Spinal Epidural Abscess Workup

Updated: Jul 12, 2018
  • Author: J Stephen Huff, MD, FACEP; Chief Editor: Niranjan N Singh, MBBS, MD, DM, FAHS, FAANEM  more...
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Approach Considerations

Errors in diagnosis of spinal epidural abscessesare common and involve inadequate history, physical examination, and test ordering. According to one study of retrospective chart reviews of 250 randomly selected patients, 119 had a new diagnosis of spinal epidural abscess, 66 (55.5%) of which experienced diagnostic error. Red flags that were frequently not evaluated in error cases included unexplained fever, focal neurological deficits with progressive or disabling symptoms, and active infection. [12]


Laboratory Studies

See the list below:

  • CBC count, blood cultures, and preoperative lab studies. Leukocytosis is present in about two thirds of patients. [1]

  • Elevated erythrocyte sedimentation rate (ESR): In one report, the mean ESR was 51 mm/h. [13] ESR may be highly elevated.

  • Leukocytosis and ESR elevation are nonspecific laboratory findings and are not invariably present. Neither the presence of these findings nor the degree of laboratory abnormality is specific for spinal epidural abscess. [1]

  • A treatment guideline incorporating ESR, C-reactive protein, and other risk factors has been proposed based on a small patient series. [14]


Imaging Studies

See the list below:

  • Immediate imaging of the spine and spinal cord is imperative when the diagnosis is clinically suspected.

  • If available, spinal MRI is the procedure of choice. Recall that symptoms are often defined by spinal cord level, while MRI is ordered by regional or vertebral levels. Because abscesses frequently extend for several levels, be certain to order the anatomically correct region.

  • If MRI is unavailable, CT myelography or conventional myelography can reveal an intraspinal extramedullary mass—a "surgical" lesion.


Other Tests

Lumbar puncture (LP) is relatively contraindicated if spinal epidural abscess is suspected. However, LP may be essential to exclude meningitis from the differential diagnosis. Lumbar puncture runs the risk of introducing purulent material into the subarachnoid space. Some advocate slowly advancing the needle with gentle syringe aspiration if spinal epidural abscess is suspected; if purulent material is encountered, it should be aspirated gently to obtain laboratory specimens, and the needle should not be advanced further.

  • Cerebrospinal fluid (CSF) may show inflammatory cells, often a mixture of polymorphonuclear and mononuclear cells. Cell counts usually are increased, ranging from 10-1000 leukocytes/µL.

  • CSF protein usually is elevated above 100 mg/dL but may be higher, particularly if spinal block is present.

  • CSF glucose is usually normal; depression may indicate coexisting meningitis.