Rapidly progressive cognitive impairment: an unusual presentation of cerebral venous thrombosis caused by JAK2 V617F-positive primary myelofibrosis: A case report.

RATIONALE Cerebral venous thrombosis (CVT) is a rare cerebrovascular condition, which mainly manifests as headaches, seizures, and focal neurological deficits. JAK2 mutation in myeloproliferative diseases increases the risk of CVT. PATIENT CONCERNS This 40-year-old woman suffered from rapidly progressive cognitive impairment and limb weakness. Her symptoms worsened while being treated with mannitol with the diagnose of cerebral hemorrhage. DIAGNOSIS The patient was diagnosed with CVT and multiple intracranial hemorrhage caused by JAK2 V617F mutation-positive primary myelofibrosis by neuroimage and whole-exome sequencing. INTERVENTION She received low-molecular-weight heparin sodium 3800 IU twice a day followed by oral anticoagulant therapy. OUTCOMES The patient showed full recovery from limb weakness and in the follow-up period she noticed no change in her memory. LESSONS Clinicians should be aware of the possibility of the JAK2 V617F mutation in CVT patients without known causes or risk factors.