A new treatment option for diabetic peripheral neuropathy
A treatment traditionally used to treat pain caused by post-surgical chronic back or neck pain and other spinal pain issues has now been approved for patients suffering from another chronic pain condition: diabetic peripheral neuropathy.
Recent FDA approval of the treatment, known as spinal cord stimulation, means a large group of patients who experience debilitating pain from their condition can find relief. Chronic foot pain from diabetic peripheral neuropathy eventually affects 50 percent of people with diabetes and about 37.3 million people in the United States have diabetes, according to the CDC.
Spinal cord stimulation is a proven long-term, opioid-free therapy for managing chronic pain by disrupting pain signals between the spinal cord and the brain. It has been used for some time to treat post-laminectomy syndrome (chronic back or neck pain following surgery), arachnoiditis (inflammation of one of the membranes that surround and protect the nerve of the spine) or complex regional pain syndrome (hyperactivity of the peripheral nerves in some ongoing pain situations).
“In the early 2000s, it worked for some diabetic patients and then others found the stimulation to be a little bit more of an annoyance,” said pain specialist Kevin Kelly, MD, at the Cape Cod Hospital Pain Center in Hyannis. “As the technology and the capabilities in terms of the types of signals that we can send has advanced, we’ve been able to change that. The improvements are not only in (the help with) pain, but also quality of life, sleep and activity levels have seen improvements as a result.”
How it Works
The exact mechanism of how spinal cord stimulation works is not entirely known, Dr. Kelly said, but one of the components is something known as the “gate control theory” where you are sending two competing signals to the brain which then makes the brain perceive the pain as less. He compared it to when you hurt yourself and then rub the injured area. The rubbing doesn’t have any particular healing properties, but sending that other touch signal to the brain makes it perceive the injury as less painful.
Some of the healing nerve cells also show improved function after treatment, and there are also changes in the perceptive part of pain in the brain that modulate pain.
“It has an opioid-sparing effect for patients, but also a medication-sparing effect,” Dr. Kelly said. “Because some of the therapies that are traditionally used for neuropathy aren’t tolerated well or we can’t get an effective enough dose for those therapies to work because of side effects.”
Who’s a Candidate?
Patients who qualify for spinal cord stimulation are those who have failed more conservative treatments, like getting blood sugars under control, using oral medications like gabapentin, Lyrica, Cymbalta and Elavil, and increasing activity levels to keep the blood flowing to the peripheries, Dr. Kelly said.
“There is a trial procedure for spinal cord stimulation first before anything is done,” he said. “The trial procedure can last anywhere from five to 10 days, where a temporary device is placed, just like an epidural for childbirth. It goes into the same space and it connects to an external battery pack”.
Patients then go home with certain activity limitations. They can’t get the electrical components of the battery wet. They should also avoid doing too much bending or lifting because the leads are just taped to the skin. Afterwards, Dr. Kelly assesses pain scores during the trial. He also wants to know if patients notice an improvement in functioning and sleep, which tend to be quality of life factors for neuropathy patients.
“If we see at least a 50 percent improvement within those parameters then we would implant a permanent system and what powers the system is a pacemaker-type battery that sits under the skin in the lower back or buttock region,” Dr. Kelly said. “They make both rechargeable and non-rechargeable batteries and typically the batteries will last between five to 10 years, depending on which type of system is used and how much stimulation the patient requires.”
The Procedure and Follow-Up
The surgical implant is an outpatient procedure that takes from one to two hours. Dr. Kelly follows up with patients 10 days after the surgery and again at the six-week mark. During those follow-up visits, he can fine-tune the device so it automatically adjusts for position changes such as sitting, standing or laying down. At that point, Dr. Kelly encourages a progression in activity either with physical therapy or a home exercise program.
Patients come back for additional follow-up visits at four-and-a-half months after surgery and again at the one-year point. After that, they don’t need to come back until it is time to change the battery five to 10 years later.
