I learned about a fascinating technique today from an outstanding Temple med student: Intravascular EEG. The concept is based off the common cardiology technique of introducing a catheter into the body via a larger artery such as the femoral, and then traversing the vasculature to a target site in the body. In this EEG technique, the catheter is passed all the way through the body until it reaches the brain - the papers I'm looking at indicate it can be parked in any one of the larger sinuses in the brain such as the cavernous sinus or the superior petrosal sinus. The electrode can then be pressed against the sinus wall and an electrical recording can be made. In theory, this means that high fidelity signals can be recorded very close to the structures of the deep brain. Presently, the electrical function of such structures must be inferred indirectly by analyzing recordings made from the scalp surface.
Intracranial EEG appears to be a neat idea with a lot of potential research applications. Can you localize and characterize deep epileptic foci with more precision than via surface EEG? Can you assess traumatic brain injury (which typically affects the deep brain moreso than the surface tissue)? And can you stimulate structures of the deep brain in this manner?