Investigations
1st investigations to order
FBC
Test
Usually shows leukocytosis, although a non-specific marker.
Serial monitoring is recommended to assess response to therapy.
Result
leukocytosis
CRP
Test
Usually elevated, although a non-specific marker.
Serial monitoring is recommended to assess response to therapy.
Result
elevated
erythrocyte sedimentation rate
Test
Usually elevated, although a non-specific marker.
Serial monitoring is recommended to assess response to therapy.
Result
elevated
MRI spine with and without intravenous contrast
Test
Imaging both with and without contrast is required. Gadolinium-enhanced diffusion-weighted MRI spine is the most sensitive, specific, and accurate imaging method for spinal epidural abscess. Comparison with pre-contrast MRI is used to confirm areas of suspected abnormality. The whole spine should be imaged.[33][34]
The degree of thecal sac compression is prognostic; compression >50% increases incidence of progressive neurological injury and late recurrences.[35]
Result
infection in epidural space ± bone involvement
blood cultures
Test
All patients should have blood cultures before antibiotic therapy. The most common pathogen in patients with SEA is Staphylococcus aureus, with MRSA increasingly reported. Other causative organisms include Pseudomonas species; other gram-negative bacteria; Mycobacterium tuberculosis; and Streptococcus species. Fungal and parasitic pathogens less commonly cause SEAs. However, no causative organism is identified in up to 25% of cases.[9][20][21][28][39]
Result
identifies causative organism
direct abscess aspiration for culture
Investigations to consider
nucleic acid amplification test (NAAT) of aspirate
Test
NAAT for suspected organisms, especially if M tuberculosis, may be considered.[36]
Result
identifies causative organism
Use of this content is subject to our disclaimer