Hippocampal perivascular spaces are related to aging and blood pressure but not to cognition.

The risk factors of hippocampal dilated perivascular spaces (H-dPVS), their radiological relevance and their impact on cognitive performance remain under investigation. These aspects were evaluated in 1818 stroke- and dementia-free participants enrolled in the 3C-Dijon MRI study, using logistic regression, multiple linear regression, and Cox models. At study entry, the load of H-dPVS was found strongly associated with age and hypertension (degree 2 vs. degree 0: odds ratio: 1.16; 95% confidence interval: 1.02-1.33 and odds ratio: 1.98; 95% confidence interval: 1.39-2.81, respectively) and positively related to the presence of lacunar infarcts, white-matter hyperintensities volume, and hippocampal volume (p ≤ 0.024). Load of H-dPVS was not related to baseline cognitive performance (p > 0.05). Cox regression modeling did not show a significant relationship between the load of H-dPVS and incident dementia risk (p > 0.05). The present results support that both aging and blood pressure do play a key role in the development of H-dPVS in the older population. In contrast with the dilated perivascular spaces located in white matter or basal ganglia, the load of H-dPVS does not appear associated with occurrence of dementia.