Aetiology and assessment of spinal epidural abscess

Spinal epidural abscess (SEA) is an infection between the thecal sac of the spinal cord and the spinal ligaments and vertebrae – it is not an infection of the central nervous systemTurner 2019.

Infections are caused by:

direct inoculation from instrumentation or surgery
contiguous spread from vertebral osteomyelitis or discitis
haematogenous spread from a distant site (eg respiratory; urinary; skin or soft tissue infection)Baralo 2020.

Most spinal epidural abscesses occur posteriorly, most commonly in the thoracolumbar region. Most cases of anterior spinal epidural abscess are associated with vertebral osteomyelitis or discitis.

Early clinical features of spinal epidural abscess are often nonspecific present with and the classic triad of fever, back pain and neurological deficit is present at diagnosis in a small number of patients (approximately 13%)Baralo 2020.

Staphylococcus aureus is the most common pathogen identified; however, spinal epidural abscess may also be caused by Gram-negative bacilli and other organisms. Polymicrobial infection is uncommon.

Magnetic resonance imaging (MRI) spine with gadolinium contrast is the preferred imaging method. Spinal epidural abscess can be associated with adjacent osteomyelitis or disc infection; for more information, see Vertebral osteomyelitis in adults.

Urgent surgical assessment is essential. If surgery is not initially performed for diagnostic or therapeutic purposes, neurological status must be closely monitored.

Advice on empirical therapy for spinal epidural abscess is included for adults and children Tetsuka 2020.