LAUSR

OBJECTIVE Cerebrospinal fluid hypovolemia (CSFH) is usually treated via an epidural blood patch (EBP). Accurate placement of the EBP at the site of cerebrospinal fluid (CSF) leakage is required for the successful treatment of CSFH. 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 the present 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 CSFH. 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 7/14 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 sites of EBP included 10 in the cervical spine and 4 in the lumbar spine. Complete recovery was observed in 13/14 patients. CONCLUSIONS In the present study the cervical spine was a common leakage site. Leakage in the cervical spine was undetectable via conventional imaging, suggesting that many cases of cervical spine leakage may remain undetected.