Abstract TP22: Temporal Lobe Involvement In Cerebral Amyloid Angiopathy Related Inflammation Is Associated With Relapse Of Inflammation And Rapidly Progressive Cognitive Decline

Abstract

Introduction: Cerebral Amyloid Angiopathy related inflammation (CAARI) is an autoimmune cause of rapidly progressive cognitive decline. Little is known about the magnetic resonance imaging (MRI) brain features associated with relapse of CAARI and the effect of treatment on relapse rates therefore we sought to study this. Methods: In this single center prospective cohort study, we analyzed MRI brain scans of 22 patients with CAARI followed at the Cleveland Clinic Cerebrovascular Center between September 2019 and July 2022. We divided patterns of edema on T2 FLAIR imaging into focal, multifocal or diffuse and assessed for temporal lobe involvement (TLI). We analyzed hemosiderin sensitive sequences for the pattern of CAA including cerebral microbleeds (CMB), macrohemorrhage (MH) and/or cortical superficial siderosis (cSS). We collected data on clinical features, treatment duration and cognition after treatment. Relapse was defined as recurrence of edema on T2 FLAIR with cognitive decline or seizure. We report percentages of each clinical feature, imaging pattern and treatment effect on relapse rates. Results: Median age was 74 (35% male, 75% White). Progressive cognitive decline (68%) and seizures (68%) were common but headaches (27.2%) occurred less frequently. Most common CAA features were asymmetric CMB (100%), followed by MH (45%) and cSS (22.7%). The most common pattern of cerebral edema was multifocal (50%), followed by focal (31.8%) and diffuse (27.2%). TLI was seen in 17 (77%) patients. 21 (95.4%) patients were treated with prednisone for median (Q1, Q3) duration of 20 (12, 24) weeks whereas 5 (22.7%) were treated with long term mycophenolate. A total of 6 (27.2%) relapses were seen during a median (Q1, Q3) follow up period of 14 (7, 21) months and occurred at a median (Q1, Q3) of 5.5 (5.12, 5.5) months after stopping steroids. Amongst those who relapsed, none were on mycophenolate, 4 (66.6%) had diffuse edema, 2 (33.4%) had focal edema and all had asymmetric CMB and TLI. No relapses were seen after initiating mycophenolate. Conclusion: Asymmetric CMBs, diffuse or focal cerebral edema with temporal lobe involvement and not being on steroid sparing therapy were associated with relapse of CAARI and rapidly progressive cognitive decline.