[Subdural abscess following chronic subdural hematoma]

This is a report of subdural abscess following chronic subdural hematoma. An 86-year-old male was admitted to our hospital due to drowsiness and left hemiparesis. He had been suffering from a spike fever which originated during chronic cholecystitis and cholelithiasis and which had continued since 2 years prior to admission. On admission, CT scans revealed right chronic subdural hematoma, and the collection of a few old hematomas was suspected in the left subdural space. An emergency removal of the right hematoma was carried out by using right single burr hole. It was found that the old hematoma accompanied a yellow-white abscess in the subdural space. Escherichia coli were detected from a bacterial culture of the abscess. Postoperative enhanced MRI clearly showed the capsule of the right subdural abscess, and the left chronic subdural hematoma. Removal of the left hematoma was performed by using a left single burr hole. But the abscess did not exist in the left subdural space, and only old hematomas had collected there. The bacterial culture of the left old hematoma was negative. Escherichia coli might be implanted on the capsule of the right chronic subdural hematoma by bacteremia derived from chronic cholecystitis. It was considered that the formation of the subdural abscess might have developed through the deterioration of the immunological function under the influence of senility.