Mild cognitive impairment, or MCI, is a transitional form of memory loss somewhere between the normal memory decline of aging and full-blown dementia. For researchers like Sarah Madsen, a Ph.D. candidate in neuroscience at UCLA, however, MCI holds significant promise in Alzheimer’s research.
“MCI is a predisease state, so these are people with a high risk for developing Alzheimer’s disease who have not yet suffered from irreversible brain damage,” Madsen says. “This makes them an ideal target for new drugs and research because they have the most to gain: they still have an intact brain that we hope can be protected by future advances in medicine.”
Madsen and her colleagues studied MRI scans from 400 elderly patients whose cognitive skills ranged from healthy to significantly impaired; half had been diagnosed with MCI. Using mathematical tools to measure size and shape difference in the caudate nucleus, a part of the brain responsible for motor control and attention, they found that those who experience significant impairment also show a decreased volume of the C-shaped caudate by as much as 7 percent. Those in MCI brains had shrunk 4 percent.
The findings, which Madsen presented last November at a Society for Neuroscience conference, suggest a gradual progression of brain-tissue loss as dementia becomes more severe. The study contributes to the goal of improved early diagnosis by revealing one more piece of a complicated puzzle. Another recent study, presented at the Radiological Society of North America, provides hope for people at all stages of dementia: walking may help guard the brain against Alzheimer’s.
“We found that walking five miles per week protects the brain structure over 10 years in people with Alzheimer’s and MCI, especially in areas of the brain’s key memory and learning centers,” says Cyrus Raji of the University of Pittsburgh. “We also found that these people had a slower decline in memory loss over five years.”
