[A case of gas-producing brain abscess with subdural empyema: timing of the operation for brain abscess]. 
A case of gas-producing brain abscess with subdural abscess was reported.  An 18-year-old boy was admitted with a five-day history of vomiting and high grade pyrexia.  Plain skull roentgenograms demonstrated left frontal multiple gas bubbles.  CT scan and MRI showed that both brain and subdural abscesses contained gas in the left frontal area.  Antibiotics and glyceol were intravenously administrated.  In serial CT scans, subdural abscess was not recognized, while brain abscess was enhanced in a ring.  Seven days after admission, milky white pus with a fecal odor was aspirated using CT guided stereotactic apparatus, and the catheter was left in the abscess cavity.  Culture of the pus grew peptostreptococcus.  On the 22nd hospital day, repeated aspiration and drainage were performed for the residual brain abscess.  The patient gradually improved after the aspiration with continuous administration of antibiotics, and he was discharged on the 59th hospital day with no neurological deficits.  Based on our experience and a review of the literature, the treatment of choice is aspiration in the late cerebritis stage of brain abscess.