Inflammation, amyloid, and atrophy in the aging brain: relationships with longitudinal changes in cognition

Amyloid deposition occurs in aging, even in individuals free from cognitive symptoms, and is often interpreted as preclinical Alzheimer's disease (AD) pathophysiology. YKL-40 is a marker of neuroinflammation, being increased in AD, and hypothesized to interact with amyloid-B (AB ) in causing cognitive decline early in the cascade of AD pathophysiology. Whether and how A and YKL-40 affect brain and cognitive changes in cognitively healthy older adults is still unknown. We studied 89 participants (mean age: 73.1 years) with cerebrospinal fluid samples at baseline, and both MRI and cognitive assessments from two time-points separated by two years. We tested how baseline levels of AB 42 and YKL-40 correlated with changes in cortical thickness and cognition. Thickness change correlated with AB 42 only in AB 42+ participants (<600 pg/mL, n = 27) in the left motor and premotor cortices. AB 42 was unrelated to cognitive change. Increased YKL-40 was associated with less preservation of scores on the animal naming test in the total sample (r = -0.28, p = 0.012) and less preservation of a score reflecting global cognitive function for AB 42+ participants (r = -0.58, p = 0.004). Our results suggest a role for inflammation in brain atrophy and cognitive changes in cognitively normal older adults, which partly depended on AB accumulation

Cohort profile: the Norwegian Registry of Persons Assessed for Cognitive Symptoms (NorCog) - a national research and quality registry with a biomaterial collection

Purpose: The Norwegian Registry of Persons Assessed for Cognitive Symptoms (NorCog) was established to harmonise and improve the quality of diagnostic practice across clinics assessing persons with cognitive symptoms in Norwegian specialist healthcare units and to establish a large research cohort with extensive clinical data. Participants: The registry recruits patients who are referred for assessment of cognitive symptoms and suspected dementia at outpatient clinics in Norwegian specialist healthcare units. In total, 18 120 patients have been included in NorCog during the period of 2009–2021. The average age at inclusion was 73.7 years. About half of the patients (46%) were diagnosed with dementia at the baseline assessment, 35% with mild cognitive impairment and 13% with no or subjective cognitive impairment; 7% received other specified diagnoses such as mood disorders. Findings to date: All patients have a detailed baseline characterisation involving lifestyle and demographic variables; activities of daily living; caregiver situation; medical history; medication; psychiatric, physical and neurological examinations; neurocognitive testing; blood laboratory work-up; and structural or functional brain imaging. Diagnoses are set according to standardised diagnostic criteria. The research biobank stores DNA and blood samples from 4000 patients as well as cerebrospinal fluid from 800 patients. Data from NorCog have been used in a wide range of research projects evaluating and validating dementia-related assessment tools, and identifying patient characteristics, symptoms, functioning and needs, as well as caregiver burden and requirement of available resources. Future plans: The finish date of NorCog was originally in 2029. In 2021, the registry’s legal basis was reformalised and NorCog got approval to collect and keep data for as long as is necessary to achieve the purpose of the registry. In 2022, the registry underwent major changes. Paper-based data collection was replaced with digital registration, and the number of variables collected was reduced. Future plans involve expanding the registry to include patients from primary care centres.publishedVersio

Meta-analysis of Alzheimer’s disease on 9,751 samples from Norway and IGAP study identifies four risk loci

Source at https://doi.org/10.1038/s41598-018-36429-6.A large fraction of genetic risk factors for Alzheimer’s Disease (AD) is still not identified, limiting the understanding of AD pathology and study of therapeutic targets. We conducted a genome-wide association study (GWAS) of AD cases and controls of European descent from the multi-center DemGene network across Norway and two independent European cohorts. In a two-stage process, we first performed a meta-analysis using GWAS results from 2,893 AD cases and 6,858 cognitively normal controls from Norway and 25,580 cases and 48,466 controls from the International Genomics of Alzheimer’s Project (IGAP), denoted the discovery sample. Second, we selected the top hits (p −6) from the discovery analysis for replication in an Icelandic cohort consisting of 5,341 cases and 110,008 controls. We identified a novel genomic region with genome-wide significant association with AD on chromosome 4 (combined analysis OR = 1.07, p = 2.48 x 10-8). This finding implicated HS3ST1, a gene expressed throughout the brain particularly in the cerebellar cortex. In addition, we identified IGHV1-68 in the discovery sample, previously not associated with AD. We also associated >i>USP6NL/ECHDC3 and BZRAP1-AS1 to AD, confirming findings from a follow-up transethnic study. These new gene loci provide further evidence for AD as a polygenic disorder, and suggest new mechanistic pathways that warrant further investigation

Factors that influence the levels of cerebrospinal fluid biomarkers in memory clinic patients

Background The cerebrospinal fluid (CSF) biomarkers amyloid β (Aβ), phospho tau (P-tau) and total tau (T-tau) are used increasingly to support a clinical diagnosis of Alzheimer’s disease. The diagnostic power of these biomarkers has been reported to vary among different studies’ results. The results are poorer when heterogeneous groups of patients have been included compared to studies where patients with Alzheimer’s dementia (AD) and healthy controls have been studied. The aim of this study was to examine if age, APOE genotype and sex were associated with the levels of CSF biomarkers among patients referred to a memory clinic. Methods We included 257 patients from two memory clinics who had been assessed for dementia, including lumbar puncture. Results The mean age of the patients was 68.1 (SD: 8.0) years; 50.2% were women and 66.5% were APOE ε4 positive. Of these patients, 80.5% were diagnosed with AD or amnestic MCI. Both APOE ε4 and increasing age were associated with decreasing levels of Aβ, but not the levels of the tau proteins. In multiple regression analyses, disease stage, defined as a MMSE ≥25 or <25, influenced factors associated with the CSF biomarkers. Among those with MMSE score ≥ 25, age, APOE ε4 genotype, and MMSE score, in addition to a diagnosis of AD, were associated with Aβ level, with an explained variance of 0.43. When using P-tau or T-tau as a dependent variable, the presence of one or two APOE ε4 alleles, and MMSE score influenced the results, in addition to the diagnosis of AD. The explained variance was lower for P-tau (0.26) and for T-tau (0.32). Among those with MMSE <25, these variables explained very little of the variance. There were no gender differences. Conclusions We found that factors in addition to a diagnosis of AD, were associated with the levels of CSF biomarkers. Among those with MMSE ≥25, lower levels of Aβ were associated with several factors including increasing age. This is not reflected in clinical practice, where age-specific cutoffs exist only for T-tau. In this study, age was not associated with the levels of tau proteins

Cortisol levels among older people with and without depression and dementia

ABSTRACTCortisol dysregulation has been reported in dementia and depression. Cortisol levels and its associates were investigated among older people living at home and in nursing homes, in a cross-sectional study. A sample of 650 older people, from the community (home and nursing homes) and specialized care (memory clinics and old age psychiatry wards), mean age 76.8 (SD = 10.3) (dementia n = 319, depression, n = 154, dementia plus depression n = 53, and reference group n = 124), was included. Assessment included the Mini Mental State Examination (MMSE), Cornell scale for depression in dementia, activities of daily living scales, and salivary cortisol. Number of drugs was registered. The results showed that the cortisol ratio was highest among patients with dementia and co-morbid depression in comparison to those with either depression or dementia and the reference group. Characteristics significantly associated with cortisol levels were higher MMSE score (in patients with dementia and co-morbid depression), male gender (in people with dementia), and number of medications (in the reference group). We conclude that the cortisol ratio was highest among patients with dementia and co-morbid depression in comparison to those with either depression or dementia and the reference group. The association of cortisol level with MMSE score among patients with dementia and depression could further indicate that increased stress is related to cognitive function.acceptedVersio

Cognitive and emotional symptoms in patients with first-ever mild stroke: The syndrome of hidden impairments

Objective: To evaluate the prevalence of cognitive and emotional impairments one year after first-ever mild stroke in younger patients Design: Prospective, observational, cohort study. Subjects: A consecutive sample of 117 previously cognitively healthy patients aged 18–70 years with mild stroke (National Institutes of Health Stroke Scale score ≤ 3) were included in 2 hospitals in Norway during a 2-year period. Methods: At 12-month follow-up, patients were assessed using validated instruments for essential cognitive domains, fatigue, depression, anxiety, apathy and pathological laughter and crying. Results: In total, 78 patients (67%) had difficulty with one or a combination of the cognitive domains psychomotor speed, attention, executive and visuospatial function, and memory. Furthermore, 50 patients (43%) had impairment in either one or a combination of the emotional measures for anxiety, depressive symptoms, fatigue, apathy or emotional lability. A total of 32 patients (28%) had both cognitive and emotional impairments. Only 21 patients (18%) scored within the reference range in all the cognitive and emotional tools. Conclusion: Hidden impairments are common after first-ever mild stroke in younger patients. Stroke physicians should screen for hidden impairments using appropriate tools

Predictors of cognitive and emotional symptoms 12 months after first-ever mild stroke

Even mild strokes may affect the patients’ everyday life by impairing cognitive and emotional functions. Our aim was to study predictors of such impairments one year after first-ever mild stroke. We included cognitively healthy patients ≤ 70 years with acute mild stroke. Vascular risk factors, sociodemographic factors and stroke classifications were recorded. At one-year post-stroke, different domains related to cognitive and emotional function were assessed with validated instruments. Logistic regression analyses were performed to identify predictors of cognitive and emotional outcome. Of 117 patient assessed at follow-up, only 21 patients (18%) scored within the reference range on all cognitive and emotional assessments. Younger age, multiple infarcts, and being outside working life at stroke onset were independent predictors of cognitive impairments (psychomotor speed, attention, executive and visuospatial function, memory). Female gender and a higher National Institutes of Health Stroke Scale (NIHSS) score at discharge were significantly associated with emotional impairments (anxiety, depressive symptoms, fatigue, apathy, emotional lability) after one year, but these associations were only seen in the unadjusted models. In conclusion, patients in working age may profit from a follow-up during the post-stroke period, with extra focus on cognitive and emotional functions

Progression of Alzheimer's Disease: A Longitudinal Study in Norwegian Memory Clinics

Background: The course of Alzheimer’s disease (AD) varies considerably between individuals. There is limited evidence on factors important for disease progression. Objective: The primary aim was to study the progression of AD, as measured by the Clinical Dementia Rating Scale Sum of Boxes (CDR-SB). Secondary aims were to investigate whether baseline characteristics are important for differences in progression, and to examine the correlation between progression assessed using three different instruments: CDR-SB (0–18), the cognitive test Mini-Mental State Examination (MMSE, 0–30), and the functional measure Instrumental Activities of Daily Living (IADL, 0-1). Methods: The Progression of AD and Resource use (PADR) study is a longitudinal observational study in three Norwegian memory clinics. Results: In total, 282 AD patients (mean age 73.3 years, 54% female) were followed for mean 24 (16–37) months. The mean annual increase in CDR-SB was 1.6 (SD 1.8), the mean decrease in MMSE score 1.9 (SD 2.6), and the mean decrease in IADL score 0.13 (SD 0.14). Of the 282 patients, 132 (46.8%) progressed slowly, with less than 1 point yearly increase in CDR-SB. Cognitive test results at baseline predicted progression rate, and together with age, ApoE, history of hypertension, and drug use could explain 17% of the variance in progression rate. The strongest correlation of change was found between CDR-SB and IADL scores, the weakest between MMSE and IADL scores. Conclusion: Progression rate varied considerably among AD patients; about half of the patients progressed slowly. Cognitive test results at baseline were predictors of progression rate

Visual Evaluation of Medial Temporal Lobe Atrophy as a Clinical Marker of Conversion from Mild Cognitive Impairment to Dementia and for Predicting Progression in Patients with Mild Cognitive Impairment and Mild Alzheimer's Disease

Background/Aims: To evaluate whether visual assessment of medial temporal lobe atrophy (vaMTA) can predict 2-year conversion from mild cognitive impairment (MCI) to dementia and progression of MCI and Alzheimer's disease dementia as measured by the Clinical Dementia Rating Scale Sum of Boxes score (CDR-SB). Methods: vaMTA was performed in 94 patients with MCI according to the Winblad criteria and in 124 patients with AD according to ICD-10 and NINCDS-ADRDA criteria. Demographic data, the Consortium to Establish a Registry for Alzheimer's Disease 10-word delayed recall, APOE ɛ4 status, Cornell Scale for Depression in Dementia, and comorbid hypertension were used as covariates. Results: vaMTA was associated with MCI conversion in an unadjusted model but not in an adjusted model (p = 0.075), where delayed recall and APOE ɛ4 status were significant predictors. With CDR-SB change as the outcome, an interaction between vaMTA and diagnosis was found, but in the adjusted model only delayed recall and age were significant predictors. For vaMTA below 2, the association between vaMTA and CDR-SB change differed between diagnostic groups. Similar results were found based on a trajectory analysis. Conclusion: In adjusted models, memory function, APOE ɛ4 status and age were significant predictors of disease progression, not vaMTA. The association between vaMTA and CDR-SB change was different in patients with MCI and Alzheimer's disease dementia.acceptedVersio