The present invention concerns an implantable cuff electrode and/or optrode (40) adapted to encircle a substantially cylindrical tissue (70), and comprising: a support sheet (43) rolled about a longitudinal axis, Z, forming a cuff of of inner diameter, Dc, and extending over a length, L, along the longitudinal axis, Z, wherein said cuff comprises, an inner surface (43d) forming an interior of the cuff, and an outer surface (43u) forming an exterior of the cuff,, a central portion, extending over a length, lc, of at least 50% of the length, L, of the cuff, and having a mean central thickness, tc, and wherein the central portion is flanked on either side by, a first edge portion (43e) of mean edge thickness, te1, and extending from a first free edge of the cuff and a second edge portion (43e) of mean edge thickness, te2, and extending from a second free edge, at least a first electrode contact or a first optrode exposed at the inner surface of the cuff, and remote from the outer surface forming the exterior of the cuff, Characterized in that, the mean edge thicknesses, te1, te2, of the first and second edge portions are each lower than the mean central thickness, tc, (te1<；tc and te2<；tc), andin that, the inner surface of the cuff extends beyond the central outer surface in both directions along the longitudinal axis, Z.
