An assembly is provided for an implantable medical lead. The assembly includes a first lead body comprising one or more electrical leads, and a hermetic encasement. The encasement comprises a housing having first and second openings and interior walls, an interior space defined by the interior walls, an electronic network housed within the interior space, and a circuit board extending through the first and second openings. The circuit board comprises a plurality of layers into which the electronic network is at least partially integrated, a first set of one or more terminals electrically coupling the electronic network to the first lead body, and a second set of one or more terminals electrically coupled to the electronic network for external electrical engagement.