Hippocampal and Amygdala Size in Patients with Ischemic Stroke: Does Small Vessel Disease Play a Role?

Abstract

Objective: The effect of Small Vessel Disease (SVD) on the size of the hippocampus and amygdala remains uncertain. We carried out an MRI volumetry study to investigate the association between the volume of White Matter Lesions (WMLs) and the size of the hippocampus and amygdala. Methods: One hundred patients with ischemic stroke were recruited in this study, with their MRIs analyzed using automatic volumetry. The volumes of the hippocampus, amygdala, Cortical Gray Matter (CGM), and WMLs were measured and standardized with intracranial volume. The subjects were divided into two groups stratified by smaller and larger hippocampus, amygdala, and CGM volumes (with the median as the cut-off), respectively. The demographic, clinical, and imaging variables of the two groups were compared in term of smaller and larger volumes in these three regions. Results: Multivariate logistic regression showed that WML volume (odds ratio [OR] = 1.869, p=0.004) and sex (male, OR=5.714, p=0.004) were significant predictors of a smaller hippocampus. Age (OR=1.062, p=0.033) was the only significant predictor of a smaller amygdala. Age and sex were predictive of a smaller CGM volume. Conclusions: The hippocampus may be vulnerable to SVD in patients with ischemic stroke, suggesting that hippocampal atrophy may result from a mixture of ischemic and degenerative pathologies. Whether SVD plays a role in atrophy of the amygdala remains uncertain.