Severe Alzheimer's Disease Group Research Articles

Comparative Analysis of Retinal Structural and Angiographic Parameters in Diabetic Patients, Alzheimer's Disease Patients, and Healthy Controls: An OCT-Based Study.

Objective: This study aimed to investigate the potential connections between Alzheimer's Disease (AD) and diabetes. Methods: This is a cross-sectional study in which AD and diabetes patients sent by the Psychiatry and Diabetes Departments for ophthalmological screening were observed for inclusion/exclusion criteria. Patients were divided into two comparison groups. The first group (n=3) consisted of the age-matched normal and diabetic patient of the stage 3 AD disease participant. The second group (n=3) was for the stage 5 AD patient with diabetes and normal age-matched controls. Each patient underwent a full ophthalmological examination and SS-OCT (Swept Source-Ocular Computer Tomography) for retinal evaluation. Results: A total of 6 patients (12 eyes) were obtained, three men and three women. In the early AD group, the patient with diabetes showed lower macular thickness compared to other groups. In the nasal-inferior (NI) and temporal-superior (TS) ganglion cell layer (GCL), the AD patient showed statistically significant lower values compared to the other patients. In the moderately severe AD group, we found that the AD patient had lower retinal nerve fiber layer (RNFL) thickness on the temporal side compared to the rest of the patients and both the AD patient and diabetes patient showed lower RNFL thickness in the nasal-superior (NS) quadrant. Also, the foveal avascular zone (FAZ) area was statistically significantly lower for both the diabetes and AD patients compared to the healthy control. Conclusions: In conclusion, distinct retinal findings associated with AD and diabetes in young and elderly patients were revealed in our study. The clinical implications and potential interplay between these conditions need to be elucidated by further research. Abbreviations: AD = Alzheimer's Disease, SS-OCT = Swept Source - Ocular Computer Tomography, GCL = Ganglion cell layer, RNFL = Retinal nerve fiber layer, FAZ = foveal avascular zone.

Assessing What Matters to People Affected by Alzheimer's Disease: A Quantitative Analysis.

In this phase of the ongoing What Matters Most study series, designed to evaluate concepts that are meaningful to people affected by Alzheimer's disease (AD), we quantified the importance of symptoms, impacts, and outcomes of AD to people at risk for or with AD and care partners of people with AD. We administered a web-based survey to individuals at risk for or with AD (Group 1: unimpaired cognition with evidence of AD pathology; Group 2: AD risk factors and subjective cognitive complaints/mild cognitive impairment; Group 3: mild AD) and to care partners of individuals with moderate AD (Group 4) or severe AD (Group 5). Respondents rated the importance of 42 symptoms, impacts, and outcomes on a scale ranging from 1 ("not at all important") to 5 ("extremely important"). Among the 274 respondents (70.4% female; 63.1% white), over half of patient respondents rated all 42 items as "very important" or "extremely important," while care partners rated fewer items as "very important" or "extremely important." Among the three patient groups, the minimum (maximum) mean importance rating for any item was 3.4 (4.6), indicating that all items were at least moderately to very important. Among care partners of people with moderate or severe AD, the minimum (maximum) mean importance rating was 2.1 (4.4), indicating that most items were rated as at least moderately important. Overall, taking medications correctly, not feeling down or depressed, and staying safe had the highest importance ratings among both patients and care partners, regardless of AD phase. Concepts of importance to individuals affected by AD go beyond the common understanding of "cognition" or "function" alone, reflecting a desire to maintain independence, overall physical and mental health, emotional well-being, and safety. Preservation of these attributes may be key to understanding whether interventions deliver clinically meaningful outcomes.

Boosting of tau protein aggregation by CD40 and CD48 gene expression in Alzheimer's disease.

Neurodegenerative diseases result from the interplay of abnormal gene expression and various pathological factors. Therefore, a disease-specific integrative genetic approach is required to understand the complexities and causes of target diseases. Recent studies have identified the correlation between genes encoding several transmembrane proteins, such as the cluster of differentiation (CD) and Alzheimer's disease (AD) pathogenesis. In this study, CD48 and CD40 gene expression in AD, a neurodegenerative disease, was analyzed to infer this link. Total RNA sequencing was performed using an Alzheimer's disease mouse model brain and blood, and gene expression was determined using a genome-wide association study (GWAS). We observed a marked elevation of CD48 and CD40 genes in Alzheimer's disease. Indeed, the upregulation of both CD48 and CD40 genes was significantly increased in the severe Alzheimer's disease group. With the elevation of CD48 and CD40 genes in Alzheimer's disease, associations of protein levels were also markedly increased in tissues. In addition, overexpression of CD48 and CD40 genes triggered tau aggregation, and co-expression of these genes accelerated aggregation. The nuclear factor kappa B (NF-ĸB) signaling pathway was enriched by CD48 and CD40 gene expression: it was also associated with tau pathology. Our data suggested that the CD48 and CD40 genes are novel AD-related genes, and this approach may be useful as a diagnostic or therapeutic target for the disease.

Reduced serum miR-202 may promote the progression of Alzheimer's disease patients via targeting amyloid precursor protein.

The current study investigated whether the expression of miR-202 was abnormal in the serum of patients with Alzheimer's disease (AD) and evaluated the potential clinical significance, thereby shedding light on the diagnosis of AD. Here, our data showed that the level of miR-202 decreased significantly in the serum of AD patients (n=121) compared with that of healthy controls (n=86). Further analysis showed that the level of serum miR-202 was gradually decreased in the mild AD group (n=31), moderate AD group (n=52) and severe AD group (n=38) compared with the healthy control group. Receiver operating characteristic (ROC) curve analysis demonstrated that serum miR-202 could differentiate AD patients from healthy controls, with an AUC of 0.892. Spearman correlation analysis showed that serum miR-202 was positively correlated with the Mini-Mental State Examination (MMSE). Based on TargetScan, a conserved binding site was identified in the 3'UTR of amyloid precursor protein (APP). The dual luciferase assay showed that miR-202 suppressed the relative luciferase activity of pmirGLO-APP-3'UTR. Western blot assays indicated that overexpression of miR-202 suppressed the expression of APP, while the expression of APP was enhanced after inhibition of miR-202 in PC12 cells, indicating that APP was a possible target gene of miR-202. Moreover, the cell apoptosis induced by transfection of miR-202 inhibitor was abolished by silencing APP. In summary, we showed novel data that downregulation of serum miR-202 may be used as a potential biomarker for AD and may promote the development of AD by targeting APP.

Trough Melatonin Levels Differ between Early and Late Phases of Alzheimer Disease.

ObjectiveMelatonin has been considered to have an essential role in the pathophysiology of Alzheimer’s disease (AD) for its regulatory function on circadian rhythm and interaction with glutamate for the modulation of learning and memory. Previous studies revealed that melatonin levels decreased in patients with AD. However, melatonin supplement didn’t show promising efficacy for AD. This study compared trough melatonin levels among elderly people with different severities of cognitive deficits.MethodsWe enrolled 270 elder individuals (consisting four groups healthy elderly, amnestic mild cognitive impairment [MCI], mild AD, and moderate-severe AD) in the learning cohort. Trough melatonin levels in plasma were measured using ELISA. Cognitive function was evaluated by Clinical Dementia Rating Scale (CDR) and Mini-Mental State Examination (MMSE). An independent testing cohort, also consisting of four groups, was enrolled for ascertainment.ResultsIn the learning cohort, trough melatonin levels decreased in the MCI group but elevated in the mild and moderate to severe AD groups. Trough melatonin levels were associated with CDR and MMSE in MCI or AD patients significantly. In the testing cohort, the results were similar to those in the learning cohort.ConclusionThis study demonstrated that trough melatonin levels in the peripheral blood were decreased in MCI but increased with the severity of AD. The finding supports the trials indicating that melatonin showed efficacy only in MCI but not in AD. Whether trough melatonin level has potential to be a treatment response biomarker for AD, especially its early phase needs further studies.

Detailed analysis of error patterns in the number-transcoding task on the Japanese version of the Rapid Dementia Screening Test.

The number-transcoding task on the Japanese version of the Rapid Dementia Screening Test requires mutual conversion between Arabic and Chinese numerals (e.g. 209 → , 4054 → , → 681, → 2027). During this task, some characteristic errors have been seen among patients with Alzheimer's disease (AD). The objective of this study was to clarify whether the frequency of appearance of error patterns differs between patients with mild and severe AD according to Clinical Dementia Rating (CDR) scores. A total of 250 patients with AD were recruited and subsequently categorized into two groups based on CDR scores (mild AD: CDR of 0.5 or 1; severe AD: CDR of 2 or 3). We analyzed 19 qualitative error patterns, including 15 that had been reported to date and 4 previously unreported errors, in each subtest. The frequency of appearance of two previously reported and four previously unreported errors in the mild and severe AD groups, respectively, were statistically significant. Characteristic error pattern distributions in number transcoding can be observed in patients with mild and severe AD according to CDR scores and offers useful information for interpreting cognitive screening data.

Correlation between serum adiponectin level and cognitive function in patients with Alzheimer's disease

To investigate serum adiponectin level in patients with Alzheimer's disease (AD) and its correlation with the patients' cognitive function. This case-control study was conducted in 90 patients with a highly probable diagnosis ofAD, who were divided into mild, moderate and severe group saccording to the MMSE score. Ninety healthy subjects matched for age and gender with the AD patients were selected as the control group. The serum levels ofadiponectin in the participants were detected using enzyme-linked immunosorbent assay. Serum adiponectin level was significantly lower in the AD group than in the control group (P<0.05). Of the 3 subgroups of the AD patients, the moderate and severe AD groups showed significantly lower serum adiponectin level sthan the control group (P<0.05), but the difference in adiponectin levels was not significant between the mild AD group and the control group (P>0.05); serum adiponectin levels also differed significantly among the 3 subgroups of AD patients (P<0.05). Serum adiponectin level was positively correlated with the MMSE score in the AD patients (r=0.683, P<0.001). Serum adiponectin levels are reduced in AD patients and associated with the degree of cognitive impairment.

Value of urine Alzheimer-associated neuronal thread protein level for diagnosing dementia

Objective To investigate the value of Alzheimer-associated neuronal thread protein (AD7c-NTP) level in urine for diagnosing dementia. Methods Mini-Mental State Examination (MMSE) and Montreal Cognitive Assessment (MoCA) were applied to evaluate cognitive function of all subjects. Enzyme-linked immunosorbent assay (ELISA) was used to detect the expression changes of urine AD7c-NTP. Spearman rank correlation was used to evaluate the correlation of urine AD7c-NTP with MMSE and MoCA scores. Receiver operating characteristic (ROC) curve was used to estimate the sensitivity, specificity and accuracy rate of AD7c-NTP on diagnosing dementia. Results There were 57 cases with Alzheimer's disease (AD), 30 cases with amnesic mild cognitive impairment (aMCI), 37 cases with frontotemporal dementia (FTD), 32 cases with vascular dementia (VaD) and 20 normal controls. There was statistically significant difference of urine AD7c-NTP levels among different groups ( P = 0.000). The levels of urine AD7c-NTP in AD group, aMCI group and FTD group were significantly higher than that of control group ( P = 0.000, 0.029, 0.005). The level of urine AD7c-NTP in moderate to severe AD group was higher than that of mild AD group, but there was no significant difference ( P = 0.359). The level of urine AD7c-NTP was negatively related with MoCA score in mild AD group ( r s = -0.506, P = 0.016), and there was no significant correlation of urine AD7c-NTP with MMSE and MoCA scores in moderate to severe AD group ( P > 0.05, for all). In ROC analysis, area under the curve (AUC) was 0.838 (95% CI: 0.732-0.945, P = 0.000), with 70.20% sensitivity and 90% specificity, and the critical value for diagnosing AD was 2.32 ng/ml of urine AD7c-NTP. There were 70.18% (40/57) of AD patients, 63.33% (19/30) of aMCI patients and 45.95% (17/37) of FTD patients had abnormal levels of urine AD7c-NTP (> 2.32 ng/ml). Conclusions AD7c-NTP level in urine has important clinical value in early diagnosis and condition assessment of patients with dementia. DOI: 10.3969/j.issn.1672-6731.2015.08.009

Elevated plasma angiogenesis factors in Alzheimer's disease.

Evidence has shown that aberrant angiogenesis is an integral part of Alzheimer's disease (AD). Angiogenesis is a complex process requiring successive activation of a rather large series of factors. The aim of this study was to determine which angiogenesis molecule(s) abnormalities were changed in plasma of AD subjects and whether plasma levels of angiogenesis factors were associated with cognitive function and risk of AD. Discovery-phase antibody arrays were used to detect plasma concentrations of 55 angiogenesis-related factors. Enzyme-linked immunosorbent assays (ELISAs) in a large cohort were further performed to identify the association of plasma angiogenesis factors with AD. We found that plasma angiogenin (ANG) and tissue inhibitor of matrix metalloproteinase-4 (TIMP-4) levels were higher in patients with AD than those in normal subjects. Significantly higher ANG and TIMP-4 were observed in the severe AD group relative to the mild AD. There were different levels of plasma ANG and TIMP-4 compared with vascular dementia and other dementias. Age or gender had no major effects on levels of these proteins. Plasma ANG and TIMP-4 levels tended to be higher in ApoE ε4 carriers compared with non-carriers, but not significantly. A multiple regression analysis after adjusting for covariates revealed correlations between plasma ANG and TIMP-4 and the MMSE and CDR. Higher plasma ANG and TIMP-4 levels were associated with significant AD risk. These results demonstrate that plasma ANG and TIMP-4 may reflect the severity of cognitive function impairment, and higher levels were associated with risk of AD.

Orexinergic system dysregulation, sleep impairment, and cognitive decline in Alzheimer disease.

Nocturnal sleep disruption develops in Alzheimer disease (AD) owing to the derangement of the sleep-wake cycle regulation pathways. Orexin contributes to the regulation of the sleep-wake cycle by increasing arousal levels and maintaining wakefulness. To study cerebrospinal fluid levels of orexin in patients with AD, to evaluate the relationship of orexin cerebrospinal fluid levels with the degree of dementia and the cerebrospinal fluid AD biomarkers (tau proteins and β-amyloid 1-42), and to analyze potentially related sleep architecture changes measured by polysomnography. We conducted a case-control study from August 1, 2012, through May 31, 2013. We included 48 drug-naive AD patients referred to the Neurological Clinic of the University Hospital of Rome Tor Vergata. Based on the Mini-Mental State Examination score, 21 patients were included in mild AD group (score, ≥21), whereas 27 were included in the moderate to severe AD group (score, <21). The control group consisted of 29 nondemented participants of similar age and sex. Laboratory assessment of cerebrospinal fluid levels of orexin, tau proteins, and β-amyloid 1-42 and polysomnographic assessment of sleep variables. Levels of orexin, tau proteins, and β-amyloid 1-42; macrostructural variables of nocturnal sleep (total sleep time, sleep efficiency, sleep onset and rapid eye movement [REM] sleep latencies, non-REM and REM sleep stages, and wakefulness after sleep onset); and Mini-Mental State Examination scores. Patients with moderate to severe AD presented with higher mean (SD) orexin levels compared with controls (154.36 [28.16] vs 131.03 [26.55]; P < .01) and with more impaired nocturnal sleep with respect to controls and patients with mild AD. On the other hand, in the global AD group, orexin levels were positively correlated with total tau protein levels (r = 0.32; P = .03) and strictly related to sleep impairment. Finally, cognitive impairment, as measured by the Mini-Mental State Examination, was correlated with sleep structure deterioration. Our results demonstrate that, in AD, increased cerebrospinal fluid orexin levels are related to a parallel sleep deterioration, which appears to be associated with cognitive decline. Therefore, the orexinergic system seems to be dysregulated in AD, and its output and function appear to be overexpressed along the progression of the neurodegenerative process. This overexpression may result from an imbalance of the neurotransmitter networks regulating the wake-sleep cycle toward the orexinergic system promoting wakefulness.

Effects of NR1H3 Genetic Variation on the Expression of Liver X Receptor α and the Progression of Alzheimer's Disease

Alzheimer's disease (AD) has been postulated to involve defects in the clearance of amyloid-β (Aβ). Activation of liver X receptor α (LXRα) increases the expression of apolipoprotein E (ApoE) as well as cholesterol transporters ABCA1 and ABCG1, leading to augmented clearance of Aβ. We have previously shown that the C allele of rs7120118 in the NR1H3 gene encoding LXRα reduces the risk of AD. Here, we wanted to assess whether the rs7120118 variation affects the progression of AD and modulates the expression of NR1H3 and its downstream targets APOE, ABCA1 and ABCG1.We utilized tissue samples from the inferior temporal cortex of 87 subjects, which were subdivided according to Braak staging into mild, moderate and severe AD groups on the basis of AD-related neurofibrillary pathology. APOE ε4 allele increased soluble Aβ42 levels in the tissue samples in a dose-dependent manner, but did not affect the expression status of APOE. In contrast, the CC genotype of rs7120118 was underrepresented in the severe group, although this result did not reach statistical significance. Also, patients with the CC genotype of rs7120118 showed significantly decreased soluble Aβ42 levels as compared to the patients with TT genotype. Although the severity of AD did not affect NR1H3 expression, the mRNA levels of NR1H3 among the patients with CT genotype of rs7120118 were significantly increased as compared to the patients with TT genotype. These results suggest that genetic variation in NR1H3 modulates the expression of LXRα and the levels of soluble Aβ42.

Mass Spectrometry Quantification Revealed Accumulation of C-Terminal Fragment of Apolipoprotein E in the Alzheimer's Frontal Cortex

Polymorphic variation in the apolipoprotein E (apoE) gene is the major genetic susceptibility factor for late-onset Alzheimer's disease (AD) and likely contributes to neuropathology through various pathways. It is also recognized that apoE undergoes proteolytic cleavage in the brain and the resultant apoE fragments likely have a variety of bioactive properties that regulate neuronal signaling and may promote neurodegeneration. ApoE fragmentation in the human brain has been intensively studied using different immunochemical methods, but has never been analyzed in a quantitative manner to establish preferably accumulated fragments. Here we report quantification using multiple reaction monitoring mass spectrometry (MRM MS) with 15N-labeled full-length apoE4 as an internal standard. Measurements were performed on frontal cortex from control and severe AD donors. Our data point to a preferable accumulation of C-terminal apoE fragment in the insoluble fraction of tissue homogenate in the severe AD group versus the control group. Further insight into the biological consequences of this accumulation may lead to a better understanding of the basic mechanism of AD pathology.

Unpicking the Semantic Impairment in Alzheimer’s Disease: Qualitative Changes with Disease Severity

Despite a vast literature examining semantic impairment in Alzheimer's disease (AD), consensus regarding the nature of the deficit remains elusive. We re-considered this issue in the context of a framework that assumes semantic cognition can break down in two ways: (1) core semantic representations can degrade or (2) cognitive control mechanisms can become impaired [1]. We hypothesised and confirmed that the nature of semantic impairment in AD changes with disease severity. Patients at mild or severe stages of the disorder exhibited impairment across various semantic tasks but the nature of those deficits differed qualitatively for the two groups. Commensurate with early dysfunction of the cognitive control, temporoparietal-frontal-cingulate network, characteristics of deregulated semantic cognition were exhibited by the mild AD cases. In contrast, the severe AD group reproduced features of additional degradation of core semantic representations. These results suggest that spread of pathology into lateral anterior temporal lobes in later stage AD produces degradation of semantic representations, exacerbating the already deregulated system. Moreover, the dual nature of severe patients’ impairment was highlighted by disproportionately poor performance on tasks placing high demand on both conceptual knowledge and control processes–e.g., category fluency.

Unpicking the semantic impairment in Alzheimer's disease: qualitative changes with disease severity.

Despite a vast literature examining semantic impairment in Alzheimer's disease (AD), consensus regarding the nature of the deficit remains elusive. We re-considered this issue in the context of a framework that assumes semantic cognition can break down in two ways: (1) core semantic representations can degrade or (2) cognitive control mechanisms can become impaired [1]. We hypothesised and confirmed that the nature of semantic impairment in AD changes with disease severity. Patients at mild or severe stages of the disorder exhibited impairment across various semantic tasks but the nature of those deficits differed qualitatively for the two groups. Commensurate with early dysfunction of the cognitive control, temporoparietal-frontal-cingulate network, characteristics of deregulated semantic cognition were exhibited by the mild AD cases. In contrast, the severe AD group reproduced features of additional degradation of core semantic representations. These results suggest that spread of pathology into lateral anterior temporal lobes in later stage AD produces degradation of semantic representations, exacerbating the already deregulated system. Moreover, the dual nature of severe patients’ impairment was highlighted by disproportionately poor performance on tasks placing high demand on both conceptual knowledge and control processes–e.g., category fluency.

Callosal atrophy in mild cognitive impairment and Alzheimer's disease: Different effects in different stages

Alzheimer's Disease (AD) is a neurodegenerative disorder that mainly affects grey matter (GM). Nevertheless, a number of investigations have documented white matter (WM) pathology associated with AD. The corpus callosum (CC) is the largest WM fiber bundle in the human brain. It has been shown to be susceptible to atrophy in AD mainly as a correlate of Wallerian degeneration of commissural nerve fibers of the neocortex. The aim of this study was to investigate which callosal regions are affected and whether callosal degeneration is associated with the stage of the disease. For this purpose, we analyzed high-resolution MRI data of patients with amnesic mild cognitive impairment (MCI) (n=20), mild AD (n=20), severe AD (n=10), and of healthy controls (n=20). Callosal morphology was investigated applying two different structural techniques: mesh-based geometrical modeling methods and whole-brain voxel-based analyses. Our findings indicate significant reductions in severe AD patients compared to healthy controls in anterior (genu and anterior body) and posterior (splenium) sections. In contrast, differences between healthy controls and mild AD patients or amnesic MCI patients were less pronounced and did not survive corrections for multiple comparisons. When correlating anterior and posterior WM density of the CC with GM density of the cortex in the severe AD group, we detected significant positive relationships between posterior sections of the CC and the cortex. We conclude that callosal atrophy is present predominantly in the latest stage of AD, where two mechanisms might contribute to WM alterations in severe AD: the Wallerian degeneration in posterior subregions and the myelin breakdown process in anterior subregions.

Test-Retest Reliability and Minimal Detectable Change Scores for the Timed “Up &amp; Go” Test, the Six-Minute Walk Test, and Gait Speed in People With Alzheimer Disease

With the increasing incidence of Alzheimer disease (AD), determining the validity and reliability of outcome measures for people with this disease is necessary. The goals of this study were to assess test-retest reliability of data for the Timed "Up & Go" Test (TUG), the Six-Minute Walk Test (6MWT), and gait speed and to calculate minimal detectable change (MDC) scores for each outcome measure. Performance differences between groups with mild to moderate AD and moderately severe to severe AD (as determined by the Functional Assessment Staging [FAST] scale) were studied. This was a prospective, nonexperimental, descriptive methodological study. Background data collected for 51 people with AD included: use of an assistive device, Mini-Mental Status Examination scores, and FAST scale scores. Each participant engaged in 2 test sessions, separated by a 30- to 60-minute rest period, which included 2 TUG trials, 1 6MWT trial, and 2 gait speed trials using a computerized gait assessment system. A specific cuing protocol was followed to achieve optimal performance during test sessions. Test-retest reliability values for the TUG, the 6MWT, and gait speed were high for all participants together and for the mild to moderate AD and moderately severe to severe AD groups separately (intraclass correlation coefficients > or = .973); however, individual variability of performance also was high. Calculated MDC scores at the 90% confidence interval were: TUG=4.09 seconds, 6MWT=33.5 m (110 ft), and gait speed=9.4 cm/s. The 2 groups were significantly different in performance of clinical tests, with the participants who were more cognitively impaired being more physically and functionally impaired. A single researcher for data collection limited sample numbers and prohibited blinding to dementia level. The TUG, the 6MWT, and gait speed are reliable outcome measures for use with people with AD, recognizing that individual variability of performance is high. Minimal detectable change scores at the 90% confidence interval can be used to assess change in performance over time and the impact of treatment.

Quantitative analysis of brain perfusion SPECT in Alzheimer's disease using a fully automated regional cerebral blood flow quantification software, 3DSRT

The clinical symptoms of Alzheimer's disease (AD) show great diversity depending on the clinical stage. We investigated the correlation of regional cerebral blood flow (rCBF) changes and the clinical severity of AD patients. Thirty-nine AD patients and 16 normal subjects participated in this study. AD patients were divided into three subgroups by clinical severity. Quantitative brain perfusion SPECT analyses were performed using a rCBF quantification software, 3DSRT. In mild AD, significant decreases of rCBF were detected in the bilateral parietal, angular gyrus, pericallosal, thalamus, right temporal and left hippocampal regions. Moderate AD patients showed significantly lower blood flow than those with mild AD only to the right hippocampus. Analysis of the severe AD group revealed a nearly diffuse decrease of rCBF throughout the cerebral cortex except for part of the frontal lobe compared with moderate patients. These results were consistent with previous findings demonstrated by qualitative analysis of CBF. The decreased thalamic blood flow was noteworthy as this finding has rarely been reported. In consideration of the structure and function of the Papez circuit, which connects the medial temporal lobe and thalamus, a remote metabolic effect might be the cause of lower rCBF in the thalamus.

Cortical rhythms reactivity in AD, LBD and normal subjects: A quantitative MEG study

The present study evaluated the reactivity of cortical rhythms in 15 Alzheimer's disease (AD) patients, 7 Lewy body dementia (LBD) patients and 9 control subjects using a 165 SQUID whole-head MEG system. The absolute power values of the rhythms recorded over different areas over the brain (frontal, parietal, temporal, occipital) were analysed in the 3–47 Hz frequency range. The cortical reactivity of the alpha (9–14 Hz) and pre-alpha rhythms (7–9 Hz) during open and closed eyes conditions differentiated the control group from the patient groups and moderate AD from severe AD and LBD groups, respectively. The cortical reactivity of the slow-band (3–7 Hz) obtained by comparing a simple mental task and the rest discriminated the severe AD group from the other groups. In addition, spectral coherence analysis in the alpha band showed that the loss of coherence in AD and LBD patients mainly involved long connections. These results suggest that investigations on rhythms reactivity and spectral coherence might help on the study of the dementias with different etiology.

Behavioral and psychological symptoms of dementia characteristic of mild Alzheimer patients

In order to clarify the characteristics of Behavioral and Psychological Symptoms of Dementia (BPSD) in patients with mild Alzheimer's disease (AD), BPSD among the severities of Clinical Dementia Rating (CDR) in 74 patients with AD were compared using the Neuropsychiatric inventory (NPI). The result, when compared between mild (CDR = 0.5, 1) and moderate or severe (CDR = 2, 3) AD, was a significant difference in frequency of euphoria, disinhibition and aberrant motor behavior, but no significant difference was found in frequency of delusions, hallucinations, agitation, dysphoria, anxiety, apathy and irritability. In addition, a significant difference was found in the mean scores of the composite score for euphoria, apathy, disinhibition and aberrant motor behavior, but no significant difference was found in the mean scores of the composite score for delusions, hallucinations, agitation, dysphoria, anxiety and irritability. That is, the mild AD groups (CDR 0.5 or 1) had delusions, hallucinations, agitation, dysphoria, anxiety, apathy and irritability as frequently as the moderate or severe AD groups (CDR 2 or 3), and had the equivalent level of composite scores to the moderate or severe AD groups (CDR 2 or 3) in delusion, hallucination, agitation, dysphoria, anxiety and irritability. Therefore, it was supposed that psychotic symptoms (delusion, hallucination) and emotional symptoms (agitation, dysphoria, anxiety, irritability) are important BPSD in patients with mild AD as well as those with moderate or severe AD, and there are needs for health, welfare and medical services for these symptoms.