Researchers from McGill University in Canada have found a link between mild behavioral impairment (MBI) in elderly individuals and biomarkers of Alzheimer’s disease.
MBI is characterized by changes in behavior in five key areas: interest, motivation (including mood and anxiety), self control (ranging from control of behavior and impulses to abiding by social norms and empathy), thoughts and perception. Already, an earlier study has shown that it is indicative of faster-than-normal decline in attention and working memory, and that it may be an early marker of neurodegenerative disease such as dementia. The study did not however use brain-imaging techniques to directly compare dementia-related biomarkers with MBI.
Thus, for this new study, researchers recruited 100 cognitively healthy elderly individuals with varying degrees of MBI and used brain-imaging techniques to measure the presence of amyloid plaque deposits in their brains, a protein linked to the onset of Alzheimer’s disease. They then compared their levels of amyloid plaque build up with their MBI scores.
"We found that the presence and severity of MBI in these cognitively healthy individuals was strongly associated with the presence of amyloid plaques in the brain, which is one of the first pathological changes in early stages of Alzheimer's,” says Firoza Lussier, one of the study’s authors and a master’s student in McGill’s Integrated Program in Neuroscience.
From these results, researchers have noted that MBI may be an interesting proxy from which clinicians may be able to diagnose early onset of Alzheimer’s disease. Rather than using brain-imaging techniques, doctors may simply use a Mild Behavioral Checklist, a tool already used to codify mental disorder symptoms linked to neurological diseases in pre-dementia populations, to assess one’s likelihood of developing the disease.
Dr Serge Gauthier, Director of the Alzheimer Disease and Related Disorders Research Unit says, “This is an important study because it may help identify people who are at a higher risk of progression of Alzheimer's disease by employing a user-friendly clinical scale developed in Canada by Dr Zahinoor Ismail, and already available world-wide.”
Lussier and her colleagues now hope to conduct longitudinal imaging studies to better understand the link between MBI and amyloid build-up in the brain.