Abstract: An intracranial apparatus that may be used for electrophysiological monitoring and stimulation of brain tissue of a patient. Embodiments comprise a stylet including a body section and a tip configured to separate brain tissue, a sheath including a body section having an outer surface defining a central opening configured to receive the stylet such that the tip of the stylet extends beyond the body section of the sheath, and a plurality of electrodes disposed at the outer surface of the sheath and configured to be connected to the brain tissue surrounding the sheath for stimulating and/or monitoring.