Cerebral venous thrombosis and myeloproliferative neoplasms: A three‐center study of 74 consecutive cases

: The recent association of cerebral venous thrombosis (CVT) with COVID-19 vaccinations prompted the current retrospective review of 74 cases of CVT (median age = 44 years, range 15-85; 61% females) associated with myeloproliferative neoplasms (MPNs), seen at the Mayo Clinic, Catholic University of Rome, and University of Florence, between 1991 and 2021. Disease-specific frequencies were 1.3% (39/2893), 1.2% (21/1811) and 0.2% (3/1888) for essential thrombocythemia, polycythemia vera and primary myelofibrosis, respectively. Cerebral venous thrombosis occurred either prior to (n = 20, 27%), at (n = 32, 44%) or after (n = 22) MPN diagnosis. A total of 72% of patients presented with headaches. Transverse (51%), sagittal (43%) and sigmoid sinuses (35%) were involved with central nervous system hemorrhage noted in 10 (14%) patients. In all, 91% of tested patients harbored JAK2V617F. An underlying thrombophilic condition was identified in 19 (31%) cases and history of thrombosis in 10 (14%). Treatment for CVT included systemic anticoagulation alone (n = 27) or in conjunction with aspirin (n = 24), cytoreductive therapy (n = 14), or both (n = 9). At a median follow-up of 5.1 years (range 0.1-28.6), recurrent CVT was documented in three (4%) patients while recurrent arterial and venous thromboses and major hemorrhage were recorded in 11%, 9% and 14%, respectively. Follow-up neurological assessment revealed headaches (n = 9), vision loss (n = 1) and cognitive impairment (n = 1). The current study lends clarity to MPN-associated CVT and highlights its close association with JAK2V617F, younger age and female gender. Clinical features that distinguish COVID vaccine-related CVT from MPN-associated CVT include, in the latter, lower likelihood of concurrent venous thromboses and intracerebral hemorrhage; as a result, MPN-associated CVT was not fatal.