Subdural empyema: burr holes or craniotomy? A retrospective computerized tomography-era analysis of treatment in 90 cases.

Ninety patients with subdural empyema were treated in the period after computerized tomography (CT) became available (1979 to 1991). Males predominated by a ratio of 2:1, and 40 patients were between 11 and 20 years old. The site of origin was the paranasal air sinuses in 53 patients, the middle ear in 19, and a superficial infection in eight; the source of infection was not known in 10. The most common clinical presentation was headache, fever, neck stiffness, seizures, or periorbital swelling; only seven patients had status epilepticus. While the erythrocyte sedimentation rate and white blood cell count were invariably elevated, the cerebrospinal fluid showed nonspecific pleocytosis in the 60 patients who underwent lumbar puncture. The definitive preoperative diagnosis was made by contrast-enhanced CT in all cases. Surgical treatment was by multiple burr holes in 37 patients, burr holes and small craniectomies in 33, burr holes with catheter drainage in seven, and a large craniotomy in 12. One patient was treated without surgery. The mortality rate was 7.7%, with 86% making a good recovery. These results compare favorably with those reported in other studies using craniotomy alone, and suggest that burr holes should not be disregarded as a method of treating subdural empyema where contrast-enhanced CT facilities are available.