Review of spinal pseudomeningoceles and cerebrospinal fluid fistulas.
Spinal pseudomeningoceles and cerebrospinal fluid (CSF) fistulas are uncommon extradural collections of CSF that may result from inadvertent tears in the dural-arachnoid layer, traumatic injury, or may be congenital in origin. Most pseudomeningoceles are iatrogenic and occur in the posterior lumbar region following surgery. The true incidence of iatrogenic pseudomeningoceles following laminectomy or discectomy is unknown; however, the authors of several published reports suggest that the incidence of lumbar pseudomeningoceles following laminectomy or discectomy is between 0.07% and 2%. Pseudomeningoceles are often asymptomatic, but patients may present with recurrence of low-back pain, radiculopathy, subcutaneous swelling, or with symptoms of intracranial hypotension. Very rarely, they present with delayed myelopathy. Although magnetic resonance imaging is the neurodiagnostic study of choice, computerized tomography myelography and radionuclide myelographic study may be helpful diagnostic tools in some cases. Analysis of suspect fluid for Beta2 transferrin may be a useful adjunctive study. Treatment options include close observation for spontaneous resolution, conservative measures such as bed rest and application of an epidural blood patch, lumbar subarachnoid drainage, and definitive surgical repair.