Neurostimulation (NS) systems are devices that generate electrical pulses and deliver the pulses to nervous tissue to treat a variety of disorders. For example, spinal cord stimulation (SCS) has been used to treat chronic and intractable pain. Another example is deep brain stimulation (DBS), which has been used to treat movement disorders such as Parkinson's disease and affective disorders such as depression. SCS therapy, delivered via epidurally implanted electrodes, is a widely used treatment for chronic intractable neuropathic pain of different origins. Traditional tonic therapy evokes paresthesia covering painful areas of a patient. During SCS therapy calibration, the paresthesia is identified and localized to the painful areas by the patient in connection with determining correct electrode placement.
Recently, new stimulation therapies such as burst stimulation and high frequency stimulation, have been developed, in which closely spaced high frequency pulses are delivered. In general, conventional neurostimulation systems seek to manage pain and other pathologic or physiologic disorders through stimulation of select nerve fibers that carry pain related signals. However, nerve fibers and brain tissue carry other types of signals, not simply pain related signals.
Although some neurological disorders have been treated through known neurostimulation methods, many other neurological disorders exhibit physiological complexity, functional complexity, or other complexity and have not been adequately treated through known neurostimulation methods.