Spinal Cord Stimulators: Living Pain Free
At least 100 million American adults – more than the total affected by heart disease, cancer, and diabetes combined – are affected by chronic pain. For those who can’t find relief with conservative therapies, implanted devices have been proven effective, but make it unsafe to receive MRI scans. That can make it difficult to diagnose future problems. Now, there is a first of its kind FDA approved device that’s changing that.
For years a simple walk with her dog Carmen was just too painful for Susan Hennen.
“On a scale of one to ten, it felt like a fourteen,” Susan told Ivanhoe.
Susan has suffered with back pain for more than two decades.
“I was depressed. I didn’t want to live a life on oxycodone,” Susan said.
She had considered an implantable spinal cord stimulator, a device similar to a pacemaker that works by interrupting pain signals to the brain. The problem was that the devices were not MRI safe, until now.
“It is a breakthrough, a significant breakthrough,” Asokumar Buvanendran, MD, Professor, Pain Medicine, Anesthesiology, at Rush University Medical Center, told Ivanhoe.
Dr. Buvanendran says the SureScan MRI neurostimulator has specially designed leads seen here, making it MRI safe.
It allows doctors to still diagnose the possible patient problems of tomorrow, while taking care of the pain today.
“If you’re able to get him or her back to functionality, it’s huge,” Dr. Buvanendran said.
Susan had the device implanted two weeks ago and is already feeling the difference.
“I’m really glad I did it,” Susan said.
Patients considering the device can do a trial before making it permanent. Patients wear an external neurostimulator around their waist during the week-long screening test to see what kind of relief they can expect for their chronic pain.
BACKGROUND: Most people experience back pain every now and then but often do not understand what is causing the pain. This pain can sometimes interfere with our daily lives and may interrupt plans. Common forms of back pain occur in the mid to low back and includes fractures, sore muscles and tendons and herniated discs. These injuries develop over an extended period of time, leaving patients with little relief. (Source: http://www.webmd.com/back-pain/guide/understanding-back-pain-basics)
CAUSES: Back pain cultivates from our own individual bad habits. Intense physical activity, poor posture, and sitting incorrectly are all self-inflecting factors that cause our backs to give us a painful and uncomfortable feeling. Generally, back pain exists in the lower part of a person’s back, but may sometimes appear at the neck. Sometimes there is not a specific reason why back pain occurs. This may happen when simple motor movements such as walking, stretching and bending become more difficult. Chronic back pain is a constant ache caused from muscle tension. This condition is called myofascial and stems from emotional issues or stress. (Source: http://www.webmd.com/back-pain/guide/understanding-back-pain-basics)
TREATMENT: A change of physical activity is one of the most common treatments for back pain. Because back pain can be so broad, it is hard for doctors to diagnose a patient immediately. Heating pads, ice packs and pain medication are all helpful in aiding back pain, but frequent trips to your chiropractor for weekly adjustments may help as well. If back pain is more serious, surgery may be necessary along with cortisone injections. (Source: http://www.mayoclinic.com/health/back-pain/DS00171/DSECTION=treatments-and-drugs)
NEW TECHNOLOGY: An implantable spinal cord stimulator is a mechanism comparable to a pacemaker. The stimulator transmits electrical pulses to the spine through a pulse generator. The pulses hinder the nerve impulses that cause pain in the lower back. This is an outpatient procedure done through local anesthesia. A trial procedure is done first to determine how successful the implant will be. Then a second procedure is done to implant a permanent stimulator. When the surgery is finished, it is expected that the stimulation will be used several times a day depending on the patient’s pain level. (Source: http://www.webmd.com/back-pain/spinal-cord-stimulation-for-low-back-pain)
Asokumar Buvanendran, MD, Professor, Pain Medicine, Anesthesiology, Rush University Medical Center, talks about a new treatment for chronic back pain.
First, can we talk about the problem with chronic back pain?
Dr. Buvanendran: Chronic back pain is probably one of the common disease states in the U.S. It spans from the middle age population to the elderly and as patients live longer, you have an increase in patient population with chronic back pain. So, back pain apart from it being debilitating, is probably also one of the most common causes why patients don’t go to work in the age. In fact, it is probably the fourth largest cause of pain and disability.
What are the treatments that have been for the most severe pain?
Dr. Buvanendran: Initially, many patients do have back pain. So, 90 percent of patients respond to simple medications and physical therapy. By six or eight weeks, several of them get better and can return to functionality. Then, it is this certain proportion of patients that have persistent pain after the initial back pain that would require conservative therapy. Some of them would have injections and obviously with some medications, such as nonsteroidal anti-inflammatory drugs, muscle relaxants in patients that do not respond to conservative treatment may end up having surgery.
Now, you implant a pain blocking device into the back?
Dr. Buvanendran: Typically, patients would have gone through the series of normal processes of injections, muscle treatment, muscle relaxants, physical therapy for 6 months before they end up in surgery. Though patients do get better after surgery of the spine, there are still a lot of patients that do not get better and these patients persist on and with chronic back pain and especially patients who have had back surgery have demonstrated that if you are able to put spinal cord stimulator in them, or neuromodulation techniques, these patients could actually get better and return to functionality. Studies have demonstrated that it is better to do a spinal cord stimulator versus having a reoperation in terms of outcomes.
What is the new SureScan stimulator?
Dr. Buvanendran: Well, the first one that comes out with a MRI compatible electrodes and IPG battery is of significant benefit. As I said at the beginning, the chronic pain patients spend a lifetime from middle age to elderly patients and the ability to do an MRI with a spinal cord stimulator is a significant benefit as there are certain patient populations, these patients obviously have back pain and one of the tools used to diagnose back pain is MRI. So, implanting a neurostimulator in these patients actually prohibits them from having MRI, but now with the ability of an MRI compatible electrodes and a battery, IPG battery, these patients could have the MRI to diagnose have another back pain injury of if they have another problem in the cervical spine. As you probably know, patients who have back pain may also have neck pain. The ease of diagnosis of neck pain again is you could do MRIs. There is a whole host of other conditions, such as multiple sclerosis, who have pain. We have seen several of them in our clinic and they are good candidates for spinal cord stimulation prior to this. However, we never implant them because these patients would require MRI frequently and therefore implanting a spinal cord stimulator in them would not be ideal. Another group of patients is cancer patients with chronic pain. Because they would need MRI scans in their future lifetime, if you implant a spinal cord stimulator then you would need to explant it if they needed an MRI for their diagnosis. So, I think it is essential that if having an MRI compatible electrodes and a battery would make that ease in this particular group of patients.
So, the problem with the former generations of the neurostimulators is the fact that you would actually have to go back in and risk, with more surgery to remove it get the MRI, right?
Dr. Buvanendran: Correct, every time a patient needed an MRI, and in our practice ordering MRIs is pretty common. MRIs are done in large quantities by these various specialities, so even though we treat patients when they go out to their individual physicians, they all want to do MRI and MRI is not possible and they have to resort to other modalities of image technology to diagnose the medical condition. If you think of cancer patients and you need an MRI to diagnose a metastases or a screening and even for back pain patients who have recurrent pain; the only way you can diagnose them is another MRI.
How does neurostimulation work?
Dr. Buvanendran: In a simplistic term, normally pain goes from the pain site to the spinal cord from the knee, the hip to the spine, to the brain where pain is actually perceived and modulated and there also is something called a descending pathways from the brain down to the spine to the area where the pain is perceived. So, the ability to interrupt this pathway from the origin of the pain, via the spine to the brain, is essentially the reason why the spinal cord stimulator works. That is in a simplistic fashion the advantage of having a spinal cord stimulator in these patients because of this interruption of the pain pathways and therefore there is no tissue destruction. We are not removing a bone, we are not removing a disc, we are not removing a pathology any part of the body, or essentially interrupting the pain pathways cycle and this is also used for various other conditions, not just back pain, but cancer pain; there a whole host of other disease conditions called neuropathic pain and even in peripheral vascular diseases, spinal cord stimulators are utilized.
How exactly does it work in the body once it is implanted?
Dr. Buvanendran: So, essentially, it sends electrical impulses from a battery source connected to the electrode and there are 8 contact points in these electrodes; there is a positive and a negative and by sending slight impulses to the spinal cord, it is able to interrupt the pathway in the pain site, pain pathways in the spinal cord. So, the battery controls the electrodes and the patient controls the battery.
How big of a breakthrough would you say this is, in the medical community?
Dr. Buvanendran: The breakthrough in the MRI compatible electrodes, I think is a significant benefit because there is patient populations that we do not use this because of the need for MRI. In those patients, this is a significant benefit. So it is a breakthrough, significant breakthrough.
Are there any negative side effects?
Dr. Buvanendran: Of course, everything in medicine has negative side effects. So, obviously there are complications that can happen, like infection and bleeding. The leads can migrate. If you have a major accident or a major fall, the leads could migrate and that happens typically in the early part of the surgical healing process.
So, this is what actually allows it to be MRI safe?
Dr. Buvanendran: Correct, the lead is what makes it MRI compatible.
FOR MORE INFORMATION, PLEASE CONTACT:
Associate Director, Media Relations
Rush University Medical Center
Copyright 2013 by Ivanhoe Broadcast News. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.