Apr 8, 2011 08:41 GMT  ·  By

Determining whether people who suffer from mild cognitive impairment will go on to develop Alzheimer’s disease is a very important issue in today's medicine, considering the heavy toll that treating this condition takes on public healthcare systems. A way of doing this has just been proposed.

Experts at the University of California in San Diego (UCSD) School of Medicine managed to demonstrate that it is possible to use functional Magnetic Resonance Imaging (fMRI) to predict which MCI patients will go on to develop Alzheimer's.

The research team was led by UCSD assistant adjunct professor of radiology Linda K. McEvoy, PhD. She is a cognitive neuroscientist with extensive experience in the application of EEG, MEG, and structural MRI methods to questions about human perception and cognitive functions.

The most interesting thing about the new method is that it will allow experts to predict whether the neurodegenerative disorder will begin developing before the indicative symptoms start manifesting.

In the general population, MCI is considered to be an intermediary step in the evolution from normal, age-related memory loss to dementia and AD. Mild cognitive impairment affects about 16 percent of the entire population, statistics show.

According to experts, seniors in general have a 2 percent chance of developing AD, whereas people with MCI have a 15 to 20 percent chance of developing this form of dementia, PsychCentral reports.

Interestingly, among individuals who have been diagnosed with MCI, some remain stable until the end of their lives. On the other hand, others' mental health gradually declines, whereas some go on to experience a very fast rate of mental deterioration, which generally leads to the development of AD.

“Being able to better predict which individuals with mild cognitive impairment are at greatest risk for developing Alzheimer’s would provide critical information if disease-modifying therapies become available,” explains Linda K. McEvoy, PhD, who was also the lead author of the new study.

In the new experiments, the UCSD team did fMRI scans on 317 MCI patients, 164 advanced AD patients, and 317 healthy control subjects. The average age for test participants was around 75.

“MRI is very sensitive to brain atrophy. There’s a pattern of cortical thinning associated with AD that indicates the patient is more likely to progress to Alzheimer’s disease,” the team leader explains.

“Compared to estimating a patient’s risk of conversion based on a clinical diagnosis only, MRI provides substantially more informative, patient-specific risk estimates,” McEvoy adds.

“The baseline MRI helped identify which patients were at very low risk of progressing to Alzheimer’s and those whose risk was doubled,” she concludes.