Cerebrospinal (CSF) leak is an abnormal drainage of cerebrospinal fluid from the subarachnoid space in the brain.
CSF essentially bathes the brain and spinal cord and protects them from injury and infection. CSF is formed within the inner spaces of the brain called ventricles. The fluid travels through the ventricles and exits the brain beneath the cerebellum, which is at the base of the head. It then travels down the spine, around the spinal cord and nerves, and back up to the head.
Finally, it passes over the top of the brain where it is absorbed. The fluid is held between the arachnoid and dura membranes. These membranes cover the brain and spinal cord. Leakage occurs when the arachnoid membrane is ruptured.
CSF is a clear, watery liquid that can leak out of the nose, ear, or a head or spinal wound following trauma or surgery. It occurs commonly following a lumbar puncture (spinal tap). Headache is the most common symptom with a CSF leak. Typically, the headache from CSF leak worsens in the upright position and is less severe when the individual lies flat.
A CSF leak is caused by a rupture of the arachnoid membrane. This usually results from trauma, surgery or after a spinal tap. It can also occur spontaneously. Tissue destruction caused by tumors can also lead to a CSF leak.
There is no way to prevent a CSF leak from trauma, lumbar puncture, or surgery. Sports safety guidelines for children, adolescents, and adults can help avoid head injury during sports.
Diagnosis is made by a complete history and physical by a trained health professional. If fluid is actively flowing out of the nose, ears, or a head wound, the fluid can be tested to verify that it is CSF.
Headache is a common symptom resulting from CSF leak. If the headache improves with lying down and worsens with standing or sitting, a CSF leak can be assumed, particularly if the individual has recently undergone a lumbar puncture or other procedure where the arachnoid membrane was breached.
Chronic leakage may occur at times following surgery, trauma or spinal tap. Headache and infection are the greatest risks.
There are no risks to others.
Leakage through the nose or ears following trauma usually gets better with rest. Antibiotics are given if an infection is present. If the leakage persists, the healthcare professional may place catheters in the lumbar spine to reroute the CSF.
Surgical closure of the ruptured membrane is rarely needed. If leakage is caused by erosion due to tumor or infection, the underlying cause must be treated.
CSF leak following a lumbar puncture can be treated with caffeine, and hydration. A blood patch may be placed at the site of the spinal tap. This is a procedure where the individual's own blood is injected at the location of the spinal tap, sealing the hole so as to prevent the leak.
Infection at the site of trauma or surgery may occur. Failure of the rupture to close spontaneously may sometimes occur.
Treatment is usually successful, although complications such as infection can occur.
A person should be monitored for infection and recurrence of CSF leakage. A change of therapy may be needed if infection or recurrence takes place. Any new or worsening symptoms should be reported to the healthcare professional.
Current Medical Diagnosis&Treatment, 39th edition.