Intrathecal Medication Therapy Effective for Painful Post-Herpetic Neuralgia Caused by Shingles

Every year, 200,000 patients in the United States develop shingles, for which there is no cure. Shingles (herpes zoster) is a viral infection that causes a painful rash. It often appears as a band of blisters that typically affects the trunk/torso. Other parts of the body may be involved such as the neck, face, scalp or limbs. The pain from shingles can be excruciating, and the cause might not be immediately evident. The virus lies inactive in all persons who have been infected with chickenpox, and decades later, the virus can reappear as shingles. While some patients have mild cases and recover fully, other patients suffer from post-herpetic neuralgia, a painful syndrome that often cannot be adequately treated with pain-relieving medications.

Post-herpetic neuralgia causes the skin to remain painful and ultrasensitive for months or even years after the rash has resolved. The current treatment for this painful syndrome is oral medication. However, 15 percent of shingles patients, including those on oral medications, continue to have severe pain a full year after having the shingles virus. Further, high doses of oral narcotics are often necessary to control the pain experienced by people with this condition. This may lead to side effects, such as sleepiness, which can negatively affect quality of life.

Researchers at University at Buffalo investigated the use of a surgical pump to deliver medication to patients with post-herpetic neuralgia.

The results of this study, Treatment of Post-Herpetic Neuralgia with Intrathecal Narcotic Administration, will be presented by Andrew J. Fabiano, MD, 3:57 to 4:08 pm, Tuesday, May 5, 2009, during the 77th Annual Meeting of the American Association of Neurological Surgeons in San Diego. Co-authors are Carolyn Doyle, FNP, and Robert J. Plunkett, MD.

A proven technique for delivering medications directly to the spinal sac is through the surgical implantation of a mechanical pump. Typically, the pump sits under the skin in the abdomen and has a small tube that goes into the spinal sac. Medications travel from the pump, through the tube, and enter the spinal fluid that surrounds the spinal cord and peripheral nerves. This type of system is used to deliver medications in many conditions including multiple sclerosis and chronic back pain. “By delivering medications directly to the spinal sac, smaller doses can be used, and many systemic side effects (such as sleepiness) can be avoided,” stated Dr. Fabiano.

In this study, five patients with shingles were treated over a 7-year period. All patients continued to have severe pain even after taking oral medications. Each patient had a drug delivery pump implanted surgically and had narcotic medications delivered directly to his or her spinal sac.

•The mean patient age was 75.

•Four patients were male and one was female.

•Each patient underwent a successful trial of either epidural or intrathecal narcotics prior to pump implantation.