Background
A spinal epidural abscess threatens the spinal cord or cauda equina by compression and also by vascular compromise (see images below). If untreated, an expanding suppurative infection in the spinal epidural space impinges on the spinal cord, producing sensory symptoms and signs, motor dysfunction, and, ultimately, paralysis and death. Intervention early in the course of the disease undoubtedly improves the outcome. Frequently, diagnosis is understandably delayed because the initial presentation may be only back pain. One half of cases are estimated to be misdiagnosed or have a delayed diagnosis.[1] At times, radicular symptoms may lead to a chief complaint of chest pain or abdominal pain[2] , mimicking a myocardial infarction or an acute abdomen.[3]
Cervical epidural abscess with spinal cord compression and spinal cord edema. 
Spinal epidural abscess lumbar area. Pathophysiology
The spinal epidural space is not a uniform space. Posteriorly, the epidural space contains fat, small arteries, and the venous plexus. Infections in this space may spread over several vertebral levels. Anteriorly, the epidural space is a potential space with the dura tightly adherent to the vertebral bodies and ligaments. Abscesses occur more frequently in the larger posterior epidural space. Most spinal epidural abscesses occur in the thoracic area, which is anatomically the longest of the spinal regions.
Some series suggest that dorsal spinal epidural abscesses are much more likely to present with weakness and severe neurologic deficit than ventral spinal epidural abscesses.[4]
Hematogenous spread with seeding of the epidural space is the suspected source of infection in most children and is thought to occur in many adults as well. Reported sources of infection are numerous and include bacterial endocarditis, infected indwelling catheters, urinary tract infection, peritoneal and retroperitoneal infections, and others.
Direct extension of infection from vertebral osteomyelitis occurs in adults and rarely in children.
Epidural catheters and injections may lead to direct innoculation of the epidural space. The source of infection is not identified in many patients.
The more clinically significant effects of the epidural abscess may be from involvement of the vascular supply to the spinal cord and subsequent infarction rather than direct compression. Staphylococcus aureus is the most commonly reported pathogen[5] , though many other bacteria have been implicated, including Staphylococcus and Pseudomonas species, Escherichia coli, Brucella, and Mycobacterium tuberculosis. Methicillin-resistant Staphylococcus aureus (MRSA) is increasingly reported particularly in patients with spinal surgery or implanted devices.
Epidemiology
Frequency
United States
The frequency in large tertiary care centers is estimated to be about 2.8 cases per 10,000 admissions. The incidence is suspected to be increasing in relation to intravenous (IV) drug abuse.[6]
International
Because these abscesses occur rarely, the frequency is unknown. It probably parallels the US experience of rarity, although limited diagnostic capabilities in medically underserved countries might increase its importance as a health risk.
Mortality/Morbidity
If untreated, spinal epidural abscess causes progressive paraplegia and death.
Sex
Older studies found an equal sex ratio; more recent data indicate a male predominance, likely reflecting the pattern of IV drug use.
Age
The average age is older than 50 years, but spinal epidural abscess can occur at any age.
Darouiche RO. Spinal epidural abscess. N Engl J Med. Nov 9 2006;355(19):2012-20. [Medline].
Bremer AA, Darouiche RO. Spinal epidural abscess presenting as intra-abdominal pathology: a case report and literature review. J Emerg Med. Jan 2004;26(1):51-6. [Medline].
Rigamonti D, Liem L, Sampath P, et al. Spinal epidural abscess: contemporary trends in etiology, evaluation, and management. Surg Neurol. Aug 1999;52(2):189-96; discussion 197. [Medline].
Karikari IO, Powers CJ, Reynolds RM, Mehta AI, Isaacs RE. Management of a spontaneous spinal epidural abscess: a single-center 10-year experience. Neurosurgery. Nov 2009;65(5):919-23; discussion 923-4. [Medline].
Joshi SM, Hatfield RH, Martin J, Taylor W. Spinal epidural abscess: a diagnostic challenge. Br J Neurosurg. Apr 2003;17(2):160-3. [Medline].
Prendergast H, Jerrard D, O'Connell J. Atypical presentations of epidural abscess in intravenous drug abusers. Am J Emerg Med. Mar 1997;15(2):158-60. [Medline].
Davis DP, Wold RM, Patel RJ, et al. The clinical presentation and impact of diagnostic delays on emergency department patients with spinal epidural abscess. J Emerg Med. Apr 2004;26(3):285-91. [Medline].
Trombly R, Guest JD. Acute central cord syndrome arising from a cervical epidural abscess: case report. Neurosurgery. Aug 2007;61(2):E424-5; discussion E425. [Medline].
Tasher D, Armarnik E, Mizrahi A, Liat BS, Constantini S, Grisaru-Soen G. Cat Scratch Disease With Cervical Vertebral Osteomyelitis and Spinal Epidural Abscess. Pediatr Infect Dis J. Jul 31 2009;[Medline].
Mehta SH, Shih R. Cervical epidural abscess associated with massively elevated erythrocyte sedimentation rate. J Emerg Med. Jan 2004;26(1):107-9. [Medline].
Siddiq F, Chowfin A, Tight R, et al. Medical vs surgical management of spinal epidural abscess. Arch Intern Med. Dec 13-27 2004;164(22):2409-12. [Medline].
Pradilla G, Ardila GP, Hsu W, Rigamonti D. Epidural abscesses of the CNS. Lancet Neurol. Mar 2009;8(3):292-300. [Medline].
Pereira CE, Lynch JC. Spinal epidural abscess: an analysis of 24 cases. Surg Neurol. 2005;63 Suppl 1:S26-9. [Medline].
Bluman EM, Palumbo MA, Lucas PR. Spinal epidural abscess in adults. J Am Acad Orthop Surg. May-Jun 2004;12(3):155-63. [Medline].
Butler KH. Spinal epidural abscess: Current diagnostic and management protocols. Emerg Med Rep. 21:95-104.
Gerberding JL, Romero JM, Ferraro MJ. Case records of the Massachusetts General Hospital. Case 34-2008. A 58-year-old woman with neck pain and fever. N Engl J Med. Oct 30 2008;359(18):1942-9. [Medline].
Grewal S, Hocking G, Wildsmith JA. Epidural abscesses. Br J Anaesth. Mar 2006;96(3):292-302. [Medline].
Hooten WM, Kinney MO, Huntoon MA. Epidural abscess and meningitis after epidural corticosteroid injection. Mayo Clin Proc. May 2004;79(5):682-6. [Medline].
Tessman PA, Preston DC, Shapiro BE. Spinal epidural abscess in an afebrile patient. Arch Neurol. Apr 2004;61(4):590-1. [Medline].
Uchida K, Nakajima H, Yayama T, Sato R, Kobayashi S, Chen KB, et al. Epidural abscess associated with pyogenic spondylodiscitis of the lumbar spine; evaluation of a new MRI staging classification and imaging findings as indicators of surgical management: a retrospective study of 37 patients. Arch Orthop Trauma Surg. Jun 30 2009;[Medline].
Print
