The discovery’s authors are neurologists at the Mayo Clinic in the U.S. — often called a “medical Mecca” — together with colleagues from medical and scientific centers in the United States and Spain. The research team, led by neurologist Nick Corriivo-Lecavalier, identified the condition and named it limbic amnestic neurodegenerative syndrome (LANS). The team hopes their work will ease the burden on healthcare providers who care for patients with different forms of memory loss.
LANS is marked by a different pattern of brain changes than Alzheimer’s disease and generally progresses more slowly, with milder symptoms. The newly identified condition primarily affects people over the age of 80.
As with Alzheimer’s disease, a definitive diagnosis of LANS can only be made post-mortem.
To help clinicians and families, the researchers developed a formal framework to distinguish LANS from Alzheimer’s disease.
What the Researchers Reported
“In our clinical work, we have seen patients whose memory impairment symptoms resembled Alzheimer’s disease, but brain scan results or biomarkers indicated that they did not have this condition,” said senior study author David Jones.
The symptoms of Alzheimer’s disease and LANS often overlap, which has caused frequent confusion between the two, according to Science Alert. LANS can sometimes occur at the same time as Alzheimer’s, which complicates diagnosis further. Still, the two conditions are distinct.
By reviewing previous studies on LANS and Alzheimer’s disease, the team identified several key clinical differences in how these two forms of dementia present.
Patients with LANS typically first show a decline in verbal fluency and episodic memory. They struggle to recall contextual details, object names, and people’s names. Their visual-spatial processing, however, tends to remain relatively intact compared with patients with Alzheimer’s disease.
MRI studies have shown that hippocampal volume loss is more closely associated with LANS, whereas in Alzheimer’s disease volume loss more typically affects the neocortex. The recently identified condition also progresses more slowly and produces milder symptoms than Alzheimer’s disease.
Deciphering the different mechanisms behind dementia is a complex task. The research team says they will continue working on better classifying the various forms of dementia.
The study’s findings were published in the journal Brain Communications.
