Dementia Brain Changes Show up Early

Mild cognitive impairment shows up years after the brain starts to show changes

(RxWiki News) Memory problems are the first symptoms of dementia. New research shows that changes in the brain may show up as much as 10 years before memory symptoms.

MRI scans were used to look for bright signals that show poor blood vessel function in the brain.

People who developed mild cognitive impairment (MCI) showed increasing levels of bright signals on their MRI years before they had any memory symptoms.

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The study, led by Lisa Silbert, MD, of the Department of Neurology at the Oregon Health & Science University in Portland, enrolled 181 elderly people with no symptoms of memory loss.

The people in the study had tests of their cognitive skills – memory and thinking skills – each year for up to 19 years.

Each year, people in the study also had a magnetic resonance imaging (MRI) scan.

The researchers looked for a certain type of change in the brain called white matter hyperintensitivity, which shows up as a bright signal on an MRI.

These bright signals are known to show areas with vascular problems - where blood vessels are not working properly.

During the study, 134 people developed MCI, which is memory loss that is worse than normal aging but less severe than Alzheimer’s Disease.

On average, 10.6 years before the symptoms of MCI appeared, the amount of bright signals in the MRI were on the rise.

Of the people who developed MCI, 63 died and had an autopsy. Of these, 28.5 percent had Alzheimer’s Disease, and 24 percent had Alzheimer’s Disease and signs of vascular disease.

The authors concluded that increases in these bright signals show up way before symptoms of cognitive decline. Tracking changes in bright signals may help doctors to catch cognitive decline early and start treatments.

This research also points to the fact that vascular issues may play a role in the development of MCI or Alzheimer’s.

It is not clear whether the vascular problems that create bright signals on the MRI are caused by dementia or if they are a risk factor for dementia.

These bright signals are also more likely to appear in an MRI as people age even when they do not have memory problems.

MRIs are expensive, so using them to track brain changes may not be feasible for most people.

This study was published August 21 in Neurology. One of the authors has served on advisory committees for Eli Lilly and Janssen.

Review Date: 
August 28, 2012