Cerebrospinal fluid tap
A cerebrospinal fluid tap (CSF tap) is a procedure done by an Internal Medicine specialist, neurologist, radiologist or surgeon to evaluate the fluid that bathes the brain. The procedure is done with your pet under general anesthesia after he has not eaten for 12 or more hours. Often CSF taps are done after a CT or MRI scan of the brain, while your pet is still under anesthesia. The tap itself only takes a few extra minutes.
CSF tap is generally a low risk procedure. The risk is higher in cases of brain swelling due to a tumor or severe inflammation. Your doctor will tell you if the risks are higher for your pet because of a specific condition. The risk of anesthesia in patients with neurologic disease is always a consideration as well.
While anesthetized, a small patch of your pet’s hair is shaved at the top of the neck, and a small needle is inserted into the area between the top of the spinal column and the back of the skull. The needle draws out some of the cerebrospinal fluid that surrounds the brain and spinal cord. In some cases, the fluid is drawn lower down on the spine; this procedure is called a lumbar puncture (LP).
The fluid withdrawn is submitted to our pathology laboratory and results are generally available within one week. Sometimes medications are prescribed based on the initial impression based on CT or MRI scan, but may be changed when additional laboratory results return in 4-7 business days.
Some patients are able to go home the same day, but often they stay overnight so they can be observed for the first 12-24 hours.