Microbleeds in dementia with Lewy bodies

Area of Science:

• Neurology
• Neuroimaging
• Geriatrics

Background:

• Cerebral microbleeds are linked to dementia and prevalent in Alzheimer's disease (AD).
• The prevalence and clinical significance of microbleeds in dementia with Lewy bodies (DLB) are not well understood.
• This study investigates microbleeds in DLB compared to AD and healthy controls.

Purpose of the Study:

• To compare microbleed rates in DLB, AD, and controls.
• To examine associations between microbleeds and amyloid deposition in DLB.
• To explore the relationship between microbleeds, vascular risk, and disease severity in DLB.

Main Methods:

• A longitudinal observational study involving DLB (n=30), AD (n=18), and control (n=20) participants.
• Clinical assessments, 3T MRI with T2* susceptibility weighted imaging, and florbetapir PET scans were performed.
• Microbleeds were visually rated, and amyloid deposition was quantified using standardized uptake value ratio (SUVR).

Main Results:

• Microbleeds were present in 40% of DLB, 50% of AD, and 15% of controls.
• DLB participants with microbleeds had higher systolic blood pressure (p=0.03) but not increased vascular disease or amyloid deposition (p=0.33).
• Preliminary evidence suggested less severe dementia in DLB with microbleeds, potentially due to shorter disease duration.

Conclusions:

• Microbleeds in DLB are associated with elevated blood pressure.
• Microbleeds in DLB are not linked to other vascular disease markers or amyloid burden.
• The clinical implications of microbleeds in DLB remain uncertain and warrant further research.