The cerebal spinal fluid (CSF)

What is the CSF?

This is a clear fluid produced by the brain. The CSF occupies the space between the layers of membranes in the meninges, the ventricular system – a series of spaces within the brain, and the area around the spinal cord in the central canal of the spine.

Together with the meninges, the CSF helps to cushion the brain and prevent friction with the skull. Its other functions include washing away the waste products that the brain produces, regulating the acidity (pH) of the environment surrounding the brain, regulating the pressure inside the skull, and distributing chemicals and hormones.

How the CSF is made and transported

The majority of the CSF is produced by choroid plexus on ventricular walls. It flows down the ventricles, then in the subarachnoid space around all the contours of the brain, and around the spinal chord. It is then reabsorbed into venous blood sinuses (via protrusions called arachnoid granulations). Venous sinuses are large veins in the head that take blood back to the body

How will a tumour in this area affect me?

Sometimes a tumour will obstruct the flow of cerebral spinal fluid. This causes a build up of excess fluid inside the brain also known as hydrocephalus. In young children, the bones of the skull are not attached together very firmly so their skull expands with the additional fluid. In adults, however, the skull bones are strongly fused together, which means that the pressure inside the skull (intracranial pressure) is forced to rise. This causes symptoms such as headache, vomiting, drowsiness, and eventually loss of consciousness.

Hydrocephalus can be treated temporarily either by putting a syringe into the brain and removing some of the excess fluid or cutting and taking out a section of your skull so that it gives the brain extra space. If the tumour can be fully or partially removed, the flow may go back to normal. If not, then it may be necessary to have an operation to put a tube, known as a shunt, between your brain and another part of your body so that the CSF can bypass the obstruction.