The causes

Our brain and spinal cord are constantly surrounded by cerebrospinal fluid, the so-called liquor. This liquor has a protective function above all, since it can prevent the tissue from being trapped or subjected to pressure. The formation and breakdown of this liquor is a continuous process.

Approximately 500ml of this fluid is formed and broken down again every day. The nervous system and the cerebrospinal fluid are surrounded by the closed system of the meninges. A cerebrospinal fluid loss syndrome occurs when large amounts of this fluid are lost through a so-called cerebrospinal fistula.

The term cerebrospinal fluid fistula refers to all defects that allow cerebrospinal fluid to escape from the surrounding meninges. These often occur in the form of small tears in the meninges of the spinal cord, which then leads to a loss of cerebrospinal fluid. This loss is intensified when the patient is standing up, as gravity forces the cerebrospinal fluid downwards, allowing it to drain out of the small tear.

When lying down, such pressure is not present, which is why only very small amounts can drain off. The loss of cerebrospinal fluid now causes the brain tissue to sink, which leads to tension in the meninges, which is perceived as a headache. The severity of these headaches varies greatly depending on the size of the tear. If the tear is only 1 millimeter in size, affected persons report only mild headaches, which become worse when standing. In the case of large defects, however, patients are often unable to stand up or lift their head in pain.

The diagnosis

Even the clinical picture of the disease can give the investigating physicians a clear indication of the presence of CSF loss syndrome. Depending on the extent of this loss, in addition to severe headaches, there may also be impaired vision or impaired consciousness. In most cases, this clinical picture leads to a rapid implementation of an imaging procedure, usually the MRI.With the help of this examination, the outflowing cerebrospinal fluid as well as the “sagging” of the brain can be shown.

In addition, the inner cerebrospinal fluid spaces of the brain are clearly narrowed. On the other hand, it is often more complicated when searching for the tear. This is often very difficult to visualize in imaging and requires an experienced radiologist and often the use of further diagnostic measures such as ultrasound or a lumbar puncture.

As part of the diagnosis of CSF loss syndrome, an MRI of the lumbar spine (lumbar spine) is performed in almost all cases. If the disease is present, a few groundbreaking signs can be displayed. Firstly, cerebrospinal fluid accumulation outside the meninges can often be detected, which makes the presence of a cerebrospinal fistula very likely. In addition, a congestion of the veins of the meninges can often be detected. In some cases, a cerebrospinal fluid fistula can also be visualized, although other imaging techniques are usually used for this purpose.