The brain stem controls vital functions, such as breath and blood pressure. It contains the central control cores of the brain nerves and drives eye and face movement, feeling of the face and the act of swallowing. All movement and sensory pathways pass through the brain stem.
Its function is mostly impaired by inflammation, strokes, tumors or vascular deformity, so-called cavernoma.
Symptoms are mostly characterised by failure of brain nerves or the failure of sensory pathways, leading to paralysis or sensory malfunction in the body or the limbs.
A complete removal of tumors of the brain stem is not always possible, because tumors tend to infiltrate diffusely into the surrounding tissue. The removal would lead to severe neurological failures. In those cases, a sample is taken and the tumor is treated radio-oncologically. Tumors which merely relocate the brain stem, such as neurinomas or meningeomas, can usually be removed surgically. Cavernomas are vascular malformations, composed of thin-walled blood capillaries. If these walls break, the rupture causes small bleedings, which can – depending on where they are located – cause severe neurological failures.
The indication for therapy concerning asymptomatic and coincidental diagnoses is provided rather cautiously. Symptomatic tumors and cavernomas are usually treated surgically.
Because of the anatomical density of pathways and nerve nuclei however, surgical treatment is not without risk. Surgery should only be indicated individually, if functionally relevant structures can be spared. Any operational intervention is planned most carefully.
The endoscopically assisted microsurgical technique has proven itself, because it allows for hidden corners to be visible during the operation and reduces injury due to access. The use of intra-operative monitoring is imperative, to control the functioning of the brain stem and nerves in the narcotised state.