according to research that released early, prior to its presentation at the annual meeting of the American Academy of Neurology.
The data represents the longest follow-up available for spinal cord stimulation at a frequency higher than the 60 Hz initially approved for diabetic neuropathy by the Food and Drug Administration, according to lead author Erika A. Petersen, MD, a professor of neurosurgery and the residency program director at the University of Arkansas for Medical Sciences, Little Rock.
University of Arkansas
Dr. Erika A. Petersen
“You would expect that somebody who continues to have diabetes for 24 months and has neuropathy would have worse neuropathy after 2 years, and what we’re seeing is that people were stable or better in terms of their nerve function at 2 years,” Dr. Petersen said in an interview. “So that’s really revolutionary.”
Encouraging preliminary findings
The findings are “promising and preliminary,” John D. Markman, MD, a professor in neurology and neurosurgery, vice chair for clinical research, and director of the Translational Pain Research Program at the University of Rochester (N.Y.) Medical Center, said in an interview. Dr. Markman, who was not involved in this study, said that, though the results are encouraging, it’s “less clear how much of [the pain improvement] is due to what we would consider to be on-target, pain-relieving benefit from stimulation versus other factors like expectation.” The crossover rate and amount of reduction in pain intensity are promising, but “I think that excitement is weighed against the fact that this is an open-label study.”
An underused treatment
Although spinal cord stimulation has been around since the late 1960s, its use only picked up steam in the 2000s, when it became more frequently used to treat chronic nerve damage related to neuropathic pain syndromes, Dr. Petersen explained. The FDA approved the treatment’s new indication for diabetic neuropathy in 2015, and data from Abbott and Medtronic have shown benefits from spinal cord stimulation at 60 Hz, but some patients are uncomfortable with the vibration or tingling feelings the devices can cause at that frequency.
“They describe creepy crawlies or ants crawling over the feet, or pins and needles, and painful sensitivity,” Dr. Petersen said. “You create a vibration feeling in the same zone where they already have those feelings of buzzing and pain and vibration, and it’s sometimes actually even more uncomfortable and less satisfying to them in terms of relief” with the spinal cord stimulation at 60 Hz, she said, “so there’s a lot of attrition in terms of who will actually use it.”
At 10 kHz, however, “people don’t feel any vibration or tingling associated with it; it just jams the signal of the pain,” she said. The difference between the frequencies is like that between “a lifeguard whistle and a dog whistle.”