Cerebrospinal fluid and positron-emission tomography biomarkers for noradrenergic dysfunction in neurodegenerative diseases: a systematic review and meta-analysis

• The noradrenergic system shows pathological modifications in aging and neurodegenerative diseases and undergoes substantial neuronal loss in Alzheimer's disease and Parkinson's disease. While a coherent picture of structural decline in post-mortem and in vivo MRI measures seems to emerge, whether this translates into a consistent decline in available noradrenaline levels is unclear. We conducted a meta-analysis of noradrenergic differences in Alzheimer's disease dementia and Parkinson's disease using CSF and PET biomarkers. CSF noradrenaline and 3-methoxy-4-hydroxyphenylglycol levels as well as noradrenaline transporters availability, measured with PET, were summarized from 26 articles using a random-effects model meta-analysis. Compared to controls, individuals with Parkinson's disease showed significantly decreased levels of CSF noradrenaline and 3-methoxy-4-hydroxyphenylglycol, as well as noradrenaline transporters availability in the hypothalamus. In Alzheimer's disease dementia, 3-methoxy-4-hydroxyphenylglycol but not noradrenaline levels were increased compared to controls. Both CSF and PET biomarkers of noradrenergic dysfunction reveal significant alterations in Parkinson's disease and Alzheimer's disease dementia. However, further studies are required to understand how these biomarkers are associated to the clinical symptoms and pathology. Lancini et al. showed that compared to controls, CSF and PET noradrenergic biomarkers are decreased in Parkinson's disease, while in Alzheimer's disease, only CSF noradrenaline metabolite 3-methoxy-4-hydroxyphenylglycol levels are significantly increased. Further studies should determine how CSF measures of noradrenergic dysfunction are related to pathology and clinical symptoms.

Subject headings

MEDICIN OCH HÄLSOVETENSKAP  -- Medicinska och farmaceutiska grundvetenskaper -- Neurovetenskaper (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Basic Medicine -- Neurosciences (hsv//eng)

Keyword

noradrenaline

norepinephrine

Alzheimer's disease

Parkinson's disease

locus coeruleus

locus-coeruleus

parkinsons-disease

alzheimers-disease

senile

dementia

frontal-cortex

neuron loss

norepinephrine

noradrenaline

mechanisms

dopamine

Neurosciences & Neurology

Publication and Content Type

ref (subject category)

art (subject category)