Summary

A 47-year-old woman presented with paresthesia in her left arm and trunk. She was diagnosed as having an arterial pure sensory stroke at first presentation. On the second hospital day, left hemiparesis developed after convulsions. Magnetic resonance (MR) imaging revealed a hyperintense lesion involving the right parietal lobe on diffusion weighted image. The T2* weighted image disclosed a linear hypointense lesion in the same area. Progressive feature of her symptoms and T2* weighted MR image prompted us to perform MR venography. MR venography confirmed the diagnosis of cortical vein and sagittal sinus thrombosis. Her symptoms attenuated gradually after anticoagulation therapy. Gene analysis showed type I anti-thrombin III (ATIII) deficiency due to the novel mutation of AT III gene. T2* weighted imaging may be much more sensitive than other imaging to detect thrombosed cortical vein during the first week after onset. Rapid diagnosis induced appropriate treatment and monitoring of the patient.