Disclosed embodiments include apparatuses, systems, and methods for positioning electrodes. In an illustrative embodiment, an apparatus includes a primary electrode defining a lumen, an elongated secondary electrode slidably receivable within the lumen, and a sheath configured to slidably receive the electrodes and to convey the electrodes toward a target region. A housing is coupled with the sheath and movably mounted to motivate the sheath relative to the target region. A primary actuator is coupled with the primary electrode and slidably coupled with the housing to motivate the primary electrode relative to the sheath. A secondary actuator is coupled with the secondary electrode and movably coupled with the primary actuator to be slidable with the electrodes in concert. The secondary actuator is rotatable independently of the primary actuator to travel along a helical path to motivate the secondary electrode to move relative to the target region independently of the primary electrode.