CSF or cerebrospinal fluid, is the water in which the brain and spinal cord sits. It is contained by the dural sheath. CSF is made deep within in the brain, and flows like a river. It is then drained downstream by the veins which overly the dura. If an openning in the dura is made and fails to close, fluid can leak out.
Why is this relevant to CSM?
During surgery for CSM, an opening in the dura can be accidentally made. This is often because, due to the disease, the dura has become stuck to the compressing tissues. Therefore during their removal it can tare open causing a leak. This is a relatively uncommon complication, but is more likely during posterior cervical surgery rather than anterior surgery.
The signs of a CSF leak would include clear, watery fluid leaking from your wound site or headaches/nausea/vomiting on standing [because the pressure inside your head has dropped a little].
If CSF is leaking out, then there is a risk that bacteria can get in and cause an infection such as meningitis. Therefore if this occurs you should return immediately to hospital.
The management of the leak will depend on the situation, but options include flat bed rest, temporary diversion of CSF flow to allow the hole to heal or an operation to repair the leaking point.