This is directed to an implantable multimodal neurostimulator having improved efficacy in treating epilepsy and other neurological disorders and to processes of using that neurostimulator. The neurostimulator itself generally has two modes of electrical stimulation: the first involves delivering a non-responsive electrical stimulation signal which is applied to the central nervous system to reduce the likelihood of a seizure or other undesirable neurological even from occurring, and a second mode that involves delivering electrical stimulation signal or signals when epileptiform waveforms are impending or extant. The responsive electrical stimulation signal or signals are intended to terminate epileptiform activity, e.g., to desynchronize abnormally synchronous brain electrical activity. Alternatively, the second mode may be used to deliver sensory stimulation, e.g., a scalp or sound stimulation, to the patient rather than deliver electrical stimulation to the patient. Finally, the implanted neurostimulator may be used by a physician to induce epileptiform activity and then verify the effectiveness of the parameters of the first and second neurostimulation signal or signals.