Intracranial atherosclerosis on 7T MRI and cognitive functioning – the SMART-MR study

Objective: To investigate the association between intracranial atherosclerosis (ICAS) and cognitive functioning in patients with a history of vascular disease.

Methods: Within the SMART-MR study cross-sectional analyses were performed in 130 patients (mean±SD age 68±9 years) with 7T vessel wall–magnetic resonance imaging data. Vessel wall lesions were rated according to established criteria and summed into a circulatory and artery-specific ICAS burden. Associations between ICAS burden and Z-scores of memory, executive functioning, working memory and processing speed, were estimated using linear regression analyses adjusted for age, sex, education, reading ability, and vascular risk factors.

Results: A total of 125 patients (96%) had ≥1 vessel wall lesions; the mean ICAS burden was 8.5±5.7.

A statistically non-significant association was found between total ICAS burden and memory (b = -0.03 per +1 lesion; 95% CI -0.05 to 0.00). No associations were found for the other domains.

A statistically significant association was found for ICAS burden of the posterior cerebral artery (PCA) and memory (b= -0.12 per +1 lesion; 95%CI -0.23 to -0.01) and executive functioning (b= -0.10 per +1 lesion; 95%CI -0.19 to -0.01). Statistically non-significant associations were found for the anterior cerebral artery (ACA) burden and memory (b= -0.13 per +1 lesion; 95%CI -0.26 to 0.01) and executive functioning (b= -0.11 per +1 lesion; 95%CI -0.22 to 0.01).

Additional adjustments for large infarcts, white matter hyperintensities, lacunes and ≥50% carotid stenosis, produced similar results.

Conclusions: Our results suggest an artery-specific vulnerability of memory and executive functioning to ICAS, possibly due to strategic brain regions involved with these cognitive domains, which are located in the arterial territory of the PCA and ACA.