The present invention concerns an implantable cuff electrode and / or optrode (40) adapted to encircle a substantially cylindrical body tissue (70), and selected among a self-sizing cuff and a split-cylinder cuff, said implantable cuff electrode and / or optrode comprising : • a support sheet (43) which is non-conductive, and o having a perimeter defined by an inner edge (43i) and an outer edge (43o) extending along a longitudinal axis (Z), wherein o the support sheet is rolled about a longitudinal axis (Z) to form a cuff electrode/optrode, • at least a first energy transfer unit including an electrode contact (40a) or an optical contact (60), which is exposed at the inner surface of the cuff, Characterized in that, an inner handling flap (45) is provided which comprises • a coupled end belonging to a coupled portion (45c) which is fixed to a portion of the outer surface (43u) of the support sheet (43) which is adjacent to the inner edge (43i), and • a free end, opposite the coupled end belonging to a free portion (45f) adjacent to the coupled portion (45c) and separated therefrom by a transition line (45t), said free portion being loose from the outer surface (43u) of the support sheet.La présente invention concerne une électrode souple implantable et/ou un optrode (40) conçu pour encercler un tissu corporel sensiblement cylindrique (70), et sélectionné parmi un brassard auto-ajustable et un brassard à cylindre fendu, ladite électrode souple implantable et/ou l'optrode comprenant : une feuille de support (43) qui est non conductrice, et ayant un périmètre défini par un bord interne (43i) et un bord externe (43o) s'étendant le long d'un axe longitudinal (Z), la feuille de support étant enroulée autour d'un axe longitudinal (Z) pour former une électrode souple ou optrode ； au moins une première unité de transfert d'énergie comprenant un contact d'électrode (40a) ou un contact optique (60), qui est exposé sur la surface interne du brassard, caractérisé par la présence
