Neurostimulation.305145613.pdf 1 8/11/12 11:32 PM Neurostimulation Neurostimulation, also called electrostimulation, uses low-level electrical impulses to interfere with pain signals or block them from reaching the brain. Neurostimulation has the potential to replace painful sensations with a tingling or massaging sensation. Neurostimulation is used to treat certain chronic pain conditions that are caused by damage to the nervous system or by abnormal processes of the nervous system. This type of pain is called neuropathic pain, and is often felt as an intense burning or stabbing. Neurostimulation is not effective in treating pain from surgery, stomachache, or tissue injury. It is most effective in relieving persistent or severe pain of the limbs and/or trunk. Neurostimulation delivers very small amounts of electricity directly to selected nerves. This is done by using a small, surgically implanted device called a neurostimulator. There are two types of neurostimulators: Spinal cord stimulators use electrodes placed in the space surrounding the spinal cord (epidural space). Peripheral nerve stimulators use electrodes placed directly over nerves located outside the central nervous system (spinal cord and brain). The neurostimulator that may be right for you depends on many factors, including the cause of your pain or neurologic disorder, as well as its type and location. Your health care provider may recommend neurostimulation if you are not able to control pain using more conservative pain therapies such as physical therapy, nerve blocks, and oral pain medications, or if you have intolerable side effects from oral pain medications. Neurostimulation may offer an alternative to surgery for chronic pain conditions and may decrease the need for pain medications. This information is intended to help you understand how neurostimulation works and what to expect if you are a candidate for neurostimulation. If you have questions about this information, talk to a member of your health care team. How Does Neurostimulation Work? Receptors in your skin and other tissues send impulses through the nerves and up the spinal cord to the brain, where pain is perceived. The sensation of pain is registered in the brain, not at the point of injury. Neurostimulation uses electrical impulses to block or override pain impulses before they reach the brain. These electrical impulses have the potential to produce a tingling sensation and can be directed to the sites where you feel pain.
Neurostimulation.305145613.pdf 1 8/11/12 11:32 PM Neurostimulation does not eliminate the source of pain, but it may provide significant relief from certain types of pain, particularly when used with other therapies, such as physical therapy or oral pain medications. A neurostimulator consists of a small device, called a generator, that is surgically placed under the skin (figure 1). This device consists of a battery and related electronics which, when turned on, send mild electrical impulses to the spinal cord or to a peripheral nerve. The electrical impulses are delivered through leads (special medical wires) that are also surgically placed (figure 1). These impulses block pain signals from reaching the brain and replace pain sensation with a sensation most people describe as tingling. The medical term for this sensation is paresthesia. A neurostimulator allows you to control the intensity and frequency of the electrical impulses you receive. You control the implanted stimulator with a wireless handheld programmer that works much like a television remote. You can turn the stimulator on and off and control the intensity of the stimulation. Periodically, your health care provider may reprogram the stimulator to optimize its function. Several different neurostimulator devices are available. Ask your health care provider to discuss the details of your device before implant. The neurostimulator device is implanted under the skin in a place that is easy to reach and close to the site to be stimulated (e.g., the abdomen, above the buttocks, in the upper chest) (figure 2). With spinal cord stimulation, the leads are placed over the spinal cord (into the epidural space surrounding the spinal cord). Peripheral nerve stimulation is similar to spinal cord stimulation, and the treatments are believed to work similarly. The difference with peripheral nerve stimulation is that electrodes are used to stimulate nerves outside the central nervous system (typically in the limbs), whereas spinal cord stimulation targets nerves within the spinal cord.
Neurostimulation.305145613.pdf 1 8/11/12 11:32 PM Who Is a Candidate for a Neurostimulator? Spinal cord stimulation If your health care provider thinks you may benefit from spinal cord stimulation, you will undergo a trial screening. The purpose of the trial is to determine how well neurostimulation reduces your pain. Before the trial, you will have a brief psychological evaluation. During the trial, which may last from one to 10 days, a temporary screening device provides stimulation through one or two implanted leads. The trial screening device is worn outside the body. One or two leads are placed through the skin in the epidural space surrounding your spinal cord using a small needle or through a small incision. This is usually done on an outpatient basis, and the procedure is done in an operating room. Your surgeon will use fluoroscopy to guide lead placement. Intravenous (IV) medication is given to ease discomfort. A local anesthetic is given to numb the area where the leads are inserted. You will be asked questions when the trial stimulator is turned on to allow your health care team to evaluate your response to the device. The placement of the leads is determined by the location of your pain. The trial screening device looks like a typical remote control for a television or stereo. The implanted leads are connected to cables that plug into the screening device. By pressing buttons on the device, you can control the amount of stimulation you feel by adjusting the amplitude (intensity) or rate of stimulation. Your health care provider will give you guidelines for controlling the amount of stimulation you receive via the screening device. You will monitor your response to the stimulation by keeping a pain diary as instructed by your health care provider.
Neurostimulation.305145613.pdf 1 8/11/12 11:33 PM Follow your health care provider s instructions for operating the trial screening device as well as instructions for caring for the device. Be careful not to drop the device or immerse it in water. If stimulation becomes uncomfortable, you can always turn off the device. If this occurs, contact your health care provider. Ask your health care provider for instructions for caring for the puncture or incision site on your back. Ask about any restrictions you may have. In general: Do not lift anything over five pounds Do not lift your arms above your head Avoid bending and twisting Restrict any moderate to intense physical activity during the trial period Do not drive Restricting your movement will help to ensure the leads stay in place. Light activities such as walking may be encouraged during the trial period to test the effectiveness of the stimulator to control your pain. Wear loose, easy-to-remove clothes during the trial period. When the trial period ends, you will meet with your health care provider to assess the effectiveness of neurostimulation for treating your pain. If you decide to go ahead with permanent implantation of a spinal cord stimulation device, the leads from the trial will be removed and a surgery date for the permanent device is scheduled (see following section). If you decide that spinal cord stimulation is not right for you, the leads will be removed in your physician s office using a simple, relatively painless procedure. Peripheral nerve Stimulation For peripheral nerve stimulation, a trial screening is not done. If your physician determines that you may benefit from this type of neurostimulation, a peripheral nerve stimulator is implanted (see below).
Neurostimulation.305145613.pdf 1 8/11/12 11:33 PM Surgical Placement of a Neurostimulator The surgical procedure to implant the neurostimulation system may require a brief hospital stay. Implantation is typically done under sedation using IV medication, and local anesthetic is given to ease discomfort. In some cases, implantation is done using general anesthesia (medication that will put you to sleep). Before the surgery, your health care team will determine the best place to position the neurostimulator. During the procedure, your surgeon will make a small incision (approximately 8 cm or 3 inches) above the area where the neurostimulator is to be placed. Your surgeon will form a pocket under the skin that is large enough to hold the device. A second incision (approximately 8 cm) is made over the area where the ends of the leads will be placed usually above the spinal cord (figure 3). Your surgeon will use fluoroscopy to guide lead placement. One end of the lead is threaded through this incision, under the skin, and is attached to the neurostimulator. The other end of the lead is placed in the space surrounding the spinal cord. Once the leads and neurostimulator device are in place, the incisions are closed. Your neurostimulation system is turned on after implantation. The procedure usually takes one to two hours. Peripheral nerve stimulators To place a peripheral nerve stimulator, the steps match those for placement of a spinal cord stimulator except the leads are placed on a peripheral nerve, not near the spinal cord. The lead placement of a peripheral nerve stimulator is a more invasive procedure. A longer incision is typically necessary to place the leads along the peripheral nerve. Placement depends on the location of your pain. Ask your health care provider questions you may have about the placement of a peripheral nerve stimulator. Are Risks Associated With This Procedure? As with any surgical procedure, infection and bleeding at the surgical site are risks. Call your surgeon if you develop any of the following: A temperature of 100.4 degrees Fahrenheit (38 degrees Celsius) or greater Drainage, redness or warmth at the surgical sites Swelling around the surgical sites Bleeding from the surgical sites Increased pain or tenderness at the surgical sites In extremely rare cases, spinal cord injury, including paralysis or worsening pain, may occur from the placement of the leads.
Neurostimulation.305145613.pdf 1 8/11/12 11:34 PM In some cases, a spinal headache may result from an unintentional puncture of the dura (the covering of the spinal cord). If the dura is punctured, cerebrospinal fluid, which surrounds the spinal cord, may leak out of the intrathecal space, and a headache may occur. These headaches are typically not harmful and may go away on their own. In certain cases, an additional injection may be required to treat the headache. Let your health care provider know if you have headaches during the trial or after implantation. A more common risk is that a lead may break or move, which would require another surgical procedure to replace the lead. Talk with your health care provider about the possible side effects and complications associated with this surgical procedure. Preparing for Surgery Two weeks before surgery Stop taking aspirin, aspirin-containing products, and ibuprofen. These products can cause increased bleeding during surgery. Discuss any medications you are taking with your health care provider. The day before surgery Follow fasting and other instructions regarding your arrival at the hospital. Take a shower or bath the evening before your procedure. This helps decrease bacteria on your skin and may reduce your risk of infection after your procedure. You may be given additional bathing instructions. Try to get a good night s rest before your surgery. The day of surgery If you are taking blood pressure or heart medicine, take your usual medicine in the morning unless told otherwise. Take the medication with enough water to swallow comfortably. If you take asthma medications or use an inhaler, bring them with you to the hospital. What to bring to the hospital Pack loose-fitting clothes that are easy to put on and take off. A button-down shirt will allow you to dress without lifting your arms over your head, and shoes that slip on and off will help reduce bending. Do not bring large amounts of cash or jewelry to the hospital. However, while in the hospital you may wish to have enough money to buy a newspaper or other small items. When you leave the hospital, you may have to pay for medications or supplies that you need at home (you may use a credit or debit card for these purchases). You may put valuables in the hospital safe until you go home.
Neurostimulation.305145613.pdf 1 8/11/12 11:34 PM Bring a list of medications you take with you to the hospital. If you take many medications, bring the bottles with you. If you have questions about any medication you are taking, ask a member of your health care team. Your arrival at the hospital After you are admitted to the hospital and get to your hospital room, your health care provider will begin preparing you for the operating room by taking your temperature and checking your vital signs (pulse, weight and blood pressure). Ask any questions you have at this time. An intravenous (IV) line may be started before the procedure to provide fluid and medication. Before going to the operating room: You will be asked to empty your bladder. Remove all jewelry (including rings), contact lenses and nail polish. Remove your glasses or dentures. However, if you wear a hearing aid, leave it in so you can communicate with members of the team in the preparation area. You will be taken to the operating room on a cart. Your anesthesiologist may talk with you about the anesthesia that will be used during the procedure. Care Following Placement of a Neurostimulator After the implantation procedure, you are taken to the Post Anesthesia Care Unit (PACU) where you will stay about an hour before being taken to your hospital room. There will be some discomfort and tenderness where your neurostimulator and leads are implanted. Your health care provider may prescribe pain medication to relieve pain caused by surgery and antibiotics to prevent infection. If you notice any redness or swelling around the incision sites, contact a member of your health care team. Physical activity Avoid the following activities for six to eight weeks after the surgery: Do not lift more than five pounds. Do not bend or twist your torso. Avoid lifting your arms over your head. This will help to assure that the leads stay in place as the surgical site heals. Avoid vigorous exercise (weight lifting, biking, running). Before resuming vigorous exercise, discuss the activity with your health care provider. Do not drive until permitted by your physician (usually six weeks). Walking is encouraged after surgery.
Neurostimulation.305145613.pdf 1 8/11/12 11:35 PM Bathing The incision sites should remain dry for at least 72 hours after surgery. After 72 hours, you may shower. For 10 days after surgery, do not soak the incision sites (in a bathtub, for example). After showering, do not rub the incisions with the towel; instead, pat them dry. Care of the incision sites If there is crusting along an incision, you may apply a thin film of antibiotic ointment two to three times per day. This may help speed the healing process and limit the risk of infection. Occasionally, your surgeon may use either sutures (stitches) or small metal clips (staples) to close the skin. Depending on the type of skin closure method used, you may need to have your stitches or staples removed approximately 10 to 14 days after surgery. Discuss any questions you have regarding your incision sites with your health care provider. Frequently Asked Questions Once my neurostimulator is working, can I stop taking other medications? Your health care provider will give you instructions regarding any medications you are taking. Do not stop taking any medication without discussing it with your health care provider. Will medical procedures such as an MRI, X-ray, or a CT scan affect my neurostimulator? Do not have magnetic resonance imaging (MRI) if you have an implanted neurostimulator. An MRI exposes your body to strong electromagnetic fields, which may have adverse effects on your neurostimulator. If you are scheduled for an MRI (magnetic resonance imaging), talk with your health care provider about possible alternatives to this test. Diagnostic X-rays or CT scans will not affect your neurostimulator. As a precaution, ask your health care provider about potential effects on your neurostimulator before undergoing any medical procedure. Can I have a diagnostic ultrasound procedure? A diagnostic ultrasound procedure that is done to produce an image for examination is unlikely to interfere with your neurostimulator. However, therapeutic ultrasound (ultrasound used to heat up a small area of your body) may interfere with the function of your neurostimulator. Talk with your health care provider before you have any ultrasound procedure. What can cause a lead to move or break? Certain motions, such as sudden or repetitive movements that put strain on the leads, may cause a lead to dislodge. You should know where your lead is placed and be aware of what movements may affect your lead. Excessive or repetitive bending, twisting, bouncing, or stretching can dislodge or break a lead. Over time, even very small movements can cause a lead to break. Surgery may be required to repair or replace the lead.
Neurostimulation.305145613.pdf 1 8/11/12 11:35 PM Exercise and other physical activities should be approached with caution. Discuss precautions you should take to protect your lead with your health care provider. Can I drive a car when my neurostimulation system is on? Because a change in stimulation may cause you to become distracted or even lose control of your car, always turn your neurostimulator off before driving. Will my neurostimulator be visible to others? Depending on your size and shape, the location of your implanted device, and the clothes you wear, your neurostimulator may be visible as a slight bulge under your clothes. Can I travel? Yes. All modes of travel are safe for people with neurostimulators. Will my neurostimulator set off theft security detectors at airports, stores, or libraries? It might. Carry your patient identification card (detailing the type of neurostimulator you have, emergency contact information and other pertinent data), and show it to security personnel if necessary. These types of detectors will not damage your neurostimulator, but they might cause inappropriate or additional stimulation if you pass through them. This can feel like a shock. At the airport, request a manual search with a handheld wand, and ask that the wand not be held near the neurostimulator any longer than necessary. If you must pass through a screening device, turn your neurostimulator off before passing through. Approach the center of the security device and walk through normally. Will the use of a cell phone or a wireless computer affect my neurostimulator? What about a microwave? No, cell phones, computers, and other household appliances will not interfere with the operation of your device. Can I use power tools? Do not use potentially dangerous equipment unless your neurostimulator is turned off. Most power tool motors create a weak electrical field, which may interact with your neurostimulator to cause inappropriate or additional stimulation. Can I skydive? What about other activities? Skydiving is not recommended as it may cause a lead to move or break. Avoid all activities that require excessive or repetitive bending, twisting, or stretching. Talk with your health care provider about any excessive or repetitive activities that may damage your neurostimulator.
Neurostimulation.305145613.pdf 1 8/11/12 11:35 PM Follow your health care provider s instructions regarding other activities. When should I contact my health care provider? Contact your health care provider if you have questions about your implanted neurostimulation device or about this information. Word List Central nervous system -Made up of the brain and spinal cord Cerebrospinal fluid -Fluid that surrounds the spinal cord. Dura -Covering of the spinal cord and brain. Epidural space -Space surrounding the spinal cord. Fluoroscopy -Use of X-rays to see motion, as opposed to still X-ray films. Intrathecal space -Fluid-filled space around the spinal cord. Intravenous -Into a vein. Neuropathic pain -Pain that originates from a damaged or malfunctioning nerve or nervous system. Paresthesia -The medical term for the tingling sensation that is felt during neurostimulation. Peripheral nerve -A nerve located outside of the central nervous system.