Epilepsy is a condition in which a person has recurrent seizures. A seizure is defined as an abnormal, disorderly discharging of the brain’s nerve cells, resulting in a temporary disturbance of motor, sensory, or mental function. Recently neurosurgeons of the Epilepsy surgery team in Helsinki University Central Hospital (HUCH) have made modifications in epilepsy therapy and they have achieved many encouraging results.
Intracranial EEG (iEEG) is an invasive technique based on recording electroencephalography (EEG) signals directly from the human cortex, as opposed to surface recordings in scalp-EEG. Stereo-EEG is one of two intracranial recording techniques and was developed already in the 1960’s. This technique is constantly improved and recently, neurosurgeons of the Epilepsy surgery team in Helsinki University Central Hospital (HUCH) have made modifications to the stereo-EEG examination and they have achieved many encouraging results.
Picture: A Patient with Epilepsy
The stereo-EEG is considered more pleasant than the earlier-used intracranial recording methods. Thin recording electrodes are placed into the brain through small holes, so no large craniotomy is required. The new method increases the recording time from one to as many as four weeks. The method conducted at HUCH benefits particularly patients with severe, drug resistant epilepsy.
The equipment and methods used in the DBS and in the stereo-EEG follow the same basic principles. The methods scientists at HUCH use complement each other. HUCH neurosurgery clinic is also getting ready to introduce the so-called deep brain stimulation therapy. Dr Karppinen from HUCH says that starting DBS therapy in the treatment of epilepsy is well-founded at the stage when they have sufficient, reliable research-based information on the results of the method in the treatment of epilepsy.
Along with other examination methods already in use, the method opens an excellent opportunity in the exploration of the electric activity of both the surface and the deep brain structures during epileptic seizures. The examination also localizes the functionally important areas of the brain exactly and improves safety of epilepsy surgery at a later stage.
30 epilepsy surgery operations are performed each year in two university hospitals in Finland more than half of the patients will be completely seizure-free thanks to the operation. It is hoped the new stereo-EEG method will be in active use and more patients will get benefits from it.