The effect of neurofibrillary tangles on MMSE scores in patients with amyloid plaque

Abstract

AbstractBackgroundThroughout the past century, research regarding Alzheimer's disease has been focused on beta‐amyloid peptides (Aβ), which can aggregate to form plaques and toxify neurons in the brain. Recently, researchers have discovered another potential primary marker of Alzheimer’s Disease known as tau protein. When overproduced without regulation, tau can aggregate to form tangles (which subsequently interrupts the communication of the neuron’s nucleus to the rest of the cell). However, it is relatively uncertain as to how the presence of neurofibrillary tangles affects the rate of degeneration of one’s cognitive ability. It is predicted that the MMSE scores of patients with positive amyloid‐PET and positive tau‐PET scans will decline at a faster rate than patients with negative tau scans.MethodEighteen total patients who were found to be amyloid(+) were included in this analysis. 7 of the subjects were tau(‐), while 11 of the subjects were tau(+). Then, the patients’ MMSE scores over the past two years were evaluated to determine a monthly rate of decline.ResultThe results of this study concluded that patients who were tau‐positive [tau(+)] had a faster decline of cognitive ability compared to those who were tau‐negative [tau(‐)]. The MMSE score of amyloid(+) and tau(+) patients declined at a rate of 0.40 points per month, while amyloid(+) and tau(‐) patients declined at a rate of 0.031 points per month.ConclusionAlthough additional research is necessary, the results of this study conclude that declining cognition may be directly correlated to the presence of tau.