Prevalence and associations of cerebral microbleeds in an Australian Memory clinic cohort
Scott Wrigley1, Ross Cody2,3,4, Sanka Amadoru1,4,5,6
1Medical and Cognitive Research Unit, Department of Geriatric Medicine, Austin Health, Melbourne, Victoria, Australia.
Background:
Cerebral microbleeds (CMBs) are small brain haemorrhages, identified by magnetic resonance imaging (MRI). They indicate potential for cognitive decline and mortality in memory clinic attendees. The presence of more than four CMBs is exclusionary for some clinical trials of disease-modifying therapies for Alzheimer's disease (AD). The prevalence and clinical relevance of CMBs in Australian memory clinic populations has not been reported.
Aims:
To highlight the prevalence of CMBs in an Australian memory clinic cohort and explore associations with diagnoses, topography and cognitive performance.
Methods:
We conducted a retrospective cohort study of 393 patients who attended a memory clinic (CDAMS) in Melbourne, Australia from January 2014 to December 2016 who underwent brain MRI. Data collected included age, gender, clinical diagnosis and cognitive scores. Univariable and multivariable regression analyses were performed to identify associations of CMBs with clinical and cognitive findings.
Results:
The prevalence of CMBs was 27% (n=107) with good inter-rater reliability (κ=0.75). CMBs were significantly associated with increasing age. Prevalence of CMBs was higher in people with mild cognitive impairment (MCI) (32%) and dementia (39%) compared with other diagnostic groups (p<0.001). Lobar-predominant CMB distribution was associated with AD diagnosis. Presence of multiple CMBs was associated with poorer cognitive performance overall.
Conclusions:
CMBs are common in an Australian memory clinic population and are associated with poorer cognitive performance. "Real world" prevalence of CMBs may limit accessibility to disease-modifying therapies for many people.
Insights
Cerebral microbleeds (CMBs) are common in Australian memory clinics, affecting 27% of patients. These small brain hemorrhages correlate with cognitive decline and may limit access to Alzheimer
Area of Science:
- Neurology
- Neuroimaging
- Geriatrics
Background:
- Cerebral microbleeds (CMBs) are small hemorrhages detectable via MRI, linked to cognitive decline and mortality.
- High CMB burden (>4) excludes patients from Alzheimer's disease (AD) clinical trials.
- Prevalence and clinical significance of CMBs in Australian memory clinics remain unreported.
Purpose of the Study:
- To determine the prevalence of CMBs in an Australian memory clinic cohort.
- To investigate associations between CMBs and patient diagnoses, location, and cognitive function.
Main Methods:
- Retrospective cohort study of 393 patients from a Melbourne memory clinic (2014-2016) with brain MRI.
- Data included age, gender, clinical diagnosis, and cognitive scores.
- Univariable and multivariable regression analyses identified CMB associations.
Main Results:
- CMB prevalence was 27% (107/393) with good inter-rater reliability (κ=0.75).
- CMBs significantly associated with older age and higher prevalence in mild cognitive impairment (32%) and dementia (39%) groups.
- Lobar CMB distribution linked to AD; multiple CMBs correlated with poorer cognitive performance.
Conclusions:
- CMBs are prevalent in Australian memory clinic attendees and associated with impaired cognition.
- The observed 'real-world' CMB prevalence may restrict eligibility for disease-modifying AD therapies.
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