Neurostimulator (20) comprising a signal generator (40) for generating stimulation pulses, connected or connectable to at least one electrode (10) implantable in the brain of a patient, comprising a signal generator control unit (36) connected to the signal generator (40) and designed to control the delivery of stimulation pulses and to make adjustments in signal generator settings as needed, comprising a device connected to the signal generator control unit (36) for determination and analysis of the heart rate of a patient (30, 32, 34), characterized in that the signal generator control unit (36) is designed to check on the health status of a patient and/or the success of a treatment using at least one heart-rate-dependent characteristic quantity determined by the device for determination and analysis of the heart rate (30, 32, 34) and to make an adjustment in the signal generator settings if necessary.