Spinal epidural abscess complicating chronic epidural analgesia in 11 cancer patients: clinical findings and magnetic resonance imaging.

We reviewed the records of all patients who had received an epidural catheter for management of chronic cancer pain in a 3-year period (1993-1996). Patients with nervous system infections were identified, and pertinent clinical, radiological (magnetic resonance imaging), and bacteriological data were analyzed. We identified 11 patients who developed spinal epidural abscess (SEA). All of these had back pain; radicular signs occurred in seven patients and spinal cord compression in two patients. Magnetic resonance imaging revealed SEA in all 11 patients. SEA was iso- to hypointense on T1-weighted images and hyperintense on T2-weighted images relative to spinal cord. After gadolinium administration seven lesions showed characteristic rim enhancement while three showed minimal enhancement. No signs of diskitis or osteomyelitis were present, and the abscess was always localized to the posterior epidural space. Cultures were positive in all cases and revealed Staphylococcus epidermidis in eight and S. aureus in three. All patients were treated with intravenous antibiotics, and four had an additional decompressive laminectomy. Two patients died within 1 week of diagnosis from overwhelming septicemia despite apparently adequate antibiotic treatment. Within 4 weeks after diagnosis of SEA two patients died from widely metastatic disease, although infection may have contributed. One patient developed septicemia while receiving appropriate antibiotics and underwent emergency laminectomy. The neurological deficits recovered in all patients who survived the acute infectious episode. We conclude that patients with chronic epidural catheters for cancer pain require prompt neurological evaluation and magnetic resonance imaging when SEA is suspected. Early evaluation and treatment may lead to full recovery.