Contralateral Acute Subdural Hematoma Immediately After Irrigation of a Chronic Subdural Hematoma: A Case Report.

Few reports describe contralateral subdural hematoma (SDH) after chronic SDH (CSDH) surgery. In this article, we present a rare case of postoperative complication. The patient was a 76-year-old woman with a history of cerebral infarction due to atrial fibrillation and who was taking an anticoagulant. She presented with a disturbance of consciousness on the Glasgow Coma Scale (GCS) E2V5M6. Computerized tomography (CT) revealed a left CSDH; drainage was performed immediately. After surgery, the CT scan revealed an acute SDH (ASDH) on the contralateral side. Three hours later, the hematoma increased, and she became comatose with a GCS of 1V1M1, and surgery was performed. The speculated cause of the contralateral hemorrhage was the damage to the bridging veins and superficial cerebral vessels due to a sudden change in intracranial pressure, combined with brain fragility and a prolonged prothrombin time (PT) and international normalized ratio (INR) resulting from warfarin therapy. Caution during the postoperative period and follow-up is required for early identification of these cases.