Epilepsy and epilepsy surgery

Epilepsy is characterized by sudden, unpredictable seizures, which are caused by neuronal dysfunction in the central nervous system. Epilepsy affects people of all ages.

Epilepsy may be related to various factors, including: 

• genetic influence, 
• brain tumors, 
• aneurysms,
•  infectious diseases, 
• head trauma. 

Often the cause of epileptic seizures is unknown (idiopatic).

Temporary, unpredictable central nervous system dysfunction is common to all forms of epilepsy. An epileptic seizure occurs due to sudden, uncontrolled, abnormally excessive electrical neuronal activity in the brain.

The character of a seizure and its impact on the individual differs from person to person and according to the affected region of the brain and the pattern of abnormal electrical activity. Possible signs and symptoms include: movement disorders such as tremor or muscle stiffness, sensory disorders such as numbness or blurred vision, hallucinations, anxiety, salivation, dizziness, drowsiness or loss of consciousness.

In most cases, epileptic seizures can be controlled with anti-epileptic/anti-convulsant medications. It is a long-term therapy that requires regular clinical supervision and combination with additional methods. It includes, for example, the adaptation to a regular daily routine and a regular sleep-wake cycle.

If drug therapy is not able to stop or significantly reduce the number of epileptic seizures or if side effects caused by medical treatment occur, a microneurosurgical intervention may be a therapeutic option. The most important indication for epilepsy surgery is a specific, identifiable, surgically accessible area of the brain, where excessive electrical neuronal activity occurs. 

Three-dimensional pre-operative planning is a significant aspect of preparation for a microsurgical intervention. Hence, before the operation the surgical target area is defined by detailed imaging with MRI, CT, PET and SPECT and an EEG is also recorded. The pathological changes of all modalities are synchronized in 3D space and delineate the surgical target zone. 

During the operation, removal of seizure-triggering nerve tissue is performed. It is important to precisely eliminate the affected area without causing impairment of the brain function. This is facilitated by a team of neurologists who are present in the operating room and monitor and analyse electrical brain waves during the resection of the epileptogenic region.

The assessment of an epileptic disease, the evaluation of treatment options and especially the planning and realization of surgery are complex and require comprehensive interdisciplinary cooperation between neurologists, neuroradiologists and neurosurgeons and as well as state of the art technical equipment.