FAQ Category: Lumbar Spine

As the technique for lumbar fusion has changed and progressed, so have the surgical instruments used in fusions. It is now possible to use small incisions yet still get the full view of the spine being operated on. That’s what we mean by minimally invasive surgery. Special tubular retractor systems hold the skin and soft tissues open over the segment being fused. Real-time (3-D) X-rays called fluoroscopy make it possible to see inside the spine and aid in the procedure.

The minimally invasive approach has been shown to reduce blood loss, speed up recovery, and shave off the number of days patients spend in the hospital. But there’s a steep learning curve for the surgeon. It takes a while before the procedure has been done enough times to gain the expertise and accuracy needed for the best possible outcomes. That’s probably the biggest drawback to minimally invasive interbody fusion.

But the new technology provides the surgeon with better lighting and magnification of the surgical site. For example, it is possible to see the entire spinal joint now with the tube that forms a working channel for the surgeon to pass surgical instruments. That’s important in this particular procedure as the surgeon is cleaning out the opening around the spinal nerve root next to the joint and possibly even removing some of the bone that helps form the joint.

All indications from studies done so far that the procedure is safe and just as effective as the open surgery. What remains to be explored are the long-term effects and differences between these two surgical techniques. Larger studies comparing equal groups of patients are also needed to generate statistical validity for results.

This type of information will help surgeons choose patients more carefully for minimally invasive lumbar spinal fusions in order to get the best outcomes.

It sounds like your surgeon is planning to use the new minimally invasive technique to perform your spinal fusion. Instead of making a long open incision and cutting through all the layers of muscle, tendons, ligaments, and other soft tissues, a smaller cut is made. The long, round tube you saw is inserted through the layers of tissue down to the bone.

The tube has an expandable retractor that pushes away the soft tissues surrounding the area. This gives the surgeon a better view of the area and more room to navigate the surgical tools. At the same time, there is a magnifier on the end of the tube that gives the surgeon a bigger view of the area.

Movement of the surgical tools is further aided by a special type of real-time, 3-D X-ray called fluoroscopy. Fluoroscopy is a moving X-ray giving the surgeon details of the vertebral bones. The entire system gives the surgeon a focused view of the anatomy magnified for easier recognition of the structures.

Knowing anatomy, and practicing identification of the bones, muscles, tendons, discs, joints, and so on using these special surgical tools takes time. But using cadavers (bodies preserved after death for study) and practicing under the supervision of other trained surgeons gives the surgeon a clear idea of what is being seen.

There are many different ways to fuse the spine. The surgeon must get to the spine before performing the actual fusion. The anterior approach (from the front of the body) avoids the spinal cord and spinal nerve roots but involves moving large blood vessels out of the way without damaging them. The <i
posterior approach requires the surgeon to cut through muscles and soft tissues close to the spinal cord and other nerve tissue.

Both the anterior and posterior approaches have definite disadvantages. That’s why the lateral approach was developed. It sounds like you may be having a fusion procedure referred to as a transforaminal lumbar interbody fusion or TLIF. The word “transforaminal” is what is meant by “lateral”.

The TLIF method of lumbar fusion has many advantages. The lateral approach gives the surgeon access to the disc and disc space without applying excess pull or traction on the nearby spinal nerve. With a lateral approach, it is only necessary to remove one spinal joint (rather than the joints on both sides of the spinal level being fused) in order to get to the disc space.

Once the surgical approach and method are selected, then the surgeon decides whether to do this procedure as an open (oTLIF) or minimally invasive (mTLIF). Just as it sounds, an open incision is done by cutting through the skin, muscle, and other soft tissues in order to give the surgeon a full view of the spine.

In a minimally invasive TLIF (mTLIF), a long thin tube is passed down through the skin, fascia, and muscle down to the spine. It is not necessary to dissect (cut through) all these layers of soft tissue. Surgical instruments and hardware (cages, screws) used to fuse the spinal segment are passed through this tubular retractor system.

A minimally invasive approach reduces blood loss during the procedure and postoperative pain afterwards. Hospital stays are shorter with the mTLIF, which means lower costs. Other advantages of the minimally invasive approach have been reported. For example, there is less damage to the muscles and less tissue trauma overall. Fusion rates are equally good between the open and minimally invasive methods with lower costs and complication rates for the minimally invasive technique.

For almost 30 years surgeons have been fusing the lumbar spine using the popular transforaminal lumbar interbody fusion (TLIF) technique. The surgeon approaches the spine from the side rather than from the front (anterior approach) or the back (posterior approach).

The procedure was first done with an open incision approach called an open transforaminal lumbar interbody fusion or TLIF. This procedure required cutting through the spinal muscles to get to the spine. Trauma to the muscles and soft tissues with this method created lots of complications with infection, bleeding, and poor wound healing.

Over time, surgical technology and equipment have improved and advanced so that the procedure could be done as a minimally invasive (MI) approach. Minimally invasive means a very small incision is made.

In a minimally invasive TLIF (referred to as mTLIF), a long thin tube is passed down through the skin, fascia, and muscle down to the spine. It is not necessary to dissect (cut through) all these layers of soft tissue. Surgical instruments and hardware (cages, screws) used to fuse the spinal segment are passed through this tubular retractor system.

The surgeon also uses 3-D navigational (surgical) tools that allow him or her to see the correct pathway and avoid injury to nerve tissue. Fusion rates are fairly equal between the open and minimally invasive approaches. And according to a recent meta-analysis, the complication rate for the minimally invasive transforaminal lumbar interbody fusion is also less.

It’s always a good idea to have a medical exam to make sure there isn’t a more serious problem underlying an apparent injury. If you are quite sure there are no fractures, infection, or tumors, then it is safe to follow today’s current evidence-based Clinical Practice Guidelines (CPGs) for acute low back pain.

“Dos” and “Don’ts” include the following: do keep active and moving. Motion is lotion! Walking is an excellent way to achieve this. Don’t stay in bed. One or maybe two days of rest is okay after the initial injury but after that, get moving and keep moving. Again motion is lotion!

Unless your doctor or physical therapist recommend using a brace or corset for a specific reason, remain unencumbered and free moving. Avoid muscle relaxants or opioid drugs (narcotics). Tylenol (acetaminophen) for pain relief is generally approved. Again, check with your physician before taking any medication.

Core stability exercises for the trunk or extension exercises for the back are popular ways to deal with low back pain. If you are already doing these, you may want to put them on hold until your back pain is relieved. You can slowly resume normal activities and exercise as you recover.

It sounds like you have been diagnosed with acute mechanical low back pain. Acute means the symptoms are fairly new (first few days to weeks). Mechanical low back pain tells us that it’s not a tumor, infection, a fracture, or inflammation. But rather, some moving (mechanical) part (ligament, muscle, disc, tendon) is involved.

According to new research, your symptoms can be most effectively treated following the published evidence-based Clinical practice guidelines or CPGs for acute low back pain. Those guidelines advise patients to avoid bed rest and to stay active.

Walking is one of the easiest and least expensive treatments for acute low back pain. The rhythmical, repetitive movement seems to help in more ways than one. Walking increases blood circulation, bringing oxygen to soft tissue and mechanical parts needed for restoration. Walking also aids in digestion as it helps enhance peristalsis (contraction of the intestines to move food along).

Exercise of any kind helps regulate insulin production and use of sugars within the body. That’s important in the prevention of chronic illnesses such as diabetes, obesity, and high blood pressure, and heart disease.

How to get started? This may depend on you. We will give you an outline of what to do, but you will need to modify it based on your general health, level of back pain, and previous exercise levels. Walking doesn’t require any fancy or expensive equipment but a good pair of shoes that are not old and worn out are essential.

Begin walking every day for five minutes. If you can do this the first day without any problems and no increase in pain over the next 24 hours, then the next day increase your walking time by two minutes. Monitor your reaction to the increased time. If there are no problems, continue increasing by one or two minutes until you are up to 10 to 15 minutes of walking at whatever pace is comfortable for you.

From there, you have several options. You can continue increasing your time minute-by-minute until you reach 30 minutes (or more!). Or you can walk 15 minutes and later add a second walking session (on the same day four or more hours later).

Since you will already have walked 15 minutes once that day, begin the second walking activity with two to five minutes. See how that works for you. If there are no new problems over the next 24 to 48 hours, increase your second session by one-minute increments as you are able.

Some people like to continue with more than one walking session per day. Others prefer to meld the two periods of time together so that the two 15-minute walks become one 30-minute walk. Either way is good!

Your situation sounds like a complex one. It may take more than a few visits to your physician to find a management plan that works for you. Usually a team approach is best for cases like this.

By team we mean a physician to help you with pain management and a physical therapist to help restore normal movement and function of the spine and surrounding soft tissues. It is also a good idea to seek the counsel of a nutritionist. He or she will help with good food choices and weight loss. And don’t neglect or discount the services of a behavioral counselor. A good counselor can help with the psychologic/emotional aspects of injury, healing, and recovery.

If a three-to-six month all out effort on your part to follow the recommendations of the team don’t net the results you need, then it might be time to ask about surgical options. Today’s minimally invasive and less invasive techniques make it possible to perform lumbar fusion procedures on overweight-out-of-shape adults with good results.

In a recent study of patients just like you, researchers specifically looked at the ability of patients to get back to work. They found patients were able to get back to work within a year’s time of the surgery.

On that positive note, it should be mentioned that none of the patients who were workers compensation patients returned to work. That type of trend has been noticed by other researchers. Further study is needed to understand this phenomenon. But for now, it sounds like your next step is to get a team of health care professionals behind you and give a rehab program a good, solid try before looking for other options.

There’s never anything wrong with seeking a second (and sometimes third) opinion for complex medical problems like obesity. The surgeon is not trying to punish you by refusing to do the procedure until you lose weight. There are some serious complications that can occur in patients who are obese.

Obesity is defined as a body mass index (BMI) of 30 or more. Patients with a BMI of 30 or more are more likely to have problems with the anesthesia. It will be more difficult to access veins for intravenous procedures. Positioning the obese patient, changing positions, and getting him or her up and moving after surgery to avoid blood clots are important tasks but can be very difficult.

Depending on your medical condition and the type of surgery needed, it might be possible to seek out a surgeon who performs less invasive spine surgery. One procedure in particular that has had good results with patients with a high BMI is called the less invasive posterior interbody lumbar fusion or LI-PLIF.

The LI-PLIF procedure is done from the back of the spine (posterior approach). The surgeon uses surgical tools that can be inserted into the spine without making a large incision. Minimally invasive procedures make it possible to spare the muscles and ligaments from being cut into, which is what happens during the more invasive open incision technique.

The surgeon removes the spinal (facet) joints on either side of the affected segment. This does two things: 1) turns off pain signals coming from the joint and 2) provides the surgeon (and patient) with bone for the fusion site. It’s a win-win situation for the patient.

The diseased disc is also removed. In its place, the surgeon inserts two metal mesh-like cages. Inside the cages are bone chips and bone dust from grinding up the bone removed from the joints. Additional bone will grow around the cage providing the strength and support of a pillar at that level.

According to the results of a recent study, putting off surgery may not be necessary with the newer minimally invasive spinal fusion procedures. Fifteen (15) patients with a BMI greater than 30 had the less invasive posterior lumbar interbody fusion (LI-PLIF). All of these individuals had tried a more conservative approach with rehab and exercise but failed to get improvement with their painful symptoms.

The results were very positive. With the less invasive posterior lumbar interbody fusion (LI-PLIF) procedure, there was less blood loss and therefore a shorter hospital stay. The less invasive technique was also credited with no blood transfusions, less pain, and faster return to full function. There were no blood clots or deaths among the 15 patients in this study.

The authors concluded that obesity (even morbid or extreme obesity) does not have to be an automatic “lose weight or no surgery” situation. Obese patients with chronic, unresponsive low back pain from degenerative disc disease can benefit from lumbar fusion.

Of course, you really need to ask your physician what he or she has in mind when saying that your prognosis is guarded. Usually the term “guarded” means there are possible reasons why you might not get better. Since that is the case, no immediate promises can be made about your recovery.

But you have probably read reports where a patient’s prognosis was “upgraded” from critical to guarded, or guarded to stable. These are words that represent different shades of the same color or to put it another way, different places on the continuum from no recovery to full recovery.

Researchers who study back pain have identified various factors that predict a poor prognosis. In a recent study from The Netherlands, they combined the data from three different high-quality studies to identify three factors that predict which patients with low back pain (LBP) will go on to develop chronic LBP.

Their predictive model had three factors: 1) no change in pain intensity and disability during the first three months of low back pain, 2) high pain intensity at baseline, and 3) the presence of kinesiophobia (fear of movement) right from the start.

Other studies have found that age (older), gender (females), poor pain coping, the presence of back and leg pain, disability status, or fear avoidance behaviors can also predict less than optimal results from treatment (and thus a poorer prognosis).

You may have some combination of these variables leading your physician to think there are reasons why your recovery may be slowed. Check it out — it’s possible what your physician meant and how you perceived what was said are two different things.

A very reasonable question when suffering chronic pain and facing spinal surgery. And one that doesn’t have a straight forward “this” or “that” answer. But it appears you already know this from your comment that your surgeon has reviewed with you all the pros and cons of each treatment option.

One of the reasons there isn’t a definitive answer to your question is the fact that disc replacements have not bee studied (in this country) for 20 or more years. Early studies comparing fusion to disc replacement haven’t really shown a huge benefit of one technique over another.

That’s a bit surprising but the one stumbling block that keeps coming up is something called adjacent segment disease (ASD). ASD refers to the fact that once the spine is fused, load is transferred to the next segment potentially causing degeneration there as well.

The word potentially is used because researchers aren’t sure that it’s the loss of motion and transfer of load that creates the problem. There are many surgeons who suspect the same amount of degenerative disc disease would develop as a natural consequence of aging. This point has not been proven yet, so until the argument is put to rest, there is no clear winner of disc replacement over spinal fusion or vice versa.

Each patient must make this decision along with his or her surgeon. Your lifestyle (active versus inactive), general health, and personal goals combined with what the surgeon tells you about each procedure will guide your final choice.

For a very long time, spinal fusion was the answer to chronic low back pain. But with time, surgeons were also able to see that once the spine was fused, load transferred to the next segment caused degeneration there as well. They call this phenomenon: adjacent segment degeneration (ASD). Many solutions to the problem of ASD have been proposed.

The use of artificial disc replacement has been one way to approach the problem. The hope is to preserve spinal motion while protecting the adjacent vertebral levels. But when comparing the results between spinal fusion and disc replacement, there hasn’t been an overwhelming benefit shown for disc replacement over spinal fusion.

For that reason, some surgeons continue to look for ways to improve results of spinal fusion. They have tried different fusion techniques. They have analyzed patient factors looking for ways to identify patients who would benefit the most from spinal fusion. Factors of both patient (age, body mass index, lifestyle) and procedure (number of levels fused at one time, use of hardware to assist fusion, surgical errors) remain under investigation.

And some people just aren’t a good candidate for disc replacement. Spinal fusion may be the only reasonable choice for them. The uses of disc replacement are expanding and may eventually include all patients with chronic low back pain from disc disease. But for now, surgeons select patients carefully in an effort to prevent complications and assure success.

To understand Schmorl’s nodes, picture two vertebral (spinal) bones with a disc between them. Now imagine a circular layer of cartilage between the disc and each vertebra. That bit of cartilage is called the end plate. Schmorl’s nodes occur when the disc pushes through the endplate and into the next vertebra. On imaging studies these look like small hollowed areas.

Schmorl’s nodes can be seen on X-rays and are often present in patients diagnosed with disc herniation. Like you, patients wonder: is this a coincidence or does it have some particular meaning? Do Schmorl’s nodes occur without disc degeneration? If a person does have Schmorl’s nodes, does that mean the disc is going to degenerate?

There are some theories about why Schmorl’s nodes develop and what they mean. In many cases, we just don’t know why they show up. They seem to develop without cause. That’s referred to as idiopathic. Sometimes, there is a clear cause such as a tumor, decreased bone mineral density, or trauma.

In order to understand the etiology (cause) of Schmorl’s nodes better, a study was done in Southern China where the researchers examined the lumbar spine of 2,449 (adult) volunteers using MRIs.

The participants in the study were everyday people from the general population. Some had low back pain but the majority had no history of back pain or problems. Anyone with a history of back surgery, spinal tumors or infection, or any diseases of the spine was not allowed to join the study.

After all the MRIs were read and interpreted, participants were divided into two groups: 1) those who had no evidence of Schmorl’s nodes and 2) anyone with clear evidence of one or more Schmorl’s nodes. As with most research, the patients’ ages, activity level and sports participation, height and weight (also known as body mass index or BMI), and use of tobacco was recorded.

They found that in the general population, slightly more than 80 per cent did not have any Schmorl’s nodes. For the nearly 20 per cent who did have evidence of this anatomic feature, more than half had multiple levels affected.

The upper lumbar spine (especially L23) was the most common site for Schmorl’s nodes to be seen. Age wasn’t a significant factor except that older adults were more likely to develop disc degeneration. And it was those participants with disc degeneration who had the most Schmorl’s nodes. In fact, the more severe the degeneration, the more likely they were to have Schmorl’s nodes.

Body mass index was also much higher in the group with Schmorl’s nodes. This seems to suggest that being overweight or obese puts older adults at increased risk for Schmorl’s nodes as a complication of disc degeneration. The most severe cases of disc degeneration also had the greatest disc narrowing.

So, is there a link between disc degeneration and Schmorl’s nodes? It looks like it. Why does it happen? It’s likely that there are multiple factors involved and not just one reason why Schmorl’s nodes develop. Genetics, nutrition, body mass index, and severity of disc degeneration may all work together to result in end-plate changes leading to Schmorl’s nodes.

Disc degeneration is a common problem as we get older. Adding a back injury or trauma to the mix could speed up that degenerative process. This injury model of disc degeneration is only one theory. There are also theories that say disc degeneration is the result of cumulative or repetitive loading of the spine. Disc loading can occur during work, sporting, or leisure activities.

To find out if a previous injury is a risk factor for later disc degeneration, researchers studied 37 pairs of twins (all men) who were part of an ongoing Twin Spine Study in Finland. They interviewed the men about past back problems and history of injuries on every job they had ever had. The same questions were asked regarding back injuries during any exercise, sporting, or leisure activity.

Conducting a twin study like this with identical twins of the same sex and age helps control for these factors that might otherwise influence the results. Various factors that might affect disc degeneration were considered. These variables included type of work (occupation) and load placed on the spine during labor, amount and type of exercise (sports or leisure), and any weight training the men had participated in over the years.

The main measure of disc health was MRI study. The height of the disc and disc signal intensity on MRI were used to assess current disc status. Everyone in the study had an MRI of the lumbar spine (L1 to S1) done.

They did not find any significant differences in disc height or signal between the twins who had a previous back injury and the twin who didn’t. This was true for all 37 pairs. Twin members who lifted more weight at work were more likely to injure their backs but this did not seem to translate into faster or greater disc degeneration later.

This is only one study but it does support the results of other studies looking into the injury model of disc degeneration. Long-term studies are really needed to see if time-delay is a factor.

There are many studies of twins trying to understand the unique connection between them. Your story is very similar to what many twins have reported about shared experiences across great distances. There is even a name for this phenomenon called nonlocality.

Nonlocality describes the direct influence of one object on another distant object. It is suspected that nonlocality is part of what is going on between twins. There is a twin study that has tried to answer the question of whether back injury or trauma predicts disc problems later.

The researchers studied 37 pairs of twins (all men) who were part of an ongoing Twin Spine Study in Finland. They interviewed the men about past back problems and history of injuries on every job they had ever had. The same questions were asked regarding back injuries during any exercise, sporting, or leisure activity.

Normally, there are 157 pairs of (identical) twins in the Twin Spine Study. The only pairs included in this study were those who had one twin with a history of back injury (or injuries) and the other twin with no recall of any back problems.

They did not find any significant differences in disc height or signal between the twins who had a previous back injury and the twin who didn’t. This was true for all 37 pairs. Twin members who lifted more weight at work were more likely to injure their backs but this did not seem to translate into faster or greater disc degeneration later.

The International Association for the Study of Pain (IASP) defines chronic pain as pain that has lasted three months or more. Other experts consider pain to be chronic if it has been present six months or more. There are variations on the intensity, freqency, and duration used by different groups to describe chronic pain.

In a case like yours, where the pain “comes and goes”, the physician must evaluate you over time to see if each episode is a recurrence of the initial bout of back pain — or if you are experiencing new symptoms of a different kind each time. For most people with chronic nonspecific low back pain, it’s one long episode interrupted by acute flare-ups of the same old problem.

Nonspecific means there is no known cause. Fractures, tumors, infections, and other specific soft tissue or disease mechanisms for the pain have been ruled out. There simply isn’t a clearly identifiable cause of the symptoms. This doesn’t mean you don’t have pain — clearly you do! But the exact reason remains a mystery.

If you are uncomfortable being given a label, talk to your physician about this. Having a better understanding of his or thinking in making the diagnosis may not make you feel any better about being described as a “chronic” anything. Just keep in mind that the term describes length of time, and is not a statement of medical condemnation or personal judgment.

Medical terms often used to explain diagnostic results of tests and imaging studies can have a profound effect on how a patient perceives his or her potential for healing. Focusing on repair and healing of disc problems rather than discussing ongoing damage may be a more helpful and positive approach in managing low back pain.

Labels and beliefs about those words are something health care workers may need to re-evaluate. As the results of a recent study showed, messages regarding low back pain and how patients perceive the words health care professionals use have an important effect on their prognosis.

For example, when told that the cause of their low back pain was disc degeneration, some people interpreted that to means their spine was crumbling or collapsing. Use of the term wear and tear by the physician was used later by the patient to say that everything was wearing out.

Medical reports from radiologists reading and interpreting imaging studies contain words like degeneration, which may have nothing to do with the patient’s symptoms. There have been plenty of studies that show the severity of changes observed on X-rays often have no correlation to patient symptoms.

For instance, it has been observed that some people with what looks like severe degeneration of the spine have no symptoms whatsoever. At the same time, there are others who report excruciating pain with nothing seen on X-rays to indicate a problem.

Your reaction is very typical of many other patients. The important thing to know is that what was seen on the X-ray may not really have much to do with your prognosis. The ability to get pain relief and experience a “cure” may have more to do with what you believe about your condition than the actual condition itself.

Pain is a subjective sensation. It can’t be seen, photographed, or shown to someone in three-dimensions (3-D). That can create a dilemma when trying to measure this symptom to show improvement with treatment.

What you were doing with all the questions was establishing a baseline for your symptoms. In other words, creating a description of the frequency, intensity, and duration of your pain on a daily basis and with various activities. You will likely have to fill some or all of these forms out again later to see if there have been any measurable changes in your pain.

If you are not improving with the prescribed treatment plan, then it might be time to look for a different treatment approach. If you are improving, then the before and after measurements will help show by how much. It’s easy to start feeling better, get used to the new (improved) level of pain but still not be pain free. The result can be the patient’s perception is that there’s been no improvement when indeed there has been!

Spinal stenosis is a narrowing of the spinal canal. The spinal canal is the channel or opening created by the vertebral bones stacked on top of each other. Inside the canal is the spinal cord as it travels from the brain down to the lumbar spine.

Degenerative changes associated with aging such as bone spurs, thinning or bulging of the discs, collapse of the vertebral bodies, and stiffening or infolding of the spinal ligaments all reduce the space inside the canal. Since the spinal cord doesn’t shrink with age, the net result of stenosis is pressure on the spinal cord and/or the spinal nerve roots.

When conservative care doesn’t help, decompression (sometimes referred to as “roto-rooter” surgery) is considered. This procedure involves scraping away the excess bone and restoring space within the canal. Sometimes the surgeon performs a laminectomy (removes a portion of the bone from around the spinal cord). But decompression doesn’t improve the disc space or realign the compressed vertebrae.

That’s where the X-stop comes in. This device is implanted between the spinous processes of two vertebrae. The spinous process is the bony knob you feel along your backbone. It is a projection of bone off the back of each vertebra that provides a place for ligaments and muscles to attach.

By slipping the X-stop between the spinous processes, it’s a little like using a jack to lift your car off the ground. It separates the vertebrae and puts them in a slight bit of flexion — just enough to take pressure off the spinal cord, spinal joints, and spinal nerve roots.

The X-stop is a good middle step between conservative care and invasive surgery for some patients. If the procedure doesn’t bring pain relief, then the more involved decompression is still an option.

That is a very good question. Spinal cord stimulation (SCS) is used for 1000s of people with chronic, debilitating pain. The device delivers a low level electrical current through wires. The wires are placed in the area near the spinal cord. The device is similar in size to a pacemaker. How it works exactly is still a mystery.

Patients are usually told upfront before ever receiving the unit that it does not provide a cure for the pain. A 50 percent or greater decrease in pain can be expected, however. Some patients get as much as 90 per cent relief of painful symptoms.

Even a 50 per cent reduction in pain should allow recipients to be more active. Also, the need for less pain medication is considered a successful result. A trial with an external device for about a week is done, before having the device implanted.

The original theory behind how these devices work is called the gate control theory of pain. According to this theory, electrical stimulation generated by the stimulator replaces the pain impulses.

The gate theory suggests that when the electrical stimulation reaches the spinal cord first, the “gate” closes and blocks the pain impulses. As pain lessens, the muscles around the sore area relax, further lessening pain.

But studies over the years have shown that this theory only explains some of the pain relief obtained. It probably isn’t the only way the stimulator works. There is evidence now that spinal cord stimulation actually affects not one, but several different neural pathways.

If you have more than one pathway involved in the formation of your symptoms, then the device may not inhibit or turn off all pathways involved. But the fact that you get a significant portion of your pain eliminated suggests that the primary problem has been taken care of.

As more and more is understood about pain pathways, the use of spinal cord stimulation may expand. Eventually, it may include patients with all types of nerve pain as well as motor disturbances.

All of the descriptions you just provided suggest a neurogenic source of pain. That means something in the nervous system is affected. Neuropathic pain can occur as a result of injury or destruction to the peripheral nerves (coming out of the spinal cord), pathways in the spinal cord, or neurons located in the brain.

This type of pain does not occur as a result of tissue damage, but rather by malfunction of the nervous system itself. For some reason, there is a disruptions in the sending and receiving of nerve impulses. The result is a change in the way you perceive touch, pressure, and/or temperature.

Neurogenic pain can be drug-induced, metabolic based, or brought on by trauma to the sensory neurons or pathways in either the peripheral (spinal nerve roots) or central nervous system.

It is usually described as sharp, shooting, burning, tingling, or producing an electric shock sensation. The pain is steady or evoked by some stimulus that is not normally considered noxious (e.g., light touch, cold). Some affected individuals report aching pain.

There is no muscle spasm in neurogenic pain. Acute nerve root irritation tends to be severe, described as burning, shooting, and constant. Chronic nerve root pain is more often described as annoying or nagging.

It is best to have a medical doctor examine you to determine the cause of these symptoms. Early diagnosis and treatment to amend the problem can save you years of chronic nerve pain that is difficult to treat.