High frequency stimulation eases back pain
Wednesday 6 February 2013
A new device helps reduce severe back and leg pain, significantly improving patients’ quality of life, according to research from the pain management and neuromodulation centre at Guy’s and St Thomas’ NHS Foundation Trust.
The technology is a new type of spinal cord stimulation, where small leads implanted near the spinal cord send high frequency electrical pulses. This disrupts pain signals to the brain, reducing constant, severe back and leg pain.
The technique expands on the existing approach, where frequencies of around 50Hz are used to stimulate the spinal cord. “The existing device causes tingling, like pins and needles. Some people find the sensation unbearable - worse than their back pain,” says Dr Adnan Al-Kaisy, Clinical Lead in Pain Management, who led the study.
“This technique uses much higher frequencies of up to 10,000Hz which can’t be felt. It also relieves back pain more effectively than conventional low frequency stimulation,” Dr Al-Kaisy added.
The researchers collaborated with Belgian hospital AZ Nikolaas, testing the device in 83 patients*. At the start of the trial, patients gave their back pain a score of 8.4 out of ten on average, with ten being the worst pain imaginable. After six months the average score was dramatically reduced to 2.7 out of ten. Most patients reported more than a 50 per cent reduction in their pain.
"These kinds of results are almost unheard of,” says Dr Thomas Smith, consultant in pain medicine. “Back pain can be debilitating, so being able to relieve people of constant pain makes a big difference to their lives.”
Charles Holleyman, 62, had the spinal cord leads fitted two years ago, after back surgery failed to relieve his pain. “For me, the implant’s been a huge success,” says Charles. “I’m getting much more sleep and I’m no longer on any regular pain medication.”
Charles is a visiting lecturer at the University of Hertfordshire, where he teaches a law course to social workers. “Prior to the implant the crippling pain was affecting my working life - I am registered disabled,” says Charles. “But now I’ve had the implant, my students can’t tell I’m disabled.”
However, this procedure is not suitable for everyone. “Before patients can have the full implant, they must have a psychological assessment, be physically and mentally suitable, and have a successful two-week trial,” says Dr Smith.
“The technology isn’t perfect,” says Charles. “You have to adapt to it and recognise its limitations, but it’s a big improvement.”
Charles now has a more active social life and an improved family life. “When you’re in constant pain, you’re bad-tempered and not yourself. My kids have noticed the difference and my wife’s happier.”
One in 15 of adults in the UK consult their GP because of back pain each year. High frequency stimulation is now being tested in patients as an alternative to back surgery.
The study was published in the journal Neuromodulation today.
*The trial results are based on 82 patients, as one patient did not attend follow-up assessments.
Last updated: February 2013