The Cervical Spine as a Predominant Site of Cerebrospinal Fluid Leak: Preliminary Results Using the Overflow Leak Test.

Background: Cerebrospinal fluid (CSF) hypovolemia is usually treated via an epidural blood patch (EBP). Accurate placement of the EBP at the site of CSF leakage is required for successful treatment of CSF hypovolemia. The thoracolumbar spine is evidently a common site of leakage, but because rates of detection of the leakage site via conventional imaging have historically not been high, there may be other common leakage sites. In this study, CSF leakage sites were identified via a combination of conventional imaging, a new method called the overflow leak test, and patient interviews.

Methods: CSF leakage sites were identified using computed tomography myelography, radioisotope cisternography, and the overflow leak test in 14 patients with CSF hypovolemia. The patients were also asked about their history with regard to potential trauma. EBP was performed, and the accuracy of leakage site identification was assessed.

Results: Conventional imaging identified a leakage site in 7 of 14 patients, and in most cases it was in the lumbar spine. In the remaining 7 cases, the overflow leak test and ascertaining a history of trauma facilitated identification of the cervical spine as a leakage site. The site of the EBP was the cervical spine in 10 patients and the lumbar spine in 4 patients. Complete recovery was observed in 13 of 14 patients.

Conclusions: The cervical spine was a common leakage site in this study. Leakage in the cervical spine was undetectable via conventional imaging, suggesting that many cases of cervical spine leakage may remain undetected.