Lead extensions for use with electrical stimulation systems and methods of making and using the lead extensions

An implantable lead extension comprising:

• an intermediate body element having a proximal end portion, a distal end portion, and a longitudinal length;
• a plurality of proximal tails attached to the proximal end portion of the intermediate body element;
• a different plurality of terminals disposed along each of the plurality of proximal tails;
• a connector assembly attached to the distal end portion of the intermediate body element, the connector assembly comprising a plurality of connectors each configured and arranged for electrically coupling with a different stimulation lead, each of the plurality of connectors comprising
• a connector housing defining a port for receiving a proximal end portion of a stimulation lead, and
• a plurality of connector contacts disposed in the connector housing, the connector contacts configured and arranged to couple to terminals of the stimulation lead when the proximal end portion of the stimulation lead is received by the port;
• and
• a plurality of conductors extending along the longitudinal length of the intermediate body element and electrically coupling the plurality of connector contacts to the plurality of terminals.