Neuropsychological differentiation between Alzheimer's disease and dementia with Lewy bodies in a memory clinic

A Mini-Mental State Examination Formula May Help to Distinguish Alzheimer's Disease from Dementia with Lewy Bodies

Background:

Alzheimer’s disease (AD) and dementia with Lewy bodies (DLB) differ in their memory, attention, and visuoconstructional characteristics. The subscales of the well-known Mini-Mental State Examination (MMSE) provide an opportunity to assess these characteristics. Previous research has shown that analysis of the MMSE subscale performance of AD and DLB patients helps to differentiate them.

Objective:

Study the MMSE scores of AD and DLB patients to see if the ability of previously reported analyses to differentiate them could be improved. Include other dementia patients for perspective.

Methods:

We studied the MMSEs of all patients seen in our clinics during an 18-month period. Different equations were studied, derived from the subscales of Memory (M, 3 points maximum), Attention (A, 5 points maximum), and Pentagon-copying (P, 1 point maximum).

Results:

We obtained 400 MMSEs, 136 from AD patients and 24 from DLB patients, scoring range 1–30. The equation P minus M provided the best discrimination between AD and DLB. Using a P-M score = 1 to identify AD, the positive predictive value was 0.97, negative predictive value 0.22, specificity 0.92, and sensitivity 0.43. As a secondary finding, the P-M = 1 equation was also helpful to differentiate AD from Parkinson’s disease dementia.

Conclusion:

Considering AD versus DLB in our clinic population, a demented patient who was unable to recall the three memory words on the MMSE but able to copy the intersecting pentagons had a 97% likelihood of having AD. Additional work is needed to improve the sensitivity of the P-M = 1 equation.

Caring for patients with cognitive dysfunction, fluctuations and dementia caused by Parkinson's disease

Cognitive dysfunction is one of the most prevalent non-motor symptoms in patients with Parkinson's disease (PD). While it tends to worsen in the later stages of disease, it can occur at any time, with 15-20% of patients exhibiting cognitive deficits at diagnosis (Aarsland et al., 2010; Goldman and Sieg, 2020). The characteristic features of cognitive dysfunction include impairment in executive function, visuospatial abilities, and attention, which vary in severity from subtle impairment to overt dementia (Martinez-Horta and Kulisevsky, 2019). To complicate matters, cognitive dysfunction is prone to fluctuate in PD patients, impacting diagnosis and the ability to assess progression and decision-making capacity. The diagnosis of cognitive impairment or dementia has a huge impact on patient independence, quality of life, life expectancy and caregiver burden (Corallo et al., 2017; Lawson et al., 2016; Leroi et al., 2012). It is therefore essential that physicians caring for patients with PD provide education, screening and treatment for this aspect of the disease. In this chapter, we provide a practical guide for the assessment and management of various degrees of cognitive dysfunction in patients with PD by approaching the disease at different stages. We address risk factors for cognitive dysfunction, prevention strategies prior to making the diagnosis, available tools for screening. Lastly, we review aspects of care, management and considerations, including decision-making capacity, that occur after the patient has been diagnosed with cognitive dysfunction or dementia.

Regression-Based Normative Data for Independent and Cognitively Active Spanish Older Adults: Digit Span, Letters and Numbers, Trail Making Test and Symbol Digit Modalities Test

In this work, we developed normative data for the neuropsychological assessment of independent and cognitively active Spanish older adults over 55 years of age.

METHOD

Regression-based normative data were calculated from a sample of 103 non-depressed independent community-dwelling adults aged 55 or older (67% women). Raw data for Digit Span (DS), Letters and Numbers (LN), the Trail Making Test (TMT), and the Symbol Digit Modalities Test (SDMT) were regressed on age, sex, and education. The model predicting TMT-B scores also included TMT-A scores. Z-scores for the discrepancy between observed and predicted scores were used to identify low scores. The base rate of low scores for SABIEX normative data was compared to the base rate of low scores using published normative data obtained from the general population.

RESULTS

The effects of age, sex, and education varied across neuropsychological measures. Although the proportion of low scores was similar between normative datasets, there was no agreement in the identification of cognitively impaired individuals.

CONCLUSIONS

Normative data obtained from the general population might not be sensitive to identify low scores in cognitively active older adults, incorrectly classifying them as cognitively normal compared to the less-active population. We provide a friendly calculator for use in neuropsychological assessment in cognitively active Spanish people aged 55 or older.

Validity and Reliability of the New Chinese Version of the Frontal Assessment Battery-Phonemic

BACKGROUND

Alzheimer's disease dementia (ADD) is an important health problem in the world.

OBJECTIVE

The present study investigated the validity and reliability of a new version of the Frontal Assessment Battery (FAB) named the FAB-phonemic (FAB-P).

METHODS

A total of 76 patients with ADD, 107 patients with amnestic mild cognitive impairment (aMCI), 37 patients with non-amnestic MCI (naMCI), and 123 healthy controls were included in this study. All participants were evaluated with the FAB-P and the cognitive assessments according to a standard procedure.

RESULTS

The global FAB-P scores in patients with ADD were lower than those of patients with aMCI, patients with naMCI, and healthy controls (p < 0.001). Patients with aMCI performed worse than healthy controls (p < 0.001). The interrater reliability, test-retest reliability, and Cronbach's alpha coefficient for the FAB-P were 0.997, 0.819, and 0.736, respectively. The test could distinguish the patients with mild ADD, aMCI, and naMCI from healthy controls with classification accuracy of 89.4%, 70.9%, and 61.6%, respectively. It could also discriminate between the patients with ADD and aMCI, between those with ADD and naMCI, and between those with aMCI and naMCI with classification accuracy of 73.8%, 83.9%, and 58.0%, respectively. The regression analysis revealed that the Montreal Cognitive Assessment and the Stroop Color Word Test Part C had the greatest contribution to FAB-P score variance.

CONCLUSION

The FAB-P is a valid and reliable tool for evaluating frontal lobe function and can effectively discriminate ADD, aMCI, and naMCI.

Predicting and Characterizing Neurodegenerative Subtypes with Multimodal Neurocognitive Signatures of Social and Cognitive Processes

BACKGROUND

Social cognition is critically compromised across neurodegenerative diseases, including the behavioral variant frontotemporal dementia (bvFTD), Alzheimer's disease (AD), and Parkinson's disease (PD). However, no previous study has used social cognition and other cognitive tasks to predict diagnoses of these conditions, let alone reporting the brain correlates of prediction outcomes.

OBJECTIVE

We performed a diagnostic classification analysis using social cognition, cognitive screening (CS), and executive function (EF) measures, and explored which anatomical and functional networks were associated with main predictors.

METHODS

Multiple group discriminant function analyses (MDAs) and ROC analyses of social cognition (facial emotional recognition, theory of mind), CS, and EF were implemented in 223 participants (bvFTD, AD, PD, controls). Gray matter volume and functional connectivity correlates of top discriminant scores were investigated.

RESULTS

Although all patient groups revealed deficits in social cognition, CS, and EF, our classification approach provided robust discriminatory characterizations. Regarding controls, probabilistic social cognition outcomes provided the best characterization for bvFTD (together with CS) and PD, but not AD (for which CS alone was the best predictor). Within patient groups, the best MDA probabilities scores yielded high classification rates for bvFTD versus PD (98.3%, social cognition), AD versus PD (98.6%, social cognition + CS), and bvFTD versus AD (71.7%, social cognition + CS). Top MDA scores were associated with specific patterns of atrophy and functional networks across neurodegenerative conditions.

CONCLUSION

Standardized validated measures of social cognition, in combination with CS, can provide a dimensional classification with specific pathophysiological markers of neurodegeneration diagnoses.

Prognosis prediction model for conversion from mild cognitive impairment to Alzheimer's disease created by integrative analysis of multi-omics data

BACKGROUND

Mild cognitive impairment (MCI) is a precursor to Alzheimer's disease (AD), but not all MCI patients develop AD. Biomarkers for early detection of individuals at high risk for MCI-to-AD conversion are urgently required.

METHODS

We used blood-based microRNA expression profiles and genomic data of 197 Japanese MCI patients to construct a prognosis prediction model based on a Cox proportional hazard model. We examined the biological significance of our findings with single nucleotide polymorphism-microRNA pairs (miR-eQTLs) by focusing on the target genes of the miRNAs. We investigated functional modules from the target genes with the occurrence of hub genes though a large-scale protein-protein interaction network analysis. We further examined the expression of the genes in 610 blood samples (271 ADs, 248 MCIs, and 91 cognitively normal elderly subjects [CNs]).

RESULTS

The final prediction model, composed of 24 miR-eQTLs and three clinical factors (age, sex, and APOE4 alleles), successfully classified MCI patients into low and high risk of MCI-to-AD conversion (log-rank test P = 3.44 × 10^-4 and achieved a concordance index of 0.702 on an independent test set. Four important hub genes associated with AD pathogenesis (SHC1, FOXO1, GSK3B, and PTEN) were identified in a network-based meta-analysis of miR-eQTL target genes. RNA-seq data from 610 blood samples showed statistically significant differences in PTEN expression between MCI and AD and in SHC1 expression between CN and AD (PTEN, P = 0.023; SHC1, P = 0.049).

CONCLUSIONS

Our proposed model was demonstrated to be effective in MCI-to-AD conversion prediction. A network-based meta-analysis of miR-eQTL target genes identified important hub genes associated with AD pathogenesis. Accurate prediction of MCI-to-AD conversion would enable earlier intervention for MCI patients at high risk, potentially reducing conversion to AD.

The Neuropsychological Profile and Phenomenology of Late Onset Psychosis: A Cross-sectional Study on the Differential Diagnosis of Very-Late-Onset Schizophrenia-Like Psychosis, Dementia with Lewy Bodies and Alzheimer's Type Dementia with Psychosis

Objective

Late onset psychosis not only occurs as a prodromal symptom to neurodegeneration, but it can also be associated with a non-progressive mild cognitive deficit. Studying the phenomenology of psychotic symptoms and the neuropsychological profile may serve as sensitive and non-invasive tools for differential diagnosis.

Method

We compared 57 individuals with very-late-onset schizophrenia-like psychosis (VLOSLP), 49 participants with Dementia with Lewy Bodies (DLB) and 35 patients with Alzheimer's type Dementia and psychosis (AD+P) concerning the phenomenology of psychotic symptoms and the neuropsychological profile using several measures of cognitive function in a cross-sectional study.

Results

Participants with DLB exhibited more visual hallucinations, especially those involving animals, and less partition/paranoid delusions than both other groups. VLOSLP showed more partition delusions and auditory hallucinations of human voices than both other groups. Hence, patients with DLB and VLOSLP showed greater dissimilarity in the phenomenology of psychosis, whereas individuals with AD+P held an intermediate position. Processing speed and executive function were comparably impaired among the three groups, as was expected considering a common underlying set of neurobiological abnormalities for psychosis. However, AD+P showed more strongly reduced learning and consolidation skills, whereas DLB was associated with prominent visuoconstructive deficits.

Conclusions

Phenomenology of psychosis may prove especially informative when comparing individuals with DLB to those with VLOSLP. Neuropsychological profiles are able to further aid differential diagnosis of the three groups.

EEG Resting-State Networks in Dementia with Lewy Bodies Associated with Clinical Symptoms

BACKGROUND

Dementia with Lewy bodies (DLB) is characterized by progressive cognitive decline, fluctuating cognition, visual hallucinations, rapid eye movement sleep behavior disorder, and parkinsonism. DLB is the second most common type of degenerative dementia of all dementia cases. However, DLB, particularly in the early stage, is underdiagnosed and sometimes misdiagnosed with other types of dementia. Thus, it is of great interest investigating neurophysiological markers of DLB.

METHOD

We introduced exact low-resolution brain electromagnetic tomography (eLORETA)-independent component analysis (ICA) to assess activities of 5 electroencephalography (EEG) resting-state networks (RSNs) in 41 drug-free DLB patients.

RESULTS

Compared to 80 healthy controls, DLB patients had significantly decreased activities in occipital visual and sensorimotor networks, where DLB patients and healthy controls showed no age dependences in all EEG-RSN activities. Also, we found correlations between all EEG-RSN activities and DLB symptoms. Specifically, decreased occipital α activity showed correlations with worse brain functions related to attention/concentration, visuospatial discrimination, and global cognition. Enhanced visual perception network activity correlated with milder levels of depression and anxiety. Enhanced self-referential network activity correlated with milder levels of depression. Enhanced memory perception network activity correlated with better semantic memory, visuospatial discrimination function, and global cognitive function as well as with severer visual hallucination. In addition, decreased sensorimotor network activity correlated with a better semantic memory.

CONCLUSION

These results indicate that eLORETA-ICA can detect EEG-RSN activity alterations in DLB related to symptoms. Therefore, eLORETA-ICA with EEG data can be a useful noninvasive tool for sensitive detection of EEG-RSN activity changes characteristic of DLB and for understanding the neurophysiological mechanisms underlying this disease.

Risk prediction models for dementia constructed by supervised principal component analysis using miRNA expression data

Alzheimer's disease (AD) is the most common subtype of dementia, followed by Vascular Dementia (VaD), and Dementia with Lewy Bodies (DLB). Recently, microRNAs (miRNAs) have received a lot of attention as the novel biomarkers for dementia. Here, using serum miRNA expression of 1,601 Japanese individuals, we investigated potential miRNA biomarkers and constructed risk prediction models, based on a supervised principal component analysis (PCA) logistic regression method, according to the subtype of dementia. The final risk prediction model achieved a high accuracy of 0.873 on a validation cohort in AD, when using 78 miRNAs: Accuracy = 0.836 with 86 miRNAs in VaD; Accuracy = 0.825 with 110 miRNAs in DLB. To our knowledge, this is the first report applying miRNA-based risk prediction models to a dementia prospective cohort. Our study demonstrates our models to be effective in prospective disease risk prediction, and with further improvement may contribute to practical clinical use in dementia.

Frontal Assessment Battery in Early Cognitive Impairment: Psychometric Property and Factor Structure

BACKGROUND

The Frontal Assessment Battery (FAB) is a reliable and valid bedside tool for testing executive function in dementia. Given the increasing interest in utility of FAB as a screening tool in early cognitive impairment (ECI), there is a surprising lack of studies evaluating its psychometric property and factor structure, nor the influence of factors such as age, education and gender, in ECI.

OBJECTIVES

This study aims to investigate the psychometric properties and factor structure of FAB in older adults with ECI, as well as the influence of age, gender and education.

DESIGN, SETTING AND PARTICIPANTS

This is a retrospective, observational cross-sectional study with 300 community dwelling, predominantly Chinese older adults (14 normal, 130 mild cognitive impairment (MCI), and 156 mild dementia) who presented to Memory Clinic from January 2011 to December 2013. Measurements and Analysis: We collected data on demographic, cognitive, functional and behavioral evaluation. To examine the psychometric properties of FAB, we examined the concurrent, convergent, and discriminant validity; internal consistency by Cronbach's alpha; and factor structure by exploratory factor analysis. The influence of age, education and gender was examined using unadjusted and adjusted correlational analyses with CDR-SOB. We performed analysis for the whole group and for MCI subgroup.

RESULTS

FAB total score decreases significantly from normal to dementia group attesting to concurrent validity. It correlated significantly with digit span backwards and Chinese Mini Mental State Examination (r=0.38 and 0.47 respectively, p<0.01) and poorly with Neuropsychiatric Inventory-Questionnaire and depression (r=0.004 and -0.02 respectively), supporting its convergent and discriminant validity. Factor analysis yielded a single-factor solution for FAB with fair Internal consistency (alpha=0.610). FAB is relatively unaffected by age, gender and education level. These good psychometric properties extend to MCI, albeit with greater influence by education level. FAB items of conceptualization and mental flexibility have good discriminatory ability between MCI and normal subjects.

CONCLUSION

FAB has good concurrent, convergent and discriminant validity with fair internal consistency in ECI that is premised on a one-factor structure. It is relatively unaffected by age, gender or education. Taken together, FAB is a useful bedside screening tool for executive function in ECI.

The frontal assessment battery in clinical practice: a systematic review

BACKGROUND

The frontal assessment battery (FAB) is a brief tool designed to evaluate executive function. Some studies have particularly focused on assessing its applicability addressing two issues: first, on detecting the brain regions responsible for the FAB performance, and second, on determining its capability for differential diagnosis. Our aim was to summarize and analyze critically the studies that assessed the neuroanatomical correspondence and the differential diagnostic value of the FAB in several study populations suffering from different pathologies.

METHODS

We completed a literature search in MEDLINE (via PubMed) database by using the term "frontal assessment battery" and the combination of this term with "applicability" or "use" or "usefulness". The search was limited to articles in English or Spanish languages, published between 1 September 2000 and 30 September 2016, human studies, and journal articles.

RESULTS

A total of 32 studies met inclusion criteria. Seventeen studies were aimed at identifying the brain regions or the neural substrates involved in executive functions measured by the FAB and 15 studies at verifying that the FAB was an appropriate tool for the differential diagnosis in neurological diseases.

CONCLUSION

Our study showed that the FAB may be an adequate assessment tool for executive function and may provide useful information for differential diagnosis in several diseases. Given that the FAB takes short time and is easy to administer, its usage may be of great interest as part of a full neuropsychological assessment in clinical settings. Copyright © 2017 John Wiley & Sons, Ltd.

Comparing the neuropsychological profiles of mild dementia with Lewy bodies and mild Alzheimer's disease

BACKGROUND

The present study was conducted to detect neuropsychological differences and to identify discriminators between mild dementia with L ewy bodies (DLB ) and mild A lzheimer's disease (AD ).

METHODS

The present study included 37 mild DLB patients, 48 mild AD patients, and 80 healthy elderly individuals. A comprehensive battery of neuropsychological tests was administrated to assess their cognitive function. Linear stepwise discriminant analysis was used to identify the neuropsychological measures with values that could differentiate between mild DLB and mild AD .

RESULTS

The mild DLB group had greater impairments in attention, executive function, and visuospatial ability, while mild AD patients performed significantly worse on memory tests. Linear stepwise discriminant analysis indicated that the M emory and E xecutive S creening's 5-min delayed recall test was the best neuropsychological discriminator between mild DLB and mild AD .

CONCLUSIONS

Different patterns of cognitive impairment facilitate the differentiation of mild DLB from mild AD . For patients with mild dementia, better performance on the M emory and E xecutive S creening's 5-min delayed recall test suggests that the diagnosis is more likely DLB than AD .

Improvement of Visuo-spatial Function Assessed by Raven's Colored Progressive Matrices in Dementia with Lewy Bodies by Donepezil Treatment

Objective

Donepezil is used to improve cognitive impairment of dementia with Lewy bodies (DLB). Visuo-spatial dysfunction is a well-known symptom of DLB. Non-verbal Raven’s Colored Progressive Matrices (RCPM) were used to assess both visual perception and reasoning ability in DLB subjects treated with donepezil.

Methods

Twenty-one DLB patients (mean age, 78.7±4.5 years) were enrolled. RCPM assessment was performed at the time of starting donepezil and within one year after starting donepezil.

Results

There were significant improvements of RCPM in the total scores between one year donepezil treatment (p=0.013), in both Set A score (p=0.002) and Set AB score (p=0.015), but trend in the Set B score (p=0.083).

Conclusion

Donepezil is useful for improving visuo-spatial impairment in DLB, but not for problem-solving impairment.

Neural basis of visual perception and reasoning ability in Alzheimer's disease: correlation between Raven's Colored Progressive Matrices test and 123 I-IMP SPECT imaging results

OBJECTIVE

Impairment of visual perception frequently occurs in Alzheimer's disease (AD) and can cause severe constraints in daily activities. The nonverbal Raven's Colored Progressive Matrices (RCPM) test consists of sets A, AB, and B and is easily performed in a short time to evaluate both visual perception and reasoning ability. The purpose of this study was to evaluate the neural basis of visual perception and reasoning ability in patients with AD using RCPM and single-photon emission computed tomography (SPECT).

METHODS

Fifty patients who fulfilled the National Institute on Aging/Alzheimer's Association criteria for probable AD dementia were examined with RCPM and SPECT. All SPECTs were performed using N-isopropyl-p-[¹²³ I]-iodoamphetamine. A multiple regression model was used to perform multivariate analyses of the relationships between regional cerebral blood flow (rCBF) and RCPM scores.

RESULTS

There was a significant positive correlation between RCPM total score and rCBF in the inferior parietal lobes bilaterally, the right inferior temporal gyrus, and the right middle frontal gyrus. Set A was positively correlated with rCBF in the right temporal and right parietal lobes. Set AB was positively correlated with rCBF in the right temporal, right parietal, and right frontal lobes. Set B was positively correlated with rCBF in the right parietal and right frontal lobes.

CONCLUSION

Our findings suggest that deteriorations of specific brain regions are associated with dysfunction of visual perception and reasoning ability in AD. RCPM is another informative assessment scale of cognition for use in patients with AD. Copyright © 2016 John Wiley & Sons, Ltd.

Validation of Neuropsychological Tests to Screen for Dementia in Chinese Patients With Parkinson's Disease

To compare the accuracy of different neuropsychological tests and their combinations for deriving reliable cognitive indices for dementia diagnosis in Parkinson's disease (PD). One hundred forty consecutive patients with PD were recruited and administrated an extensive battery of neuropsychological tests. Discriminant analysis and receiver-operator characteristic curve were used to evaluate their correct classifications and validity. Patients with PD having dementia (PDD; 23.5%) performed significantly worse in all tests than patients without dementia. Age of onset, disease duration, Hoehn-Yahr grade, Unified Parkinson's Disease Rating Scale part III scores, and education were associated with dementia in patients with PD. Mini-Mental State Examination (MMSE), Montreal Cognitive Assessment, and Block Design (BD) showed better specificity and sensitivity when used alone, and combined use of MMSE and BD further increased the validity. Our results indicated that the accuracy of MMSE was better in dementia diagnosis of Chinese patients with PD, and combined use of MMSE and BD could further increase the validity of dementia diagnosis.

Differential subtypes of diabetic older adults diagnosed with Alzheimer's disease

AIM

The clinical management of diabetic elderly patients with Alzheimer's disease (AD) is hindered by several difficulties. The present study aimed to clarify the clinical characteristics and pathophysiological properties of AD in diabetic older adults.

METHODS

A total of 91 patients with type 2 diabetes mellitus and 161 non-diabetic individuals who were diagnosed with AD were recruited. Diabetic patients were classified into two groups with glycated hemoglobin (HbA1c) < 7.0% or ≥ 7.0%. The demographics, cognition, daily-life function, metabolic changes, treatment, and behavioral and psychological symptoms of dementia (BPSD), as well as brain pathophysiology, were compared among the three groups.

RESULTS

Patients with higher HbA1c had increased diabetic vascular complications and impaired activities of daily living with decreased levels of serum high-molecular-weight adiponectin and 25-hydroxyvitamin D. Although cognitive status was similar among the three groups, BPSD, including apathy, overeating and excessive daytime sleeping appeared to be increased in the patients with HbA1c ≥ 7.0%. The frequency of apolipoprotein E4 carriers and of posterior cerebral hypoperfusion (AD-pattern) on single-photon emission computed tomography in poorly controlled diabetic subjects was similar to that in non-diabetic AD patients, whereas diabetic patients with HbA1c <7.0% included fewer apolipoprotein E4 carriers and fewer patients with an AD pattern on single-photon emission computed tomography.

CONCLUSION

Subtypes of older diabetic patients with AD were identified based on clinical features and brain pathophysiology. Physical and psychological complications of dementia are prevalent in patients with higher HbA1c. It seems likely that difficulties in the management of diabetes with AD are due not only to non-adherence to diabetes treatment, but also several symptoms and pathophysiological characteristics of dementia.