Workers With Back Pain Deserve Better

Workers’ Comp (WC) patients don’t seem to get better or get back to work after spinal fusion for low back pain (LBP). Is that because they are involved in a WC claim? Or are there other physical, psychological, or social factors at play?

An ongoing study of WC patients with LBP in Ohio is looking for some answers. Data is being collected on two groups. The first group are the WC patients who have had lumbar spine fusion for LBP.

The second (control) group are workers with similar back problems but who have not had any surgery. By matching the two groups up this way, the researchers can compare results of treatment.

Studies in the past have reported high rates of reoperation and disability among WC patients. Early results from the Ohio study show that 64 per cent of workers were still off work a year after their surgery. Patients with fusion ended up on more narcotics for pain after the operation than before. The lead author was quoted as saying, Workers with back pain deserve better.

Efforts will continue to find out why the results are so poor. Patients with different causes of their back pain will be included and compared. Everyone will be followed for at least two years.

It’s possible that the long-term results will show better pain control and function with fewer narcotics being used and more patients returning to work. Maybe it’s true that time heals all wounds.

Artificial Disc Replacements Must Reach Insurance Payers’ Standards

Two companies are now selling the new artificial disc replacements (ADRs) in the United States. The first approved was the Charité ADR. More recently, the ProDisc-L won FDA approval and has entered the marketplace.

Even though the FDA has approved their sale and use, insurance companies want proof they work better than current treatment. They say they won’t pay for this treatment until independent researchers prove the ADRs are safe and cost effective.

Other countries are asking for larger studies with higher standards. Clear evidence is needed before these motion-sparing implants will become the gold standard for chronic disc pain. And there needs to be a better way to reliably identify patients who do have pain from disc problems.

Surgeons using ADRs predict the trend away from fusion will continue. There will always be some patients who still need spinal fusion. They say that nonfusion treatment with motion sparing technology is the wave of the future.

Insurance companies (private and government backed) are asking for objective proof that ADRs are better than fusion or other methods. The problem is: what is the best definition of success? How is it measured?

The FDA wants trials to measure success based on a mathematical formula. Critics of this method say it doesn’t take into account patients’ satisfaction or improvement in quality of life.

Suggestions have been made for future studies. Patients who want spinal fusion should be compared to patients who want an ADR. Results may be different if patients are randomly assigned to one of those two groups if some patients were hoping to be in one group and got placed in the other.

And the ADR must be compared to lumbar fusion using a variety of different fusion methods since not all fusions are done the same way. Long-term studies over 10, 20, or 30 years are needed. But will third party payers refuse to pay (reimburse) for ADRs until then? Stay tuned — we’ll keep you posted!

The High Cost of Depression

Psychiatrists at the New York State Psychiatric Institute did a study to find out how much it costs to treat patients with pain who are also depressed. They compared the results with a group of pain patients who did not have a depressive disorder.

Over 1,000 patients were included in this study. Patients filled out several health surveys. One gave a measure of how much their pain interferes with daily activities. Another included a medical illness checklist. A disability scale and mental health questionnaire were also included.

The cost of health care for six-months before and after the doctor visit for pain were also added up. Patients with depression had much higher total charges for medical care during the time period. When pain interfered with activities, the cost of medical care was much higher, too.

When these two factors (depression and pain interference) were put together, depression was only linked with patients who had moderate to extreme pain interfering with their daily activities.

This study supports the belief that pain and depression often go hand in hand. Health care costs are on the rise. We may see these costs continue to go up with the increased number of adults who have back pain and mood disorders such as depression.

Could back pain be a symptom of depression? Could treating depression more aggressively reduce the number of patients suffering from back pain? More studies are needed to sort out the role of depression and pain-related interference.

Advantages of Microendoscopic Discectomy

Surgeons from China describe the use and results of a new treatment method for minimally invasive discectomy. The procedure is called a microendoscopic discectomy (MED). It was done on 873 patients with disc herniation. Results were compared to a control group of patients treated with open discectomy for the same problem. All patients were treated by the same surgeon in the same hospital.

A special endoscopic instrument called the MEDTRx system was used. Detailed drawings and photographs of the equipment and patient position are included. With this system, the surgeon is able to see a high-quality image of the disc and surrounding tissues on a video screen. MED allows the surgeon to use both microsurgical and endoscopic techniques.

The authors report that pain was improved equally in both groups. Recovery time in the MED group was much faster. Patients’ stay in the hospital was shorter. They were able to return to work and to their daily activities faster.

With the smaller incision, there was less bleeding and less tissue trauma. Only a light anesthesia was need so the side effects of general anesthesia were avoided. There is also less trauma to the nerve root because the patient could tell the surgeon if there is any pain or numbness during the procedure. Operative time decreased as the surgeon gained experience with this new technique.

MED isn’t for every patient with disc problems. The best patient for this procedure is someone who has a single-level disc protrusion causing sciatica. Older adults with spinal stenosis (narrowing of the spinal canal) are not good candidates for MED. Patients with spinal instability are also poor candidates.

With time and effort, surgeons can obtain the necessary training and practice to use this new three-dimensional treatment for patients with disc herniation.

Physical Therapy for Lumbar Spinal Stenosis

What kind of physical therapy (PT) program works best for lumbar spinal stenosis (LSS)? That’s the topic of this study by a group of PTs from around the United States. Spinal stenosis is a narrowing of the spinal canal where the spinal cord is located. Anything that narrows the spinal canal can also put pressure on the spinal nerves as they exit the canal through special holes called the neural foraminae.

Physical therapy treatment is designed to relax the soft tissues around the openings and to improve the position of the spinal column, thereby taking pressure off the nerves.

In this study, patients with LSS were divided into two separate treatment groups. The first group was treated with flexion exercises, a walking program, and ultrasound (a form of deep heat).

The second group received manual therapy (stretching, joint manipulation, strengthening), flexion exercises, and a walking program. The walking program for the second group was with a body-weight supported (BWS) treadmill. The BWS is a system of cables and trunk harness that unloads weight from the patient while walking.

Both exercise programs lasted for six weeks (twice each week). Results were measured by levels of pain, satisfaction, and function. Patients in both groups were followed for at least one year. Patients in both groups benefitted from nonsurgical care. Patients in the manual physical therapy, flexion exercises, and BWS walking had the best results.

The authors suggest ongoing studies to compare surgical versus nonsurgical results in LSS patients. Cost, pain reduction, and changes in function should be compared for different kinds of conservative care as well.

MRI Not a Good Predictor of Low Back Pain

It’s a well-known fact that low back pain (LBP) occurs in people with no obvious problems seen on X-ray or MRI. And it’s also true that people with degenerative changes seen on imaging studies often have no symptoms at all. It would be helpful if people could have a baseline MRI done and kept on file. Then, if back problems come up, a second MRI could be done to compare any changes that have occured.

That’s exactly what they did in this observational study. Baseline X-rays and MRIs were taken of 200 subjects who were then followed for five years. No one was disabled or had a previous history of back pain. All were working but had a known increased risk of LBP.

Anyone in the group who had a first-time episode of LBP had new imaging studies done within six to 12 weeks of their symptoms. The authors report the following findings:

  • One-fourth of the 200 patients developed LBP during the five-year study period
  • Most (84 per cent) had no changes seen on the second MRI.
  • Changes observed were all related to gradual degeneration from age.
  • Patients involved in compensation claims were three times more likely to have an MRI when LBP occurs.
  • It didn’t matter if the LBP started after trauma or injury or just came on
    without a known cause. New findings weren’t any more likely with one or the other.

    The results of this study do not support the idea that structural injury occurs with LBP even after trauma. It’s more likely that minor trauma adds to injury already present in the aging and degenerative spine.

    MRI findings are not good predictors of future episodes of LBP. Other studies support the idea that psychosocial factors are much better predictors of significant low back problems.

  • Comparing Artificial Disc Replacement at One- Versus Two-Levels

    There have been problems with lumbar fusion for chronic low back pain (LBP). Research is ongoing to develop a long-lasting artificial disc replacement (ADR) to avoid these problems. Right now the FDA has approved the Charité ADR for use at one lumbar level. It has not been cleared for two-level use yet.

    In this study, researchers used a computer-simulated model to compare results using a one-level ADR versus a two-level ADR. The one-level ADR also had a one-level fusion at the level below. The fusion was also simulated using a cage and pedicle screw system. The authors describe the simulation process in detail including software used and special features of each program.

    The simulated spinal segments were tested under a variety of conditions and motions. As expected, motion was decreased at the fused segment and increased at the ADR levels. Loads on facet joints at the level of the ADR were decreased. There was no measurable change in disc pressure above or below the ADR segments.

    In both cases, motion changed about the same amount at the lumbar level above the segment operated on. The difference was that the motion increased in the fusion/ADR model and decreased in the two-level ADR model.

    The authors could not say if one procedure was better than the other. The computer simulation does not include the effect of muscles. Likewise changes that occur during surgery when soft tissues are cut to insert the ADR or cages could not be accounted for. Various tiny micro-motions of the spine present in the live model are also impossible to recreate in a simulated model.

    More study is needed to compare fusion with ADRs at different levels and in different combinations. Effect on motion, load, discs, and joints should be measured with each scenario. Both simulated and cadaver studies are important before live studies can be done.

    Magnetic Nerve Stimulation Used to Diagnose Piriformis Syndrome

    In this study, scientists compare the results of needle electromyography (EMG) tests with magnetic nerve conduction velocity (NCV) tests to diagnose piriformis syndrome.

    Piriformis syndrome is a group of symptoms caused by pressure on the sciatic nerve as it passes through the piriformis muscle in the buttocks. Symptoms include buttock and/or leg pain, numbness, tingling, and muscle weakness.

    MRI or ultrasound studies are not always able to pinpoint the cause of buttock pain. NCV to measure the speed of signals along the sciatic nerve are invasive and can be painful. Magnetic stimulation of the nerve is painless and can be used to test the deep nerves such as the sciatic nerve.

    Testing was done on 23 patients with piriformis syndrome. Results were compared when the same tests were done on 15 normal, healthy adults (control group). Both electrical and magnetic testing of the sciatic nerve was performed. The authors describe how much stimulation is needed to get the most accurate results.

    Magnetic NCV showed that nerve impulses were slowed along the sciatic nerve from the L5 nerve root to the bottom of the buttocks. No such change was measured at the S1 nerve segment. Slower magnetic NCV were observed more often in patients who have had sciatic nerve compression for a longer period of time.

    The authors conclude magnetic NCV is an accurate measure of sciatic nerve function in patients with piriformis syndrome. This test offers a painless, noninvasive way to test patients with piriformis syndrome. It can be used instead of the more painful, invasive needle EMG studies.

    Should Back Pain Be Ignored?

    Low back pain (LBP) has become such a common problem that experts call it a national crisis. Most of the time, LBP goes away by itself. One proposed solution to this crisis is to ignore it. This concept is called demedicalization.

    Demedicalization of LBP could reduce health care costs and decrease disability. It could get rid of unnecessary medical care for millions of potential patients.

    At the same time that demedicalization was proposed, the American Pain Society advised paying more attention to pain and treating it right away. They say pain relief is a basic human right. Patients deserve to have their pain treated.

    Debate on the issue of ignore-versus-treat LBP continues. There may be some people who should always be offered treatment. Cancer patients, postoperative pain, and end-of-life pain would qualify for treatment. On the other hand, treatment of pain may not be advised for chronic pain, especially pain that comes and goes.

    Before a final decision can be made, the following questions need to be answered:

  • Is pain an important and valuable warning symptom or a disease itself?
  • How much pain is okay or acceptable?
  • Can treatment really change or improve pain, especially chronic pain?
  • When does someone with pain move from being well to ill?

    Careful scientific study is needed before treating all LBP patients. Studies should include people who routinely seek medical treatment for pain and those who choose to cope on their own.

  • Risks with Anterior Revision Procedures

    In this study, surgeons report on the risks of having implants called cages removed from the spine. Fourteen (14) patients with spinal fusion were included.

    Original devices used to support the spine were put in anteriorly (from the front), posteriorly (from the back), or transforaminal (from the side at an angle). All implants were taken out anteriorly. Bone graft was used to fuse the spine after hardware removal.

    The reasons for revision surgery included pseudoarthrosis, movement of the cage, and infection. Pseudoarthrosis means false joint. There is movement where there shouldn’t be.

    One patient had nerve compression from the hardware (a screw) pressing on it. More than half of the patients had cage removal from the L45 level. The rest were from L5S1.

    The authors report lumbar interbody revisions are complicated operations. A laceration or cut of the blood vessels is the biggest problem. In this group of patients, 71 percent had major problems. More than half were from vascular injuries.

    This is the first study published to report complication rate with revision surgery after lumbar fusion with interbody devices. Scar tissue from the first operation increased the risk of blood vessel damage during revision surgery. Surgeons are advised to find and control the blood vessel above and below the operative site to avoid vascular complications during revision procedures.

    Using Work Status as an Outcome Measure After Back Surgery

    Is there any real way to predict the outcome of lumbar spine fusion? More than 2000 studies have been published on the topic of predicting disability after low back injury. Factors identified so far include physical health; use of drugs, alcohol, or tobacco; and job satisfaction. Other variables include family support and Workers’ Comp status.

    Work status at the time of surgery is the focus of this study. Can work status predict the final outcome of lumbar fusion? Anterior lumbar interbody fusion (ALIF) with titanium cages was the treatment for 106 patients with disc problems.

    Three-fourths of the group had a single-level fusion. The rest had two levels fused at the same time. One patient had a three-level fusion. Pain, levels of function and activity, and work status were measured before and after surgery. Everyone was followed for at least one year. Many patients were re-evaluated periodically for two years or more.

    The authors report that patients who were working at the time of surgery were 10 times more likely to go back to work after surgery. This was compared with patients who weren’t working at all. Pain levels were improved for the workers after surgery. Their function didn’t change significantly.

    About 90 per cent of the patients who were working before surgery went back to work. Only about 43 per cent of the nonworkers returned to a work setting or job of some kind.

    The results of this study agree with other studies that suggest patients with chronic low back pain needing surgery should work right up until the surgery is done. This is true even if the job has to be modified. Lighter duties or fewer hours may be necessary on a temporary basis.

    Backache Index (BAI): New Tool for Measuring Treatment Success

    Doctors, therapists, and nurses need a quick and easy tool to assess backache. A reliable and accurate measure of pain before and after treatment would be very helpful. In this study, physical therapists from Belgium test the Backache Index (BAI) for reliability and validity.

    The BAI is based on a set of five movements in the standing position. Pain intensity is measured instead of spinal range of motion (ROM). A one-page form with drawings of each position is filled out. Each position is scored as follows:

  • 0 No irritation and full ROM
  • 1 Irritation but no pain at full ROM
  • 2 Pain but full ROM is possible
  • 3 Severe pain and reduced ROM

    The test was given to 75 back pain patients before and after physical therapy treatment. The results were compared with several other standard tests often given to back pain patients. Some of the more commonly known tests used included the Visual Analogue Scale (VAS), the McGill Pain Questionnaire, and the Oswestry Disability Questionnaire (ODQ).

    The authors report the BAI has good reliability and validity. It is a good tool to measure overall restricted spinal movements in patients with low back pain. It can be used to show if treatment has been successful. It was not as useful in measuring changes in quality of life.

  • Neurologic Symptoms After Steroid Injection

    Surgeons from Ohio State University report a single case of neurologic symptoms from air trapped in the spine. The 43-year-old woman had a steroid injection for chronic low back pain (LBP) and leg pain.

    The surgeon inserted the needle into the epidural space using fluoroscopy to guide the procedure. The epidural space is located between the vertebral bone and the spinal canal and contains veins, arteries, and fat. Fluoroscopy is a special X-ray imaging used during surgery to help the surgeon see inside the patient.

    The patient had increased back and leg pain right away after the injection. Both legs hurt and she noticed weakness in the right foot. There was also a loss of sensation in both legs.

    An MRI was done and showed air trapped in the L45 epidural space. As the air slowly leaked out, the patient’s symptoms got better. Her pre-injection level of pain did not change.

    This is the first case reported of air trapped in the epidural space causing worse neurologic symptoms after lumbar steroid injection. The authors suggest that many of the patients who have worse symptoms right after epidural injection may be suffering from this very same problem without knowing it.

    Surgeons are advised to use less air or switch to nitrous oxide (NO) instead of air when injecting a steroid into the epidural space. Patients with chronic compression of the epidural space from bulging or herniated discs may be at risk for this problem. Scar tissue or adhesions may reduce the space available for the injection.

    Results of Revision Surgery After Failed Spinal Fusion

    Ten to 30 per cent of spinal fusion surgeries fail. Patients get worse instead of better. The reasons for failure are many and varied. Broken screws or other broken hardware, spinal stenosis, and spinal instability top the list of causes.

    In this study, surgeons report the results of at least two years of follow up for patients with poor results after instrumentation-augmented spinal surgery.

    Tests done on 103 patients included myelography and CT scans. When these tests failed to find a reason for surgical failure, then electromyography (EMG) and nerve conduction velocity (NCV) tests were done.

    When testing could show a specific cause of the symptoms, then revision surgery was done. In this study, pain and function after the second operation were measured for up to two years.

    Patients who were helped the most by revision surgery had spinal stenosis or else instability in the lumbar segment above or below the previous fusion. With instability there can be forward slippage of the vertebra. This causes the size of the spinal canal to narrow putting pressure on the spinal nerve. This condition is called spinal stenosis. The patient has back and/or leg pain with spinal stenosis.

    The authors conclude a correct diagnosis is needed before doing revision surgery for failed spinal fusion. Despite testing, 20 per cent of the patients have no known cause for fusion failure making the decision more difficult.

    Repositioning Test Is Not Useful For Low Back Pain

    The proprioceptive system helps the spine assume an exact position when moving from one position to another. Studies show that this repositioning mechanism is altered in patients with chronic neck pain. But what happens with patients who have chronic low back pain (LBP)?

    In this study, a repositioning test is used to see if this mechanism is disturbed in LBP patients. Patients with LBP for more than six months were compared to healthy adults the same age without back pain.

    An electromagnetic tracking system was used to record the position of the spine. Each person in the study was seated on a stool in a straight spine position. The pelvis was tilted forward slightly. After bending forward, the subjects were asked to sit up and assume the target (upright) position. Everyone wore a blindfold to keep them from using their vision to return to the exact position.

    The authors report that there were no differences in repositioning errors between the healthy group and the group with LBP. This suggests that abnormal sensory cues aren’t measurable with this test.

    The repositioning test may not be the best measure of changes in proprioception that can occur with LBP. More study is needed to find a test of sensorimotor dysfunction in chronic LBP patients. Once the abnormal sensory cues can be measured, a rehab program to address the problem can be designed.

    Low Back Pain: No Benefit from Stabilization Exercises

    Spinal stabilization exercises have become a popular choice for treating nonspecific low back pain (LBP). But is there any value added from these exercises over the usual physical therapy program?

    Physical therapists (PTs) from England examined this question. They divided patients with recurrent LBP into two treatment groups. The first group did general active exercises. They also received manual therapy from a PT. The second group had the same program plus the added spinal stabilization exercises.

    Stabilization exercises are low load, high repetition training exercises for the back and abdominal muscles. The goal is to restore normal contraction, timing, and balance of these two groups of muscles.

    Both groups exercised 30 minutes for a maximum of 12 sessions over 12 weeks. Everyone improved in terms of pain level, activity level, or function. Quality of life also improved.

    Essentially, there were no differences in results between the two groups. The general exercise group had fewer treatment sessions over a shorter period of time with the same results.

    This study investigated the usefulness of stabilization exercises as a standard method of treating nonspecific LBP. It does not appear that endurance training for the deep abdominal muscles has any added benefit over a program of general back exercises.

    More study is needed to identify specific back conditions for which spinal stabilization exercises are more effective.

    MRI for Low Back Pain: Abnormalities Are Not Linked to Symptoms

    Magnetic resonance imaging (MRI) and other imaging studies are not recommended for nonspecific low back pain (LBP). Even so, the use of these tests continues when they aren’t needed. Often treatment isn’t any different for patients who have an MRI compared to those who don’t.

    In this study, patients with nonspecific LBP were given an MRI to look for abnormal changes. The majority of patients in the study had observable changes on MRI. Eighty-nine per cent (89%) had severe disc disease. Only 11 per cent had no pathologic changes visible at any lumbar level. In other words, their discs appeared “normal” at every level.

    Pain and disability were measured before and after treatment. These results were compared for patients with and without structural abnormalities. Treatment consisted of physical therapy, weight training, or low-impact aerobic exercises and stretching.

    Patients with MRI changes did not appear to have greater pain or disability compared to those who didn’t have significant changes on MRI. Likewise, the results of treatment with conservative care were not affected by observed MRI changes.

    The authors report the number and extent of abnormalities seen on MRI increases with age. The changes observed included disc degeneration, disc bulging, and end plate changes. The authors conclude MRI abnormalities are not linked with severity of symptoms.

    Emotional Distress Linked to Chronic Low Back Pain

    In recent years researchers have discovered that fear-avoidance beliefs (FAB) are linked with chronic low back pain (LBP) and disability. FAB is observed in LBP patients who alter the way they move out of fear that movement will hurt. Two types of FAB have been identified. One is linked with general physical activity. The other is work-related.

    In this study, the impact of emotional distress is measured and compared to FAB. Emotional distress included anxiety, depression, and somatization. Somatization is the process of expressing emotional distress as physical symptoms. Somatic symptoms often include headaches, neck or back pain, and joint or muscle aches and pains.

    Two groups of patients were included. Group A had acute LBP (lasting less than three weeks). Group B had chronic LBP, which was present for more than three months.

    Everyone was given tests of function and a FAB survey. Acute patients were reexamined after four weeks. Chronic LBP patients were given the same testing after three months. All patients in both groups were followed at regular intervals until the end of 12 months.

    The authors report the following findings:

  • FAB was greater for work-related activities than for general physical activities
  • FAB for physical activity decreased in the acute group but stayed the same for
    the chronic group

  • Distress was a stronger predictor of disability compared to FAB after 12 months
  • Smoking was a greater factor than FAB in predicting pain intensity

    The authors suggest that emotional distress and FAB may not be separate. Both may be linked to chronic back pain. Distress may be a greater predictor of disability than FAB. More study is needed to identify which factors best predict who will go from acute to chronic pain and disability. Finding ways to prevent this process is the final goal.

  • Evidence Demands Compliance in Care of Acute Low Back Pain

    Patients with acute low back pain (LBP) can and often do receive a wide range of medical treatment for the same back problem. To help standardize treatment, the military healthcare system (MHS) developed clinical practice guidelines (CPGs) for LBP. The goal of CPGs is to improve quality of care and outcomes after treatment.

    This study looks at two things related to CPGs for LBP. First, do doctors use the CPGs? Second, how do the results compare between patients treated according to the CPGs and those who aren’t treated using CPGs?

    With more than nine million members of the MHS, the authors had a large sample for this study. The patients came from a computerized database of patient care records kept by the Department of Defense.

    Results of treatment were measured using patient satisfaction, general health, and function. The cost of care was also calculated for each patient. The authors report less than half of the patients (42 per cent) received care for their acute LBP according to the established CPGs.

    Younger patients on active duty and in good health were most likely to receive CPG care. Patients receiving CPG care had higher levels of satisfaction and function. The cost of their care was also much lower ($222.00 versus $712.00).

    The authors think the evidence-based CPGs aren’t used as they should be. This may be because healthcare providers expect that most patients with LBP will get better without treatment. Doctors may think there are many steps in the CPGs that may not be needed so they don’t use them at all.

    The results of this study clearly show that following CPGs for acute LBP is linked with improved outcomes. More efforts should be made to educate health care professionals treating patients with LBP to use these guidelines. Patient costs would be less and there would be better results and greater patient satisfaction.

    Factors Contributing to Disability in Lumbar Spinal Stenosis

    Lumbar spinal stenosis can be a very disabling condition. The spinal canal narrows and pressure on the spinal nerves can cause significant back and/or leg pain. Spinal extension or even just standing up straight can become very painful.

    What are the factors leading to disability in this condition? The authors of this study hope by finding out, steps can be taken earlier to prevent disability. Patients usually think pain is the major limiting factor. But studies don’t bear this out. Pain intensity is only a portion of the problem.

    In this study the Oswestry Disability Index (ODI) was used to measure how pain affects activities of daily living. The ODI is a survey with questions that help measure disability. Other tests and measures conducted included pain intensity, muscle strength, spinal flexibility, and vibration sense.

    The authors report the biggest factor in disability associated with lumbar spinal stenosis was the location of the patient’s symptoms. Patients who had pain in the low back and leg were more likely to be disabled compared to patients who only had back pain.

    Pain intensity and a loss of vibration sense added to the problem. Disability was much more likely for patients with all three factors plus muscle weakness. Age was not a factor. Younger adults with these risk factors could be more disabled than older adults with fewer risk factors.

    The results of this study support the idea that symptoms are not necessarily greater when more spinal levels are involved. Symptom location and intensity are the main factors of disability. Vibration sense and muscle weakness are added factors toward disability.