Epidural abscess (spinal)

Background

• Abscess confined to epidural adipose tissue in spine
• Thoracic and lumbar spine most common; C-spine least common and usually spans up to 3-5 vertebral spaces
• Usually hematogenous spread from other source of infection
• S. aureus, strep, pseudomonas, e. coli most common

Risk Factors

• 98% of pts have at least one of the following risk-factors:

1. Injection drug use
2. Immunocompromised
3. Alcohol abuse
4. Cancer
5. Recent spine procedure
6. Recent spine fracture
7. Distant site of infection
8. Indwelling catheter
9. Chronic renal failure
10. DM

Clinical Features

1. Fever + localized back pain is epidural abscess until proven otherwise
   1. Classic triad of fever, back pain, and neuro deficits is rare (13%)
   2. Fever is only present in ~50% of cases

Diagnosis

1. Labs
   1. ESR elevated in >90% of pts
   2. WBC elevated in only 60% of pts
   3. Blood cultures are indicated to identify the source organism (Staph in 2/3 of cases)
2. Imaging
   1. MRI is diagnostic test of choice
   2. CT with IV contrast may provide usual information regarding boney integrity and fluid collections while awaiting MRI (MRI is preferred)

Differential Diagnosis

• Disc and bony disease
• Vertebral discitis and osteomyelitis
• Metastatic tumors
• Meningitis
• Herpes zoster (prior to appearance of skin lesions)

Treatment

1. Early surgical decompression and drainage
2. Aspiration (for diagnosis) and antibiotics may be sufficient for patients without neuro deficits

Antibiotics

• Antibiotics target Stap, Strep, and Gram-negative bacilli

1. 1. Vanco + metronidazole + (cefotaxime or ceftriaxone or ceftazadine)
      1. Ceftazidine is preferred if pseudomonas is considered likely
      2. Can substitute nafcillin or oxacillin for vanco if not MRSA
   2. Treat for 6-8 weeks

See Also

• Epidural Abscess (Intracranial)
• Epidural Compression Syndromes