Brainstem or skull base surgery

During surgery, we use specialized procedures to monitor the activity of muscles controlled by certain cranial nerves. Routine procedures include monitoring free electromyogram (EMG) and motor evoked potentials (MEP) from cranial nerves such as the facial nerve, the glossopharyngeal nerve, or the vagus nerve, which affect many bodily functions  *,*. 

In addition, we can specifically localize the motor cranial nerves during the operation. This is called mapping. It allows us to determine important functional areas in the brain or near the tumor in real time.

For tumors that are located deep inside the brain, we search the surface of the brain directly to find the best and safest point for access to the tumor. This allows us to minimize the risk to the patient.

In addition to monitoring motor functions (MEP), we can also measure sensory and sensory information during the operation. To do this, we use procedures such as somatosensory evoked potentials (SEP) for the nerve pathways, auditory evoked potentials (AEP) for the hearing or visual evoked potentials (VEP) for the optic nerves.

In addition, we are actively working on the development of new methods to better monitor the complex neural connections in the brainstem. This includes intraoperative monitoring of reflexes such as:

• blink reflex  *, which indicates the protective function of the eyes,
• H-reflex of the masseter  *, which checks important chewing nerves,
• and laryngeal adduction reflex  *, which measures the function of the laryngeal nerves.

A special form of neuromonitoring is used for patients suffering from hemifacial spasm – an involuntary twitching of the facial muscles. During surgery, success can be verified directly by performing the lateral spread response (LSR) test on the facial nerve (nervus facialis) *. If the overactive muscle responses in the EMG (electromyogram) disappear, this indicates that the operation was successful and the patient is cured.