Characteristic deterioration of ADAS-Jcog subscale scores and correlations with regional cerebral blood flow reductions in Alzheimer's disease

Ginsenoside Rh2 Alleviate Sepsis-related Encephalopathy via Up-regulating Nrf2/HO-1 Pathway and Apoptosis Inhibition

Sepsis patients are highly prone to sepsis-associated encephalopathy (SAE) complications, resulting in a high mortality rate. Recently, there has been no specific treatment for long-term improvement of cerebral function. Ginsenoside Rh2 is a form of steroidal saponins isolated from plant ginseng and has been shown to possess anti-inflammatory as well as neuroprotective characteristics; yet, the effect of ginsenoside Rh2 on SAE treatment is obscure. Accordingly, we proposed to investigate the effect of ginsenoside Rh2 in alleviating SAE damage. We established and utilized the SAE mouse model to determine the effect of Rh2 treatment on alleviating SAE. We determined the expression levels of Heme oxygenase-1(HO-1) and Nuclear factor erythroid 2-related factor 2 (Nrf2) as well as measured neural apoptosis by flow cytometry. Also, we quantified the levels of caspase-3, malondialdehyde (MDA), GSH-Px superoxide dismutase (SOD) and evaluated the animals' neural reflex function. First, used Rh2 to treat microglia BV2 and mouse neuron MN-c whether LPS exist or not, and then measured expression level of Iba-1, apoptotic rate, and ROS content applying flow cytometry. Also, we quantified the levels of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and interleukin-6 (IL-6). In comparison with the Sham group, the SAE model exhibited an elevated MDA content, caspase-3 activity, and cell apoptosis. On the other hand, the GSH-Px activity and SOD level were decreased along with a decreased neural reflex score. Our investigation concluded that Rh2 treatment significantly alleviated SAE damage and inhibited LPS-induced response via up-regulation of the Nrf2/HO-1 pathway to promote anti-oxidative stress capacity and inhibit neural cell apoptosis.

Using eZIS of SPECT to evaluate the therapeutic effect of carotid endarterectomy

OBJECTIVE

Stroke is an acute cerebrovascular disease with high morbidity and mortality. The main causes of ischemic stroke include carotid artery stenosis, and carotid endarterectomy (CEA) can be used to improve the blood flow of the lesion site. Regional cerebral blood flow (rCBF) can be decreased by using single photon emission computed tomography (SPECT). The Easy Z-Score imaging system (eZIS) can display the changes of rCBF as Z-Score. The purpose of this study was to determine whether eZIS of SPECT can be used to evaluate the therapeutic effect of CEA in the treatment of carotid artery stenosis.

METHODS

In this study, subjects were divided into the surgery group and the control group. The surgery group included seven patients with unilateral or bilateral internal carotid artery stenosis who received CEA treatment, and the control group included 11 patients who only received conventional drug treatment but did not receive surgery. Cerebral perfusion imaging (CPI) was collected twice before and after the corresponding treatment (within 6 months). rCBF of the lesion site was measured and Z-score was calculated before and after treatment by the eZIS technique.

RESULTS

The postoperative Z-score of the surgery group was 0.54 ± 2.71 compared with that of the preoperative -1.34 ± 2.68 ( P  = 0.0034; t  = 4.687; df  = 6), while the z-score of the control group was -0.33 ± 2.58 compared with that of the pretreatment 1.84 ± 2.62 ( P  = 0.0010; t  = 4.618; df  = 10).

CONCLUSION

CEA can effectively improve the blood flow in the lesion area of patients with carotid artery stenosis. eZIS of SPECT can be used to evaluate the therapeutic effect of CEA on carotid artery stenosis visually.

Education reduces cognitive dysfunction in Alzheimer's disease by changing regional cerebral perfusion: An in-vivo arterial spin labeling study

OBJECTIVE

Formal education and other cognitive challenges influence brain structure and improve function. It is believed that cognitive activities create a cognitive reserve (CR) that can slow the decline due to aging and neurodegenerative diseases. This study investigated alterations of regional cerebral blood flow (rCBF) associated with high and low CR in different stages of Alzheimer's disease (AD) and examined whether rCBF alteration mediates the relationship between education and cognitive performance.

METHODS

Patients with AD or amnestic mild cognitive impairment (aMCI) and healthy controls were divided into low cognitive reserve (LCR) and high cognitive reserve (HCR) subgroups according to median of education years (≤ 9 vs. > 9 years). The final study population included 89 AD patients (67 LCR, 22 HCR), 74 aMCI patients (44 LCR, 30 HCR), and 66 healthy controls (29 LCR, 37 HCR). All subjects were examined by arterial spin labeling magnetic resonance imaging and a neurocognitive test battery. rCBF was compared among groups by two-way analysis of variance. Mediation analyses were used to explore the relationships among education, rCBF, and cognitive test scores.

RESULTS

There were significant interaction effects of disease state (AD, aMCI, HC) and education level (LCR, HCR) on CBF in right hippocampus, posterior cingulate cortex, and right inferior parietal cortex (R_IPC). Education regulated episodic memory score by influencing right hippocampal CBF in HC_HCR and aMCI_HCR subgroups.

CONCLUSION

Our results indicate that the protective effect of education against cognitive dysfunction in early-stage AD is mediated at least partially by altered CBF in right hippocampus.

Longitudinal changes in cerebral blood flow and their relation with cognitive decline in patients with dementia: Current knowledge and future directions

The pathophysiology underlying cognitive decline is multifactorial, with increasing literature suggesting a role for cerebrovascular health. Cerebral blood flow (CBF) is an important element of cerebrovascular health, which raises questions regarding the relation between CBF and cognitive decline. Cross-sectional studies demonstrate lower CBF in patients with cognitive decline compared to healthy age-matched peers. Remarkably, longitudinal studies do not support a link between CBF reductions and cognitive decline. These studies, however, are often limited by small sample sizes and may therefore be underpowered to detect small effect sizes. Therefore, through a systematic review and meta-analysis of longitudinal studies, we examined whether longitudinal changes in global CBF are related to cognitive decline in subjects with Alzheimer's disease, and qualitatively described findings on regional CBF. Considering the growing impact of dementia and the lack of treatment options, it is important to understand the role of CBF as a prognostic biomarker and/or treatment target in dementia.

The Visuospatial and Sensorimotor Functions of Posterior Parietal Cortex in Drawing Tasks: A Review

Drawing is a comprehensive skill that primarily involves visuospatial processing, eye-hand coordination, and other higher-order cognitive functions. Various drawing tasks are widely used to assess brain function. The neuropsychological basis of drawing is extremely sophisticated. Previous work has addressed the critical role of the posterior parietal cortex (PPC) in drawing, but the specific functions of the PPC in drawing remain unclear. Functional magnetic resonance imaging and electrophysiological studies found that drawing activates the PPC. Lesion-symptom mapping studies have shown an association between PPC injury and drawing deficits in patients with global and focal cerebral pathology. These findings depicted a core framework of the fronto-parietal network in drawing tasks. Here, we review neuroimaging and electrophysiological studies applying drawing paradigms and discuss the specific functions of the PPC in visuospatial and sensorimotor aspects. Ultimately, we proposed a hypothetical model based on the dorsal stream. It demonstrates the organization of a PPC-centered network for drawing and provides systematic insights into drawing for future neuropsychological research.

The Neuropsychological Correlates of Brain Perfusion and Gray Matter Volume in Alzheimer's Disease

BACKGROUND

Neuropsychological tests, structural neuroimaging, and functional neuroimaging are employed as diagnostic and monitoring biomarkers of patients with Alzheimer's disease (AD)Objective:We aimed to elucidate the similarities and differences in neuropsychological tests and neuroimaging with the use of the Mini-Mental State Examination (MMSE), Alzheimer's Disease Assessment Scale cognitive subscale (ADAS-cog), structural magnetic resonance image (MRI), and perfusion single photon emission computed tomography (SPECT), and parametric image analyses to understand its role in AD.

METHODS

Clinically-diagnosed AD patients (n = 155) were scanned with three-dimensional T1-weighted MRI and N-isopropyl-p-[123I] iodoamphetamine SPECT. Statistical parametric mapping 12 was used for preprocessing images, statistical analyses, and voxel-based morphometry for gray matter volume analyses. Group comparison (AD versus healthy controls), multiple regression analyses with MMSE, ADAS-cog total score, and ADAS-cog subscores as variables, were performed.

RESULTS

The AD group showed bilateral hippocampal volume reduction and hypoperfusion in the bilateral temporo-parietal lobe and posterior midline structures. Worse MMSE and ADAS-cog total score were associated with bilateral temporo-parietal volume loss and hypoperfusion. MMSE, but not ADAS-cog, was associated with the posterior midline structures. The ADAS-cog subscores were associated with the temporal volume, while perfusion analyses were linked to the left temporo-parietal region with the language function and right analogous region with the constructional praxis subscore.

CONCLUSION

MMSE and ADAS-cog are associated with temporo-parietal regions, both in volume and perfusion. The MMSE score is associated with posterior midline structures and linked to an abnormal diagnostic AD pattern. Perfusion image analyses better represents the cognitive function in AD patients.

A New Serum Biomarker Set to Detect Mild Cognitive Impairment and Alzheimer's Disease by Peptidome Technology

Background:

Because dementia is an emerging problem in the world, biochemical markers of cerebrospinal fluid (CSF) and radio-isotopic analyses are helpful for diagnosing Alzheimer’s disease (AD). Although blood sample is more feasible and plausible than CSF or radiological biomarkers for screening potential AD, measurements of serum amyloid- β (Aβ), plasma tau, and serum antibodies for Aβ_1 - 42 are not yet well established.

Objective:

We aimed to identify a new serum biomarker to detect mild cognitive impairment (MCI) and AD in comparison to cognitively healthy control by a new peptidome technology.

Methods:

With only 1.5μl of serum, we examined a new target plate “BLOTCHIP^®” plus a matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF/MS) to discriminate control (n = 100), MCI (n = 60), and AD (n = 99). In some subjects, cognitive Mini-Mental State Examination (MMSE) were compared to positron emission tomography (PET) with Pittsburgh compound B (PiB) and the serum probability of dementia (SPD). The mother proteins of candidate serum peptides were examined in autopsied AD brains.

Results:

Apart from Aβ or tau, the present study discovered a new diagnostic 4-peptides-set biomarker for discriminating control, MCI, and AD with 87% of sensitivity and 65% of specificity between control and AD (^***p < 0.001). MMSE score was well correlated to brain Aβ deposition and to SPD of AD. The mother proteins of the four peptides were upregulated for coagulation, complement, and plasticity (three proteins), and was downregulated for anti-inflammation (one protein) in AD brains.

Conclusion:

The present serum biomarker set provides a new, rapid, non-invasive, highly quantitative and low-cost clinical application for dementia screening, and also suggests an alternative pathomechanism of AD for neuroinflammation and neurovascular unit damage.

Variáveis psicomotoras, cognitivas e funcionais em idosas saudáveis e com doença de Alzheimer

RESUMO A teoria da retrogênese descreve os declínios apresentados na doença de Alzheimer a partir dos estágios do desenvolvimento neuropsicomotor de Piaget. O objetivo deste estudo transversal é avaliar e descrever aspectos psicomotores, cognitivos e quedas, investigando a relação de dependência entre essas variáveis de acordo com a teoria da retrogênese. A amostra foi composta por 45 idosas (27 saudáveis e 18 com Alzheimer fase leve), residentes em São Paulo entre 2016 e 2017. Para a avaliação foram utilizados: anamnese, Escala de Depressão Geriátrica de Yesavage (GDS-30), Montreal Cognitive Assessment (MoCA), Cambridge Cognitive Exam-Revised (CAMCOG-R), Escala de Equilíbrio de Berg (EEB), timed up and go test (TUGT), Avaliação Direta do Estado Funcional (DAFS-BR), teste U de Mann-Whitney, coeficiente de correlação de Spearman e análise de regressão múltipla com p<0,05. Observou-se ordem de perda semelhante à sugerida pela teoria da retrogênese nos dois grupos estudados. Quanto menor o índice CAMCOG-R, maior o número de quedas (p=0,03). Itens praxia (p<0,00) e funções executivas (p<0,00) do CAMCOG-R mostraram-se altamente correlacionados com o TUGT e a EEB. Sugere-se relação de dependência entre funcionalidade e cognição e equilíbrio e cognição, bem como correlação entre risco de queda e desempenho cognitivo nos dois grupos estudados. As perdas observadas estão de acordo com o que a teoria da retrogênese propõe, mas com diferentes intensidades entre os grupos. Estudos longitudinais são necessários, com uso de exames de imagem para validar a teoria nos padrões de perda em idosos com e sem doença de Alzheimer.

Psychometric properties of Cognitive Instruments in Vascular Dementia and Alzheimer's disease: a neuropsychological study

OBJECTIVES

To describe elderly performance in the Bender Gestalt Test (BGT) and to discriminate its score by using types of errors as comparison among healthy controls, Alzheimer's disease (AD) patients, and vascular dementia (VD) patients.

METHODS

We performed a cross-sectional analysis of 285 elderly individuals of both sexes, all over 60 years old and with more than 1 year of schooling. All participants were assessed through a detailed clinical history, laboratorial tests, neuroimaging, and neuropsychological tests including the BGT, the Cambridge Cognitive Examination (CAMCOG), the Mini-Mental State Examination (MMSE), the Geriatric Depression Scale (GDS), and the Pfeffer Functional Activities Questionnaire (PFAQ). The BGT scores were not used to establish diagnosis.

RESULTS

Mean BGT scores were 3.2 for healthy controls, 7.21 for AD, and 8.04 for VD with statistically significant differences observed between groups (p<0.0001). Logistic regression analysis was used to identify the main risk factors for the diagnostic groups. BGT's scores significantly differentiated the healthy elderly from those with AD (p<0.0001) and VD (p<0.0001), with a higher area under the curve, respectively 0.958 and 0.982. BGT's scores also showed that the AD group presented 12 types of errors. Types of errors evidenced in the execution of this test may be fundamental in clinical practice because it can offer differential diagnoses between senescence and senility.

CONCLUSION

A cut-off point of 4 in the BGT indicated cognitive impairment. BGT thus provides satisfactory and useful psychometric data to investigate elderly individuals.