A system for differential recording connectable to an electrical lead with at least two electrodes, including:the lead having a distal end；at least one amplifier electrically connectable to the at least two electrodes, wherein the at least one amplifier subtracts a signal recorded by one of the at least two electrodes, from a signal recorded by the other one of the at least two electrodes to generate a differential signal；a memory configured for storing said differential signal and reference indications of electrical signals associated with neural tissue；a processing circuitry for detection of an anatomical position, wherein the processing circuitry calculates an anatomical position of the electrical lead based on processing of the differential signal and the reference indications of electrical signals associated with the neural tissue.
