Abstract: An improved apparatus and method for insertion of a sphenoidal wire electrode. The apparatus includes a needle (22) carrying a wire (24) having a turned-back distal portion (34) beside the needle and terminating forwardly along the slant-tip (28). The method includes positioning the wire in the needle with such turned-back distal portion as described, inserting the needle and wire, engaging the tissue with the turned-back portion to resist unintended relocation during needle withdrawal and the subsequent test period, and unfolding the turned-back portion of the wire to straighten it by initial pulling of the wire after the test period.

Abstract: An improved subdural strip electrode for determining epileptogenic foci. The strip has a long gradually tapered proximal end portion terminating in a narrow tip from which lead wires extend, allowing withdrawal of the strip electrode without substantial incision. The strip width and thickness are much less than in prior subdural strip electrodes, and the strip may be withdrawn after extended implantation without the need for general surgery. One preferred embodiment includes a reinforced central region along the strip.