Two major clinical studies to identify significant markers for Alzheimer’s disease have recently published their results. One of them tracked the depletion of a special protein in the cerebrospinal fluid (CSF) and the other one studied the toxic accumulation of a substance in the brain of patients.
David M. Holtzman et al. studied the CSF presence of Neurogranin—a postsynaptic neuronal protein that decreases with neuronal destruction—in a well-defined cohort of individuals with diagnosed Alzheimer’s disease and a group of cognitively normal individuals with both a cross-sectional and longitudinal approach from January 21, 2000 through March 31, 2011.
Neurogranin is a neuronal protein that “is involved in synaptic plasticity, synaptic regeneration, and long-term potentiation through the modulation of calcium and calmodulin-signaling pathways and plays an important role in memory and learning.” Using an immunoassay for the CSF neurogranin, they found that its levels “correlate with brain atrophy in AD, with amyloid load in preclinical AD and with other CSF markers in AD and controls.”
MR Brier et al. studied the accumulation of Tau in the brains of normal individuals and patients with Alzheimer’s diagnosis using special imaging. They recruited 46 individuals who had traditional cognitive tests and both PET and MRI scans; a subset agreed to have a lumbar puncture to measure the levels of Tau and A-beta. Thirty-six were found to be cognitively normal.
For the first time, the scientists were able to track the Alzheimer’s pathology in real time in living patients. In the normal aging process Tau accumulates in the hippocampus. But when the accumulated Tau started to spread from the temporal lobe to the neocortex, it was a predictor sign in the preclinical stage of which individuals would end up developing a cognitive decline.
Some physicians predict that eventually measuring these markers would be similar to the control of cholesterol to prevent cardiovascular disease. Even though these results look promising, we believe that there is still a long way to go to fulfill that optimistic prophecy.
What do you think? Please tell us.
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