Brain Changes May Precede Memory Loss

Structural Differences Seen in Brain Years Before Memory Loss

 

By Miranda Hitti
Reviewed by Louise Chang, MD

April 17, 2007 -- Memory loss may follow structural changes in the brain that begin while the mind is still sharp.

That's according to researchers from the University of Kentucky.

They studied 136 people aged 65 and older for about five years, on average.

When the study started, all participants were healthy, with no memory problems. They got brain scans using magnetic resonance imaging ( MRI) and took several mental skills tests.

Participants repeated the mental skills test yearly for about five years, on average.

During that time, 23 participants developed mild but clearly abnormal memory loss that didn't significantly hamper daily activities.

The researchers compared the MRI brain scans of the 23 participants who developed memory loss and the 113 patients who didn't develop memory loss.

Remember, those MRI brain scans were done at the study's start, when none of the patients had memory problems.

The brain scans of participants who developed memory loss showed less brain volume in several brain areas.

Those structural differences were present an average of four years before memory loss was diagnosed, note the researchers, who included neurologist Charles D. Smith, MD.

The finding is "not surprising," write Smith and colleagues in Neurology. They note that nine of the 23 participants with mild memory loss later developed Alzheimer's disease.

Alzheimer's disease may begin many years before symptoms become apparent, "slowly increasing in intensity and extent over time," Smith's team writes.

However, the study doesn't prove that the brain volume differences seen on the MRI brain scans caused memory loss. The study also doesn't show the participants' brain volume earlier in life, so it's not clear whether their brain volume changed.

A Shake a Day?

Another company is placing its bets on a treatment that makes an end run around poor sugar metabolism in the brains of many Alzheimer’s patients.

The drug, called Ketasyn, which comes in the form of a shake-like drink, delivers a dose of proteins called ketone bodies to the brain. Brain cells can use ketones as an alternative energy source so that they don’t have to rely on glucose.

If it works, one advantage of Ketasyn could be that patients can begin taking it as soon as doctors detect poor sugar metabolism in their brains. In many patients that’s a decade or more before the onset of Alzheimer’s symptoms.

This is far upstream of some of the other therapies you’ve been hearing about,” said Lauren Costantini, MD, a vice president of Accera Inc., the drug’s maker.

Of a study of 152 patients who received either Ketasyn or placebo, those who were given Ketasyn had improvement in mental test scores compared with those on placebo at 45 days.

The drug doesn’t seem to work in everyone. Patients positive for a gene known as ApoE4, a known factor in Alzheimer's disease, didn’t respond to Ketasyn. But those who don’t have the gene showed better memory and thinking after three months than those who took placebo.

Alzheimer's can be an elusive to spot in a loved one, especially in the early stages. How did you and your loved one's medical team determine it was Alzheimer's? What was your diagnostic journey?

 

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