scholarly journals A Comparative Analysis of Structural Brain MRI in the Diagnosis of Alzheimer’s Disease

2009 ◽  
Vol 21 (1-2) ◽  
pp. 13-19 ◽  
Author(s):  
Jason Appel ◽  
Elizabeth Potter ◽  
Qian Shen ◽  
Gustavo Pantol ◽  
Maria T. Greig ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Cognitive Impairment ◽  
Cognitive Decline ◽  
Medial Temporal Lobe ◽  
Rating Scales ◽  
Brain Mri ◽  
Alzheimer’S Dementia ◽  
Alzheimer's Dementia ◽  
Increased Risk

Dementia is a debilitating and life-altering disease which leads to both memory impairment and decline of normal executive functioning. While causes of dementia are numerous and varied, the leading cause among patients 60 years and older is Alzheimer’s disease. The gold standard for Alzheimer’s diagnosis remains histological identification of amyloid plaques and neurofibrillary tangles within the medial temporal lobe, more specifically the entorhinal cortex and hippocampus. Although no definitive cure for Alzheimer's disease currently exists, there are treatments targeted at preserving cognition and memory while delaying continued loss of function. Alzheimer's disease exists along a spectrum of cognitive decline and is often preceded by Mild Cognitive Impairment (MCI). Patients with MCI demonstrate memory loss and cognitive impairment while still continuing normal activities of daily living, and are considered to be at increased risk for developing Alzheimer's Dementia. Identifying patients with prodromal states of Alzheimer's dementia such as MCI may allow initiation of appropriate treatment planning and delay of cognitive decline. Therefore, the need for a non-invasive early biomarker for the detection of Alzheimer's disease has never been greater. Multiple neuroimaging methods utilizing visual rating scales, volumetric measurements, and automated methods have been developed to identify, quantify, and track anatomic sequelae of Alzheimer’s Disease.

scholarly journals Subjective cognitive decline: The first clinical manifestation of Alzheimer's disease?

2016 ◽  
Vol 10 (3) ◽  
pp. 170-177 ◽  
Author(s):  
Adalberto Studart Neto ◽  
Ricardo Nitrini
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Cognitive Impairment ◽  
Mild Cognitive Impairment ◽  
Cognitive Decline ◽  
Clinical Manifestation ◽  
Neurodegenerative Disorder ◽  
Subjective Cognitive Decline ◽  
Subjective Memory ◽  
Increased Risk

ABSTRACT Background: Mild cognitive impairment is considered as the first clinical manifestation of Alzheimer's disease (AD), when the individual exhibits below performance on standardized neuropsychological tests. However, some subjects before having a lower performance on cognitive assessments already have a subjective memory complaint. Objective: A review about subjective cognitive decline, the association with AD biomarkers and risk of conversion to dementia. Methods: We performed a comprehensive non-systematic review on PubMed. The keywords used in the search were terms related to subjective cognitive decline. Results: Subjective cognitive decline is characterized by self-experience of deterioration in cognitive performance not detected objectively through formal neuropsychological testing. However, various terms and definitions have been used in the literature and the lack of a widely accepted concept hampers comparison of studies. Epidemiological data have shown that individuals with subjective cognitive decline are at increased risk of progression to AD dementia. In addition, there is evidence that this group has a higher prevalence of positive biomarkers for amyloidosis and neurodegeneration. However, Alzheimer's disease is not the only cause of subjective cognitive decline and various other conditions can be associated with subjective memory complaints, such as psychiatric disorders or normal aging. The features suggestive of a neurodegenerative disorder are: onset of decline within the last five years, age at onset above 60 years, associated concerns about decline and confirmation by an informant. Conclusion: These findings support the idea that subjective cognitive complaints may be an early clinical marker that precedes mild cognitive impairment due to Alzheimer's disease.

Diabetes is associated with cognitive impairment no dementia in the aging, demographics, and memory study (ADAMS)

2012 ◽  
Vol 25 (1) ◽  
pp. 167-168 ◽  
Author(s):  
Christine E. Gould ◽  
Sherry A. Beaudreau ◽  
Huma Salman
Keyword(s):  
Diabetes Mellitus ◽  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Cognitive Impairment ◽  
Mild Cognitive Impairment ◽  
Cognitive Decline ◽  
Vascular Dementia ◽  
Increased Risk ◽  
Cognitive Impairment No Dementia

Individuals with diabetes mellitus have a 1.39 times increased risk of Alzheimer's disease, a 2.38 times increased risk of vascular dementia, and a faster rate of cognitive decline compared to individuals without diabetes (Lu et al., 2009). In a study, over a 9-year follow-up diabetes was associated with accelerated progression from mild cognitive impairment (MCI) to dementia, but was not associated with progression from no impairment to MCI (Xu et al., 2010). Many previous studies on cognitive impairment and diabetes are limited by the use of cognitive screens to diagnose and assess cognitive impairment. A few studies diagnosing cognitive impairment with comprehensive neuropsychological batteries provide mixed results. For instance, Luchinger et al. (2007) found that diabetes was correlated with the presence of MCI, whereas diabetes was not associated with the presence of dementia versus no dementia in the Aging, Demographics, and Memory Study ADAMS; (Llewellyn et al., 2010).

scholarly journals ACE2 activation protects against cognitive decline and reduces amyloid pathology in the Tg2576 mouse model of Alzheimer’s disease

2020 ◽  
Vol 139 (3) ◽  
pp. 485-502 ◽  
Author(s):  
Charles E. Evans ◽  
James S. Miners ◽  
Giulia Piva ◽  
Christine L. Willis ◽  
David M. Heard ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Cognitive Impairment ◽  
Animal Models ◽  
Cognitive Decline ◽  
Intraperitoneal Administration ◽  
Tg2576 Mouse ◽  
Model Of Alzheimer’S Disease ◽  
Increased Risk ◽  
Tg2576 Mice

Abstract Mid-life hypertension and cerebrovascular dysfunction are associated with increased risk of later life dementia, including Alzheimer’s disease (AD). The classical renin–angiotensin system (cRAS), a physiological regulator of blood pressure, functions independently within the brain and is overactive in AD. cRAS-targeting anti-hypertensive drugs are associated with reduced incidence of AD, delayed onset of cognitive decline, and reduced levels of Aβ and tau in both animal models and human pathological studies. cRAS activity is moderated by a downstream regulatory RAS pathway (rRAS), which is underactive in AD and is strongly associated with pathological hallmarks in human AD, and cognitive decline in animal models of CNS disease. We now show that enhancement of brain ACE2 activity, a major effector of rRAS, by intraperitoneal administration of diminazene aceturate (DIZE), an established activator of ACE2, lowered hippocampal Aβ and restored cognition in mid-aged (13–14-month-old) symptomatic Tg2576 mice. We confirmed that the protective effects of DIZE were directly mediated through ACE2 and were associated with reduced hippocampal soluble Aβ42 and IL1-β levels. DIZE restored hippocampal MasR levels in conjunction with increased NMDA NR2B and downstream ERK signalling expression in hippocampal synaptosomes from Tg2576 mice. Chronic (10 weeks) administration of DIZE to pre-symptomatic 9–10-month-old Tg2576 mice, and acute (10 days) treatment in cognitively impaired 12–13-month-old mice, prevented the development of cognitive impairment. Together these data demonstrate that ACE2 enhancement protects against and reverses amyloid-related hippocampal pathology and cognitive impairment in a preclinical model of AD.

Alzheimer's disease in the NAS–NRC Registry of ageing twin veterans, IV. Performance characteristics of a two-stage telephone screening procedure for Alzheimer's dementia

1995 ◽  
Vol 25 (6) ◽  
pp. 1211-1219 ◽  
Author(s):  
Joseph J. Gallos ◽  
John C. S. Breitner
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Cognitive Impairment ◽  
Operating Characteristic ◽  
Cognitive Status ◽  
Alzheimer’S Dementia ◽  
Screening Procedure ◽  
Two Stage ◽  
Alzheimer's Dementia ◽  
Telephone Screening

SynopsisIn the course of a large twin study of Alzheimer's disease we used a two-stage telephone screening procedure. The modified Telephone Interview for Cognitive Status (TICS-m) served as an initial screen for dementia in 12709 individuals. The telephone Dementia Questionnaire (DQ) was then asked of collateral informants for subjects with TICS-m scores below 28, as well as for samples of persons with higher TICS-m scores. Based upon DQ responses, individuals with cognitive impairment not attributable to focal causes underwent assessment for the clinical diagnosis of Alzheimer's disease (‘Alzheimer's dementia’), as did their twins. Well-defined Alzheimer's dementia was apparent in 39 subjects. Employing a cut-off of 27 or lower as indicative of cognitive impairment, the sensitivity of the TICS-m in the detection of Alzheimer's dementia was estimated at >99% and specificity at 86%. Inclusion of the DQ increased the specificity at the 27/28 cut-point to 99%. The TICS-m score was associated with an area under the receiver operating characteristic (ROC) curve of 0·88 (95% confidence interval 0·81 to 0·94). The maximum number of cases of Alzheimer's dementia remaining undetected in the sample was estimated to be 34.

scholarly journals Subtle Cognitive Decline predicts progression to Mild Cognitive Impairment Above and Beyond Alzheimer’s Disease Risk Factors

2019 ◽  
Vol 34 (6) ◽  
pp. 846-846
Author(s):  
J Osuna ◽  
K Thomas ◽  
E Edmonds ◽  
K Bangen ◽  
A Weigand ◽  
...  
Keyword(s):  
Risk Factors ◽  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
At Risk ◽  
Cognitive Impairment ◽  
Mild Cognitive Impairment ◽  
Cognitive Decline ◽  
Disease Risk ◽  
Preclinical Ad ◽  
Increased Risk

Abstract Objective Early identification of those at risk for mild cognitive impairment (MCI) and Alzheimer’s disease (AD) is critical for early intervention. Recent work shows that subtle cognitive decline (SCD), operationally-defined using sensitive neuropsychological scores, predicts progression to MCI/AD and is associated with AD biomarkers. We aimed to determine whether SCD adds unique value in predicting progression to MCI/AD above and beyond other AD risk factors. Method 547 cognitively unimpaired participants from the Alzheimer’s Disease Neuroimaging Initiative (359 without SCD; 188 with SCD) underwent neuropsychological testing and lumbar puncture. Participants were classified as SCD if they performed >1 SD below the demographically-adjusted mean on 1) two neuropsychological total scores in different cognitive domains, or 2) two memory test process scores (e.g., intrusion errors), or 3) one total score and one process score. Cox regressions examined whether SCD status predicted progression to MCI and AD within 5 years after adjusting for age, education, sex, MMSE, depressive symptoms, ischemia risk, apolipoprotein E genotype, and AD biomarker “positivity” based on the cerebrospinal fluid phosphorylated tau-to-β-amyloid ratio. Results SCD status predicted progression to MCI (HR = 2.74, 95% CI = 2.07-3.63, p < .001) and AD (HR = 2.20, 95% CI = 1.04-4.65, p = .04) within 5 years, even after including known AD risk factors in the model. Conclusion SCD conveys a 2-3 fold increased risk of progression to MCI/AD and is a unique predictor above and beyond risk factors that are commonly used in preclinical AD research. These findings support our novel SCD criteria as a cost-effective and non-invasive method for identifying those at risk for future cognitive decline.

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