Epidural abscess

Today we discussed spinal epidural abscess. This is a very serious and comonly missed diagnosis, requiring a high index of suspicion.

Some points:

Predisposing conditions
1) Immunocompromise - DM2, EtOH, HIV
2) Spinal abnormality/intervention - degenerative disk disease, trauma, surgery, catheters
3) Local or systemic source of infection - skin, osteomyelitis, UTI, sepsis, catheter

Pathophysiology
Contiguous spread in a third, bacteremia in half, rest not identified.

Microbiology
1) St. aureus (MSSA or MRSA) in over half of cases
2) St. epidermidis (with devices/hardware)
3) GNs (e.coli, pseudomonas)
Rare: anaerobes, TB, fungal, parasitic

Complications:
1) cord compression
2) cord ischemia
3) osteomyelitis
4) endocarditis
5) psoas abscess

Staging of symptoms
1) back pain
2) nerve root pain
3) motor weakness, sensory deficit, bowel/bladder
4) paralysis

Tempo of progression is variable; may be hours to days.

Location: more common in posterior, thoracic, lumbar areas (more fat). Occasionally, pan-spinal.
Diagnosis:
MRI with gad and myelography then CT are methods of choice (MRI best). Bacteremia in 60%.

Treatment:
Surgical if neurological impairment and less than 24-36h of symptoms, and not panspinal infection (tx is laminectomy, drainage)
Abx: Empric coverage of staph (usu vanco), gram negatives, (ceftriaxone or pseudomonas coverage if high risk) Best to have microbiologic diagnosis prior to abx; aspirate may be needed if BC are negative.

Link:

Click here for a good NEJM review on paraspinal abscess