FRIDAY, April 20, 2007 (HealthDay News) -- Brain structure changes occur years before a person shows signs of memory loss caused by Alzheimer's disease or other forms of dementia, a new U.S. study suggests.
The study, published in the April 17 issue of the journal Neurology, included 136 healthy people over the age of 65 who underwent brain scans and cognitive tests at the start of the study and were all found to be cognitively normal. They were then assessed once a year for five years.
By the end of the five years, 23 participants had developed mild cognitive impairment (MCI), and nine of those 23 people were later diagnosed with Alzheimer's disease.
The brain scans revealed that the 23 who developed MCI or Alzheimer's had less gray matter in key memory processing areas of their brains at the beginning of the study. Those 23 people also scored lower on cognitive tests at the start of the study, although their scores were within the normal range.
"We found that changes in brain structure are present in clinically normal people an average of four years before MCI diagnosis," study author Dr. Charles D. Smith, of the University of Kentucky Medical Center in Lexington, said in a prepared statement.
"We knew that people with MCI or Alzheimer's disease had less brain volume, but before now, we didn't know if these brain structure changes existed, and to what degree, before memory loss begins," he said.
More information
The American Academy of Family Physicians has more about memory loss in older people.
