Abstract Body

Early diagnosis of cognitive diseases is crucial to initiate therapy prior to the development of synaptic and neuronal loss and ensuing clinical changes. Dementia occurs in much older populations where neurofibrillary tangles (NFT), cortical Lewy bodies and vascular lesions such as multiple strokes or, more importantly, microvascular cerebral pathology are its most powerful correlates.

Cortical microinfarcts (CMI) are common at advanced ages, can be encountered in the hippocampus in 50% of older brains, can explain up to 36% of the clinical variability of the presence of dementia and represent the strongest vascular correlate of dementia in the oldest-old. The vast majority of CMI cannot be visualized on ante-mortem or post-mortem MRI.

Cortical microbleeds (CMB) have been correlated to cognitive dysfunction and the development of dementia. While many CMB can be visualized thanks to the blooming effect on MRI, smaller lesions remain invisible resulting in a false negative rate that can reach 45%.

In the absence of markers or clinical findings suggestive of CMI or CMB, the presence of vascular or bleeding risk has been explored. We determined the CHA₂DS₂-VASc and HAS-BLEDs scores in 148 consecutively autopsied subjects (mean age 84 years). A CHA₂DS₂-VASc > 5 more than doubled the odds of finding CMI (OR 2.23, p=0.020); accuracy was 61% which is much higher than MRI but discrimination was still too low for individual prediction. The HAS-BLED score was not significantly related to the presence of CMB.

Recognition of CMI and CMB in cognitively impaired people is key to the interpretation of therapeutic trials and the development of population approaches to the prevention and treatment of dementing disorders. Further efforts are needed to identify new and effective methods for their detection.