[A case of infected subdural hematoma (subdural empyema) secondary to septicemia caused by agranulocytosis].

A 76-year-old female was admitted with a headache. She had no febrile course before admission. Computed tomography (CT) demonstrated bilateral frontal hypodense areas without enhanced rim. She was made a diagnosis of a chronic subdural hematoma. Because her general condition was poor and she had no neurological deficit, she was planned to be treated conservatively. On a few days after the admission, she was suffered from agranulocytosis. However, leukopenia disappeared within a few days by the effective treatment and any neurological deficit was not observed in these period. On thirty days after the admission, she rapidly became semicomatous state and showed left side hemiparesis. A subdural empyema was demonstrated by the subsequent operation. Both culture of subdural fluid and urine yielded Escherichia coli. Her neurological deficits cleared after the operation and subsequent antibiotic therapy. We speculated that infection of urinary tract produced a E. coli bacteremia and subsequently infected subdural hematoma occurred by this microorganism. We stressed that when the neurological deterioration was observed during the conservative treatment of chronic subdural hematoma, infected hematoma would be one which should be one differentiated from an enlargement of hematoma. The mechanisms of the rim enhancement observed at CT are also discussed.