Brain Changes May Precede Memory Loss
Structural Differences Seen in Brain Years Before Memory Loss
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.