Cerebrospinal fluid leak is usually caused by a tear in the membrane that encloses the brain and the spinal cord. The leakage through the spinal cord can also be caused by spinal tap, pain medications, surgeries and head injury. Leakage of the spinal fluid causes pressure to fall in the brain and the spinal cord, as stated by National Institutions of Health's MedlinePlus.
The fluid can drain through the ear or the nose depending on the location of the tear on the skull bone. The main symptom of this condition is the drainage of a clear fluid from the ear or nose. It may also be accompanied by other signs, such as headaches, hearing loss and change in vision.
A diagnosis of this condition involves a physical exam and checking the medical history of a patient. The doctor uses an endoscope to examine through the nose. The drainage may be collected and taken to the lab for a testing. MRIs or a CT scan can be recommended to help examine the damages on the skull bone, as stated by Cleveland Clinic.
Depending on the cause, the condition can clear up without treatment after some days. Increasing fluids intake can help treat the condition and prevent headaches, as stated by MedlinePlus.