A rhizotomy (rī-zŏt'ə-mē) is a neurosurgical proceure that selectively severs problematic nerve roots in the spinal cord, most often to relieve the symptoms of neuromuscular conditions such as multiple sclerosis, spastic diplegia and other forms of spastic cerebral palsy. In extreme cases, a rhizotomy may also be considered for a person suffering from severe back pain or a pinched nerve. The sensory nerve roots are first separated from the motor ones. Identification of the nerve fibers to be cut is then made by means of electrical stimulation. The one(s) producing the pain or other problems are identified in this way, then selectively cut.