Abstract TMP117: Subclinical Imaging Changes in Cerebral Cavernous Angiomas During Prospective Surveillance

Abstract

Introduction: Studies on the natural clinical course of Cavernous Angioma (CA) have reported a <0.5% annual risk of symptomatic hemorrhage (SH). CAs, however, may undergo subclinical changes that can reflect lesional activity. We assess the frequency of asymptomatic hemorrhage or growth (AH) in CAs, and new lesion formation (NLF) during systematic longitudinal follow-up using magnetic resonance imaging (MRI), and correlate with prior SH. Methods: Patients with CA diagnosis were prospectively enrolled in IRB approved database from 09/2009 to 02/2019 (N=327). Imaging and clinical follow-up were recommended annually, or sooner with new symptoms. Patients with 1 or more CA with maximum diameter >4 mm on T2 MRI, not excised or irradiated, and 1 or more clinical/imaging follow-up were included (N=192). New AH and SH were assessed per prospectively articulated criteria, and rates were estimated per lesion-year and patient-year, and NLF in familial cases. Results: There were no demographic or disease confounders among cases included and excluded from the study cohort, except for higher rates of prior SH and greater prevalence of cases with solitary lesion excluded because of surgical treatment. Total follow-up was 410 patient-years (2539 lesion-years). During prospective follow-up, the rate of AH was higher than the rate of SH (12.9% vs. 7.5% per patient-year and 2.1% vs. 1.2% per lesion -year, p=0.02 and p=0.01 respectively). Patients presenting with SH in the prior year had higher rate of AH than those presenting incidentally or with seizures (19.83% and 8.2% per patient-year respectively; p=0.003). A higher rate of NLF on T2 (p=0.0002) and SWI (p=0.0004) was also observed in patients with prior SH compared to stable patients. After an AH, 3 of 6 sporadic patients with solitary lesion and only 2 of 28 familial cases with multiple lesions underwent surgical resection of the lesion with AH. Conclusions: Subclinical imaging changes are more common than SH during prospective follow-up of CAs. They are more common in patients presenting with prior SH, and likely reflect a more sensitive biomarker of CA instability. AH more likely provokes a surgical decision in cases with solitary lesion than in familial cases with multiple lesions.