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New Approaches for the Quantification and Targeting of Noradrenergic Dysfunction in Alzheimer's Disease

Overview
Specialty Neurology
Date 2022 Mar 16
PMID 35293158
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Abstract

There is clear, early noradrenergic dysfunction in Alzheimer's disease. This is likely secondary to pathological tau deposition in the locus coeruleus, the pontine nucleus that produces and releases noradrenaline, prior to involvement of cortical brain regions. Disruption of noradrenergic pathways affects cognition, especially attention, impacting memory and broader functioning. Additionally, it leads to autonomic and neuropsychiatric symptoms. Despite the strong evidence of noradrenergic involvement in Alzheimer's, there are no clear trial data supporting the clinical use of any noradrenergic treatments. Several approaches have been tried, including proof-of-principle studies and (mostly small scale) randomised controlled trials. Treatments have included pharmacotherapies as well as stimulation. The lack of clear positive findings is likely secondary to limitations in gauging locus coeruleus integrity and dysfunction at an individual level. However, the recent development of several novel biomarkers holds potential and should allow quantification of dysfunction. This may then inform inclusion criteria and stratification for future trials. Imaging approaches have improved greatly following the development of neuromelanin-sensitive sequences, enabling the use of structural MRI to estimate locus coeruleus integrity. Additionally, functional MRI scanning has the potential to quantify network dysfunction. As well as neuroimaging, EEG, fluid biomarkers and pupillometry techniques may prove useful in assessing noradrenergic tone. Here, we review the development of these biomarkers and how they might augment clinical studies, particularly randomised trials, through identification of patients most likely to benefit from treatment. We outline the biomarkers with most potential, and how they may transform symptomatic therapy for people living with Alzheimer's disease.

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References
1.
Sano M, Rosen W, Stern Y, Rosen J, Mayeux R . Simple reaction time as a measure of global attention in Alzheimer's disease. J Int Neuropsychol Soc. 1995; 1(1):56-61. DOI: 10.1017/s1355617700000102. View

2.
Betts M, Cardenas-Blanco A, Kanowski M, Spottke A, Teipel S, Kilimann I . Locus coeruleus MRI contrast is reduced in Alzheimer's disease dementia and correlates with CSF Aβ levels. Alzheimers Dement (Amst). 2019; 11:281-285. PMC: 6439222. DOI: 10.1016/j.dadm.2019.02.001. View

3.
Liguori C, Placidi F, Izzi F, Spanetta M, Mercuri N, Di Pucchio A . Sleep dysregulation, memory impairment, and CSF biomarkers during different levels of neurocognitive functioning in Alzheimer's disease course. Alzheimers Res Ther. 2020; 12(1):5. PMC: 6942389. DOI: 10.1186/s13195-019-0571-3. View

4.
Jacobs H, Muller-Ehrenberg L, Priovoulos N, Roebroeck A . Curvilinear locus coeruleus functional connectivity trajectories over the adult lifespan: a 7T MRI study. Neurobiol Aging. 2018; 69:167-176. DOI: 10.1016/j.neurobiolaging.2018.05.021. View

5.
Langley J, Hussain S, Flores J, Bennett I, Hu X . Characterization of age-related microstructural changes in locus coeruleus and substantia nigra pars compacta. Neurobiol Aging. 2019; 87:89-97. PMC: 7064384. DOI: 10.1016/j.neurobiolaging.2019.11.016. View