Plasma viscosity, a component of whole blood viscosity, may serve as a sensitive and specific marker for diagnosing and differentiating Alzheimer's disease and vascular dementia. According to a February 2013 article published in the American Journal of Alzheimer's Disease and Other Dementias, plasma viscosity was significantly higher in both dementia subtypes when compared with controls (p < 0.001). Additionally, plasma viscosity in patients with vascular dementia (1.70 ± 0.06 mPa S) was significantly higher than that seen in patients with Alzheimer's disease (1.61 ± 0.08 mPa S). Because these two types of dementia are overlapping in their clinical presentation, pathophysiology, and diagnosis; complicated and expensive measures are often required to make an accurate distinction to guide disease treatment and management. Plasma viscosity and likely whole blood viscosity may serve as a more specific and sensitive diagnostic test to allow clinicians to more cheaply and accurately differentiate between vascular dementia and Alzheimer's disease. Larger prospective studies need to be done to support these findings.
Aras S, Tek I, Varli M, et al. Plasma viscosity: is a biomarker for the differential diagnosis of Alzheimer's disease and vascular dementia? American journal of Alzheimer's disease and other dementias. Feb 2013;28(1):62-68.