Intracranial complications resulting from frontal pyocele: case presentation and review of experience in Japan.

A case of subdural empyema resulting from an acute infection of frontal cysts is reported. Urgent surgery was performed to create a right frontal burr hole, followed by an osteoplastic frontal sinusotomy and postoperative chemotherapy. Thus, this intracranial complication was successfully treated with no further sequelae. MRI was useful for clearly revealing a transtentorial herniation and the affected site of the dura mater from which bacterial infection spread intracranially. Review of rhinogenic intracranial complications in Japan shows a dramatic decrease in the mortality rate from the preantibiotics era to the pre-CT-scan era, and also from the pre-CT-scan era to the present CT-scan era. This suggests that CT scan and, more recently, MRI, have indirectly helped to reduce the mortality rate by enabling an earlier and accurate diagnosis.