Spinal epidural abscess
From IDWiki
Background
- Infection of the epidural space, between the dura mater and bone, in the spine
- Acquired from contiguous spread (e.g. discitis, otitis media/sinusitis/mastoiditis, direct inoculation (e.g. spinal anaesthesia or neurosurgery), or hematogenous spread
- Risk factors include intravenous drug use, hemodialysis, diabetes mellitus, and older age
Microbiology
- Staphylococcus aureus is most common cause (63%)
- Gram-negative bacilli (16%)
- Streptococci (9%)
- Coagulase-negative staphylococci (3%), mostly in patients with hardware
- Anaerobes (2%)
- Fungal or parasitic (1%)
- Unknown (6%)
- Tuberculosis, in endemic countries
Etiologies
- Idiopathic (30%)
- Skin and soft tissue infection (22%)
- Spinal surgery or procedure (12%)
- Injection drug use (10%)
- Other sources including epidural catheters (8%)
- Bone and joint infections (7%), including decubitus ulcers
- Urinary tract (3%)
- Upper respiratory tract (3%)
- Sepsis (2%)
- Abdomen (2%)
- Intravascular catheter (<1%)
Risk Factors
- Diabetes mellitus (present in 50%)
- Injection drug use
- Spinal surgery or procedure
Clinical Manifestations
- Severe low-back pain often worse with palpation
- Fever
- Malaise
- Neurologic deficits associated with mass effect on spinal cord, interruption of arterial supply, venous thrombosis, or toxin
Staging of Spinal Epidural Abscess
- Stage 1: back pain at the level of the affected spine
- Stage 2: nerve-root pain radiating from the involved spinal area
- Stage 3: motor weakness, sensory deficit, and bladder and bowel dysfunction
- Stage 4: paralysis
Diagnosis
- Usually made by MRI (or CT with contrast)
- Blood cultures may be helpful
- Cultures from the abscess fluid, if possible
Management
- May need urgent neurosurgical drainage if neurological symptoms
- Intravenous antibiotics, ideally after blood cultures are drawn
- Typical empiric antibiotics are ceftriaxone and vancomycin
- Duration typically 6 to 8 weeks after source control
- Patients treated non-operatively may need to have antibiotics continued to radiographic resolution of the abscess
