Incidence and Mortality of Cerebral Venous Thrombosis in a Norwegian Population

Background and Purpose: There are conflicting figures of the incidence of cerebral venous thrombosis (CVT). The incidence was previously estimated to around 0.5/100 000/y, but more recent studies have suggested 1 to 1.5/100 000/y. The purpose of this study was to explore the incidence and mortality of CVT in a Norwegian population. Methods: A retrospective cross-sectional hospital population-based study conducted at Akershus University Hospital serving roughly 10% of the total Norwegian population. Patients were identified through chart reviews based on the relevantInternational Classification of Diseases(Tenth Revision) codes for new CVT cases in a 7-year period between January 1, 2011, and December 31, 2017. Only inhabitants living in the hospital's catchment area were included. Results: Sixty-two patients aged 0 to 80 years were identified and included. The median age was 46 years and 53% were females. The overall incidence of CVT was 1.75 (95% CI, 1.36-2.23) per 100 000/y with no significant sex differences. The incidence for children and adolescents (<18 years, n=9) was lower than for adults (>= 18 years, n=53); 1.08 (0.52-1.97) versus 1.96 (1.49-2.55) per 100 000/y per year, with the highest incidence for those >50 years with 2.10 (1.38-3.07)/100 000/y. Headache was the most prevalent symptom, reported in 83%, followed by nausea, motor deficits, and seizures observed in 45%, 32%, and 32% of the patients. Transverse sinuses and the jugular vein were the most frequent sites of thrombosis. In most patients (61%), thrombosis occurred in multiple sinuses/veins. Risk factors were found in 73% of the patients, and most of the patients had a combination of 2 or more risk factors. The 30-day and 1-year mortality rates were 3% and 6%. Conclusions: The incidence of CVT in this population was higher than previously reported. The mortality rate was similar to previous studies.