Spinal Stimulation May Best 'Medicine' for Intractable Spine, Limb Pain

By Marilynn Larkin

July 25, 2019

NEW YORK (Reuters Health) - In patients with intractable spine and limb pain, spinal stimulation (SS), particularly with newer technologies, was associated with better pain relief than medical therapy, a systematic review and meta-analysis reveals.

"Conservative therapy such as pain medications often does not provide sufficient pain and/or functional improvement," Dr. Tim Lamer of Mayo Clinic in Rochester, Minnesota, told Reuters Health by email. "We confined our final analysis to only...randomized controlled trials (and) our study demonstrated that SS was more effective than medical therapy in reducing pain in patients with intractable spine and limb pain from many different causes."

"These findings are consistent with my clinical experience," he added. "In my 30 years of treating patients with chronic painful conditions, only about 50% of patients respond adequately to medical therapy."

Dr. Lamer and colleagues searched the literature from 1995 through 2017 to synthesize the evidence on SS versus medical therapy and the impact of newer SS technologies on pain reduction.

As reported online July 3 in Mayo Clinic Proceedings, 12 trials involving 980 patients were included. Compared with medical therapy, SS significantly increased the odds of pain reduction by 50% or more in three trials (OR, 13.01) and significantly reduced pain as measured by visual analogue scale scores in three trials (weighted mean difference, 1.43 scale points).

Further, newer stimulation technology, such as high-frequency 10 kilohertz spinal stimulation, Burst, and dorsal root ganglion, was associated with increased odds of pain relief compared with conventional SS (OR, 2.07).

"The number one barrier is lack of clinician and patient awareness of this therapy and...of its effectiveness," Dr. Lamer said. "Thus, many patients who could benefit from this treatment are not referred to a pain specialist."

Further, he noted, while studies have shown SS to be cost-effective compared with medical therapy, "many payers have significant limitations and restrictions regarding reimbursement such that many patients who could benefit cannot get the treatment."

Dr. Jenna Walters, Associate Chronic Pain Fellowship Director at Vanderbilt University Medical Center in Nashville, Tennessee, commented by email, "The findings of this study are absolutely consistent with my clinical experience."

"With appropriate patient selection, I have seen better and longer pain relief with the new stimulator programming options," she told Reuters Health. "I have also had success with helping wean or discontinue opioids after implantation of a stimulator to improve pain control for my patients."

"Ultimately, this therapy is another promising option for patients to improve their quality of life and get back to doing the things they love rather than feeling dependent on medications."

Like Dr. Lamer, she noted that insurance coverage is a big barrier. "We can't offer this therapy, even if we think it might be helpful, if it isn't covered by insurance," she said.

Dr. Zeeshan Sardar, a spine surgeon at the NewYork-Presbyterian Och Spine Hospital in New York City, told Reuters Health, "There is a definite role for SS in a select number of patients with non-compressive neuropathic pain without significant weakness. One must be careful in trying to generalize these findings, as SS has not really been reported to improve back pain and has not been shown to have a high rate of success in improving symptoms."

The placebo effect should also be considered, he said by email, "especially in studies with short-term follow up. Even though patients were randomly assigned to get medical treatment or SS, it is not possible to remove the inherent bias, since patients undergoing surgery for placement of a spinal stimulator cannot ignore the fact that they had surgery."

"As we know from other studies in the literature, people who are made to believe that they received surgery, even if they didn't, can see improvement in their symptoms due to the power of the placebo effect," he said.

Further, the authors reported moderate potential of bias because most studies were funded by companies that produce spinal stimulators.

"The key is to identify patients that are most likely to benefit from these stimulators," he stressed. "Patients with back pain as a major complaint, those with leg weakness from nerve compression, or those with spinal instability, tumors, or fractures are not good candidates... whereas patients with neuropathic leg pain may be better suited to undergo a spinal stimulator procedure."

SOURCE: https://mayocl.in/2SAU0yv

Mayo Clin Proc 2019.