Aggravation of Enlarged Perivascular Spaces in the Centrum Semiovale of Patients with Aneurysmal Subarachnoid Hemorrhage

Purpose This study aimed to investigate whether enlarged perivascular spaces (ePVS) within the basal ganglia (BG) or centrum semiovale (CSO) aggravate in patients with aneurysmal subarachnoid hemorrhage (aSAH). Methods We retrospectively evaluated 139 patients who had undergone brain magnetic resonance imaging (MRI) within 1 month of aSAH occurrence from January 2007 to November 2018. Follow-up brain MRI of 99 patients were available. We scored ePVS in the BG and CSO on a score of 0-4 (0 = no ePVS, 4 ≥ 40 ePVS) on initial and follow-up T2-weighted MRI. Aggravation of ePVS was defined as an ePVS score increase of ≥ 1 on follow-up MRI compared to the initial score. We compared the characteristics between patients with and without aggravation of ePVS and investigated associated variables using logistic regression. Results Aggravation of ePVS in the CSO and BG was noted in 31 (31.3%) and 6 (6.1%) patients, respectively. After adjusting for age, sex, and the MRI follow-up period, aggravation of ePVS in the CSO was independently associated with a high Fisher grade (p = 0.007) and high burden of initial ePVS in the CSO (p = 0.049). Conclusion Aggravation of ePVS, particularly those in the CSO, had occurred in the long-term follow-up of aSAH patients. This was independently associated with a high burden of aSAH. The amount of subarachnoid blood might have aggravated the drainage of interstitial fluid through glymphatic dysfunction.