An apparatus includes a lead body extending from a proximal end to a
distal end and having an intermediate portion therebetween. The lead body
includes two or more individually insulated conductors, where a first
conductor traverses along less than an entire length of the lead body and
a second conductor traverses from the proximal end to the distal end of
the lead body. Optionally, the first conductor has a different material
than the second conductor, for instance having differing electrical
properties and/or differing stiffnesses. A method includes varying the
stiffness of a coiled conductor assembly including winding a plurality of
conductors to form the coiled conductor assembly, and pulling at least
one loop of a first conductor away from the coiled conductor assembly.