Cortical Superficial Siderosis: A Descriptive Analysis in a Memory Clinic Population.

Background: Cortical superficial siderosis (cSS) is a hemorrhagic marker of blood-brain barrier disruption detected in brain MRI. Together with cerebral microbleeds (CMB), they are recognized as a small vessel disease marker associated with cerebral amyloid angiopathy.

Objective: This study aims to determine the prevalence and the characteristics of cSS in a memory clinic population.

Methods: Cross-sectional retrospective analysis of 613 patients from Geneva University Hospitals memory clinic. All patients underwent standardized brain MRI and neuropsychological assessment with diagnosis confirmed by an expert. The presence of cSS was visually assessed and classified as focal (restricted to 3 sulci) or disseminated within the correspondent topography. CMB were classified according to the Microbleed Anatomical Rating Scale.

Results: cSS was detected in 26/613 patients (4.2%), classified as disseminated in 5/26 cases (19%). Alzheimer's disease (AD) and AD associated with a significant vascular component were the diagnoses more frequently related to cSS (18/26; 69%). Patients with cSS had an increased prevalence of both hypertension (81% versus 57%; p = 0.015) and WMH burden (p = 0.012). The overall prevalence of cerebral microbleeds (69% versus 32%; p < 0.01), as well as their mean number (0.69±0.47 versus 0.32±0.46; p < 0.01) were both increased in patients with cSS. In the logistic regression model, the presence of 5 or more CMB (OR 11.35; 95% CI 4.68-27.55; p < 0.01) and hypertension (OR 3.31; 95% CI 1.19-9.15; p = 0.021) were significantly associated with cSS.

Conclusions: cSS is observed in patients diagnosed with AD and AD with a vascular component, being independently associated with multiple CMB and hypertension.