Neuromodulation is technology that acts directly upon nerves. It is the alteration—or modulation—of nerve activity by delivering electrical or pharmaceutical agents directly to a target area.
Peripheral nerve stimulation, a type of neuromodulation, is used to alter nerve activity by delivering electrical stimulation directly to a target area which then stimulates related pathways throughout the central nervous system (i.e. the brainstem, cerebellum, cortex, etc.)
Most frequently, people think of neuromodulation in the context of chronic pain relief, the most common indication. However, there are a plethora of neuromodulation applications, such as deep brain stimulation (DBS) treatment for Parkinson's disease, sacral nerve stimulation for pelvic disorders and incontinence, and spinal cord stimulation for ischemic disorders (angina, peripheral vascular disease).