Using MRI, researchers may predict which adults will develop Alzheimer's

Apr 06, 2011

Using MRI, researchers may be able to predict which adults with mild cognitive impairment are more likely to progress to Alzheimer's disease, according to the results of a study published online and in the June issue of Radiology.

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 , a group of that includes Alzheimer's disease (AD).

Individuals with MCI develop AD at a rate of 15 to 20 percent per year, which is significantly higher than the one to two percent rate for the general population. Some people with MCI remain stable while others gradually decline and some quickly deteriorate.

"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 the study's lead author, Linda K. McEvoy, Ph.D., assistant professor in the Department of Radiology at the University of California, San Diego School of Medicine.

Dr. McEvoy and a team of researchers analyzed MRI exams from the Neuroimaging Initiative (ADNI), a large publicly and privately sponsored study, which performed imaging and other tests on hundreds of healthy individuals and others with MCI and early AD between 2005 and 2010 in hopes of identifying valuable of the disease process.

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 AD. The average age of the study participants was 75.

Using MRI, the researchers measured the thickness of the — the outermost layer of the cerebral hemispheres of the brain that plays a key role in memory, attention, thought and language — and observed the pattern of thinning to compute a risk score. One of the characteristics of AD is a loss of brain cells, called atrophy, in specific areas of the cortex.

"MRI is very sensitive to brain atrophy," Dr. McEvoy said. "There's a pattern of cortical thinning associated with AD that indicates the patient is more likely to progress to AD."

Using the baseline MRI, the researchers calculated that the patients with MCI had a one-year risk of conversion to AD ranging from three to 40 percent.

"Compared to estimating a patient's risk of conversion based on a clinical diagnosis only, MRI provides substantially more informative, patient-specific risk estimates," Dr. McEvoy said. "The baseline MRI helped identify which patients were at very low risk of progressing to Alzheimer's and those whose risk was doubled."

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 percent.

"Rapid thinning of the cortex is reflective of a degenerative disorder," Dr. McEvoy explained.

Although no treatments currently exist that slow or prevent the neurodegeneration associated with AD, Dr. McEvoy said patients at high risk of progressing to AD might want to enroll in clinical trials of disease-modifying therapies. She said the information would also help ensure patients receive optimal care and allow families more time for planning.

Explore further: Dengue fever strikes models in Japan

More information: "Mild Cognitive Impairment: Baseline and Longitudinal Structural MR Imaging Measures Improve Predictive Prognosis." Collaborating with Dr. McEvoy were Dominic Holland, Ph.D., Donald J. Hagler, Jr., Ph.D., Christine Fennema-Notestine, Ph.D., James B. Brewer, M.D., Ph.D., and Anders M. Dale, Ph.D. radiology.rsna.org/

add to favorites email to friend print save as pdf

Related Stories

MRI shows brain atrophy pattern that predicts Alzheimer's

Feb 10, 2009

Using special MRI methods, researchers have identified a pattern of regional brain atrophy in patients with mild cognitive impairment (MCI) that indicates a greater likelihood of progression to Alzheimer's disease. The findings ...

Walking slows progression of Alzheimer's

Nov 29, 2010

Walking may slow cognitive decline in adults with mild cognitive impairment (MCI) and Alzheimer's disease, as well as in healthy adults, according to a study presented today at the annual meeting of the Radiological Society ...

Recommended for you

Ebola kills 31 people in DR Congo: WHO

52 minutes ago

An outbreak of the Ebola virus in the Democratic Republic of Congo has killed 31 people and the epidemic remains contained in a remote northwestern region, UN the World Health Organization (WHO) said Tuesday.

Dengue fever strikes models in Japan

3 hours ago

A worsening outbreak of dengue fever in Japan has claimed its first celebrities—two young models sent on assignment to the Tokyo park believed to be its source.

Japanese researchers develop 30-minute Ebola test

3 hours ago

Japanese researchers said Tuesday they had developed a new method to detect the presence of the Ebola virus in 30 minutes, with technology that could allow doctors to quickly diagnose infection.

Senegal monitors contacts of 1st Ebola patient

15 hours ago

Senegalese authorities on Monday were monitoring everyone who was in contact with a student infected with Ebola who crossed into the country, and who has lost three family members to the disease.

Cerebral palsy may be hereditary

21 hours ago

Cerebral palsy is a neurological developmental disorder which follows an injury to the immature brain before, during or after birth. The resulting condition affects the child's ability to move and in some ...

User comments : 0