According to a study by Mayo Clinic, published in Radiology, a common condition called leukoaraiosis, made up of tiny areas in the brain that have been deprived of oxygen and appear as bright white dots on MRI scans, is not a harmless part of the aging process; it is a disease that changes the function of the brain in elderly people.
Kirk M. Welker, M.D., assistant professor of radiology in the College of Medicine at Mayo Clinic in Rochester, said: “There has been a lot of controversy over these commonly identified abnormalities on MRI scans and their clinical impact. In the past, leukoaraiosis has been considered a benign part of the aging process, like gray hair and wrinkles.”
Leukoaraiosis, also known as small vessel ischemia, is often referred to as unidentified bright objects (UBOs) on brain scans. It is common in the brains of people above the age of 60, although the severity of the condition varies from person to person. It is a condition in which diseased blood vessels eventually cause small lesions or damage in the white matter of the brain.
Dr. Welker said:
“We know that aging is a risk factor for leukoaraiosis, and we suspect that high blood pressure may also play a role.”
The study involved performing functional magnetic resonance image (fMRI) scans on cognitively normal elderly participants who were recruited from the Mayo Clinic Study of Aging between 2006 and 2010. The findings revealed that 18 participants had a moderate amount of leukoaraiosis (25 milliliters), and18 age-matched control participants had an amount less than 5 milliliters.
Whilst the participants performed a semantic decision task where they had to identify word pairs, and a visual perception task that involved differentiating straight from diagonal lines, the team took fMRI scans of the patients in order to measure metabolic changes in an active part of the brain. They noted that even though the results in both groups were similar, the fMRI scans showed a difference in brain activation patterns between both patient groups.
The results of the fMRI scans demonstrated that patients with moderate levels of leukoaraiosis had atypical activation patterns that showed a lesser activation of brain areas involved in language processing during the semantic decision task, and more activated areas in the visual-spatial locations of the brain during the visual perception task, compared with those in the control group.
Dr. Welker explained:
“Different systems of the brain respond differently to disease. White matter damage affects connections within the brain’s language network, which leads to an overall reduction in network activity.”
Welker highlighted the importance of identifying leukoaraiosis in the brain for those patients who undergo brain mapping for surgery or other treatments, as well as for research studies, adding that efforts should be made to prevent the condition from occurring.
He concluded: “Our results add to a growing body of evidence that this is a disease we need to pay attention to. Leukoaraiosis is not a benign manifestation of aging but an important pathologic condition that alters brain function.”
Written by Grace Rattue