessed. A subgroup of participants was planned to undergo functional magnetic resonance imaging (fMRI) to measure changes in brain activity. Feedback from those attending CT was collected. Primary trial outcomes will be participants' cognition and HRQoL. Results: The mean (SD) age of the randomised participants was 83.1 (5.4) years, 72% were female and 37% at a moderate stage of dementia. The intervention and control groups were comparable at baseline. Compliance with CT was good, with a mean attendance of 22/24 sessions. General subjective gain was achieved by three-fourths of the feedback respondents. However, the fMRI was not feasible in this patient group. Conclusions: We successfully randomised 147 persons with mild-to-moderate dementia in the FINCOG trial. The feedback from participants in cognitive intervention was favourable. The trial will provide important information on the effects of CT in patients with dementia. (C) 2017 Elsevier Masson SAS and European Union Geriatric Medicine Society. All rights reserved.
  • Int Parkinson's Dis Genomics Cons; Guerreiro, Rita; Escott-Price, Valentina; Tienari, Pentti J.; Myllykangas, Liisa; Oinas, Minna (2019)
    Recent large-scale genetic studies have allowed for the first glimpse of the effects of common genetic variability in dementia with Lewy bodies (DLB), identifying risk variants with appreciable effect sizes. However, it is currently well established that a substantial portion of the genetic heritable component of complex traits is not captured by genome-wide significant SNPs. To overcome this issue, we have estimated the proportion of phenotypic variance explained by genetic variability (SNP heritability) in DLB using a method that is unbiased by allele frequency or linkage disequilibrium properties of the underlying variants. This shows that the heritability of DLB is nearly twice as high as previous estimates based on common variants only (31% vs 59.9%). We also determine the amount of phenotypic variance in DLB that can be explained by recent polygenic risk scores from either Parkinson's disease (PD) or Alzheimer's disease (AD), and show that, despite being highly significant, they explain a low amount of variance. Additionally, to identify pleiotropic events that might improve our understanding of the disease, we performed genetic correlation analyses of DLB with over 200 diseases and biomedically relevant traits. Our data shows that DLB has a positive correlation with education phenotypes, which is opposite to what occurs in AD. Overall, our data suggests that novel genetic risk factors for DLB should be identified by larger GWAS and these are likely to be independent from known AD and PD risk variants.
  • Kaivola, Karri; Jansson, Lilja; Saarentaus, Elmo; Kiviharju, Anna; Rantalainen, Ville; Eriksson, Johan G.; Strandberg, Timo E.; Polvikoski, Tuomo; Myllykangas, Liisa; Tienari, Pentti J. (Helsingin yliopisto, 2018)
    Biallelic loss-of-function mutations in TYROBP and TREM2 cause a rare disease that resembles early-onset frontotemporal dementia with bone lesions (PLOSL). Some PLOSL-causing variants in TREM2 have also been associated with Alzheimer’s disease when heterozygous. Here, we studied the PLOSLFIN TYROBP deletion that covers four of the gene’s five exons. We genotyped 3220 older Finns (mean age 79, range 58-104) and found 11 deletion carriers (mean age 78, range 60-94). The carrier prevalence was 0.0034 (1 in 293) that matches previous findings in younger cohorts suggesting no significant early mortality. By comparing MMSE scores and diagnoses of dementia we did not find any significant differences between TYROBP deletion carriers and non-carriers (all p-values >0.5). Neuropathological analysis of two deletion carriers (aged 89 and 94) demonstrated only minimal beta-amyloid pathology (CERAD score 0). Collectively these results suggest that heterozygous carriership of the TYROBP deletion is not a major risk factor of dementia.
  • Kaivola, Karri; Jansson, Lilja; Saarentaus, Elmo; Kiviharju, Anna; Rantalainen, Ville; Eriksson, Johan G.; Strandberg, Timo E.; Polvikoski, Tuomo; Myllykangas, Liisa; Tienari, Pentti J. (2018)
    Biallelic loss-of-function mutations in TYROBP and TREM2 cause a rare disease that resembles early-onset frontotemporal dementia with bone lesions called polycystic lipomembranous osteodysplasia with sclerosing leukoencephalopathy (PLOSL). Some PLOSL-causing variants in TREM2 have also been associated with Alzheimer's disease when heterozygous. Here, we studied the PLOSLFIN TYROBP deletion that covers 4 of the gene's 5 exons. We genotyped 3220 older Finns (mean age 79, range 58-104) and found 11 deletion carriers (mean age 78, range 60-94). The carrier prevalence was 0.0034 (1 in 293) that matches previous findings in younger cohorts suggesting no significant early mortality. By comparing Mini-Mental State Examination (MMSE) scores and diagnoses of dementia, we did not find any significant differences between TYROBP deletion carriers and noncarriers (all p-values >0.5). Neuropathological analysis of 2 deletion carriers (aged 89 and 94 years) demonstrated only minimal beta amyloid pathology (Consortium to Establish a Registry for Alzheimer's Disease (CERAD) score 0). Collectively these results suggest that heterozygous carriership of the TYROBP deletion is not a major risk factor of cognitive impairment. (C) 2017 Elsevier Inc. All rights reserved.
  • Kero, Mia; Raunio, Anna; Polvikoski, Tuomo; Tienari, Pentti J.; Paetau, Anders; Myllykangas, Liisa (2018)
    Background: There are only few population-based studies that have systemically investigated the prevalence of hippocampal sclerosis (HS) in the very old. The frequency of unilateral versus bilateral HS has been rarely studied. Objective: We investigated the prevalence and laterality of HS and its association with other neurodegenerative and vascular pathologies in a population-based sample of very elderly. Furthermore, the concomitant presence of immunoreactivity for TDP-43, p62, and HPtau was studied. Methods: The population-based Vantaa 85(+) study includes all inhabitants of the city of Vantaa, who were > 85 years in 1991 (n = 601). Neuropathological assessment was possible in 302 subjects. Severity of neuronal loss of CA sectors and subiculum was determined bilaterally by HE-staining. Immunohistochemistry performed using antibodies for TDP-43, p62, and HPtau. Results: Neuronal loss and pathological changes in the hippocampus sector CA1 and subiculum were observed in 47 of the 302 individuals (16%), and 51% of these changes were bilateral. HS without comorbid neurodegenerative pathology was found in 1/47 subjects with HS (2%). Dementia (p <0.001) and TDP-43 immunopositivity of the granular cell layer of the dentate fascia (p <0.001) were strongly associated with HS. The CERAD score, immunopositivity for HPtau and p62 in the granular cell layer of the fascia dentate were also associated. Conclusion: HS is prevalent (16%) in the oldest old population, but HS without any comorbid neurodegenerative pathology is rare. The high frequency of unilateral HS (49%) implied that bilateral sampling of hippocampi should be routine practice in neuropathological examination.
  • Savolainen-Peltonen, Hanna; Mikkola, Tomi (2019)