Depth electrodes

Surgery is an effective therapeutic option for the treatment of drug resistant epilepsy. In most cases non-invasive presurgical investigations are sufficient for the definition of the Epileptogenic Zone (EZ). In about 1/3 of subjects the identification of the EZ entails the use of intracranial EEG recording. While electrodes arranged in subdural grids and strips offer the possibility to record electrical activity only from brain surfaces, intracerebral electrodes enable direct recording from every cerebral structure, including depth of sulci and white matter.

The term depth electrodes may refer both to the recording devices (multilead intracerebral electrodes) or to an invasive recording methodology. In fact, intracerebral electrodes may be employed with the main goal of lateralizing seizures (depth electrodes, DE), or with the more ambitious aim of defining the EZ by StereoElectroEncephaloGraphy (SEEG), a methodology originally developed by Talairach and Bancaud at Hôpital Sainte Anne, Paris, France.