ABSTRACT NUMBER: ESOC2026A1309 THE NORWEGIAN CEREBRAL VENOUS THROMBOSIS STUDY (NOCVT): CLINICAL CHARACTERISTICS AND FUNCTIONAL OUTCOMES IN AN UNSELECTED COHORT WITH CEREBRAL VENOUS THROMBOSIS

Abstract Background and aims Cerebral venous thrombosis (CVT) is a rare subtype of stroke that is primarily studied in referral centres and tertiary care hospitals. Consequently, our understanding of unselected CVT populations is limited. NoCVT aims to describe the characteristics and functional outcomes of an unselected CVT population. Methods We conducted a retrospective study across 12 Norwegian hospitals, ranging from community hospitals to referral centres, covering approximately 75% of the Norwegian adult population. Adults diagnosed with CVT from January 2014 to December 2023 were identified using relevant ICD-10 codes in electronic hospital records. Data on demographics, clinical and radiological characteristics, and functional outcomes were extracted from medical charts. Predictors of poor outcomes (modified Rankin Scale score ≥ 2 at six months) were assessed using multivariate logistic regression. Results A total of 511 patients (median age 46 years; 61% female) were included. Active cancer was prevalent in 15% of patients, while pregnancy-related cases accounted for 9% of women. At six months, 32% exhibited poor functional outcomes. Active cancer (adjusted odds ratio [aOR] 2.6, 95% CI 1.5–4.5) and seizures at presentation (aOR 1.8, 95% CI 1.1–3.0) were identified as predictors of poor functional outcomes. Conclusions This study of an unselected CVT population reveals distinct characteristics, including older age, a higher prevalence of cancer, and fewer pregnancy-related cases compared to previously reported tertiary care cohorts. These findings highlight the need for future research focusing on unselected CVT populations to broaden our understanding of CVT. Conflict of interest Iselin T. Syberg Dahl: Nothing to disclose. Ola Nakken: Nothing to disclose. Diana Aguiar de Sousa: has no disclosures related with the specific topic, but has received personal fees from AstraZeneca, Organon, and Johnson & Johnson for advisory board participation, DSMB participation for the SECRET trial (University of British Columbia), and speaking fees from Astrazeneca and Bial. Else Charlotte Sandset: Nothing to disclose. Kjersti Grøtta Vetvik: no disclosures related with the specific topic, but has received honoraria for lecturing and/or participation in advisory boards from Novartis, TEVA, Roche, Pfizer, Lundbeck, Eli Lilly. Espen Saxhaug Kristoffersen: Nothing to disclose.