The invention provides an implantable multi-electrode device (300) and related methods and apparatuses. In one embodiment, the invention includes an implantable device (300) comprising: an assembly block (320); and a plurality of leads (340...348) radiating from the assembly block (320), each of the plurality of leads (340...348) containing at least one electrode (342A), such that the electrodes are distributed within a three-dimensional space, wherein the assembly block (320) includes a barb (350) for anchoring the assembly block (320) within implanted tissue.