Association of Chronic Pain with Biomarkers of Neurodegeneration, Microglial Activation, and Inflammation in Cerebrospinal Fluid and Impaired Cognitive Function.

OBJECTIVE: Debate surrounds the role of chronic pain as a risk factor for cognitive decline and dementia. This study aimed at examining the association of chronic pain with biomarkers of neurodegeneration using data from the Alzheimer's Disease Neuroimaging Initiative. METHODS: Participants were classified using the ATN (amyloid, tau, neurodegeneration) classification. Chronic pain was defined as persistent or recurrent pain reported at baseline. For each ATN group, analysis of covariance models identified differences in cerebrospinal fluid (CSF) levels of amyloid ß1-42 , phosphorylated tau 181 (ptau181 ), total tau (t-tau), soluble triggering receptor expressed on myeloid cells 2 (sTREM2), and cognitive function between chronic pain states. Differences in CSF levels of inflammatory markers between chronic pain states were further analyzed. Linear mixed effect models examined longitudinal changes. RESULTS: The study included 995 individuals, with 605 (60.81%) reporting chronic pain at baseline. At baseline, individuals with suspected non-Alzheimer pathophysiology and chronic pain showed increased CSF levels of t-tau and sTREM2. Chronic pain was associated with increased tumor necrosis factor α levels, irrespective of the ATN group. Longitudinally, an increase in ptau181 CSF levels was observed in chronic pain patients with negative amyloid and neurodegeneration markers. Amyloid-positive and neurodegeneration-negative chronic pain patients showed higher memory function cross-sectionally. No significant longitudinal decline in cognitive function was observed for any ATN group. INTERPRETATION: Our study suggests that chronic pain induces neuronal damage and microglial activation in particular subgroups of patients along the AD spectrum. Further studies are needed to confirm these findings. ANN NEUROL 2023.

Cognitive function in amyotrophic lateral sclerosis: a cross-sectional and prospective pragmatic clinical study with review of the literature.

BACKGROUND: Amyotrophic lateral sclerosis (ALS) can present with either bulbar or spinal symptoms, and in some cases, both types of symptoms may be present. In addition, cognitive impairment has been observed in ALS. The study aimed to evaluate the frontal and general cognitive performance in ALS not only cross-sectionally but also longitudinally. METHODS AND MATERIALS: The Frontal Assessment Battery (FAB) and the Montreal Cognitive Assessment (MoCA) were employed to assess cognitive function in 52 adults with ALS and 52 cognitively healthy individuals. The statistical analyses encompassed the Pearson Chi square test, the Skillings-Mack test, the Spearman's rank correlation coefficient, and the Proportional Odds Logistic Regression Model (POLR). RESULTS: Cross-sectionally, lower cognitive performance was associated with ALS diagnosis, older age, and motor functional decline. The cognitive impairment of individuals with bulbar and spinal-bulbar symptoms showed faster deterioration compared to those with spinal symptoms. The spinal subgroup consistently performed worst in delayed recall and attention, while the spinal-bulbar and bulbar subgroups exhibited inferior scores in delayed recall, attention, visuospatial skills, orientation, and verbal fluency. CONCLUSION: The incorporation of cognitive screening in the diagnostic workup of ALS may be beneficial, as early detection can enhance symptom management and improve the quality of life for both individuals with ALS and their care partners.

Depressive symptoms in the entire spectrum of cognitive ageing in Greece: evidence from the Hellenic Longitudinal Investigation of Aging and Diet (HELIAD).

OBJECTIVES: To study (i) the prevalence of mild and moderate-to-severe depressive symptoms in the entire spectrum of cognitive ageing in Greece and (ii) the relationship between these symptoms and demographic and clinical data. METHODS: The study was based on the randomly selected cohort of the Hellenic Longitudinal Investigation of Aging and Diet (HELIAD). Depressive symptoms were assessed with the 15-item version of the Geriatric Depression Scale. Participants also received a comprehensive neuropsychological assessment, while the clinical diagnoses of dementia and mild cognitive impairment were established according to international diagnostic criteria. Statistical analyses relied on comparison tests and a logistic (proportional odds) ordinal regression model. RESULTS: Depressive symptoms were detected in 19.5% of the 1936 study participants, while 11.3% of both people with MCI and dementia had moderate-to-severe depressive symptoms. The regression model revealed that older adults with more severe depressive symptoms were more likely female, cognitively impaired, less educated, were treated with psychotropic medication and lived in Attica versus Thessaly. CONCLUSIONS: Since depressive symptoms were detected in almost one in five older adults, healthcare professionals in Greece should safeguard the timely detection and effective treatment of such symptoms and the post-diagnostic care of older adults with depression.

Depressive symptoms are present in approximately 20% of older adults.More than 10% of older individuals with dementia or mild cognitive impairment report moderate-to-severe depressive symptoms.Female sex, lower education, lower cognitive performance, living in urban areas and treatment with psychotropic medication pertain to more severe depressive symptoms in ageing.Timely detection and effective treatment of depressive symptoms are crucial in the clinical practice of the care of older adults.Further research is needed in order to elucidate the complex relationship between depressive symptoms and cognitive impairment in ageing.

Low cognitive functioning and depressive symptoms in patients with rheumatoid arthritis and systemic sclerosis: a clinical study.

BACKGROUND: Recently, cognitive deficits occurring in rheumatic diseases have attracted scientific attention. Cognitive symptoms in patients with Rheumatoid Arthritis (RA) and Systemic Sclerosis (SSc) have not been thoroughly studied. This study aimed to assess cognitive function and its relationship with depressive symptoms in RA and SSc and compare it to mild neurocognitive disorder due to Alzheimer's disease (MiND) and to individuals without cognitive impairment. METHODS: Cognitive function and depressive symptoms were tapped with the Cognitive Telephone Screening Instrument plus (COGTEL+), the Serial Seven Test (SST), the Mini-Mental State Examination (MMSE) and the Geriatric Depression scale-15 (GDS), respectively. Statistical analyses included between groups-, correlation- and regression analyses. Demographic characteristics were considered in the regression models. RESULTS: The study included 30 individuals with RA, 24 with SSc, 26 adults without cognitive impairment and 33 individuals with MiND. Lower performance in verbal short-term memory, concentration/attention, verbal fluency and MMSE in patients with RA compared to individuals without cognitive impairment was detected. Of note, performance on verbal fluency, concentration/attention, inductive reasoning and MMSE was lower in RA compared to MiND. Individuals with SSc performed worse in verbal fluency and in MMSE in comparison to adults without cognitive deficits. Verbal fluency deficits in SSc exceeded that in MiND. Performance on MMSE, COGTEL+, prospective memory, working memory, verbal fluency and concentration/attention was related to GDS scores, which did not vary across the groups. CONCLUSIONS: Patients with RA and SSc encountered cognitive dysfunction, which partially pertains to depressive symptoms. Of note, the severity of cognitive dysfunction in many cases exceeded that of MiND.

Old-age mental telehealth services at primary healthcare centers in low- resource areas in Greece: design, iterative development and single-site pilot study findings.

BACKGROUND: Even though communities in low-resource areas across the globe are aging, older adult mental and cognitive health services remain mainly embedded in tertiary- or secondary hospital settings, and thus not easily accessible by older adults living in such communities. Here, the iterative development of INTegRated InterveNtion of pSychogerIatric Care (INTRINSIC) services addressing the mental and cognitive healthcare needs of older adults residing in low-resource areas of Greece is depicted. METHODS: INTRINSIC was developed and piloted in three iterative phases: (i) INTRINSIC initial version conceptualization; (ii) A 5-year field testing in Andros island; and (iii) Extending the services. The INTRINSIC initial version relied on a digital platform enabling videoconferencing, a flexible battery of diagnostic tools, pharmacological treatment and psychosocial support and the active involvement of local communities in service shaping. RESULTS: Ιn 61% of the 119 participants of the pilot study, new diagnoses of mental and/or neurocognitive disorders were established. INTRINSIC resulted in a significant reduction in the distance travelled and time spent to visit mental and cognitive healthcare services. Participation was prematurely terminated due to dissatisfaction, lack of interest or insight in 13 cases (11%). Based on feedback and gained experiences, a new digital platform, facilitating e-training of healthcare professionals and public awareness raising, and a risk factor surveillance system were created, while INTRINSIC services were extended to incorporate a standardized sensory assessment and the modified problem adaptation therapy. CONCLUSION: The INTRINSIC model may be a pragmatic strategy to improve access of older adults with mental and cognitive disorders living in low-resource areas to healthcare services.

Hospital workforce mental reaction to the pandemic in a low COVID-19 burden setting: a cross-sectional clinical study.

Τhe COVID-19 pandemic has mental health implications for both healthcare workforces and general population, particularly in regions heavily hit by the crisis. Τhe study aimed (i) to investigate anxiety- and depression severity differences between staff of a COVID-19 treatment unit (N = 84) and a hospital without such a unit (N = 55) in comparison to participants of a convenience general population online survey (N = 240) and (ii) to explore relations between such symptoms and hospital staff reaction to COVID-19 in a low COVID-19 burden setting. Anxiety was studied with the Generalized Anxiety Disorder 7-Item in hospital workforces and with the Hospital Anxiety Depression Scale (HADS) in online survey participants. Depression symptoms were assessed with the Patient Health Questionnaire-9 in hospital employees and the HADS in the online survey sample. Symptoms were classified as absent/minimal, borderline abnormal or indicating clinical caseness. Staff reaction to COVID-19 was tapped with a 9-item-questionnaire and the 22-item Impact of Event Scale-revised (IES-R). Proper tests for differences and stepwise ordered logistic regression models were employed. Anxiety- and depression severity was higher in hospital workforces than in online survey participants (P < 0.05). Anxiety was more severe in frontline- compared to backstage employees (P < 0.001) was inversely correlated with age (P = 0.011) and positively with avoidance (P = 0.028). Both anxiety and depression symptoms related to intrusion symptoms (P < 0.001). Regarding the relatively long data collection period, an inverse association between crisis duration and depression symptoms was detected (P = 0.025). These observations point to the urgent need for distress-mitigating interventions for hospital workforces even in low COVID-19 burden settings.

Naming ability assessment in neurocognitive disorders: a clinician's perspective.

BACKGROUND: Detecting impaired naming capacity is valuable in diagnosing neurocognitive disorders (ND). A. clinical practice- oriented overview of naming tests validated in ND is not available yet. Here, features of naming tests with validated utility in ND which are open access or available for purchase are succinctly presented and compared. METHODS: Searches were carried out across Pubmed, Medline and Google Scholar. Additional studies were identified by searching reference lists. Only peer-reviewed journal articles were eligible. A narrative- and tabullar synthesis was used to summarize different aspects of the naming assessment instruments used in patients with ND such as stimuli type, administration time, assessment parameters and accessibility. Based on computational word frequency calculations, the tests were compared in terms of the average frequency of their linguistic content. RESULTS: Twelve naming tests, relying either on visual or auditory stimuli have been validated in ND. Their content and administration time vary between three and 60 items and one and 20 minutes, respectively. The average frequency of the words of each considered test was two or lower, pointing to low frequency of most items. In all but one test, scoring systems are exclusively based on correctly named items. Seven instruments are open access and four are available in more than one language. CONCLUSIONS: Gaining insights into naming tests' characteristics may catalyze the wide incorporation of those with short administration time but high diagnostic accuracy into the diagnostic workup of ND at primary healthcare and of extensive, visual or auditory ones into the diagnostic endeavors of memory clinics, as well as of secondary and tertiary brain healthcare settings.

Alzheimer's disease research progress in the Mediterranean region: The Alzheimer's Association International Conference Satellite Symposium.

As research and services in the Mediterranean region continue to increase, so do opportunities for global collaboration. To support such collaborations, the Alzheimer's Association was due to hold its seventh Alzheimer's Association International Conference Satellite Symposium in Athens, Greece in 2021. Due to the COVID-19 pandemic, the meeting was held virtually, which enabled attendees from around the world to hear about research efforts in Greece and the surrounding Mediterranean countries. Research updates spanned understanding the biology of, treatments for, and care of people with Alzheimer's disease (AD_ and other dementias. Researchers in the Mediterranean region have outlined the local epidemiology of AD and dementia, and have identified regional populations that may expedite genetic studies. Development of biomarkers is expected to aid early and accurate diagnosis. Numerous efforts have been made to develop culturally specific interventions to both reduce risk of dementia, and to improve quality of life for people living with dementia.

The Effects of COVID-19 lockdown on neuropsychiatric symptoms in patients with dementia or mild cognitive impairment: A systematic review and meta-analysis.

The COVID-19 pandemic may have a disproportionate impact on people with dementia/mild cognitive impairment (MCI) due to isolation and loss of services. The aim of this systematic review was to investigate the effects of the COVID-19 lockdown on neuropsychiatric symptoms (NPS) in people living with dementia/MCI. Two authors searched major electronic databases from inception to June 2021 for observational studies investigating COVID-19 and NPS in people with dementia/MCI. Summary estimates of mean differences in NPS scores pre- versus post-COVID-19 were calculated using a random-effects model, weighting cases using inverse variance. Study quality and risk of bias were assessed by the Newcastle-Ottawa Scale. From 2730 citations, 21 studies including 7139 patients (60.0% female, mean age 75.6 ± 7.9 years, 4.0% MCI) with dementia were evaluated in the review. Five studies found no changes in NPS, but in all other studies, an increase in at least one NPS or the pre-pandemic Neuropsychiatric Inventory (NPI) score was found. The most common aggravated NPS were depression, anxiety, agitation, irritability, and apathy during lockdown, but 66.7% of the studies had a high bias. Seven studies including 420 patients (22.1% MCI) yielded enough data to be included in the meta-analysis. The mean follow-up time was 5.9 ± 1.5 weeks. The pooled increase in NPI score before compared to during COVID-19 was 3.85 (95% CI:0.43 to 7.27; P = 0.03; I2  = 82.4%). All studies had high risk of bias. These results were characterized by high heterogeneity, but there was no presence of publication bias. There is an increase in the worsening of NPS in people living with dementia/MCI during lockdown in the COVID pandemic. Future comparative studies are needed to elucidate whether a similar deterioration might occur in people without dementia/MCI.

Associations between APOE-, COMT Val108/158Met- and BDNF Val66Met polymorphisms and variations in depressive and anxiety symptoms, sense of coherence and vital exhaustion in the real-life setting of mandatory basic military training.

Apolipoprotein E (APOE) ε, catechol-O-methytranferase (COMT) Val108/158Met and brain-derived neurotrophic factor (BDNF) Val66Met single nucleotide polymorphisms (SNPs) were shown to affect stress perception and response. The present study explored possible associations between these SNPs and changes in subclinical anxiety- and depressive symptoms, sense of coherence (SOC) and vital exhaustion (VE) during compulsory basic military training. The study encompassed 179 conscripts of a training base in Greece. The neuropsychiatric assessment was based on the Beck Depression Inventory, the State-Trait Anxiety Inventory, the Antonovsky SOC scale and the Maastricht Questionnaire. It was conducted at three time points of the 19-day basic military training: on day one (baseline), day six (follow-up I) and day 13 (follow-up II). Statistical analyses included Mann-Whitney test, Chi-square test and cross-sectional time series regression models based on the Skillings-Mack statistic. APOE ε4 non-carriers encountered significant changes in anxiety- and depressive symptoms and SOC (in all cases P < 0.001) over the observation period, whilst ε4 carriers did not. The changes in anxiety, depressive symptoms and SOC attained statistical significance in both BDNF Met66 carriers (in all cases P < 0.001) and non-carriers (P = 0.036; < 0.001; < 0.001, respectively) as well as in COMT Met108/158 carriers (P = 0.004; < 0.001; < 0.001, respectively) and non-carriers (P = 0.02; 0.01; 0.021, respectively. Changes over time in VE were not significant (P > 0.05). The observed resistance of APOE ε4 carriers vs non-carriers to changes in anxiety- and depressive symptoms and SOC when exposed to a stressful environment may point to superior coping capacities of healthy young men carrying the ε4 allele.

Differences in cause and 12-month follow-up outcome of parkinsonian symptoms in depressed older adults treated with antipsychotics: a case series.

BACKGROUND: Parkinsonian symptoms are common adverse effects of antipsychotics. Older adults are particularly vulnerable to drug-induced parkinsonism. Nonetheless, parkinsonian symptoms in seniors treated with antipsychotics cannot be straightforwardly attributed to antipsychotic medication. A comprehensive diagnostic workup is necessary in many cases in order to shed light on the cause of such symptoms in this patient population. CASE SERIES: Eight cases of hospitalized depressed older adults with parkinsonian symptoms, who were treated for at least one year with antipsychotics, are reported. Based on neurological consultation, structural brain imaging and Ioflupane (I-123) dopamine transporter (DAT) single photon emission computerized tomography (SPECT), Parkinson's disease was diagnosed in one case, idiopathic tremor in another, vascular parkinsonism in another one, while in another individual parkinsonian symptoms persisted at 12-month post-discharge follow-up even though his/her symptoms were classified as drug-induced on discharge. In four patients, parkinsonian symptoms were definitely drug-induced and no movement disturbances were reported at follow-up. CONCLUSIONS: Differences in the cause and outcome of parkinsonian symptoms in seniors treated with antipsychotics merit systematic and in-depth study considering the therapeutic and prognostic implications of an accurate detection of the cause of such symptoms. Familiarizing clinical psychiatrists with these differences could pave the way towards approaching seniors with severe, atypical and/or persistent parkinsonian symptoms in a more individualized diagnostic and therapeutic manner, and towards more cautious prescribing of antipsychotics in this age group.

Age and the association between apolipoprotein E genotype and Alzheimer disease: A cerebrospinal fluid biomarker-based case-control study.

BACKGROUND: The ε4 allele of apolipoprotein E (APOE) gene and increasing age are two of the most important known risk factors for developing Alzheimer disease (AD). The diagnosis of AD based on clinical symptoms alone is known to have poor specificity; recently developed diagnostic criteria based on biomarkers that reflect underlying AD neuropathology allow better assessment of the strength of the associations of risk factors with AD. Accordingly, we examined the global and age-specific association between APOE genotype and AD by using the A/T/N classification, relying on the cerebrospinal fluid (CSF) levels of ß-amyloid peptide (A, ß-amyloid deposition), phosphorylated tau (T, pathologic tau), and total tau (N, neurodegeneration) to identify patients with AD. METHODS AND FINDINGS: This case-control study included 1,593 white AD cases (55.4% women; mean age 72.8 [range = 44-96] years) with abnormal values of CSF biomarkers from nine European memory clinics and the American Alzheimer's Disease Neuroimaging Initiative (ADNI) study. A total of 11,723 dementia-free controls (47.1% women; mean age 65.6 [range = 44-94] years) were drawn from two longitudinal cohort studies (Whitehall II and Three-City), in which incident cases of dementia over the follow-up were excluded from the control population. Odds ratio (OR) and population attributable fraction (PAF) for AD associated with APOE genotypes were determined, overall and by 5-year age categories. In total, 63.4% of patients with AD and 22.6% of population controls carried at least one APOE ε4 allele. Compared with non-ε4 carriers, heterozygous ε4 carriers had a 4.6 (95% confidence interval 4.1-5.2; p < 0.001) and ε4/ε4 homozygotes a 25.4 (20.4-31.2; p < 0.001) higher OR of AD in unadjusted analysis. This association was modified by age (p for interaction < 0.001). The PAF associated with carrying at least one ε4 allele was greatest in the 65-70 age group (69.7%) and weaker before 55 years (14.2%) and after 85 years (22.6%). The protective effect of APOE ε2 allele for AD was unaffected by age. Main study limitations are that analyses were based on white individuals and AD cases were drawn from memory centers, which may not be representative of the general population of patients with AD. CONCLUSIONS: In this study, we found that AD diagnosis based on biomarkers was associated with APOE ε4 carrier status, with a higher OR than previously reported from studies based on only clinical AD criteria. This association differs according to age, with the strongest effect at 65-70 years. These findings highlight the need for early interventions for dementia prevention to mitigate the effect of APOE ε4 at the population level.

Associations between (sub) clinical stress- and anxiety symptoms in mentally healthy individuals and in major depression: a cross-sectional clinical study.

BACKGROUND: Responses to stressful circumstances have psychological and physiological dimensions, and are related to anxiety symptoms and mental disorders such as depression. Nonetheless, the relationship between subclinical stress and anxiety symptoms is still elusive. METHODS: To explore possible associations between stress and anxiety symptoms, patients with major depression (N = 77) and mentally healthy individuals of different age clusters and occupations (N = 412) were enrolled into the study. Stress was assessed with the new subclinical stress symptom questionnaire (SSQ-25). Anxiety was studied with the Beck Anxiety Inventory (BAI), mainly focusing on clinical anxiety, whilst anxiety as a personality trait was assessed with the trait aspect of the State Τrait Αnxiety Ιnventory Y (STAI Y). Statistical analyses included ANOVA, Scheffe test, linear regression models and a two-step cluster analysis using Log-Likelihood Distance measure and fixed number of two clusters. RESULTS: Age, stress symptoms and BAI scores differed significantly between among groups (P < 0.001), whilst STAI Y scores did not. Stress levels were found to be related to clinical anxiety (P < 0.001), while neither group identity nor age exerted any influence on anxiety levels (P > 0.05). The two Step Cluster analysis classified 76 out of 77 participants with milder stress (subclinical) symptoms into the cluster with moderate anxiety, as indicated by BAI scores, and all individuals with more severe stress into the severe anxiety cluster. CONCLUSIONS: The observed associations between stress and anxiety shed light on the interrelations between even very mild (subclinical) stress and anxiety symptoms and may point to the potential of mild stress to serve as a target for early interventions aiming to prevent anxiety morbidity.

Berkson's paradox and weighted distributions: An application to Alzheimer's disease.

One reason for observing in practice a false positive or negative correlation between two random variables, which are either not correlated or correlated with a different direction, is the overrepresentation in the sample of individuals satisfying specific properties. In 1946, Berkson first illustrated the presence of a false correlation due to this last reason, which is known as Berkson's paradox and is one of the most famous paradox in probability and statistics. In this paper, the concept of weighted distributions is utilized to describe Berskon's paradox. Moreover, a proper procedure is suggested to make inference for the population given a biased sample which possesses all the characteristics of Berkson's paradox. A real data application for patients with dementia due to Alzheimer's disease demonstrates that the proposed method reveals characteristics of the population that are masked by the sampling procedure.

The overnight reduction of amyloid ß 1-42 plasma levels is diminished by the extent of sleep fragmentation, sAPP-ß, and APOE ε4 in psychiatrists on call.

INTRODUCTION: In mice there might be an association between sleep deprivation and amyloid ß plasma levels. Hence, we examined whether amyloid plasma levels are associated with sleep duration or fragmentation in 17 psychiatrists on-call. METHODS: Amyloid ß (Aß)42, Aß40, and soluble amyloid precursor protein ß (sAPP-ß) plasma concentrations were measured at the beginning and end of 90 on-call nights, and analyzed using generalized linear models. RESULTS: In on-call nights, a 10.7% reduction of Aß42 was revealed overnight. Every single short sleep interruption diminished this reduction by 5.4%, as well as every pg/mL of sAPP-ß by 1.2%, each copy of APOE ε4 by 10.6%, and each year of professional experience by 3.0%. DISCUSSION: The extent of sleep fragmentation diminishes the physiological overnight reduction of Aß42 but not Aß40 plasma levels in the same direction as the enzyme for Aß42 production, the genetic risk factor for Alzheimer's disease (AD), and on-call experience. Might on-call duty and sleep fragmentation in general alter the risk for AD?

Determinants of self- and carer-rated quality of life and caregiver burden in Alzheimer disease.

OBJECTIVE: We aimed to investigate factors associated with self- and carer-rated quality of life (QoL) and caregiver burden related to very mild to severe clinical Alzheimer disease (AD). METHODS: One hundred patient-carer dyads were recruited, and assessments of relevant outcomes were performed, including sociodemographic characteristics, QoL, activities of daily living (ADL), cognitive performance, behavioural and psychological symptoms of dementia (BPSD), caregiver burden, and health resource utilisation. RESULTS: There was a strong correlation between carer- and self-rated QoL, with patients consistently rating their QoL higher than caregivers. Duration of illness did not affect the QoL ratings. There was an inverse association between both self- and carer-rated QoL with age, age at symptom onset, impairment of ADL, time spent on assisting the patient, and depression. Both self- and carer-rated QoL ratings were higher if the caregiver was a spouse vs a child. Carer-rated QoL was inversely associated with severity of dementia, BPSD, caregiver burden, and requirement to supervise the patient. The variables age at symptom onset, ADL, and living together with the primary caregiver explained 34.50% of the variance in self-rated QoL, whereas age at symptom onset, ADL, and BPSD explained 48.20% of the variance in carer-rated QoL. For caregiver burden, 26% of the variance was explained by the variables ADL, living together with the primary caregiver, and agitation. CONCLUSION: Our study highlights the need for a stronger focus on QoL in clinical AD research by providing further pieces of evidence on the key determinants, including the important aspect of caregiver burden.

Alzheimer Disease and Mild Cognitive Impairment: Integrated Pulsed Arterial Spin-Labeling MRI and 18F-FDG PET.

Purpose To compare PET/MR hypoperfusion and hypometabolism in patients with Alzheimer disease (AD) and mild cognitive impairment (MCI) compared with healthy control (HC) participants. Materials and Methods Maps of cerebral blood flow (CBF; pulsed arterial spin-labeling [ASL] MRI), glucose metabolism (fluorine 18 [18F] fluorodeoxyglucose [FDG] PET), and gray matter (GM) volume (structural T1-weighted MRI) were calculated from integrated PET/MR data in 45 patients with AD (mean age, 69 years ± 9 [standard deviation]; age range, 51-89 years), 20 patients with MCI (mean age, 64 years ± 10; age range, 45-82 years), and 11 HC participants (mean age, 65 years ± 8; age range, 54-80 years) between 2011 and 2014. After preprocessing, voxel-wise analyses of variance, volume of interest, and independent component analyses were performed for comparisons of CBF and glucose metabolism. Results Analyses revealed high overlap between components, regional and quantitative hypoperfusion, and hypometabolism in patients with AD compared with HC participants in precuneus, parietal, temporal, and occipital cortex. In patients with MCI compared with HC participants, FDG PET exclusively demonstrated quantitative hypometabolism and a component in the precuneus. Volume-of-interest analysis in global GM in patients with AD compared with HC participants showed lower CBF (42 mL/100 g per minute ± 8 vs 49 mL/100 g per minute ± 7, respectively; P = .035) and lower FDG uptake (0.8 ± 0.1 vs 1 ± 0.1, respectively; P < .001). Conclusion In patients with AD, pulsed ASL MRI revealed regional and quantitative abnormalities and components similar to 18F-FDG PET with a reduced extent. In patients with MCI, 18F-FDG PET exclusively demonstrated quantitative hypometabolism and a component in the precuneus, indicating higher sensitivity to detect preclinical AD compared with the currently used pulsed ASL MRI sequence.

Fluid biomarker agreement and interrelation in dementia due to Alzheimer's disease.

The cerebrospinal fluid (CSF) levels of ß-amyloid 42, total tau, and phosphorylated tau 181 are supposed to be all continuously abnormal in dementia due to Alzheimer's disease (AD), being the most advanced disease stage. The aim of the present study, which included a monocentric and a multicentric sample (N = 119 and 178, respectively), was to investigate the degree of CSF biomarker agreement and interrelation in AD dementia. Based on previously published cut-off values, biomarker values were categorized as positive or negative for AD (dichotomization strategy) and as either positive, negative, or borderline (trichotomization strategy). The statistical analyses relied on distance correlation analysis and kappa (k) statistics. Poor agreement (k < 0.4) and low interrelations between the studied biomarkers were detected in all cases with the exception of the interrelation between the markers total tau and phosphorylated tau 181, especially in the monocentric sample. Interestingly, lower interrelation and agreement degrees were observed in carriers of the Apolipoprotein E ε4 allele compared to non-carriers. The clinical phenotype currently referred to as "AD dementia" is characterized by an inhomogeneous CSF biomarker profile, possibly mirroring the complex genesis of AD-typical dementia symptoms and pointing to the necessity of shedding more light on the hypothesis of biomarker stability over time in symptomatic AD.

Cerebrospinal Fluid BACE1 Activity and sAßPPß as Biomarker Candidates of Alzheimer's Disease.

BACKGROUND/AIMS: The utility of ß-site amyloid-ß precursor protein (AßPP) cleaving enzyme 1 (BACE1) activity and soluble AßPP ß (sAßPPß) levels in cerebrospinal fluid (CSF) in detecting Alzheimer's disease (AD) is still elusive. METHODS: BACE1 activity and sAßPPß concentration were measured in patients with AD dementia (n = 56) and mild cognitive impairment (MCI) due to AD (n = 76) with abnormal routine AD CSF markers, in patients with MCI with normal CSF markers (n = 39), and in controls without preclinical AD (n = 48). In a subsample with available 18F-fluorodeoxyglucose positron emission tomography (FDG PET) data, ordinal regression models were employed to compare the contribution of BACE1 and sAßPPß to correct diagnostic classification to that of FDG PET. RESULTS: BACE1 activity was significantly higher in patients with MCI due to AD compared to both controls and patients with MCI with normal CSF markers. sAßPPß did not differ between any of the studied groups. Interestingly, BACE1 activity was not found to be inferior to FDG PET as predictive covariate in differentiating between the diagnostic groups. CONCLUSIONS: Further studies using biomarker-underpinned diagnoses are warranted to shed more light on the potential diagnostic utility of BACE1 activity as AD biomarker candidate in MCI.