Neuropathic Pain Relief - It's Electric!

Neuropathic pain eased in two thirds of patients who received deep brain stimulation

(RxWiki News) Scientists have considered deep brain stimulation (DBS) a possible treatment for a hard-to-treat type of nerve pain. In the past, the cost and invasive nature of DBS have made it difficult to conduct medical trials.

A small study has looked at the long-term effectiveness of DBS to treat neuropathic pain, a common type of pain caused by nerve damage.

The study showed that DBS can lead to long-term pain relief for those living with difficult-to-treat neuropathic pain.

About two-thirds of patients who received DBS for neuropathic pain experienced pain relief after the first year.

"Discuss pain treatment options with your doctor."

Sandra G. J. Boccard, PhD, of the University of Oxford, and colleagues studied 197 patients with chronic neuropathic pain. Eighty-five of the study participants received temporary deep brain stimulators to determine if DBS was a good treatment for them; the remainder did not.

DBS is a treatment in which a medical device is implanted in the brain. The medical device, or brain pacemaker, sends electrical impulses to specific parts of the brain in order to change electrical activity in a controlled manner.

DBS has proven to work for movement disorders like Parkinson’s disease and various types of chronic pain. Its role in treating neuropathic pain is less clear.

Neuropathic pain is often seen in patients with trauma, diabetes and amputations. The most common cause of neuropathic pain among the study participants was stroke, followed by head and face pain, spinal disease, amputation and upper spinal cord injury to nerves.

The study participants were monitored for a week to see if they were good candidates for permanent implantation of an electric pulse generator. Of the 85 patients, 74 had enough pain relief with the temporary electrode to warrant a more permanent implantation.

The patients had follow-up appointments at five weeks, three months, six months and then yearly thereafter. Study participants could turn the stimulation on or off and modify the amount of voltage.

Pain and health quality of life were assessed before and after surgery. 

The patients were given a pain diary in which they documented pain levels on a 0-10 scale and corresponding DBS settings twice a day. Pain was also measured using the McGill pain questionnaire, a commonly used scale for rating pain.

A 36 question quality-of-life survey was used to measure quality of life. The questions measure ability to perform physical activities, ability to perform work activities physically and emotionally, bodily pain, general health, vitality, social functioning and mental health.

The EuroQol-5D questionnaire was also used to measure health quality of life. This questionnaire evaluates mobility, self-care, usual activities, pain and anxiety.

Positive results were seen in 66 percent of patients that underwent permanent DBS.

Patients with certain conditions had higher success rates than others. The treatment was beneficial in 89 percent of the study’s amputation patients, 70 percent of stroke patients and 50 percent of upper spinal cord injury.

On average, pain was reduced from eight to four on a ten point pain scale within the first three months and remained about the same for follow-up. A small number of patients continued to see improvement after three months.

While DBS is used in the UK to treat neuropathic pain, it is yet to be approved for use in the United States. The authors encouraged more clinical trials to better understand DBS treatment for neuropathic pain.

The study was published in Neurosurgery. The authors received support from the Norman Collisson Foundation, Oxford NIHR, BRC, UK MRC, Charles Wolfson Charitable Trust and EPSRC. The authors specify that they have no financial ties to drugs, materials or devices used in the study.

Review Date: 
February 20, 2013