Spinal cord stimulation reduces pain and improves function in people with prosthetic legs

FRIDAY, Dec. 15, 2023 (HealthDay News) — People who have lost a leg due to injury or illness often experience what is known as phantom limb pain, which is discomfort that arises in the area, despite the absence of the limb.

Now, researchers report that people using a prosthetic limb after an amputation can relieve that pain, as well as improve sensation in their new feet, using spinal cord stimulation.

“We are using electrodes and stimulation devices that are already commonly used in the clinic and that doctors know how to implant,” said the study’s lead author, Lee Fisher, from the University of Pittsburgh. “We are taking advantage of these technologies to significantly improve function and reduce pain. This is exciting and we have been building on that for a while.”

This technology involves special pressure sensors that are placed in the foot of the prosthesis. These sensors activate signals that are sent to a person’s spinal cord. The research team said this technology appears to relieve pain and help users walk better.

If proven successful, the spinal stimulation technique could help a wide range of people facing amputation: those who have had their leg amputated due to trauma, as well as those who have fallen victim to nerve damage caused by advanced diabetes.

“We are able to produce sensations as long as the spinal cord is intact,” said Fisher, associate professor of physical medicine and rehabilitation at Pitt. “Our approach has the potential to become an important intervention for lower limb amputations.”

According to supporting information provided in a Pitt press release, more than 1.5 million Americans now live with a lower limb amputation. About eight in 10 say they experience phantom limb pain in their missing leg and/or foot. Most of this pain does not respond to medications.

In addition, many prosthetics do not include the type of sensory feedback function used by Fisher’s group. This makes balance more difficult when wearing a prosthesis.

The new technology essentially replaces the broken connections between the spinal cord and foot with new spinal cord stimulation technology.

“A pair of thin electrode strands implanted over the top of the spinal cord in the lower back were connected to a cell phone-sized stimulation device that delivered electrical pulses of varying amplitude and frequency,” the researchers said.

Using this technology, Fisher’s team was able to help study participants walk or stand in real time over the course of the three-month study.

The participants appeared to make real improvements in balance control, Fisher’s team reported in the December 14 issue of Nature Biomedical Engineering. This was true even under difficult conditions, for example, standing with eyes closed on an unstable moving platform.

As an added benefit, participants also reported an average 70% reduction in phantom limb pain.

How long until patients around the world can benefit? According to Fisher, with “the right support from industry partners, [esto podría] Translate to the clinic in the next five years.

Researchers from Carnegie Mellon University and the University of Chicago collaborated on this research.

more information

Learn more about phantom limb pain at Cleveland Clinic.

Source: University of Pittsburgh, press release, December 14, 2023