Lewy body disease onset could begin earlier than known

Lewy body disease, the second most common brain degenerative disease after Alzheimer’s disease, may be more common in middle-aged people than previously thought, Finnish researchers reported on March 26, 2024 in the Annals of Neurology.

“In the study, we found disease changes in nine percent of people over 50 who did not have a clinical diagnosis of Parkinson’s disease or Lewy body disease. However, further studies are needed to confirm the results,” said investigator Liisa Myllykangas, M.D., Ph.D, Associate Professor, Department of Pathology, University of Helsinki.

As background, the authors noted that the symptoms of Lewy body disease can be difficult to identify in the early stages of the disease due to its slow progression.

In this new study, the investigators sought to identify Lewy body disease markers in young and middle-aged subjects not diagnosed with Lewy body or Parkinson’s diseases.

The Tampere Sudden Death Study involved evaluation of 700 forensic autopsy cases collected from 2010 to 2015, involving subjects aged 16 to 97 years who lived and died outside hospital institutions. Brain tissue samples were collected from 586 of the subjects.

Brain tissue samples came from the cerebellar cortex, frontal cortex, hippocampus, insula-putamen, pons, and substantia nigra.

Of the 562 subjects eligible for final analyses, 42 tested positive for alpha-synuclein pathology. LRP (Lewy related pathology)-positive  cases amounting to 9% of the entire group over 50 years-old;  the youngest was 54.

Of these findings, the authors said, “When effective treatments against neurodegenerative diseases become a reality, it will be important to know the age these pathologies begin to develop. We investigated alpha-synuclein pathology in brain tissue of the Tampere Sudden Death Study—unselected forensic autopsies on individuals living outside hospital institutions in Finland. Of 562 (16–95 years) participants, 42 were positive for Lewy-related pathology (LRP). The youngest LRP case was aged 54 years, and the frequency of LRP in individuals aged ≥50 years was 9%. This forensic autopsy study indicates LRP starts already in middle age and is more common than expected in the ≥50 years-of-age non-hospitalized population.”

Myllykangas added. “Finding out the prevalence of disease changes in younger age groups is therefore important as this will be the most effective time to start therapies.”