I-eeg = intracranial or invasive eeg... the name varies depending on where you look...
The closest thing to an intercranial EEG that I had, was the GRID Test. Before they could proceed with my brain surgery, they had to map out the exact location of my seizures. The GRID are basically electrodes inside this soft plastic and is put on top of the brain behind a portion of the skull..
Before my surgery I had 4 holes drilled in my skull where they placed wire stripes into my brain.
They also took long needles and placed a wire into my jaws. Where they drill into the skull they will deaden the skin where they drill. After this they will wrap your head to keep out infections. When they get through wrapping your head in gauze your head may look like a bees hive. For as pain they will deaden where they put the wire strips.and when the feeling comes back there is very little or no pain. If your are to go through this. Don't worry every thing will be fine. Really the only pain you will feel is when they stick the needles in to deaded the scalp.