Serum GFAP levels correlate with astrocyte reactivity, post-mortem brain atrophy and neurofibrillary tangles.

Glial fibrillary acidic protein (GFAP), a proxy of astrocyte reactivity, has been proposed as biomarker of Alzheimer's disease. However, there is limited information about the correlation between blood biomarkers and post-mortem neuropathology. In a single-centre prospective clinicopathological cohort of 139 dementia patients, for which the time-frame between GFAP level determination and neuropathological assessment was exceptionally short (on average 139 days), we analysed this biomarker, measured at three time points, in relation to proxies of disease progression such as cognitive decline and brain weight. Most importantly, we investigated the use of blood GFAP to detect the neuropathological hallmarks of Alzheimer's disease, while accounting for potential influences of the most frequent brain co-pathologies. The main findings demonstrated an association between serum GFAP level and post-mortem tau pathology (ß = 12.85; P < 0.001) that was independent of amyloid deposits (ß = 13.23; P = 0.02). A mediation analysis provided additional support for the role of astrocytic activation as a link between amyloid and tau pathology in Alzheimer's disease. Furthermore, a negative correlation was observed between pre-mortem serum GFAP and brain weight at post-mortem (r = -0.35; P < 0.001). This finding, together with evidence of a negative correlation with cognitive assessments (r = -0.27; P = 0.005), supports the role of GFAP as a biomarker for disease monitoring, even in the late phases of Alzheimer's disease. Moreover, the diagnostic performance of GFAP in advanced dementia patients was explored, and its discriminative power (area under the receiver operator characteristic curve at baseline = 0.91) in differentiating neuropathologically-confirmed Alzheimer's disease dementias from non-Alzheimer's disease dementias was determined, despite the challenging scenario of advanced age and frequent co-pathologies in these patients. Independently of Alzheimer's disease, serum GFAP levels were shown to be associated with two other pathologies targeting the temporal lobes-hippocampal sclerosis (ß = 3.64; P = 0.03) and argyrophilic grain disease (ß = -6.11; P = 0.02). Finally, serum GFAP levels were revealed to be correlated with astrocyte reactivity, using the brain GFAP-immunostained area as a proxy (ρ = 0.21; P = 0.02). Our results contribute to increasing evidence suggesting a role for blood GFAP as an Alzheimer's disease biomarker, and the findings offer mechanistic insights into the relationship between blood GFAP and Alzheimer's disease neuropathology, highlighting its ties with tau burden. Moreover, the data highlighting an independent association between serum GFAP levels and other neuropathological lesions provide information for clinicians to consider when interpreting test results. The longitudinal design and correlation with post-mortem data reinforce the robustness of our findings. However, studies correlating blood biomarkers and neuropathological assessments are still scant, and further research is needed to replicate and validate these results in diverse populations.

Brain structure and episodic learning rate in cognitively healthy ageing.

Memory normally declines with ageing and these age-related cognitive changes are associated with changes in brain structure. Episodic memory retrieval has been widely studied during ageing, whereas learning has received less attention. Here we examined the neural correlates of episodic learning rate in ageing. Our study sample consisted of 982 cognitively healthy female and male older participants from the Vallecas Project cohort, without a clinical diagnosis of mild cognitive impairment or dementia. The learning rate across the three consecutive recall trials of the verbal memory task (Free and Cued Selective Reminding Test) recall trials was used as a predictor of grey matter (GM) using voxel-based morphometry, and WM microstructure using tract-based spatial statistics on fractional anisotropy (FA) and mean diffusivity (MD) measures. Immediate Recall improved by 1.4 items per trial on average, and this episodic learning rate was faster in women and negatively associated with age. Structurally, hippocampal and anterior thalamic GM volume correlated positively with learning rate. Learning also correlated with the integrity of WM microstructure (high FA and low MD) in an extensive network of tracts including bilateral anterior thalamic radiation, fornix, and long-range tracts. These results suggest that episodic learning rate is associated with key anatomical structures for memory functioning, motivating further exploration of the differential diagnostic properties between episodic learning rate and retrieval in ageing.

Residence, Clinical Features, and Genetic Risk Factors Associated with Symptoms of COVID-19 in a Cohort of Older People in Madrid.

BACKGROUND: The older population has been especially affected by the severe acute respiratory syndrome coronavirus 2 pandemic (COVID-19). OBJECTIVE: The aim of the study was to explore the incidence, severity, mortality rate, clinical features, and risk factors of symptoms of COVID-19 in home-dwelling older people, and its association with type of residence, cognitive deterioration, and neurodegenerative diseases. METHODS: Data about symptoms of COVID-19 were collected through a telephone survey in the cohort of 913 older volunteers of the Vallecas Project, aged 75-90 years, most of them (902) home-dwelling, in Madrid, Spain. The association of demographic and anthropometric measures, genetic polymorphisms, comorbidities, life habits, type of residence, and frailty surrogates were explored as potential risk factors for the incidence, severity, and mortality of COVID-19 in the older population. FINDINGS: Sixty-two cases reported symptoms compatible with COVID-19; 6 of them had died, 4 in their home and 2 in the nursing home. Moderate/severe cases were significantly older and more frequently males. The APOE ε4 allele was associated with the presence of symptoms of COVID-19. Higher systolic blood pressure, more intense smoking habit, more alcohol intake, lower consumption of coffee and tea, and cognitive impairment were associated with disease severity. CONCLUSIONS: The estimated incidence of symptomatic COVID-19 in this older cohort of Madrid was 6.8%, with an overall mortality rate of 0.7% (18.2% in those living in a nursing home) and a fatality rate of 9.9%. Our exploratory study indicates that life habits, other clinical conditions and, the ε4 variant of the APOE gene are associated with the presence and clinical severity of coronavirus infection.

[Discriminant validity and inter-rater concordance of two scoring systems for the clock test]. / Validez discriminante y concordancia interobservador de 2 métodos de puntuación del test del reloj.

OBJECTIVE: To compare the discriminant validity and inter-rater reliability of the two scoring systems for the Clock test that are most used in Spain. METHODOLOGY: Two collections of clock drawings obtained in a clinical context (116 cases; 56.8% women, mean age 73.1±7.7 years) and in a cohort of volunteers (2039 drawings of 579 subjects; 59.5% women, mean age 78.3±3.8 years) have been assessed. All subjects were classified as cognitively normal (CN) or cognitively impaired (CI) after extensive clinical and neuropsychological evaluation. Expert raters have evaluated these drawings independently and without knowledge of the diagnosis using the Sunderland and Solomon systems standardized in Spanish by Cacho (range 0 to 10) and del Ser (range 0 to 7) respectively. The discriminant validity of each method was calculated in the two samples using the area under the ROC curve (aROC), and the inter-rater reliability was calculated in the clinical sample, that was assessed by the two evaluators, using the intraclass correlation coefficient (ICC) and the kappa coefficient. RESULTS: There are no significant differences in the discriminant validity of the Sunderland and Solomon systems in any of the samples (clinical: aROC 0.73 [CI95%: 0.64-0.81] and 0.77 [CI95%: 0.69-0.85] respectively, P=.19; volunteers: aROC 0.69 [CI95%: 0.67-0.71] and 0.72 [CI95%: 0.69-0.73] respectively, P=.08). The cut-off points ≤8 and ≤5 correctly classify 71% and 73% of the clinical sample and 82% and 84% of the volunteer sample, respectively. Both systems have good agreement in the clinical sample (Sunderland: ICC 0.90 [CI95%: 0.81-0.93], kappa 0.76 [CI95%: 0.70-0.83]; Solomon: 0.92 [CI95%: 0.88-0.95] and 0.77 [CI95%: 0.71-0.83] respectively), somewhat higher in the second, although the differences are not significant. CONCLUSIONS: The discriminant validity and inter-observer reliability of these two Clock Test correction systems are similar. Solomon's method, shorter and simpler, may be more advisable in pragmatic terms.

Dimensions of cognitive reserve and their predictive power of cognitive performance and decline in the elderly.

Background: The relative importance of different components of cognitive reserve (CR), as well as their differences by gender, are poorly established. Objective: To explore several dimensions of CR, their differences by gender, and their effects on cognitive performance and trajectory in a cohort of older people without relevant psychiatric, neurologic, or systemic conditions. Methods: Twenty-one variables related to the education, occupation, social activities, and life habits of 1,093 home-dwelling and cognitively healthy individuals, between 68 and 86 years old, were explored using factorial analyses to delineate several dimensions of CR. These dimensions were contrasted with baseline cognitive performance, follow-up over 5 years of participants' cognitive trajectory, conversion to mild cognitive impairment (MCI), and brain volumes using regression and growth curve models, controlling for gender, age, marital status, number of medications, trait anxiety, depression, and ApoE genotype. Results: Five highly intercorrelated dimensions of CR were identified, with some differences in their structure and effects based on gender. Three of them, education/occupation, midlife cognitive activities, and leisure activities, were significantly associated with late-life cognitive performance, accounting for more than 20% of its variance. The education/occupation had positive effect on the rate of cognitive decline during the 5-year follow up in individuals with final diagnosis of MCI but showed a reduced risk for MCI in men. None of these dimensions showed significant relationships with gray or white matter volumes. Conclusion: Proxy markers of CR can be represented by five interrelated dimensions. Education/occupation, midlife cognitive activities, and leisure activities are associated with better cognitive performance in old age and provide a buffer against cognitive impairment. Education/occupation may delay the clinical onset of MCI and is also associated with the rate of change in cognitive performance.

ICF-based disability survey in a rural population of adults and older adults living in Cinco Villas, Northeastern Spain: design, methods and population characteristics.

BACKGROUND: This article describes the methods of a door-to-door screening survey exploring the distribution of disability and its major determinants in northeastern Spain. This study will set the basis for the development of disability-related services for the rural elderly in northeastern Spain. METHODS: The probabilistic sample was composed of 1,354 de facto residents from a population of 12,784 Social Security card holders (age: > or = 50 years). Cognitive and disability screenings were conducted (period: June 2008-June 2009). Screening instruments were the MMSE and the World Health Organization Disability Assessment Schedule. Participants screened positive for disability underwent an assessment protocol focusing on primary care diagnoses, disability, lifestyle, and social and health service usage. Participants screened positive for cognitive functioning went through in-depth neurological evaluation. RESULTS: The study sample is described. Usable data were available for 1,216 participants. A total of 625 individuals (51.4%) scored within the positive range in the disability screening, while 135 (11.1%) scored within the positive range of the cognitive screening. The proportion of positively screened individuals was higher for women and increased with age. CONCLUSIONS: Screening surveys represent a feasible design for examining the distribution of disability and its determinants among the elderly. Data quality may benefit from methodological developments tailored to rural populations with a low education level.

Effects of commonly prescribed drugs on cognition and mild cognitive impairment in healthy elderly people.

BACKGROUND: Chronic drug intake has been associated with negative and positive cognitive effects in elderly people, although subjacent conditions may be confounding factors. AIM: To study the effects on cognitive performance of commonly prescribed medications in a cohort of cognitively normal older adults. METHODS: Medication intake was recorded during two years in 1087 individuals 70-85 years old, without neurological or psychiatric conditions. The influence of every drug, drug family and therapeutic group on six cognitive scores and on the conversion to mild cognitive impairment over two years was ascertained by cross-sectional and longitudinal analyses controlling for demographic and clinical variables. RESULTS: Small effects of several drugs on information processing were found in cross-sectional analyses but only confirmed for a positive effect of vitamin D in case-control analyses. Longitudinal analyses showed no drug effects on the cognitive slopes. Several hypotensive drugs reduced, whereas bromazepam and glucose lowering drugs increased, the conversion rate to mild cognitive impairment with very small effects (R2=0.3-1%). CONCLUSIONS: Cognitively healthy elderly individuals show minimal negative effects on information processing associated with chronic intake of some drugs probably related to the subjacent condition. Some drugs slightly affect the rate of conversion to mild cognitive impairment. Positive effects of vitamin D, chondroitin, atorvastatin and antihypertensive drugs, and negative effects of antidepressants and benzodiazepines, should be further explored in studies with longer follow-up.

Burden, perceived health status, and mood among caregivers of Parkinson's disease patients.

The objective of this study is to describe the characteristics of the caregivers of patients with Parkinson's disease (PD) and to analyze the association between these characteristics and caregiver burden, perceived health and mood status, and identify their predictors. A multicenter, nationwide, observational, cross-sectional study that included 289 patient-caregiver pairs was conducted. Caregiver self-assessments were the Hospital Anxiety and Depression Scale (HADS), EuroQol (EQ), and Zarit Caregiver Burden Inventory (ZCBI). Most caregivers in the study were women aged 60 years or thereabouts. Over two thirds were gainfully employed or housewives, 75% were patients' spouses, and the majority (96.5%) had been permanently taking care of the patient for 6 +/- 5.4 years. Less than 5% of patients were in the most advanced stages of disease, and direct costs were 6,350 euros per patient per year. Caregivers had more mood disorders and worse health-related quality of life (HRQol; EQ-Tariff) than did the general population. Caregiver HADS and EuroQol scores displayed a weak correlation (r(S) = 0.01-0.28) with patient-related variables (disease duration, HY, SCOPA-Motor, SCOPA-AUT, HADS, PPRS, and CISI-PD) whereas the ZCBI correlated moderately (r(S) = 0.27-0.47). Among caregivers, the EQ-Tariff was significantly lower and the HADS-Anxiety scores significantly higher for women. ZCBI and HADS-depression, though not EuroQol and HADS-anxiety, scores significantly increased with increasing PD severity levels. Caregivers' affective status proved the most important factor influencing their burden and perceived health, whereas patient-related variables influenced caregiver burden and mood but not health status. In PD, prevalence of affective disorders among patients' caregivers is high and influences both burden and HRQoL.

The SCOPA-Motor Scale for assessment of Parkinson's disease is a consistent and valid measure.

OBJECTIVE: The SCOPA-Motor Scale (S-MS) for assessment of Parkinson's disease (PD), contains 21 items in three domains: Motor examination, Disability, and Complications. Our objective was to validate the S-MS Spanish version. STUDY DESIGN AND SETTING: This validation study was based on a multicenter, cross-sectional, one-point-in-time evaluation design. The applied measures were: Unified Parkinson's Disease Rating Scale-3.0 (UPDRS); S-MS; PD Global Evaluation (PDGE); and Clinical Global Impression of severity (CGI). Completeness of data collection, floor and ceiling effect, internal consistency, precision, and construct and discriminative validity were analyzed in 151 PD patients. RESULTS: Scores from S-MS were fully computable. Floor effect was high for Complications (43.7%). Cronbach's alpha was > 0.90 for every domain, and item-total correlation was > 0.70 except for Examination. Standard error of measurement (SEM) ranged from 0.40 to 2.4. Convergent validity with corresponding UPDRS sections yielded coefficients > 0.90. Discriminative validity across Hoehn and Yahr (HY) and CGI stages was significant (Kruskal-Wallis, P < .0001). Insofar as internal consistency was concerned, alpha-values of the Examination sections were marginally higher for the UPDRS than for the S-MS (a finding perhaps accounted for by redundancy in this part of the UPDRS). CONCLUSION: The S-MS is a consistent and valid scale, shorter by almost half than the UPDRS.

The Vallecas Project: A Cohort to Identify Early Markers and Mechanisms of Alzheimer's Disease.

INTRODUCTION: Alzheimer's disease (AD) is a major threat for the well-being of an increasingly aged world population. The physiopathological mechanisms of late-onset AD are multiple, possibly heterogeneous, and not well understood. Different combinations of variables from several domains (i.e., clinical, neuropsychological, structural, and biochemical markers) may predict dementia conversion, according to distinct physiopathological pathways, in different groups of subjects. METHODS: We launched the Vallecas Project (VP), a cohort study of non-demented people aged 70-85, to characterize the social, clinical, neuropsychological, structural, and biochemical underpinnings of AD inception. Given the exploratory nature of the VP, multidimensional and machine learning techniques will be applied, in addition to the traditional multivariate statistical methods. RESULTS: A total of 1169 subjects were recruited between October 2011 and December 2013. Mean age was 74.4 years (SD 3.9), 63.5% of the subjects were women, and 17.9% of the subjects were carriers of at least one ε4 allele of the apolipoprotein E gene. Cognitive diagnoses at inclusion were as follows: normal cognition 93.0% and mild cognitive impairment (MCI) 7.0% (3.1% amnestic MCI, 0.1% non-amnestic MCI, 3.8% mixed MCI). Blood samples were obtained and stored for future determinations in 99.9% of the subjects and 3T magnetic resonance imaging study was conducted in 89.9% of the volunteers. The cohort is being followed up annually for 4 years after the baseline. CONCLUSION: We have established a valuable homogeneous single-center cohort which, by identifying groups of variables associated with high risk of MCI or dementia conversion, should help to clarify the early physiopathological mechanisms of AD and should provide avenues for prompt diagnosis and AD prevention.

Motor effects of radio electric asymmetric conveyer in Alzheimer's disease: results from a cross-over trial.

We conducted a randomized, cross-over trial to investigate the feasibility, safety, and motor effects of brain stimulation with radio electric asymmetric conveyer (REAC) technique in patients with Alzheimer's disease (AD). Neuropostural optimization (NPO) and sham protocol were administered to 60 patients from the nursing home and day care units of the Alzheimer Center Reina Sofía Foundation. The mean age was 84.1 (SD 7.9) years and 86.7% of the subjects were female. Motor measures were collected at baseline (T1), immediately (T2), seven (T3), and 11 days (T4) after treatment and, following cross-over, immediately (T5), seven (T6), and 11 (T7) days after treatment. Close safety surveillance was conducted from seven days before T1 to the end of the study (T7), with total study duration of 35 days. Wilcoxon test was utilized in the efficacy analysis, considering T1 and T5 as independent baseline assessments and using a threshold of p < 0.05 (corrected) for statistical significance. The NPO protocol was easily administered and well accepted by the participants. Axial movements improved at T3 and T4 after NPO and at T2 after sham NPO, but no significant effects were observed in axial movements in the second phase of the trial. The effects of NPO in gait performance were not consistent. There were six falls between T2 and T7, but only two of them occurred in patients who had received NPO. In light of safety and feasibility of REAC, a trial with the more intense neuropsycho-physical optimization protocol is warranted.

Assessment of preference for edible and leisure items in individuals with dementia.

We conducted 2 studies on reinforcer preference in patients with dementia. Results of preference assessments yielded differential selections by 14 participants. Unlike prior studies with individuals with intellectual disabilities, all participants showed a noticeable preference for leisure items over edible items. Results of a subsequent analysis with 3 participants showed reinforcement effects when highly preferred items were delivered as consequences.

Promoting research in advanced dementia: early clinical results of the Alzheimer Center Reina Sofía Foundation.

The Alzheimer Center Reina Sofía Foundation (ACRSF) was envisaged to address the complex and multi-disciplinary research and care needs posed by Alzheimer's disease (AD) and other neurodegenerative dementias. Patients may be admitted at ACRSF either as inpatients (i.e., nursing home) or outpatients (i.e., day-care center). The research program includes clinical, social, biochemical, genetic, and magnetic resonance investigations, as well as brain donation. We present the inception of the clinical research protocol for the ACRSF, the early results, and the amendments to the protocol. Foreseen as distinct populations, inpatient and outpatient results are presented separately. Data were collected from 180 patients (153 inpatients, 27 outpatients) (86% AD), with informed consent for participation in the research program of the ACRSF. Most patients (95%) had moderate to severe dementia. Nursing home patients were older, displayed marked gait dysfunction, and were significantly more dependent in the activities of daily living (ADL), compared to the day-care patients (p < 0.05). Some cognitive, ADL, and quality of life (QoL) scales were eliminated from the protocol due to floor effect or lack of specificity of contents for advanced dementia. New measurements were added for evaluation of cognition, apathy, agitation, depression, ADL, motor function, and QoL. The final assessment is expected to be sensitive to change in all the clinical aspects of advanced degenerative dementia, to promote multidisciplinary and, desirably, inter-center collaborative research and, eventually, to contribute to the improvement of treatment and care for these patients.

Global versus factor-related impression of severity in Parkinson's disease: a new clinimetric index (CISI-PD).

In Parkinson's disease (PD), the Clinical Global Impression of Severity (CGIS) is often used as an additional outcome in clinical trials. It is hypothesized that this measure summarizes clinical assessment and is mainly influenced by the rating of four domains, namely, motor signs, disability, motor complications, and cognitive impairment. Ratings of these four factors were combined to form a new Clinical Impression of Severity Index for Parkinson's Disease (CISI-PD). A sample of 150 PD patients was evaluated using the following scales: Hoehn and Yahr staging, Schwab and England scale, Unified Parkinson's Disease Rating Scale, Scales for Outcomes in Parkinson's Disease-Motor Scale, CGIS, and CISI-PD. The results show that the CGIS is closely related to the above-mentioned measures (r=0.49-0.89). CISI-PD correlation with these scales was very similar (r=0.55-0.91), to the extent that the difference between corresponding coefficients was systematically less than 0.10. A multiple regression model showed that 92% of the CIGS variance was explained by the four CISI-PD items. Finally, the CISI-PD displayed adequate psychometric properties, with satisfactory internal consistency (alpha=0.90) and convergent (r>0.75) and known-groups validity. The CISI-PD is a valid and reliable measure that expands the information obtained via the CGIS.

Impact of fatigue in Parkinson's disease: the Fatigue Impact Scale for Daily Use (D-FIS).

The Fatigue Impact Scale for Daily Use (D-FIS) was used in a cross-sectional study including 142 consecutive Parkinson's disease (PD) patients. Usual clinical measures for PD, the Montgomery-Asberg Depression Rating Scale and the Parkinson's Disease Questionnaire-8 items were applied. In addition to the D-FIS, patients with fatigue (67.6%, PWF) completed the Multidimensional Fatigue Inventory (MFI), a visual analogue scale for fatigue (VAS-F) and a Global Perception of Fatigue scale (GPF). Relevant psychometric D-FIS results were: floor effect = 4.2%; ceiling effect = 1.1%; skewness = 0.44; item homogeneity = 0.63; Cronbach's alpha = 0.93; item-total correlation = 0.68 (item 1)-0.82 (item 8); standard error of measurement = 2.15; convergent validity with other fatigue measures = 0.54 [GPF]-0.62 [VAS-F] (p<0.001). In a multiple linear regression model, fatigue, depression, and disability independently influenced HRQoL, as measured by the PDQ-8. Patients on amantadine had lower prevalence of fatigue. In PD, D-FIS is a consistent and valid measure for fatigue, a frequent symptom previously found to impair patients' HRQoL. Fatigue was also linked to depression and disability in this study.