Autoimmune conditions, such as rheumatoid arthritis (RA) and thyroid disease, were recently identified as potential risk factors for hippocampal sclerosis (HS) in a cohort of 134 participants with dementia from The 90+ Study. Lewy body disease (LBD) was the only pathology that was associated with increased odds of HS and those harboring HS pathology had a longer duration of dementia. This suggests multiple pathways of HS pathology among the oldest-old. Researchers divided participants into 2 groups, 1 with and 1 without HS pathology, and differences in clinical and pathologic characteristics were compared. They found:

• Persons with HS tended to have a longer duration of dementia compared to participants without HS.
• HS was more likely in participants with a history of autoimmune diseases (RA or thyroid disease), high thyroid-stimulating hormone, or high thyroid antibodies.
• LBD pathology was also associated with an increased likelihood of HS.