Alpha-synuclein pathology of olfactory bulbs/peduncles in the Vantaa85+cohort exhibit two divergent patterns : a population-based study

Peer reviewe

A postmortem study suggests a revision of the dual-hit hypothesis of Parkinson's disease

The dual-hit hypothesis of Parkinson's disease (PD) originally postulated that a neurotropic pathogen leads to formation of alpha-synuclein pathology in the olfactory bulb (OB) and dorsal motor nucleus of the vagus (DMV) and then invades the brain from these two entry points. Little work has been conducted to validate an important underlying premise for the dual-hit hypothesis, namely that the initial Lewy pathology does arise simultaneously in the OB and the enteric nervous system (ENS) plexuses and DMV at the earliest disease stage. We conducted a focused re-analysis of two postmortem datasets, which included large numbers of mild Lewy body disease (LBD) cases. We found that cases with alpha-synuclein pathology restricted to the peripheral autonomic nervous system and/or lower brainstem (early body-first LBD cases) very rarely had any OB pathology, suggesting that Lewy pathology commonly arises in the ENS without concomitant involvement of the OB. In contrast, cases with mild amygdala-predominant Lewy pathology (early brain-first LBD cases) nearly always showed OB pathology. This is compatible with the first pathology being triggered in the OB or amygdala followed by secondary spreading to connected structures, but without early involvement of the ENS or lower brainstem. These observations support that the pathologic process starts in either the olfactory bulb or the ENS, but rarely in the olfactory bulb and gut simultaneously. More studies on neuropathological datasets are warranted to reproduce these findings. The agreement between the revised single-hit hypothesis and the recently proposed brain-first vs. body-first model of LBD is discussed.Peer reviewe

Primary age-related tauopathy in a Finnish population-based study of the oldest old (Vantaa 85+)

Abstract Aims Few studies have investigated primary age-related tauopathy (PART) in a population-based setting. Here, we assessed its prevalence, genetic background, comorbidities and features of cognitive decline in an unselected elderly population. Methods The population-based Vantaa 85+ study includes all 601 inhabitants of Vantaa aged ≥ 85 years in 1991. Neuropathological assessment was possible in 301. Dementia (DSM IIIR criteria) and Mini-Mental State Examination (MMSE) scores were assessed at the baseline of the study and follow-ups. PART subjects were identified according to the criteria by Crary et al and were compared with subjects with mild and severe Alzheimer's disease (AD) neuropathological changes. The effects of other neuropathologies were taken into account using multivariate and sensitivity assays. Genetic analyses included APOE genotypes and 29 polymorphisms of the MAPT 3′ untranslated region (3′UTR region). Results The frequency of PART was 20n = 61/301, definite PART 5. When PART subjects were compared with those with severe AD pathology, dementia was less common, its age at onset was higher and duration shorter. No such differences were seen when compared with those with milder AD pathology. However, both AD groups showed a steeper decline in MMSE scores in follow-ups compared with PART. APOE ε4 frequency was lower, and APOE ε2 frequency higher in the PART group compared with each AD group. The detected nominally significant associations between PART and two MAPT 3′UTR polymorphisms and haplotypes did not survive Bonferroni correction. Conclusions PART is common among very elderly. PART subjects differ from individuals with AD-type changes in the pattern of cognitive decline, associated genetic and neuropathological features.Peer reviewe

Distribution of Lewy-related pathology in the brain, spinal cord, and periphery : the population-based Vantaa 85+study

Evolving evidence has supported the existence of two anatomically distinct Lewy-related pathology (LRP) types. Investigation of spinal cord and peripheral LRP can elucidate mechanisms of Lewy body disorders and origins of synuclein accumulation. Still, very few unselected studies have focused on LRP in these regions. Here we analysed LRP in spinal cord, dorsal root ganglion, and adrenal gland in the population-based Vantaa 85 + study, including every ≥ 85 years old citizen living in the city of Vantaa in 1991 (n = 601). Samples from spinal cord (C6-7, TH3-4, L3-4, S1-2) were available from 303, lumbar dorsal root ganglion from 219, and adrenal gland from 164 subjects. Semiquantitative scores of LRP were determined from immunohistochemically stained sections (anti-alpha-synuclein antibody 5G4). LRP in the ventral and dorsal horns of spinal cord, thoracic intermediolateral column, dorsal root ganglion and adrenal gland were compared with brain LRP, previously determined according to DLB Consortium criteria and by caudo-rostral versus amygdala-based LRP classification. Spinal LRP was found in 28% of the total population and in 61% of those who had LRP in the brain. Spinal cord LRP was found only in those subjects with LRP in the brain, and the quantity of spinal cord LRP was associated with the severity of brain LRP (p Peer reviewe

Ger hundägande upphov till ökad motion och därmed bättre hälsa och välmående bland äldre finländare?

Internationell forskning har visat att hundägande kan ha en gynnsam effekt på fysisk aktivitet, psykiskt välbefinnande och kardiovaskulär hälsa, men resultaten har inte varit entydiga. Målet med denna undersökning var därför att utreda ifall hundägare i Finland motionerar mera, och ifall de har bättre hälsa och välmående än icke-hundägare. Deltagarna i undersökningen var 732 individer i åldern 67-78 år tillhörande Helsingfors födelsekohortstudie (HBCS). Materialet bestod av data från en hundägarenkät och data som insamlats vid undersökningar av funktionsförmågan. Deltagarna indelades i 3 grupper (Grupp 1: aldrig varit hundägare, Grupp 2: tidigare hundägare, Grupp 3: hundägare), vilka jämfördes sinsemellan med avseende på motionsmängd, kardiovas-kulära riskfaktorer och psykiskt välbefinnande. I undersökningen konstaterades en trend där hundägarna motionerade något mer än icke-ägarna, men fyndet var icke-signifikant. Hundägarna hade inte ett bättre hälsotill-stånd än icke-ägarna. De mådde varken psykiskt bättre eller sämre, och hade inte heller en gynnsammare kardiovaskulär profil i jämförelse med icke-hundägarna