Spinal Epidural Abscess: A Series of 101 Cases

Abstract

Background: Spinal epidural abscesses are uncommon but potentially devastating infections that often elude early diagnosis. An increasing incidence has been suggested; however, few contemporary data are available regarding risk factors and epidemiologic trends over time.

Methods: A retrospective study of spinal epidural abscesses from 2004 to 2014 at a large academic hospital was conducted. Cases were identified using International Classification of Diseases, Ninth Revision (ICD-9) code 324.1, and a review of medical and radiographic records was performed to confirm each case. Data collected included sociodemographics, medical history, suspected route of infection, treatments, and outcome.

Results: The incidence was 5.1 cases for each 10,000 admissions, with no significant changes during the study period. The route of infection was identified in 52% of cases, with bacteremia as the most common (26%), followed by recent surgery/procedure (21%) and spinal injection (6%). An identifiable underlying risk factor was present in 84% of cases, most commonly diabetes and intravenous drug use. A causative organism was identified in 84% of cases, most commonly Staphylococcus aureus; methicillin-resistant isolates accounted for 25% of S. aureus cases. All cases received intravenous antibiotic therapy, and 73% underwent a drainage procedure. Fifteen percent had an adverse outcome (8% paralysis and 7% death).

Conclusions: The incidence of spinal epidural abscesses may be increasing, with the present study demonstrating a ≥5-fold higher rate compared with historical data. Although the outcome in most cases was favorable, spinal epidural abscesses continue to cause substantial morbidity and mortality and should remain a "not to be missed diagnosis."

Keywords: Epidemiology; Outcome; Risk factors; Spinal epidural abscess; Treatment.