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 cathet er for management of chronic cancer pain in a 3-year period (1993-1996). Pa tients with nervous system infections were identified, and pertinent clinic al, radiological (magnetic resonance imaging), and bacteriological data wer e analyzed. We identified 11 patients who developed spinal epidural abscess (SEA). All of these had back pain; radicular signs occurred in seven patie nts and spinal cord compression in two patients. Magnetic resonance imaging revealed SEA in all 11 patients. SEA was iso- to hypointense on T1-weighte d images and hyperintense on T2-weighted images relative to spinal cord. Af ter gadolinium administration seven lesions showed characteristic rim enhan cement while three showed minimal enhancement. No signs of diskitis or oste omyelitis were present, and the abscess was always localized to the posteri or epidural space. Cultures were positive in all cases and revealed Staphyl ococcus epidermidis in eight and S. aureus in three. All patients were trea ted 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 week s after diagnosis of SEA two patients died from widely metastatic disease, although infection may have contributed. One patient developed septicemia w hile 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 cathet ers for cancer pain require prompt neurological evaluation and magnetic res onance imaging when SEA is suspected. Early evaluation and treatment may le ad to full recovery.