Researchers at Mayo Clinic have defined criteria for a memory-loss syndrome in older adults that affects the brain’s limbic system and often is mistaken for Alzheimer’s disease.
Limbic-predominant amnestic neurodegenerative syndrome, or LANS, progresses more slowly than Alzheimer’s disease and has a better prognosis, the scientists announced. Their report published Wednesday in Brain Communications should help physicians better diagnose memory loss.
Before the criteria was established, the only way to confirm the syndrome was to evaluate brain tissue after a person died.
The proposed criteria can help experts classify the condition in people who have symptoms, so they can receive a precise diagnosis. Factors that play a role in LANS include age, brain scans, severity of memory impairment, and biomarkers that show specific proteins in the brain.
The researchers evaluated the buildup of a protein called TDP-43 in the limbic system that scientists have found in the brain tissue of people. The researchers have classified the build-up of those protein deposits as limbic-predominant age-related TDP-43 encephalopathy, or LATE. Those protein deposits could be associated with the newly defined memory loss syndrome, but there also are other likely causes, and more research is needed, the authors said.
To create the criteria, the clinicians used data from more than 200 participants in databases for the Mayo Clinic Alzheimer’s Disease Research Center, the Mayo Clinic Study of Aging and the Alzheimer’s Disease Neuroimaging Initiative.
Understanding the condition will help doctors better manage people’s symptoms and tailor therapies for it, David T. Jones, MD, a Mayo Clinic neurologist and senior author of the study, said in a statement.
“In our clinical work, we see patients whose memory symptoms appear to mimic Alzheimer’s disease, but when you look at their brain imaging or biomarkers, it’s clear they don’t have Alzheimer’s. Until now, there has not been a specific medical diagnosis to point to, but now we can offer them some answers,” Jones said. “This research creates a precise framework that other medical professionals can use to care for their patients. It has major implications for treatment decisions, including amyloid-lowering drugs and new clinical trials, and counseling on their prognosis, genetics and other factors.”
“Historically, you might see someone in their 80s with memory problems and think they may have Alzheimer’s disease, and that is often how it’s being thought of today,” Nick Corriveau-Lecavalier, PhD, the paper’s first author, said in the same statement. “With this paper, we are describing a different syndrome that happens much later in life. Often, the symptoms are restricted to memory and will not progress to impact other cognitive domains, so the prognosis is better than with Alzheimer’s disease.”
