Influence of seizures on stroke outcomes A large multicenter study

Objective: To investigate the associations among beta-amyloid (A beta), cortical thickness, and episodic memory in a cohort of cognitively normal to mildly impaired individuals at increased risk of vascular disease. Methods: In 67 subjects specifically recruited to span a continuum of cognitive function and vascular risk, we measured brain A beta deposition using [C-11] Pittsburgh compound B-PET imaging and cortical thickness using MRI. Episodic memory was tested using a standardized composite score of verbal memory, and vascular risk was quantified using the Framingham Coronary Risk Profile index. Results: Increased A beta was associated with cortical thinning, notably in frontoparietal regions. This relationship was strongest in persons with high A beta deposition. Increased A beta was also associated with lower episodic memory performance. Cortical thickness was found to mediate the relationship between A beta and memory performance. While age had a marginal effect on these associations, the relationship between A beta and cortical thickness was eliminated after controlling for vascular risk except when examined in only Pittsburgh compound B-positive subjects, in whom A beta remained associated with thinner cortex in precuneus and occipital lobe. In addition, only the precuneus was found to mediate the relationship between A beta and memory after controlling for vascular risk. Conclusion: These results suggest strong links among A beta, cortical thickness, and memory. They highlight that, in individuals without dementia, vascular risk also contributes to cortical thickness and influences the relationships among A beta, cortical thickness, and memory.