Brain biopsy

What is a brain biopsy?

A biopsy is a tissue sample taken from a specific area of the body. Consequently, one speaks of a brain biopsy when sample material is taken from the brain. One has to decide between the different sections of the brain.

Samples can be taken particularly well from the superficial areas of the brain (especially the cerebral cortex). But the cerebellum and diencephalon can also be biopsied. Deeper brain areas such as the so-called thalamus or the brain stem are more difficult to reach.


A brain biopsy is rarely performed, since direct intervention on the brain is always associated with risks. It is therefore particularly important to weigh up the risks against the benefits of brain biopsy. Frequent indications for a brain biopsy are space requirements in the brain.

These can be caused by both benign and malignant processes and must therefore be clarified as quickly as possible so that a sensible therapy strategy can be developed. Brain biopsy therefore plays an important role in tumor diagnostics. Biopsies can also be performed in degenerative diseases, in which the brain substance is increasingly diminishing, in order to identify the cause of the symptoms. Brain biopsy is rarely used in infectious diseases. Here, one usually falls back on a cerebrospinal fluid examination (examination of the cerebrospinal fluid).

What is a stereotactic brain biopsy?

In medicine, stereotactic is the term used to describe procedures that are performed from several directions. For example, a brain biopsy that is to be performed on a very small area of the brain can best be performed stereotactically. For this purpose, three-dimensional imaging of the brain is required first.

Computer simulations can then be used to determine the exact location of the brain region to be examined. A ring is then placed on the head to which the biopsy instruments are attached at various points. The instruments enter the brain through small holes drilled into the skull. The place where the instruments meet is the place where the brain biopsy is to be taken. Compared to other procedures, stereotactic brain biopsy is particularly gentle on tissue due to its precision.