A cerebrospinal fluid leak (CSF leak or CSFL) is a medical condition where the cerebrospinal fluid (CSF) surrounding the brain or spinal cord leaks out of one or more holes or tears in the dura mater. A cerebrospinal fluid leak can be either cranial or spinal, and these are two different disorders. A spinal CSF leak can be caused by one or more meningeal diverticula or CSF-venous fistulas not associated with an epidural leak.A CSF leak is either caused by trauma including that arising from medical interventions or spontaneously sometimes in those with predisposing conditions (known as a spontaneous cerebrospinal fluid leak or sCSF leak). Traumatic causes include a lumbar puncture noted by a post-dural-puncture headache, or a fall or other accident. Spontaneous CSF leaks are associated with heritable connective tissue disorders including Marfan syndrome and Ehlers–Danlos syndromes.A loss of CSF greater than its rate of production leads to a decreased volume inside the skull known as intracranial hypotension. Any CSF leak is most often characterized by orthostatic headaches, which worsen when standing, and improve when lying down. Other symptoms can include neck pain or stiffness, nausea, vomiting, dizziness, fatigue, and a metallic taste in the mouth. A CT myelography scan can identify the site of a cerebrospinal fluid leakage. Once identified, the leak can often be repaired by an epidural blood patch, an injection of the patients own blood at the site of the leak, a fibrin glue injection, or surgery.
The evidence of the last decade suggests however, that these leaks result from either a discogenic pathology, such as microspur, osteophyte or intra-dural disc herniation that pierces the dura like a knife, connective tissue disorder (which can often lead to discogenic pathology), or spinal drainage problems.A cerebrospinal fluid leak can be a rare complication of an anterior cervical discectomy and fusion (ACDF). One study suggested a CSF leak to follow from 0.5% of operations. Another study suggests a CSF leak to follow from 1% of operations. In most of these cases repair is successful. Discogenic causes
The most common cause of an intractable "sCSF" leak is discogenic, either from an intra-dural disc herniation, osteophyte or microspur on the disc or vertebral body. "Recent radiological and microsurgical investigations revealed that a calcified, degenerative bony microspur is often the culprit lesion in cases of intractable CSF leaks. Arising from the level of the intervertebrate disk space, these microspurs pierce the ventral dura and produce a slit-like defect a few millimeters in length. These microspurs and the associated CSF leak have to be localized exactly, and then they are amenable to surgical treatment." Connective tissue theory
Various scientists and physicians have suggested that SCSFLs may be the result of an underlying connective tissue disorder affecting the spinal dura. It may also run in families and be associated with aortic aneurysms and joint hypermobility.Up to two thirds of those affected demonstrate some type of generalized connective tissue disorder.