Pathophysiological link between carotid atherosclerosis and cerebral white matter lesions

Carotid atherosclerosis is associated with white matter hyperintensity (WMH), potentially resulting in cognitive and gait problems. We assessed the relationship between carotid atherosclerosis patterns and regional WMH, offering insights into possible mechanisms. We reviewed 1,058 consecutive healthy individuals in a health check-up program, who chose both optional carotid doppler ultrasonography and brain magnetic resonance imaging. Total, periventricular, and subcortical WMH volumes were measured using automatic segmentation and quantification. Carotid atherosclerosis stages were defined as: normal, no atherosclerosis; plaque without stenosis, atherosclerotic plaque without stenosis; anatomic stenosis, angiographic stenosis without sonographic flow alteration; and hemodynamic stenosis, sonography-measured hemodynamically significant stenosis. These stages were analyzed for association with regional WMH volumes using linear regression. Total and periventricular WMH volumes increased with anatomic and subsequent hemodynamic stenosis; however, only hemodynamic stenosis was independently associated with total (B [95% confidence interval], 0.240 [0.057-0.423]; p = 0.010) and periventricular WMH volumes (0.232 [0.066-0.399]; p = 0.006). Hemodynamic stenosis degree, not plaque extent and anatomic stenosis degree, was significantly associated with total (0.178 [0.033-0.323]; p = 0.016) and periventricular WMH volumes (0.176 [0.044-0.308]; p = 0.009). Subcortical WMH was not associated with carotid atherosclerosis. Hemodynamic compromise may be a key factor linking carotid atherosclerosis and WMH, mainly affecting periventricular white matter.