Screening for beta-amyloid (beta-amyloid) in the CSF is used to investigate Alzheimer's disease and in patients with memory loss.
Beta-amyloid is the major component of plaques and is formed by the amyloid precursor protein (APP). Beta-amyloid levels reflect beta-amyloid metabolism and plaque formation. Low levels are observed in Alzheimer's disease and Lewy body dementia.
- Alzheimer's Disease: Moderate to severe beta-amyloid decrease (sensitivity> 85%)
- Creutzfeldt-Jakob Disease (CJD): Normal levels or slightly reduced β-amyloid concentration
- Frontal dementia: Normal levels or slightly reduced β-amyloid concentration
- Lewy body dementia: Slight to moderate decrease in beta-amyloid levels
- Vascular dementia: Normal levels or slightly reduced β-amyloid concentration
- Amyotrophic lateral sclerosis (ALS): normal β-amyloid levels
Normal aging, mild cognitive impairment without progression to Alzheimer's disease, depression, Parkinson's disease and non-acute cerebrovascular disease have normal β-amyloid levels.