An active implantable medical device for neurostimulation by controlled injection of electric currents simultaneously at a plurality of points of a physiological tissue, said active implantable medical device comprising: - a neurostimulation lead suitable for being placed around, in the vicinity of, or inside an organ, which neurostimulation lead includes at least one arrangement of sectoral electrodes (E O, E N, E E, E S) that are suitable for forming stimulation poles with a neurostimulation current flowing between at least one anode and at least one cathode of a predetermined stimulation configuration; and - a generator of electric current pulses, which generator comprises: • a plurality of current sources (S O, S N, S E, S S; S 1, S 2, S 3, S 4); • a plurality of current sinks (P O, P N, P E, P S; P 1, P 2, P 3, P 4); • a first distribution structure for distributing currents coming from said current sources (16; 26), for selectively coupling at least one of the current sources to an electrode, so that said electrode constitutes an anode active electrode of said predetermined stimulation configuration; and • a second distribution structure for distributing currents coming from said current sinks (20; 36) for selectively coupling at least one of the current sinks to another electrode so that said other electrode constitutes a cathode active electrode of said predetermined stimulation configuration; wherein the arrangement of electrodes comprises M electrodes (O, N, E, S) and the generator comprises N current sources and N current sinks, where N = M or N ≠ M, the N current sources and the N current sinks being defined independently from the M electrodes: - the first distribution structure is suitable for coupling indifferently at least one of the N current sources (S 1, S 2, S 3, S 4) to any one of the M electrodes (O, N, E, S); - the second distribution structure is suitable for coupling indifferently at least one of the N current sinks (P 1, P 2, P 3, P 4) to any one of the M electrodes (O, N, E, S); and - the generator further comprises control means for controlling the first and second distribution structures, which control means are suitable for defining a combination of couplings of a plurality of current sources and/or of a plurality of current sinks procuring the same average neurostimulation current for different respective predetermined stimulation configurations; and wherein the control means are multi-phase control means suitable for cyclically producing a plurality of combinations of couplings for the same stimulation configuration, in such a manner as to average the neurostimulation current delivered by the plurality of current sources and the plurality of current sinks. - a neurostimulation lead suitable for being placed around, in the vicinity of, or inside an organ, which neurostimulation lead includes at least one arrangement of sectoral electrodes (E O, E N, E E, E S) that are suitable for forming stimulation poles with a neurostimulation current flowing between at least one anode and at least one cathode of a predetermined stimulation configuration; and - a generator of electric current pulses, which generator comprises: • a plurality of current sources (S O, S N, S E, S S; S 1, S 2, S 3, S 4); • a plurality of current sinks (P O, P N, P E, P S; P 1, P 2, P 3, P 4); • a first distribution structure for distributing currents coming from said current sources (16; 26), for selectively coupling at least one of the current sources to an electrode, so that said electrode constitutes an anode active electrode of said predetermined stimulation configuration; and • a second distribution structure for distributing currents coming from said current sinks (20; 36) for selectively coupling at least one of the current sinks to another electrode so that said other electrode constitutes a cathode active electrode of said predetermined stimulation configuration; • a plurality of current sources (S O, S N, S E, S S; S 1, S 2, S 3, S 4); • a plurality of current sinks (P O, P N, P E, P S; P 1, P 2, P 3, P 4); • a first distribution structure for distributing currents coming from said current sources (16; 26), for selectively coupling at least one of the current sources to an electrode, so that said electrode constitutes an anode active electrode of said predetermined stimulation configuration; and • a second distribution structure for distributing currents coming from said current sinks (20; 36) for selectively coupling at least one of the current sinks to another electrode so that said other electrode constitutes a cathode active electrode of said predetermined stimulation configuration; - the first distribution structure is suitable for coupling indifferently at least one of the N current sources (S 1, S 2, S 3, S 4) to any one of the M electrodes (O, N, E, S); - the second distribution structure is suitable for coupling indifferently at least one of the N current sinks (P 1, P 2, P 3, P 4) to any one of the M electrodes (O, N, E, S); and - the generator further comprises control means for controlling the first and second distribution structures, which control means are suitable for defining a combination of couplings of a plurality of current sources and/or of a plurality of current sinks procuring the same average neurostimulation current for different respective predetermined stimulation configurations; and