New Clue for Diagnosing Alzheimer’s Disease

Despite many billions of dollars spent by the National Institutes of Health (NIH) and pharmaceutical companies around the world in recent years trying to tackle Alzheimer’s disease, we still have no idea what causes it.

Well, there are ideas. I moderated a panel of six prominent Alzheimer’s researchers at a breakout session of the American Neurological Association’s conference in Washington, D.C., two years ago, and each of the panelists, handpicked as leading Alzheimer’s researchers from around the world, was asked what they thought causes Alzheimer’s. Each forwarded a suspicion — six different ones.

Alzheimer’s has proven not only a mystery as to its causes but a riddle to even diagnose. Although PET scan procedures are getting better at analyzing who may have the disease, the only way to be sure of a diagnosis is to do an autopsy.

Alzheimer’s has proven not only a mystery as to its causes but a riddle to even diagnose. Although PET scan procedures are getting better at analyzing who may have the disease, the only way to be sure of a diagnosis is to do an autopsy.

Nonetheless, PET scans increasingly are used to look for the sticky beta-amyloid protein plaques that surround brain cells, the assumption long being that the more of these plaques you have, the more likely Alzheimer’s is to be progressing. People with an abnormal amount of the amyloid plaques that show up in PET scans are often diagnosed as having early-stage Alzheimer’s.

But there’s a bug in this theory. We also know from autopsy evidence that nearly a third of all people who do not exhibit any signs of dementia have lots of amyloid plaques in their brains at death.

A new small study reported recently in the journal Science Translational Medicine emphasizes this conundrum and puts the spotlight on a different plaque also associated with Alzheimer’s — tau protein.

A recent advance in scanning techniques allows researchers to bind an agent to tau proteins in the brain so they can see how much of them are present. Sixteen researchers at Washington University in St. Louis used the technique to study 10 patients diagnosed with early-stage Alzheimer’s and 36 adults without it. They used binding agents to see both amyloid plaques and tau plaques. They found that the more tau plaques they could find in the temporal lobe of the brain, the more likely the person was to not do well on memory tests. The amyloid plaques did not predict impaired memory function as well as the tau plaques.

One theory the research supports is that the brain may be able to deal with a certain level of amyloid plaque progression, but when tau plaques start forming in mass, they can push a patient into late-stage disease. The research supports the idea that PET scans for tau might be useful in diagnosing Alzheimer’s more conclusively.

Because both tau and amyloid plaques are associated with Alzheimer’s, subsequent research confirming the results could eventually lead to different and complimentary medicines to prevent the disease.

To your health and wealth,

Stephen Petranek
for The Daily Reckoning

P.S. To read more in-depth articles on the prospects for treating Alzheimer’s Disease as well as other cutting-edge technology updates and how you can benefit from owning the hidden companies driving the biggest advances in high-tech right now, click here to subscribe to Breakthrough Technology Alert written by Stephen Petranek.