Brain scans may help predict which adults with mild cognitive impairment are likelier to develop Alzheimer`s disease, according to a new study.
Mild cognitive impairment (MCI) is an intermediate stage between the decline in mental abilities that occurs in normal aging and the more pronounced deterioration associated with dementia, a group of brain disorders that includes Alzheimer`s disease.
Individuals with MCI develop Alzheimer`s at a rate of 15 to 20 per cent per year.
"Being able to better predict which individuals with MCI are at greatest risk for developing Alzheimer`s would provide critical information if disease-modifying therapies become available," said lead author Linda K. McEvoy, assistant professor in the Department of Radiology at the University of California, San Diego School of Medicine.
Included in the study were a baseline MRI exam, serving as an initial point of measurement, and a second MRI performed a year later on 203 healthy adults, 317 patients with MCI and 164 patients with late-onset Alzheimer`s. The average age of the study participants was 75.
The researchers used the MRI to measure the thickness of the cerebral cortex - key to memory, attention, thought and language and observed the pattern of thinning to compute a risk score.
Using the baseline MRI, they calculated that the patients with MCI had a one-year risk of conversion to AD ranging from three to 40 per cent.
By combining results of the baseline MRI and the MRI exam performed one year later, the researchers were able to calculate a rate of change in brain atrophy that was even more informative.
The MCI patients` risk of disease progression based on the serial MR exams ranged from 3 to 69 per cent.
The results appear online and will be published in the June issue of Radiology .