A new study aimed to characterize factors related to cerebral venous thrombosis (CVT) linked to myeloproliferative neoplasms (MPN). The findings were reported in the American Journal of Hematology. The researchers undertook this retrospective analysis based on recent reports of CVT in association with receipt of a COVID-19 vaccine in some persons.

For this study, the researchers reviewed data on CVT in connection to MPN through the evaluation of patient records dated from 1991 through 2021 obtained from the Mayo Clinic in Rochester, Minnesota (36 patients), and at 2 Italian sites: the Catholic University of Rome (23 patients) and the University of Florence (15 patients). CVT diagnosis was based on results of computed tomography or magnetic resonance imaging with venography.

Median age was 44 years (range, 15 to 85) for the 74 patients with MPN-associated CVT evaluated in this analysis, and 61% of patients were female. CVT occurred prior to the diagnosis of MPN in 27% of patients, at the diagnosis of MPN in 44% of patients, and after the MPN diagnosis in 30% of patients. Headache was reportedly a presenting symptom with CVT in 72% of cases.

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Slightly more than half of the patients (53%) had essential thrombocythemia, 28% had polycythemia vera, 8% had prefibrotic myelofibrosis, 5% had MPN-unclassified, 4% had primary myelofibrosis, and 1% had post-polycythemia vera myelofibrosis. By subtype of MPN, the disease-specific frequencies for CVT appeared to be 1.3% with essential thrombocythemia, 1.2% with polycythemia vera, and 0.2% with primary myelofibrosis.

Evaluations of driver mutations in 65 patients showed that 91% had a JAK2V617F mutation, 3% had a CALR type 1 mutation, 2% had an MPL mutation, and 5% had triple-negative status. Nearly one-third (31%) of patients had underlying thrombophilia or a predisposing condition.

Systemic anticoagulation on its own was used in 36% of patients. It was used in combination with aspirin in 32% of patients, with cytoreductive therapy in 19% of patients, or with both aspirin and cytoreductive therapy in 12% of patients. A median follow-up of 5.1 years (range, 0.1 to 28.6) revealed recurrent CVT in 4% of patients. Reportedly, other arterial and venous thrombosis incident rates were 11% and 9%, respectively, and the incidence rate for major hemorrhage was 14%.

“In summary, the current study provides MPN subtype-specific incidence of CVT, and confirms its association with younger age, female gender, and JAK2V617F mutation,” the researchers concluded in their report.


Gangat N, Guglielmelli P, Betti S, et al. Cerebral venous thrombosis and myeloproliferative neoplasms: a three-center study of 74 consecutive cases. Am J Hematol. Published online August 28, 2021. doi:10.1002/ajh.26336