What is a CSF Leak?

A cerebrospinal fluid (CSF) leak is a medical condition characterized by loss of the fluid that bathes the spinal cord and brain. There can be a number of reasons for a patient to develop a CSF leak. The prognosis varies depending on the cause, but is often quite good, and there are several treatment options that can be considered when deciding how to manage the condition.

Patients develop CSF leaks when a small tear in the dura, the tough membrane that encases the brain and spinal cord, develops. The tear allows some of the fluid to leak out, causing a decline in the pressure of the cerebrospinal fluid. This condition is also known as intracranial hypotension, in a reference to the decreased pressure that can be seen in the patient. The patient may experience headaches and drainage from the ears or nose. Some patients feel nauseous or dizzy, depending on the cause. Lying down tends to relieve discomfort.

Sometimes a CSF leak is spontaneous, with no apparent cause. Leaks can also be caused by surgical procedures and diagnostic testing, such as spinal taps. Trauma can be another cause, as seen in people with penetrating head injuries or damage to the spinal cord. Sometimes a shunt implanted for drainage to relieve intracranial hypertension can be too efficient, removing too much CSF. In all cases, the fluid leaks out more quickly than it can be replaced by the body.

There are several diagnostic tools that can be used with a patient who has a suspected CSF leak. A patient interview can provide revealing information, as can medical imaging studies with contrast. Measuring the pressure of the cerebrospinal fluid can also be used to determine whether a patient has a leak. Conservative treatments for a CSF leak include hydration and rest, with the patient lying down to reduce the rate of leakage. Surgeons can also perform patches by introducing clotting agents to the site of the tear in the dura to encourage the hole to close.

If a patient is at risk for a CSF leak, monitoring may be recommended to identify the early warning signs. This will allow for a prompt intervention to reduce the risk of complications. People who have recently undergone spinal taps or who have received head injuries, for example, may be advised to rest and report any symptoms, including behavioral ones, to a doctor. A neurosurgeon is usually involved in the management of a cerebrospinal fluid leak, as the surgeon will have access to advanced treatment tools.