A case of delayed emergence from anesthesia caused by postoperative brain edema associated with unexpected cerebral venous sinus thrombosis.

Cerebral venous sinus thrombosis (CVST) is rare but displays various and often dramatic clinical symptoms. Few cases of CVST have been reported in the field of anesthesiology. We encountered an unexpected case of CVST that presented with delayed emergence from anesthesia after resection of a brain tumor. A 55-year-old man was scheduled for resection of an oligoastrocytoma in his right frontal lobe. After smooth induction of general anesthesia, anesthesia was maintained uneventfully for about 7 h with target-controlled infusion (TCI) of propofol and remifentanil, except for a seizure generated when the right anterior central gyrus was stimulated to allow motor evoked potential monitoring. Immediately after the cessation of TCI, spontaneous respiration was restored. However, the patient was unexpectedly comatose, and no response to painful stimuli or coughing during tracheal suctioning was observed. A computed tomogram taken 2 h after surgery showed diffuse brain edema, even though the neurosurgeons did not notice any cerebral swelling during closing of the dura mater. A magnetic resonance venogram revealed thromboses in the superior sagittal and straight sinuses. On the 9th postoperative day, the patient died without recovering consciousness or his brainstem reflexes. Anesthesiologists should be aware of CVST as a cause of delayed emergence from anesthesia after craniotomy.