Prevalence and severity of microbleeds in a memory clinic setting

TLDR

Microbleeds are linked to age, white matter changes, lacunar and infarct lesions, and occur more frequently in memory clinic patients than in community cohorts but less often than in stroke patients. The study aimed to determine the prevalence and severity of microbleeds in a large memory clinic cohort. The authors examined 772 memory clinic patients, assessing microbleed prevalence and count across demographics, diagnoses, and MRI findings. Microbleeds were present in 17% of patients, with prevalence varying by diagnosis—65% in vascular dementia, 18% in Alzheimer’s disease, 20% in mild cognitive impairment, and 10% in subjective complaints—highlighting a vascular contribution to neurodegeneration.

Abstract

To determine prevalence and severity of microbleeds (MBs) in a large cohort of patients attending a memory clinic.The authors consecutively included patients attending their memory clinic between January 2002 and April 2005. They analyzed prevalence and number of MBs according to demographic, diagnostic, and MRI data.The authors included 772 patients (53% men, age 66 +/- 11). One hundred twenty-seven patients (17%) exhibited at least one MB. The prevalence differed according to diagnostic groups (p < 0.0001): Sixty-five percent of patients with vascular dementia exhibited MBs vs 18% of Alzheimer disease patients, 20% of mild cognitive impairment patients, and 10% of patients with subjective complaints. The presence of MBs was associated with age, white matter hyperintensities, lacunar infarcts, and infarcts.The prevalence of microbleeds (MBs) in a large cohort of patients attending a memory clinic is higher than previously described in community samples and lower than reported in stroke patients. This finding of a relatively high proportion of MBs in Alzheimer disease and mild cognitive impairment provides further evidence for the involvement of vascular factors in neurodegenerative diseases such as Alzheimer disease.