31. Usually, a posterolateral disc hernia will affect the nerve root exiting at the level of the disk. 32. As a result, there is less space through which the spinal cord and nerve roots may pass. 33. Tests last week revealed pressure on a nerve root , which was causing pain in his left leg. 34. Percutaneous sacral nerve root stimulation was able to produce statistically significant improvements in several parameters, including pain. 35. In November, he was sidelined for an estimated minimum of two weeks due to nerve root irritation. 36. The proteins, known as nerve growth factors, were given to rats whose nerve roots had been crushed. 37. The difference in nomenclature is derived from which nerve roots on the spinal cord are being electrically stimulated. 38. "It is indicated when pain doesn't respond to conservative treatment and is clearly associated with nerve root compression. 39. Nerves roots are numbered according to the vertebral body below them ( except the C8 nerve root ).40. Nerves roots are numbered according to the vertebral body below them ( except the C8 nerve root ).