Also known as cerebrospinal fluid (CSF), brain fluid is a bodily fluid that normally flows throughout the central nervous system. Specifically, it can be found between the skull and the brain. It offers some important benefits to the nervous system because of its location, including circulation of nutrients and shock absorption.
CSF assists in transporting nutrients from food throughout the central nervous system structures, just like blood. It also filters out waste, like the kidneys, except that it cleans the spinal cord and brain instead of the blood. This allows the nervous system to be completely detoxified.
The other important benefit brain fluid provides is shock absorption. Specifically, it protects the spinal cord and brain from damaging trauma that occurs from blows, falls, sharp movement and more. Of course, CSF does have its limitations; if the trauma is too severe, the spinal cord and brain will be affected by it. This can cause a cerebrospinal fluid leak.
Patients who suffer from a spontaneous cerebrospinal fluid leak will experience a sudden, acute headache that is orthostatic — worse while standing, better while lying down. Additional symptoms can include nausea, vomiting, double vision, facial weakness or numbness, severe vertigo and dizziness, along with a metallic taste in the mouth. Sometimes, leaking CSF can be observed through ear and nose discharges.
A number of disorders can occur in which brain fluid builds up without draining. Hydrocephalus, also known as "water on the brain," occurs when too much CSF infiltrates the cavities, or ventricles, of the brain. This leads to pressure within the brain, enlarging the head and causing convulsions and disability. It has also been known to cause death. Symptoms include headaches, nausea, vomiting and seizures.
Meningitis is a disease that inflames the membranes that protect the spinal cord and brain, and it occurs when the brain fluid pocketed in that part of the body becomes infected with bacteria. The disease is in such close proximity to the brain that having meningitis qualifies as a medical emergency. The most common symptoms associated include neck stiffness and headache, but confusion, fever, photophobia and phonophobia might also be present.
Directly related to meningitis is encephalitis, and it's possible to have the two diseases together, a condition known as meningoencephalitis. Encephalitis also inflames the brain, often because of the herpes simplex virus. This condition is diagnosed by examining the patient's brain fluid. Symptoms include headache, confusion, fever, drowsiness and fatigue.