INTRODUCTION: Cognitive changes can occur following procedural interventions and subarachnoid hemorrhage in unruptured intracranial aneurysms (UIA). The International Study of Unruptured Intracranial Aneurysms conducted cognitive assessment using the Mini-Mental State Exam at baseline and the Telephone Interview Cognitive Status Exam (TICS) at follow-up. Hypothesis: The purpose of this analysis was to compare the 1 year and 5 year outcome in the treatment cohorts (surgery and endovascular) with those of the untreated subgroup. Methods: Patients were subdivided into the initial treatment and untreated cohorts based upon observation or treatment practices in 61 centers from 1991-1998. 1691 patients were in the observational cohort and 2388 in the treated cohort. The cohorts were followed annually with measures of neurological status, Rankin Scale and cognition (TICS). Outcomes were determined prospectively. Comparison of outcomes was done using continuous data and by categories. Covariate adjustment was done using general linear models. Stratified analysis was done by Rankin Score at the time of follow-up. Results: The mean TICS score at 1 year in the cohort was 33.4 with a median of 34 (maximum is 40). In the treated patients the mean was 33.5 and in the untreated patients it was 33.3 (P=0.644). However, Rankin Score at 1 year was significant with a higher percentage of 3-5 scores in the treated group (P=0.003) Categorical analysis of the TICS Score when stratified by Rankin Score at 1 year showed small but significant differences, P=0.03 for Rankin 0-2, and P=0.07 for Rankin 3-5. However after adjustment for baseline variables treatment TICS Score was no longer significant.. The 5 year results showed that the untreated patients did worse than the treated group in TICS. However after adjustment no differences were apparent. Conclusions: Cognitive changes associated with treatment may be minor source of disability post-treatment compared to observation and patient outcomes may be worse in the observation group over time. Differences in outcome also were better explained through the Rankin Score at follow-up than by cognitive deficits.
Abstract WP346: Frequency of Convexal Subarachnoid Hemorrhage in the General Population
Background: Non-traumatic convexal subarachnoid hemorrhages (cSAH) in the elderly can be a manifestation of cerebral amyloid angiopathy (CAA) and predict future intracerebral hemorrhage risk. The frequency of cSAH in the elderly population is unknown. Our objective was to determine the frequency of convexal subarachnoid hemorrhage in a population-based study among individuals who underwent amyloid PET imaging. Methods: Between 11/29/2004 and 3/11/2017 there were 1,687 participants ages 50-years and older in the population-based Mayo Clinic Study of Aging (MCSA) with Pittsburgh compound B (PiB) PET imaging. All intracerebral hemorrhages among participants were identified utilizing the Rochester Epidemiology Project’s records linkage system, and records and images were reviewed to identify those with both symptomatic and asymptomatic convexal subarachnoid hemorrhage. Neuroimaging characteristics, demographics, medications, and ApoE genotype were recorded. Results: Four (0.23%) cSAHs were identified among the individuals who underwent PiB PET imaging. Three were women and median age was 73 (range: 67-84). cSAH occurred in the following locations: right frontal (3), and right parieto-occipital (1). Two went on to develop a lobar intracerebral hemorrhage at a median of 4.75 years after cSAH. Coexisting cerebral microbleeds were identified in one case. The APOE allele combinations of the four participants were: 3/3, 3/3, 2/2, and 2/3. On PiB PET imaging, the median SUVR was 1.81 (range: 1.38-2.34). Conclusion: cSAH is a relatively rare manifestation of CAA occurring in less than 1% of the general population, but may represent a subset with a high risk of future intracerebral hemorrhage. Half of the participants with cSAH had an APOE e2 allele.