142 - MEDIAL DORSAL THALAMIC ATROPHY PLAY A CRUCIAL ROLE IN THE EFFECT OF ASYMPTOMATIC CAROTID STENOSIS ON COGNITIVE IMPAIRMENT
Abstract
Aims
Our aims were to assess subcortical nuclei abnormalities and their relationships with cognitive deficits in patients with asymptomatic carotid stenosis (ACS) by combining volume and shape analyses.
Methods
Twenty-nine patients with severe ACS of the unilateral internal carotid artery and 31 age, sex, and education level matched control subjects were enrolled. All participants underwent a comprehensive neuropsychological cognitive assessment, biochemical measurements, and structural magnetic resonance imaging (MRI). Longitudinally, cognitive assessments and MRI scans were followed up in a group of 11 patients 6 months after carotid endarterectomy (CEA).
Results
The patients had worse performance in all cognitive domains and had higher apolipoprotein B / apolipoprotein A1 (ApoB/ApoA1) ratio than the controls. ACS patients had more thalamic atrophy assessed by shape and volume, especially in the medial dorsal thalamus, however, no significant differences were found in other subcortical nuclei after correction for multiple comparisons. The Fazekas scores of white matter hyperintensities were not different between the groups. These biochemical and structural brain changes were significantly correlated with cognitive decline. Notably, mediation analysis at baseline showed that the association between carotid intima-media thickness and executive function and processing speed were mediated by medial dorsal thalamic volume and ApoB/ApoA1 ratio respectively. After CEA, beneficial cognitive recovery and increased right medial dorsal thalamic volume were observed.
Conclusions
Our study identified for the first time the distinct atrophy of subcortical nuclei that correlated with cognitive decline in patients with ACS. Assessment of the thalamus may provide an early and sensitive biomarker for cerebral ischemia and reperfusion.
