1. A method of treating a brain disorder of a patient comprising: implanting at least a first and a second electrode in a first and a second region of a brain network associated with the brain disorder of the patient; implanting an implantable neurostimulation device, having a processor, a sensing subsystem, and a stimulation subsystem, the device configured to operate upon said first and said second electrode to provide at least one of sensing and stimulation; operating the processor of the implantable neurostimulation device, to implement a therapy program which is configured for providing therapy of the brain network by operating to control the sensing subsystem to operate upon the at least one of the first and second electrodes in order to sense data, operating to evaluate at least one measured feature, that is measured from the sensed data of at least two regions of the brain network, in relation to treatment criteria that define at least one network event, in order to detect the at least one type of network event, and operating to control the stimulation subsystem to adjust stimulation as a function of the detected network event.