Epidural abscess other diagnostic studies

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1] Associate Editor(s)-in-Chief: João André Alves Silva, M.D. [2]; Anthony Gallo, B.S. [3]

Lumbar puncture is likely not helpful in the diagnosis of epidural abscess. Cerebrospinal fluid study is not routinely performed because it offers little information, and has high associated risks. It should be analyzed only when myelography is performed.

Lumbar puncture is likely not helpful in the diagnosis of epidural abscess. Cerebrospinal fluid study is not routinely performed because it offers little information, and has high associated risks. It should be analyzed only when myelography is performed. Approximately 75% of patients whose cerebrospinal fluid is studied demonstrate:

• High protein level
• Pleocytosis, with either polymorphonuclear or mononuclear predominance

These findings, although suggestive of parameningeal infection, are not specific of epidural infection. The Gram-stain results of the cerebrospinal fluid are positive in approximately 19% of cases, while the majority of tests return Gram-negative.^[1][2] The risks associated with lumbar puncture include:^[1][2][3]

• Inducing meningitis
• Subdural infection if the needle transverses the epidural abscess
• Inducing neurologic deterioration if lumbar puncture is performed below a complete spinal subarachnoid block