Personality, Alzheimer's disease and behavioural and cognitive symptoms of dementia: the PACO prospective cohort study protocol

Impaired Facial Emotion Recognition and Gaze Direction Detection in Mild Alzheimer's Disease: Results from the PACO Study

BACKGROUND

Facial emotion recognition (FER) and gaze direction (GD) identification are core components of social cognition, possibly impaired in many psychiatric or neurological conditions. Regarding Alzheimer's disease (AD), current knowledge is controversial.

OBJECTIVE

The aim of this study was to explore FER and GD identification in mild AD compared to healthy controls.

METHODS

180 participants with mild AD drawn from the PACO study and 74 healthy elderly controls were enrolled. Participants were asked to complete three socio-cognitive tasks: face sex identification, recognition of facial emotions (fear, happiness, anger, disgust) expressed at different intensities, and GD discrimination. Multivariate analyses were conducted to compare AD participants and healthy controls.

RESULTS

Sex recognition was preserved. GD determination for subtle deviations was impaired in AD. Recognition of prototypically expressed facial emotions was preserved while recognition of degraded facial emotions was impacted in AD participants compared to controls. Use of multivariate analysis suggested significant alteration of low-expressed fear and disgust recognition in the AD group.

CONCLUSION

Our results showed emotion recognition and GD identification in patients with early-stage AD compared to elderly controls. These impairments could be the object of specific therapeutic interventions such as social cognition remediation or raising awareness of primary caregivers to improve the quality of life of patients with early AD.

Effect of Metabolic Syndrome on the Incidence of Dementia Based on National Insurance Data in Korea

Background: To evaluate the association between metabolic syndrome (MetS) and the incidence of dementia using big data from national health claims and health examinations. Methods: This study involved 3,619,388 subjects categorized with MetS of three status based on the results of health examinations conducted in 2009. This was a longitudinal study of the incidence of dementia based on the national health claims from the date of health examinations in 2009 until December 31, 2018. This study was conducted for men and women aged 50 to 69 years living in Korea. A Cox proportional hazard regression was performed to analyze the risk of dementia according to the status of MetS. Results: The cumulative incidence of Alzheimer dementia was 0.41% in the non-Mets group, 0.54% in the pre-MetS group, and 0.67% in the MetS group. The cumulative incidence of vascular dementia was 0.19% in the non-Mets group, 0.27% in the pre-MetS group, and 0.34% in the MetS group. The risk of Alzheimer dementia in the pre-MetS group compared to the non-Mets group was 1.20-fold greater (95% confidence interval, CI: 1.14-1.26) and was 1.39-fold (95% CI: 1.31-1.48) greater in the MetS group. The risk of vascular dementia in the pre-MetS group compared to the non-Mets group was 1.30-fold greater (95% CI: 1.21-1.40) and the risk of vascular dementia was 1.53-fold (95% CI: 1.44 1.71) greater. Conclusions: This study showed that pre-MetS and MetS were related to an increased incidence of Alzheimer dementia and vascular dementia. Also, these results support efforts to decrease the incidence of Alzheimer dementia and vascular dementia through managing the Mets.

Brain Volume Predicts Behavioral and Psychological Symptoms in Alzheimer's Disease

BACKGROUND

Behavioral and psychological symptoms of dementia (BPSD) are frequent and troublesome for patients and caregivers. Considering possible preventive approaches, a better understanding of underlying neural correlates of BPSD is crucial.

OBJECTIVE

The aim is to assess whether brain regional volume predicts behavioral changes in mild AD.

METHODS

This work took part from the PACO study, a multicenter and prospective study that included 252 patients with mild AD from 2009 to 2014. Fifty-three patients were retained. Forty healthy matched control subjects from the ADNI cohort were included as controls. Voxel-based morphometry analysis was conducted to assess regional brain volume using baseline MRI scans as a predictor of future behavioral changes over a period of 18 months. Behavior was assessed at baseline and longitudinally at 6-month intervals using the shortened form of the Neuropsychiatric Inventory (NPI).

RESULTS

The volume of 23 brain structures in frontal, temporal, parietal, occipital, subcortical regions and cerebellum predicted the evolution of NPI scores. Frontal volume was the most powerful predictor with frontal gyri, anterior cingulate cortex, and orbital gyri being particularly involved.

CONCLUSION

To our knowledge, this is the first study assessing regional brain volumes as predictors of behavioral changes considered at earlier stages of AD. Up to 23 brain structures were associated with an increased risk of developing BPSD. Frontal lobe volume was the strongest predictor of future evolution of NPI. The involvement of multiple structures in the prediction of behavior suggests a role of the main large-scale networks involved in cognition.

Does Personality Predict Behavioral and Psychological Symptoms of Dementia? Results from PACO Prospective Study

BACKGROUND

Premorbid personality could play a role in the onset of behavioral and psychological symptoms (BPS) in Alzheimer's disease (AD) but prospective studies are lacking.

OBJECTIVE

The present study aimed at prospectively assessing the influence of premorbid personality traits on BPS evolution in a population of patients with prodromal or mild AD.

METHODS

We used a multicenter prospective cohort study of 237 patients followed-up for 18 months. The influence of personality traits on BPS evolution, measured with Neuropsychiatric Inventory (NPI), was assessed using linear mixed-effect models.

RESULTS

A principal components analysis of the 12 NPI behavioral domains yielded five factors labelled as psychotic symptoms, affective symptoms, behavioral dyscontrol, apathy/appetite symptoms, and sleep disorders. During the follow-up, higher neuroticism was significantly associated with a higher progression of affective symptoms (p < 0.0001), apathy/appetite symptoms (p = 0.002), sleep disorders (p = 0.001) as well as global NPI scores (p < 0.0001). Greater conscientiousness was related to a lower evolution of psychotic (p = 0.002), affective (p = 0.02) and apathy/appetite symptoms (p = 0.02), and global NPI score (p < 0.0001). Higher openness was associated with lower affective symptoms evolution (p = 0.01). A significant relationship was found between higher extraversion, lower affective symptoms (p = 0.02), and higher behavioral dyscontrol (p = 0.04).

CONCLUSION

The present analysis suggests that premorbid personality may influence the evolution of BPS in prodromal or mild AD. Given these results, it seems important to give more importance to personality assessment in early AD, in order to better identify and manage patients at risk of adverse behavioral changes.

Prevalence of Comorbidities in Individuals Diagnosed and Undiagnosed with Alzheimer's Disease in León, Spain and a Proposal for Contingency Procedures to Follow in the Case of Emergencies Involving People with Alzheimer's Disease

Background: Alzheimer's disease (AD) which is the most common type of dementia is characterized by mental or cognitive disorders. People suffering with this condition find it inherently difficult to communicate and describe symptoms. As a consequence, both detection and treatment of comorbidities associated with Alzheimer's disease are substantially impaired. Equally, action protocols in the case of emergencies must be clearly formulated and stated. Methods: We performed a bibliography search followed by an observational and cross-sectional study involving a thorough review of medical records. A group of AD patients was compared with a control group. Each group consisted of 100 people and were all León residents aged ≥65 years. Results: The following comorbidities were found to be associated with AD: cataracts, urinary incontinence, osteoarthritis, hearing loss, osteoporosis, and personality disorders. The most frequent comorbidities in the control group were the following: eye strain, stroke, vertigo, as well as circulatory and respiratory disorders. Comorbidities with a similar incidence in both groups included type 2 diabetes mellitus, glaucoma, depression, obesity, arthritis, and anxiety. We also reviewed emergency procedures employed in the case of an emergency involving an AD patient. Conclusions: Some comorbidities were present in both the AD and control groups, while others were found in the AD group and not in the control group, and vice versa.

Neuroticism-Withdrawal and Neuroticism-Volatility Differently Influence the Risk of Neuropsychiatric Symptoms in Alzheimer's Disease

BACKGROUND

Neuroticism is recognized as the personality domain that is most strongly associated with behavioral and psychological symptoms (BPS) of Alzheimer's disease (AD). Two sub-components of neuroticism have been recently isolated. Neuroticism-withdrawal (N-withdrawal) refers to the tendency to internalize negative emotion, whereas neuroticism-volatility (N-volatility) reflect the predisposition to externalize negative emotions.

OBJECTIVE

The objective of the current study was to investigate the specific influence of these two sub-components of neuroticism on BPS.

METHODS

One hundred eighty-seven patients with prodromal or mild AD were drawn from the PACO study (Personalité Alzheimer COmportement). Neuroticism and its facets were assessed at baseline using the NEO-PI-R inventory. N-withdrawal and N-volatility were isolated using a principal component analysis led on the six facets composing neuroticism. BPS were measured with the short version of Neuropsychiatric Inventory (NPI-Q) and collected at baseline, then every 6 months over an 18-month follow-up. Linear mixed-effect analyses were conducted to investigate the association between N-withdrawal, N-volatility, and the severity of BPS over the follow-up.

RESULTS

Mean age of the participant was 79.2±6.5; 59% were female; mean MMSE was 24.5±2.5. Both N-volatility and N-withdrawal were related with the NPI-Q (p < 0.001; p = 0,004). N-withdrawal was positively associated with anxiety (p = 0.001) and depression (p = 0.002), while N-volatility was positively related to delusions (p = 0.004), agitation/aggression (p < 0.001), irritability/volatility (p = 0.037), and apathy (p = 0.021).

CONCLUSION

The present study demonstrates that N-volatility and N-withdrawal influence the risk of developing BPS in a different way. These results highlight the relevance of considering sub-components of neuroticism when studying links between personality and BPS.

Long-Term Pantethine Treatment Counteracts Pathologic Gene Dysregulation and Decreases Alzheimer's Disease Pathogenesis in a Transgenic Mouse Model

The low-molecular weight thiol pantethine, known as a hypolipidemic and hypocholesterolemic agent, is the major precursor of co-enzyme A. We have previously shown that pantethine treatment reduces amyloid-β (Aβ)-induced IL-1β release and alleviates pathological metabolic changes in primary astrocyte cultures. These properties of pantethine prompted us to investigate its potential benefits in vivo in the 5XFAD (Tg) mouse model of Alzheimer's disease (AD).1.5-month-old Tg and wild-type (WT) male mice were submitted to intraperitoneal administration of pantethine or saline control solution for 5.5 months. The effects of such treatments were investigated by performing behavioral tests and evaluating astrogliosis, microgliosis, Αβ deposition, and whole genome expression arrays, using RNAs extracted from the mice hippocampi. We observed that long-term pantethine treatment significantly reduced glial reactivity and Αβ deposition, and abrogated behavioral alteration in Tg mice. Moreover, the transcriptomic profiles revealed that after pantethine treatment, the expression of genes differentially expressed in Tg mice, and in particular those known to be related to AD, were significantly alleviated. Most of the genes overexpressed in Tg compared to WT were involved in inflammation, complement activation, and phagocytosis and were found repressed upon pantethine treatment. In contrast, pantethine restored the expression of a significant number of genes involved in the regulation of Αβ processing and synaptic activities, which were downregulated in Tg mice. Altogether, our data support a beneficial role for long-term pantethine treatment in preserving CNS crucial functions altered by Aβ pathogenesis in Tg mice and highlight the potential efficiency of pantethine to alleviate AD pathology.

Personality Traits are Related to Selective Cognitive Impairment in Early Alzheimer's Disease

BACKGROUND

A link between personality traits and cognitive performance has been shown in normal adults and elderly individuals. Very few studies have evaluated this link in Alzheimer's disease (AD).

OBJECTIVE

To better understand cognitive performance as regards to personality traits, our study was aimed to evaluate the role of premorbid personality on cognitive functioning in a population of patients presenting prodromal or mild AD.

METHODS

181 elderly with prodromal or mild AD participated in a cross-sectional, prospective cohort study. The participants completed a personality inventory and a neuropsychological battery exploring memory, attention, executive function, language, and praxis. Cognitive performance were compared according to the level of each personality trait, using multivariate MANOVA models.

RESULTS

A higher level of neuroticism was associated with lower performance at similarities test (D = 9.49, p = 0.003), delayed Free and Cued Selective Reminding test (D = 5.22, p = 0.02), and digit span score (D = 7.99, p = 0.006). A higher level of openness was related to better performance at similarities (D = 4.33, p = 0.04), letter fluency (D = 11.45, p = 0.001), and category fluency test (D = 5.85, p = 0.02). Neuroticism interfered negatively with cognitive functioning at the prodromal stage; the association between openness and cognitive function was observed at both prodromal and mild AD stage.

CONCLUSION

These results suggest that personality traits, in particular neuroticism and openness, modulate cognitive abilities in patients with early AD. These results encourage the development of stress management programs to prevent its negative effects on cognitive aging.

Metabolic Syndrome, Mild Cognitive Impairment, and Dementia: A Meta-Analysis of Longitudinal Studies

OBJECTIVE

A systematic review and a meta-analysis of both clinical and population-based studies was undertaken according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement to clarify whether Metabolic Syndrome (MetS) is a risk or a protective factor for incident dementia, Alzheimer disease (AD), and vascular dementia (VaD), and whether it's involved in progression to dementia in patients affected by mild cognitive impairment (MCI).

METHODS

Search terms included ("metabolic syndrome" OR "syndrome x" OR "plurimetabolic syndrome") AND ("dementia" OR "Alzheimer disease" OR "vascular dementia" OR "mild cognitive impairment" OR "MCI"). Research was restricted to articles published in English between January 1, 2000 and August 31, 2018. No age limit was set.

RESULTS

At the end of the selection procedure, nine longitudinal studies were selected for the meta-analysis: six studies enrolled cognitively well-functioning participants and three studies involved MCI patients. A total of 18,313 participants aged older than 40 years with mean MetS prevalence of 22.7% were followed on average for 9.41years. A fixed model was used to estimate pooled hazard ratios and 95% confidence intervals.

CONCLUSION

No statistically significant pooled association emerged between MetS and incident dementia and AD. MetS increased the incidence of pure VaD. MetS increased the risk of progression from MCI to dementia. Follow-up length might be a key factor in investigating these associations further. Because MetS is constituted by a set of potentially modifiable factors, further studies with longer follow-up and repeated assessment of both MetS and cognitive status are desirable to draw definite conclusions.

Personality and the risk factors for developing behavioral and psychological symptoms of dementia: a narrative review

Premorbid personality traits have been implicated as risk factors for the development of behavioral and psychological symptoms of dementia (BPSD), although there is a paucity of studies investigating this relationship. In this narrative review, a number of studies found that premorbid neuroticism has consistently been observed to have a significant association with the development of BPSD symptoms while premorbid conscientiousness, extraversion, openness and agreeableness may be protective factors against future BPSD symptoms. In conclusion, premorbid personality traits appear to affect the risk of BPSD symptoms among individuals with dementia.

Meta-Analysis of Personality Traits in Alzheimer's Disease: A Comparison with Healthy Subjects

BACKGROUND

The role of specific personality traits as factor risks of Alzheimer's disease (AD) has been consistently found, whereas personality traits specifically related to AD (after the diagnosis) have not been outlined yet.

OBJECTIVE

A meta-analysis of published studies was performed to determine whether AD patients have a distinctive personality trait profile compared to healthy subjects (HC), similar to or different from a premorbid personality profile consistently reported in previous studies.

METHODS

A systematic literature search was performed using PsycInfo (PROQUEST), PubMed, and Scopus. The meta-analysis pooled results from primary studies using Hedges' g unbiased approach.

RESULTS

The meta-analysis included 10 primary studies and revealed that, when the personality was evaluated by informant-rated measures, AD patients had significantly higher levels of Neuroticism, lower levels of Openness, Agreeableness, Conscientiousness, and Extraversion than HCs. When the personality was evaluated by self-rated measures, the results obtained from informants were confirmed for Neuroticism, Openness, and Extraversion but not for Agreeableness and Conscientiousness where AD patients and HCs achieved similar scores.

CONCLUSIONS

The meta-analysis revealed that high Neuroticism and low Openness and Extraversion are distinctive personality traits significantly associated with a diagnosis of AD when evaluated both self-rated and informant-rated measures. This personality trait profile is similar to premorbid one, which contributes to development of AD over time. Therefore, our findings indirectly support the idea of specific premorbid personality traits as harbingers of AD.

In Vitro Anti-Cholinesterase and Antioxidant Activity of Extracts of Moringa oleifera Plants from Rivers State, Niger Delta, Nigeria

This study evaluated Moringa oleifera extracts from two locations in Niger Delta for in vitro anti-cholinesterase and antioxidant activities. Methanolic, aqueous and ethanolic extracts of Moringa oleifera were evaluated for inhibition of acetylcholinesterase (AChE) activity, antioxidant properties, and total phenolic and flavonoid contents using standard procedures. M. oleifera extracts possessed significant and concentration dependent AChE inhibitory activity for methanolic, aqueous, and ethanolic extracts. For the most potent extracts, the percentage AChE inhibition/IC₅₀ (µg/mL) values were Moringa oleifera root methanolic extracts (MORME): ~80%/0.00845; Moringa oleifera root ethanolic extract 1 (MOREE1): ~90%/0.0563; Moringa oleifera root ethanolic extract 2 (MOREE2): ~70%/0.00175; and Moringa oleifera bark ethanolic extract (MOBEE): ~70%/0.0173. The descending order of AChE inhibitory potency of plant parts were: root > bark > leaf > flowers > seed. All M. oleifera methanolic extracts at a concentration of 1000 µg/mL displayed significant (p < 0.05–0.001) DPPH radical scavenging activity, with values of ~20–50% of that of ascorbic acid. The total phenolic content and total flavonoid content (TPC/TFC) of MORME, Moringa Oju bark methanolic extract (MOBME), MOREE1, MOREE2 and Moringa leaf ethanolic leaf extract (MLEE) were (287/254), (212/113), (223/185), (203/343) and (201/102) mg gallic acid equivalents/g and quercetin equivalents/g, respectively. There was an inverse correlation between plant extract AChE inhibition and total phenolic (p < 0.0001) and total flavonoid contents (p < 0.0012). In summary, this study revealed 5 of 19 extracts of M. oleifera that have potent in vitro anti-cholinesterase and antioxidant activities.

Language background in early life may be related to neuropsychiatry symptoms in patients with Alzheimer disease

Background

The relationship between early life experience and the occurrence of neuropsychiatry symptoms (NPSs) in patients with Alzheimer disease (AD) is unclear.

Methods

From 2012 to 2014, we prospectively recruited 250 patients with probable AD from the memory clinic of Taipei Veterans General Hospital. All patients underwent standard assessments, including brain magnetic resonance imaging or computed tomography, neuropsychological tests, neuropsychiatry inventory (NPI-Q) and related blood tests. A linear regression analysis was performed to investigate the relationship between NPSs and age, gender, disease severity, depression, language background (with or without Japanese education).

Results

Among the 250 participants, 113 (45.2%) were women. Their average age was 82.6 years. Of all the participants, 93 (37.2%) had received formal Japanese education, whereas 157 (62.8%) did not receive Japanese education. The participants with Japanese education were slightly younger (83.1 ± 3.6 vs. 81.4 ± 3.4, P = 0.006), with a higher proportion of them were women (30.5% vs. 69.8%, P < 0.001) and fewer years of total education (10.8 ± 4.5 vs. 7.7 ± 3.2, P < 0.001), compared to the participants without Japanese education. NPI-Q scores significantly differed between the two groups (15.8 vs. 24.1, P = 0.024). Both disease severity and language background predicted NPI-Q scores.

Conclusions

Language background in early life may be related to NPSs in patients with AD, and this effect is more significant in patients with a lower education level than in those with a higher education level. More NPSs may be the result of negative effects on dominant language or early life experiences.

Electronic supplementary material

The online version of this article (doi:10.1186/s12877-017-0435-2) contains supplementary material, which is available to authorized users.