The patient, “Harry”, was a 77 year old Korean War Veteran who suffered from both pain and numbness on the top and bottom of both his feet. This was caused by nerve damage he had gotten from multiple episodes of frostbite during the war. He had been treated unsuccessfully using physical therapy and a number of pain relieving drugs including ones specifically used for nerve pain.

Harry was sent to see Dr. Christopher J. Winfree at the Center for Peripheral Nerve Surgery. With stubborn nerve pain like Harry’s, neurosurgeons like Dr. Winfree consider implanting an electrical nerve stimulating device (ENSD) in the spine for pain relief. Because of the very specific pattern of Harry’s symptoms his doctors could trace the irritated nerves in his feet back to a specific spinal segment where these nerves emerged from the spinal cord.

Dr. Winfree felt that placing the ENSD in the foramen or tunnel where the nerve emerged from the spine would give Harry the most targeted pain relief. An ENSD has a battery powered unit similar to it’s cousin, the pacemaker, that is placed just under the skin. This unit generates electrical impulses that travel through a wire to an electrode that is implanted next to the offending nerve. Using a remote control, the patient can control the intensity of the stimulation and thus his pain. Where and how these electrodes were placed in Harry’s spine was the subject of a paper Dr. Winfree and his colleague Raqeeb Haque, MD published in the July, 2009 issue of the journal Neuromodulation.

They used a new technique called, Transforaminal (meaning through the tunnel on the side of the spine where the nerve comes out) Nerve root (the name for the nerve when it first comes out of the spinal cord) Stimulation. It can be tricky to implant an electrode in this area because the nerve’s exit tunnel or foramen is small and narrow and as a person gets older and the spine degenerates it gets even harder to access.

Dr. Winfree has found a clever way to sequentially use three different shaped probes to guide the electrode into the narrow space. He says it is actually faster, easier, and requires less radiation from guiding X-Rays to access the foramen from the inside out. Here is how he did it.

He started by making a small incision in the skin above the level of the spine where the troublesome nerve was located. He then cut a small segment of bone out of the back to access the spinal canal. Using a slightly curved probe, Dr. Winfree threaded the electrode down the canal and over to the side where the foramen is. Once at the foramen entrance he switched to a highly curved probe to guide the electrode around the corner and into the narrow passage. Then, he switched again to a straight probe that wouldn’t get hung up on the nerve root and pushed the electrode into place. In the end, four electrodes where placed at two levels of the spine to target both Harry’s feet.

To learn more about this case, see the July 2009 Issue of Neuromodulation and look for Dr. Winfree and Dr. Haque’s paper, Transforaminal Nerve Root Stimulation: A Technical Report.

Posted on Dec 16, 2009 by Department Author
In Blog, Peripheral Nerve, Peripheral Nerve Blog Tags: , Center for Peripheral Nerve, Center for Peripheral Nerve Surgery, Dr. Christopher J. Winfree, Dr. Raqeeb Haque, Dr. Winfree, electrical nerve stimulating device, electrode, ENSD, feet, foramen, frostbite, irritated, nerve, nerve damage, neuromodulation, numbness, Pain, Raqeeb Haque, relief, spinal cord, Spine, transforaminal nerve root stimulation, tunnel, Veteran, Winfree