Spinal epidural abscess: Contemporary trends in etiology, evaluation, and management

BACKGROUND Despite advances in neuroimaging and neurosurgical treatment, spinal epidur al abscess remains a challenging problem; early diagnosis is often difficul t and treatment is delayed. Optimal management is unclear, and morbidity an d mortality are significant. To define contemporary trends in etiology and management, and establish diagnostic and therapeutic guidelines, we reviewe d our 10-year experience with spinal epidural abscess. METHODS We examined medical records, laboratory data, radiological (CT and MRI) stu dies, and operative reports from 75 cases of spinal epidural abscess betwee n 1983 and 1992. Demographic characteristics, frequency, clinical features, pathogens, risk factors, surgical and medical treatment, and outcome were analyzed. RESULTS We found a significant increase in the frequency of spinal epidural abscess over the 10-year period (p-value = 0.0195). Intravenous drug abuse was pre sent in 28 patients (33%), diabetes mellitus in 22 patients (27%), and prio r spinal surgery in 11 patients (17%). Back pain, progressive neurologic de ficit, and low grade fever remained the distinguishing diagnostic features. Erythrocyte sedimentation rate was elevated in 48 of 50 patients (95%); pe ripheral leukocyte count was elevated in 45 patients (60%). MRI was the mos t effective technique for diagnosing spinal epidural abscess, revealing or suggesting the diagnosis in all 59 patients (100%) studied. Sites of spinal epidural abscess were equally distributed along the spinal axis. Staphyloc occus aureus was the predominant organism (67% of patients, with 15% having a methicillin-resistant strain); 8% of patients had Streptococcal species. Most patients had open surgical drainage followed by prolonged antibiotic treatment; 22 patients were managed with antibiotics alone; 50 patients (66 %) had a good clinical outcome after treatment. Multiple medical problems, prior spinal surgery, and methicillin-resistant Staphylococci were correlat ed with a significantly worse outcome. CONCLUSIONS The frequency of diagnosis of spinal epidural abscess is increasing. To pre vent serious morbidity and mortality, early diagnosis is essential. Patient s with localized back pain who are at risk for developing such abscesses or who have an increased erythrocyte sedimentation rate and/or neurologic def icit should have an immediate MRI scan with contrast enhancement. Surgical drainage and prolonged antibiotic use are the cornerstones of treatment, al though selected patients may be treated conservatively. (C) 1999 by Elsevie r Science Inc.