Journal of Alzheimer's disease : JAD
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The phenomena of severe agitation is not well understood and often not adequately treated. ⋯ Severe agitation in nursing home residents with dementia is a relevant clinical issue as approximately 70% of residents have a dementia. Residents with elation/euphoria and delusions may have a stronger risk of showing severe agitation. We consider delusions as a possible cause of agitation and therefore a prelude to agitation. Although it might be possible that elation/euphoria follows from agitation, we hypothesize that the residents first experience elation/ euphoria and exhibit agitation afterwards.
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Cerebrospinal fluid (CSF) biomarker studies have shown variable accuracy for diagnosis of Alzheimer's disease (AD); therefore, internal validation is recommended. ⋯ CSF t-tau/Aβ42 ratio appears to be the most accurate AD CSF marker. The presence of intermediate values for CSF markers among the subjects with inconclusive Amyloid-PET suggests the presence of other dementias associated with AD pathology or intermediate phenotypes.
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To evaluate whether genetically increased serum uric acid levels influence the risk of Alzheimer's disease (AD), we used genome-wide significant single nucleotide polymorphisms for uric acid as the instrumental variables, and undertook a Mendelian randomization (MR) study to estimate the effect of uric acid on the risk of AD. The MR method prevents bias due to reverse causation (e.g., uric acid changes because of AD) and minimizes bias due to confounding of both measured and unmeasured confounders. We used the summary statistics from The International Genomics of Alzheimer's Project Consortium that is the largest AD genome-wide association study of 74,046 individuals of European ethnicity including 25,580 AD cases. ⋯ The MR analyses did not support a causal role of genetically elevated serum uric acid on AD risk (odds ratio: 1.02, 95% confidence interval: 0.93-1.12, p = 0.65). Sensitivity analyses, including MR-Egger regression, suggested no strong evidence of bias due to pleiotropy. In conclusion, lifelong genetically increased serum uric acid levels have no protective effect on the risk of AD.
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Cerebral hypoperfusion and degeneration of the noradrenergic locus coeruleus (LC) occur early in Alzheimer's disease (AD). Cerebral blood vessels are densely innervated by noradrenergic projections from the LC suggesting a functional role for the regulation of cerebral blood flow (CBF). Experimental LC stimulation, however, has provided no clarity as decreases or increases in CBF were reported from different experimental settings and investigators. ⋯ Pharmacological evidence suggests that NE released in the brain of anesthetized pigs raises CABF involving β-adrenergic mechanisms and nitric oxide. If in awake humans NE released from the LC had vasodilator effects early LC degeneration could be involved in early cerebral hypoperfusion of AD. Moreover, a cerebral adrenergic vascular innervation deficit, possibly resulting from LC degeneration, and systemic endothelial dysfunction together may act synergistically to reduce CBF.
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Chronic neuroinflammation has been implicated in Alzheimer's disease (AD) pathology. ⋯ CSF CCL2 levels are associated with the degree of medial temporal lobe and gray matter atrophy, and cognitive decline in AD.