John Hamilton

A genetic analysis of the nerve cells found a distinctive pattern of gene mutations in brains with CTE.

The pattern was not present in brains that appeared healthy despite exposure to head trauma.

Researchers say the mutations associated with CTE are similar to those found in brain cells from people with Alzheimer's disease.

Both conditions are marked by an accumulation of a protein called tau.

John Hamilton, NPR News.

The study involved 92 healthy people who were 65 and older.

Half spent 30 minutes a day for 10 weeks playing video games like Solitaire and Candy Crush.

The other half did exercises from a demanding cognitive training program called BrainHQ.

Etienne de Villers-Sidani of McGill University says in people who got the training, levels of a key chemical messenger increased in a brain area involved in making decisions.

De Villers-Sidani said the chemical messenger, called acetylcholine, typically declines by about 2.5 percent every 10 years starting in middle age.

So cognitive training, he says, rolled back the clock by about a decade.

John Hamilton, NPR News.

Feeling heartbroken?

People who inherit two copies of a gene called ApoE4 face at least 10 times the average risk for Alzheimer's.

But Dr. Susan Abushakra of the biotech firm Alzeon says existing treatments often cause dangerous side effects in these people.

So Alzion has been testing a drug that appears to be safer but has yet to prove its effectiveness.

In a study of 325 people with two copies of the ApoE4 gene, the drug failed to help people with more severe symptoms of Alzheimer's.

But in people with milder symptoms, the drug helped preserve memory and thinking and dramatically reduced brain atrophy.

John Hamilton, NPR News.

In Alzheimer's and other neurodegenerative diseases, nerve cells decide to self-destruct long before they should.