The Modern Treatment of Chronic Pain

 Video Presentation

1. Defining Pain and Locating its Source
2. Anesthesiologist's Role in Diagnosis and Treatment
3. Initial Drug Therapies
4. Back Pain and Epidural Cortisone Injections
5. Acupuncture for Pain Control
6. Benefits of Therapy
7. Integrative Care Center

Stephen A. Paget, MD: My name is Dr. Stephen Paget. I'm the Chief of Rheumatology at Hospital for Special Surgery. And it is a real pleasure today to introduce Dr. Jeffrey Ngeow, who is a Clinical Associate Professor of Anesthesiology at the Weill Medical College of Cornell University. He is also an attending anesthesiologist at Hospital for Special Surgery. His main area of focus and care of patients relates to the control of pain, and he works in our Pain Service at Hospital for Special Surgery. Dr. Ngeow what is pain?

Defining Pain and Locating its Source

Jeffrey Ngeow, MD: Well, pain is a very complex subjective and experiential sensation which, in an acute sense, could be purely from a sensation on the skin or whatever structure in the body. But when it becomes chronic, it involves a whole lot of other things. It could be a structural basis, but it could also have psychosocial basis also. So depending on what kind of pain we are talking about, it could be a simple situation, or it could be a very complex condition.

Stephen A. Paget, MD: Now if I have pain here in my arm that pain can originate from that site if I have an infection or a local trauma?

Jeffrey Ngeow, MD: Correct

Stephen A. Paget, MD: Or it could be referred from the neck or an upper part of the arm. How do you determine what the source of pain is?

Jeffrey Ngeow, MD: Well, we go through a kind of detective process. First, we want to find out if there is a local reason for the pain to exist there. If this local factor is eliminated, then we have to look at little further away. Now, you mentioned referred pain. Pain can be found in any part of the body because the nerves that are serving that part of the body come from the spine. So we might have to look into the spine to find out whether the cause of pain is there.

Stephen A. Paget, MD: What is the actual chemistry of pain? When a person perceives pain in an area, what is actually happening with the connections between the brain and the peripheral nerves. And what chemicals mediate pain?

Jeffrey Ngeow, MD: Well, actually there are a whole lot of different chemicals that are connected with the sensation of pain. There are local chemicals for example in the area of tissue damage, the chemicals are secreted from nerve endings that could mediate or cause inflammatory changes, but there are chemicals that are connected with the conduction of nerve impulse that are manufactured within the nerve and are secreted in areas like spinal cord or the connections further up, even to the brain stem and the surface of the brain itself, that are concerned with the sensation of pain conduction.

Some of these chemicals enhance pain sensations. Others would actually diminish it depending on what type of nerve is producing it and which system the nerve belongs to. So when we talk about chemicals concerned with pain we really have to clarify where we are talking about - whether it is peripheral or central.

The Anesthesiologist's Role in Diagnosis and Treatment

Stephen A. Paget, MD: How does an anesthesiologist get associated with pain relief?

Jeffrey Ngeow, MD: Well, as anesthesiologists, we are concerned with relieving the patient's pain during the operation. We use different methods. Sometimes we use general anesthesia; sometimes we use regional anesthesia, which means blocking the nerve with different drugs. And treating chronic pain is an extension of our work experience from the Operating Room to the day-to-day clinical situation or clinical setting, where we would use the techniques we learned, experience we gained in the Operating Room, to apply to pain conditions on an on-going basis - so that patients with chronic pain can also benefit from our experience and expertise.

Stephen A. Paget, MD: What is chronic pain as opposed to acute pain? Is it defined by its severity, its length, and its caliber?

Jeffrey Ngeow, MD: Typically chronic pain is defined as a pain sensation that has lasted longer than three months. Now, with most acute pain, there is a clear relationship between the course of the pain and the sensation that is felt. Most conditions are healed after a period of three to four months, so that original course of the pain no longer exists. But, however, if the pain sensation continues, then there might be other causes that are maintaining this pain sensation, and that is where chronic pain starts.

Stephen A. Paget, MD: So when patients come in to see you, they may come in by themselves or be referred by a doctor who has treated them for those three or four months trying to control their problem. What do you do and how do you decide on which modality of pain control is going to be employed?

Jeffrey Ngeow, MD: Well, first of all, we have to do a very detailed history and physical examination to find out what the patient is actually feeling, how the pain sensation is perceived, and how it affects the daily life. And then we have to go through detective work, as I mentioned, first of all to try to identify local factors if any. If that is ruled out, then we have to go further up what we call the neuraxis, which means the nerve from the periphery into the spinal cord, into the brain to find out where along this pathway of conduction there may be pathology. Now, if all of these are eliminated, then we have to face the possibility of the pain actually being a psychological issue.

Stephen A. Paget, MD: Is that a common problem or a common source?

Jeffrey Ngeow, MD: You mean psychological pain?

Stephen A. Paget, MD: Yes.

Jeffrey Ngeow, MD: Well my modus operandi is that every pain has a physical basis unless that physical cause is totally eliminated. Now that is not to say that psychological factors are uncommon. Any patient who has suffered pain for more than two or three months will have a psychological component because he is not an isolated person. His interaction with his family, society will all be affected by his pain condition. So there is always a psychological and social element in chronic pain, which we cannot totally ignore.

Stephen A. Paget, MD: But they shouldn't be branded as crazy. When patients come in complaining of pain, usually you try to address the source and the cause, and then try to make their lives better through some methodology or another.

Jeffrey Ngeow, MD: Absolutely, yes.

Initial Drug Therapies

Stephen A. Paget, MD: So what are the methods of pain control, and how do you define which method you are going to use in what situation?

Jeffrey Ngeow, MD: Well, we have a whole armamentarium of techniques. First of all, we use the most conventional methods of pain control, such as simple drugs like painkillers. There are other drugs that also affect the pain by modulating the conduction of the nerves. There are drugs which are called antidepressants [which were originally developed to treat depression] but which also change the chemical mixture of the conduction medium between nerves [thus modulating pain]. There are drugs that are called anticonvulsants, which were originally developed to treat seizures, but we use these drugs in the chronic pain setting to modify the sensitivity of nerves so that they don't fire so rapidly or so persistently. All these different drugs can be used either individually or in combination to produce the results that we are looking for.

Stephen A. Paget, MD: What proportion of people that come to your office with chronic pain are actually cared for, and their lives made better, simply by the institution of medications?

Jeffrey Ngeow, MD: I would say in the early stages of chronic pain, when the psychosocial factors are not a prominent part of the overall make-up, a fairly large percentage - say 60 to 75% of people - would be helped by these medications. Of course, we also have other techniques to isolate and identify causes and the location pain, such as nerve blocks and so on which we can use to help us.

Back Pain and Epidural Cortisone Injections

Stephen A. Paget, MD: Do the majority of your patients come in for care of chronic pain due to low back pain or back pain in general?

Jeffrey Ngeow, MD: Well, back pain accounts for a very large percentage of our patient population here at Hospital for Special Surgery. I would say almost 75% of our patients have some sort of back pain, be it acute or chronic.

Stephen A. Paget, MD: So they come to you with back pain. They've been treated for four or five months by their doctor with various pain medications, some of which you have already mentioned, and they say they can't live the life they are living. And you've tried those pain medications that you mentioned, either simple pain medications, narcotics, anticonvulsants or antidepressants, although you are not treating the depression, you are treating the pain component. What happens then if they still are limited in function?

Jeffrey Ngeow, MD: Well, when conventional methods, such as simple pain medications and physical therapy, fail to control the pain, then we have to be a little bit more aggressive in finding out really what is the underlying cause of pain. And we would go ahead and do more invasive studies, such as X-ray of the spine. We would do CAT scan for MRI of the spine to find out whether there are any other underlying causes.

Stephen A. Paget, MD: Say they have arthritis and they have problems with low back discomfort that stop them from functioning and going to work. What do you then do? What other treatment possibilities exist?

Jeffrey Ngeow, MD: Well, that depends on how severe the arthritis is. In the early states of arthritis, perhaps an antiinflammatory drug and combination of physical therapy and body posture training might be adequate to control the conditions. When the arthritis is a little bit more advanced, when there is evidence that there is compression of nerve roots, for example, then they might need something more aggressive such as a nerve block at the nerve root level or an epidural cortisone injection to relieve the inflammation that is happening around the nerve.

Stephen A. Paget, MD: Could you show us on this model how that is done?

Jeffrey Ngeow, MD: Yes. We have here a model of a spine. This is the lumbar spine showing the lower back. This is the back part, and this is front part of the spine. As you can see, there are gaps between the bones called the intervertebral spaces where the nerve passes through them. If there is arthritis of these joints, sometimes bone spurs or enlargement of the joint that causes narrowing of the space and compression of the nerve root underneath it, in those situations we can introduce the cortisone by inserting a needle into these spaces. And that is the technique called epidural injection, where we would insert a needle into these locations, whether down here or even up here. And sometimes they happen in the neck, and we put the needle up in the neck also. That is how we introduce the drug.

Stephen A. Paget, MD: Is that a safe procedure?

Jeffrey Ngeow, MD: Well, obviously any injection dealing with the spine has to be done with great care because if the technique of the person performing it is not skilled in this technique, you can easily cause damage to the nerve that is in this area. So it has to be done only by people with proper training.

Stephen A. Paget, MD: Now what proportion of patients with low back problems, say a disk problem or arthritis or spinal stenosis, will respond to one or a regimen of these epidural injections of steroids?

Jeffrey Ngeow, MD: In my experience, close to 85% of people - sometimes even with fairly advanced conditions, such as spinal stenosis - will respond more or less to these kinds of treatment injections. Very few of them, perhaps maybe 10 to 15% of them, will have such severe compression of the nerve that eventually would require surgery for a solution.

Acupuncture for Pain Control

Stephen A. Paget, MD: Now, say you tried all of this and the person goes to an Orthopaedic surgeon, and the surgeon recommends surgery for the lower back. And yet the person either has significant medical problems or really would just as soon avoid that. Are there other ways of controlling chronic pain, some of which may be borrowed from other parts of the world?

Jeffrey Ngeow, MD: Definitely. That is the other part of my practice here in the Hospital for Special Surgery. We use techniques such as acupuncture to help patients who are in this category because there is a limit to the number of injections we can do with the steroid injection in the spine. Steroid being a drug with its own side effects, we cannot do it infinitely. So in between scheduled steroid injections, I would employ acupuncture to help the patient get through this period when the back pain is intense.

Stephen A. Paget, MD: How does acupuncture control pain?

Jeffrey Ngeow, MD: Well, nobody really knows. The most recognized scientific evidence that we have to date is that acupuncture affects specific meridians and acupuncture points. When the needles are inserted in these points, they would actually cause secretions of the endogenous morphine, called the endorphins, in the spine and the brain, that help to control the pain sensation. And this has been confirmed in animal studies. The traditional, classical explanation for acupuncture is that it allows the energy of so-called chi to flow along pathways. That has not been confirmed scientifically.

Stephen A. Paget, MD: What proportion of patients that come to you respond to one degree or another to acupuncture?

Jeffrey Ngeow, MD: Well, surprisingly, a very large number of people actually do react to acupuncture in a favorable way. Even some of those skeptics who didn't believe that acupuncture would work sometimes surprise themselves and me by responding favorably. Of course there are a certain percentage about 5 to 10% that we simply cannot help.

Benefits of Therapy

Stephen A. Paget, MD: How do you define the outcome of pain? Is it simply asking the patient whether they are better, whether they are now doing things that they weren't before? Is there an actual quantitation of pain that you have see in order to define the fact that you have had a positive outcome?

Jeffrey Ngeow, MD: Well, there are several objective measures that we then use. Besides the subjective report of a patient's being better, we can have a visual analog scale where the patient assigns a number to the pain intensity. We can have a daily activity scale, whereby the patient can tell us what activities that they can do now which they could not have done before. And we can also have a social scale, whereby the interactions of the family or society are reflected upon their behavior.

Stephen A. Paget, MD: So 10 is the worst you can be, 0 is fine, and you are 10 now before we institute the therapy. Where do you move after the therapy? Is that the type of thing that is done?

Jeffrey Ngeow, MD: Typically, a reduction of four points on the 0 to 10 scale is considered significant. If we can achieve a reduction, say from 9 to 5 on the pain scale that is reported by the patient, I would consider that a successful outcome.

Stephen A. Paget, MD: What research is being done for the control of pain?

Jeffrey Ngeow, MD: At this time at Hospital for Special Surgery, I'm involved in a research project on acupuncture in patients with chronic back pain with members of the Rheumatology Department. We have just finished the preliminary study, in which acupuncture is given compared to conventional therapy, which gives us a positive result. And, at this time, we are embarking on a new study which is randomized, placebo-controlled, using acupuncture in patients with chronic back pain.

Integrative Care Center

Stephen A. Paget, MD: We have an Integrative Care Center at Hospital for Special Surgery. What is the focus of that, as opposed to Hospital for Special Surgery here on the East Side?

Jeffrey Ngeow, MD: Well, at the Integrative Care Center, we strive to use complementary modalities which involve other methods, such as message, physical therapy, postural training, even exercises such as Tai-Chi and yoga, and also psychological methods, such as biofeedback, body imaging, medication, relaxation, and so on. So that we take care of the patient as a whole, the so-called holistic approach to treatment.

Stephen A. Paget, MD: So, in many ways, it's expanding the menu of opportunities for therapy to patients who live with chronic pain despite everything else medicine could give to them and, also, in that setting doing research on new modalities of treatment.

Jeffrey Ngeow, MD: Correct. That is what we are trying to do.

Stephen A. Paget, MD: What do you see for the future for the patients out there as far as ways to control the pain in the next five or ten years?

Jeffrey Ngeow, MD: I would see new drugs coming down the pipeline that are more specifically addressed in specific pain conditions. With genetic modification and manipulation, we can produce a whole new generation of drugs that are specifically targeted to certain nerves - certain parts of our nervous system -whereby they would depress our suppressive sensation of pain without affecting other body systems.

Stephen A. Paget, MD: So for the patients out there living with chronic pain, there is hope in the future in your point of view?

Jeffrey Ngeow, MD: Oh, definitely. We never give up hope.

Stephen A. Paget, MD: Thank you very much, Dr. Ngeow.

Jeffrey Ngeow, MD: It's a pleasure.


For more information, contact the Pain Medicine Department at HSS.

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posted 10/31/2001

From an interview with Dr. Jeffrey Y.F. Ngeow by Dr. Stephen A. Paget