A lead includes a plurality of electrodes disposed on the distal end of the lead, a plurality of contact terminals disposed on the proximal end of the lead, a plurality of conductor wires extending along the lead to couple the electrodes electrically to the contact terminals, a central lumen defined by the lead and extending from the proximal end of the lead towards the distal end of the lead, and a tubular stiffener disposed in the proximal end of the central lumen. The tubular stiffener is configured and arranged to facilitate insertion of the proximal end of the lead into a connector.
