Doctor, I have peripheral neuropathic pain that isn't improving with other treatments. Would a peripheral nerve stimulator reduce my pain?

For people with chronic peripheral neuropathic pain who have not improved after trying usual treatments, a peripheral nerve stimulator inserted under the skin may reduce pain.

What is the evidence?

SUMMARY OF FINDINGS

Peripheral nerve stimulator vs usual medical management

Outcome at 3 months	Peripheral Nerve Stimulator* (no. of people)	Medical Management (no. of people)	Effect
Percent of people who had at least 50% reduction in pain	84% (36/43)	3% (1/29)	About 81 more people out of 100 had at least 50% reduction in pain with the peripheral nerve stimulator compared to people without one
Percent pain relief	67%	6%	People with the peripheral nerve stimulator reported a higher percentage of pain relief (on average) compared to people without one
Percent of people with at least 80% reduction in pain	30%	3%	About 27 more people out of 100 had at least 80% reduction in pain with the peripheral nerve stimulator compared to people without one

Outcome at 3 months

Peripheral Nerve Stimulator*

(no. of people)

Medical Management

(no. of people)

Effect

Percent of people who had at least 50% reduction in pain

84%

(36/43)

(1/29)

About 81 more people out of 100 had at least 50% reduction in pain with the peripheral nerve stimulator compared to people without one

Percent pain relief

67%

People with the peripheral nerve stimulator reported a higher percentage of pain relief (on average) compared to people without one

Percent of people with at least 80% reduction in pain

30%

About 27 more people out of 100 had at least 80% reduction in pain with the peripheral nerve stimulator compared to people without one

*people had to experience at least 50% improvement in pain during a trial period with a temporary peripheral nerve stimulator to be allowed to continue in the trial and have a permanent peripheral nerve stimulator inserted (5 out of 57 people did not meet this goal)

What kind of study was this?

This was a randomized controlled trial (RCT).

Who? This study included 89 adults (average age 57 years; 70% female) who had peripheral neuropathic pain in their lower back, shoulder, knee, foot or ankle for at least 6 months and had not responded to usual treatments (which could include oral medications, physical therapy, nerve blocks, epidural injections, and others). People with peripheral nerve pain due to shingles or complex regional pain syndrome or taking 90 mg or more of morphine per day were excluded.

What? The study compared using a peripheral nerve stimulator with usual medical management.

Peripheral Nerve Stimulator	vs	Usual Medical Management
Peripheral Nerve Stimulator = small device known as a micro-implantable pulse generator inserted under the skin together with wires that deliver electrical pulses to block pain signals from travelling from the peripheral nerve to the brain. It is powered by a small battery attached to the skin over top of the stimulator using a type of medical glue. A temporary peripheral nerve stimulator was used to test that the participant experienced at least a 50% reduction in pain when using the device. If this goal was achieved, a permanent device was inserted under the skin. People were allowed to continue oral medications for treatment of their pain during the study.		People continued usual treatments for chronic peripheral nerve pain including oral medications, physical therapy, nerve blocks, epidural injections and others. After 3 months, people in this group were allowed to crossover to the Peripheral Nerve Stimulator group.

Peripheral Nerve Stimulator

Usual Medical Management

Peripheral Nerve Stimulator = small device known as a micro-implantable pulse generator inserted under the skin together with wires that deliver electrical pulses to block pain signals from travelling from the peripheral nerve to the brain. It is powered by a small battery attached to the skin over top of the stimulator using a type of medical glue.

A temporary peripheral nerve stimulator was used to test that the participant experienced at least a 50% reduction in pain when using the device. If this goal was achieved, a permanent device was inserted under the skin.

People were allowed to continue oral medications for treatment of their pain during the study.

People continued usual treatments for chronic peripheral nerve pain including oral medications, physical therapy, nerve blocks, epidural injections and others.

After 3 months, people in this group were allowed to crossover to the Peripheral Nerve Stimulator group.

Why was this research done?

Peripheral nerve stimulators generate electrical pulses that interrupt the pain messages flowing from the peripheral nerve to the brain. Researchers in this study wanted to know if a particular peripheral nerve stimulator was effective at reducing chronic peripheral nerve pain in people who had not improved with usual treatments. They found that people who had a permanent peripheral nerve stimulator inserted were more likely to experience at least 50% reduction in pain compared to people who continued usual treatments at 3 months.

Currently, peripheral nerve stimulators are only offered to people who have not improved with less invasive treatments. There is the potential for complications with these devices including breakage of the wires or either the device or the wires moving out of position. Some people may also experience pain in the skin pocket where the stimulator is implanted. One concern about this study is that more people in the peripheral nerve stimulator group have withdrawn from the study than people in the usual medication group for reasons that have not been explained. This study is ongoing so more data on how well the peripheral nerve stimulator works and how safe it is over longer periods of time will be reported in the future.

This Evidence Summary is based on the following article:

Hatheway J, Hersel A, Song J, et al. Clinical study of a micro-implantable pulse generator for the treatment of peripheral neuropathic pain: 3-month and 6-month results from the COMFORT-randomised controlled trial. Reg Anesth Pain Med. 2024 May 31:rapm-2023-105264. doi: 10.1136/rapm-2023-105264. PubMed

Published: Thursday, September 5, 2024

Please note that the information contained herein is not to be interpreted as an alternative to medical advice from a professional healthcare provider. If you have any questions about any medical matter, you should consult your professional healthcare providers, and should never delay seeking medical advice, disregard medical advice or discontinue medication based on information provided here.

This Evidence Summary was printed from the PAIN+ CPN website on 2024/12/21.

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