Structural Brain Changes Precede Cognitive Impairment
Subjects who develop impairment have reductions in gray matter in certain brain areas
MONDAY, April 16 (HealthDay News) -- Older patients with normal cognitive function who have a smaller volume of gray matter in the memory-processing areas of the brain may have a greater risk of developing mild cognitive impairment than their peers, according to a study in the April 17 issue of Neurology.
Charles D. Smith, M.D., and colleagues from the University of Kentucky Medical Center in Lexington examined changes in brain structure by structural magnetic resonance imaging in 136 patients 65 years and older with normal cognitive function at baseline.
During an average follow-up of 5.4 years, 23 subjects developed mild cognitive impairment, and 9 of these progressed to Alzheimer disease. The researchers found that subjects who eventually developed cognitive impairment had a smaller volume of gray matter in the bilateral anteromedial temporal lobes and left angular gyrase at baseline. These subjects also had lower cognitive function at baseline although still within the normal range, according to the study.
"Structural brain changes in anatomic areas involved in higher cognitive processes precede clinical signs and symptoms in longitudinally followed normal subjects destined to develop mild cognitive impairment," Smith and colleagues concluded.