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4 Articles in Volume 2, Issue #4
An Historical Perspective: A Global View of Evolving Pain Treatment Modalities
Percutaneous Disc Decompression/ Discectomy - A Case Report
Practical Headache Pearls
Temporomandibular Joint Disorder Mimic Ernest Syndrome Diagnosis and Treatment

An Historical Perspective: A Global View of Evolving Pain Treatment Modalities

The former head of the largest pain clinic in Central Europe offers observations on multi-disciplinary treatment modalities evolving over the past 25 years and concludes with comments on the current World Health Organization pain reduction guidelines.

Over a period of 13 years, as head of the pain clinic Ambulatorium Süd in Austria in the period 1976 to 1989, the author personally treated, on average, 3,800 new pain patients each year. Experience derived from the large volume of pain patients (comprised of 4% benign diseases-various, 7% cancer pain, 10% sympathetic dystrophies, 25% articular pain, and 54% neuralgias), the extended timeline, and numerous intervening research projects, has given the author a unique perspective and an extensive knowledge base. While the average pain reduction for all patients observed over the 13 years was 56%, evolving techniques over that time period resulted in the last 5,500 patients (including 3,000 private patients) experiencing an average pain reduction of 92%.

Treatments can be grouped into three basic strategies: procedures (to treat underlying causes of pain), conservative measures (that comprises a continuum from PM&R to drugs in the opiate- and morphine-derivative group), and operative measures. Ideally, a practitioner should be able to freely select the optimum treatment modality for a given diagnosis, yet due to resource limitations (especially in certain parts of the world), alternatives can be used. Table 1 summarizes the three basic strategies together with the resource requisites.

Pain Reduction Strategies
Pain Relieving Strategy Resource Requirement
Procedures
Treat underlying condition or disease
medical specialists (internist, orthopedist, etc.)
Conservative methods Non-drug use
physical medicine
neuropsychology
Pharmacology
non-opiates
opiates
PM&R facilities, specialists, equipment



medication to prevent gastric damage
medication for obstipation
Operative methods
non-destructive
destructive
operative facilities & neurosurgeons
 

Table 1. Summary of pain reduction strategies with corresponding resource requirements.

Procedures for Underlying Conditions

Pain associated with a specific disease or condition is often reduced or eliminated by treating the underlying causes. Several examples illustrate pain-generating conditions that, when treated, often reduces or eliminates associated pain.

Thalamic pain, often reported in the aftermath of a stroke, is caused by diminished circulation through certain areas of the thalamus. A stellate block to increase the circulation in that region, while not considered a method for pain reduction, does eliminate the pain.1

A patient with osteoporosis is encouraged to increase physical activity in order to decrease the amount of calcium leaving the bone structures. The patient may be also be prescribed a drug which replaces the loss of calcium and strengthens the bony structure (e.g., fluorine and a biphosphonate) to reduce the possibility of fractures. The side benefit is a long-term reduction in pain without analgesics.

Pain occurring with breast cancer has been found to be exacerbated by hormones. For this condition, adjusting hormone levels will reduce the pain, again with no analgesics.

Similarly, gout is a disease that causes pain due elevated levels of uric acid. Medication to excrete the excess uric acid and maintain a normal level will, in most cases, cause the pain to disappear.

Non-Pharmacological Methods

Methods for reducing pain without drugs are available mainly from the specialties of physical medicine and neuropsychology. These various principles may be separated into several special fields, which are listed in Table 2 and summarized in the following sections.

Non-Pharmalogical
Methods of physical medicine2
Mechanotherapy
Electrotherapy
Thermotherapy
Hydrotherapy
Methods of neuropsychology3
Biofeedback
Psychotherapy
Hypnotherapy
Group Therapy

Table 2. Summary of non-pharmacological modalities.

Physical Medicine

The determination of which type of physical therapy to be used for the optimum reduction in pain should be determined by a physician with special training in physical medicine. The particular method to be selected for the appropriate patient largely depends on the particular disease or cause of pain. The following is a brief description of the listed methods of physical medicine.

Mechanotherapy comprises passive and active exercises, various types of massage, extensions, suspensions, ultrasound — sometimes as phonophoresis; various techniques of relaxation and therapeutic dance methods — sometimes combined with music therapy. There are special types of manual therapy and exercise variations for different types and locations of pain. Of course, this approach may be contraindicated for certain causes of pain (e.g. a disc protrusion).

Electrotherapy may be used either as direct current (DC) in the form of galvanisations, iontophoresis, and pulsed currents. Transcutaneous Electrical Nerve Stimulation (TENS) in its DC form is optimally effective and suited for treating pain. Electrotherapy may also be used as alternating current (AC) in the form of low or middle frequency currents, interferential currents, and high frequency AC, (short waves, microwaves, decimeter waves). TENS in its AC form, however, is only minimally — if at all — useful for reducing pain; the main application for instruments delivering AC are muscular indications. Application of electricity also includes magnetic field therapy, as well as the various forms of laser. The latter is only used at a special frequency and solely for the treatment of joint pain — having little impact on neurogenic pain.

Thermotherapy may be applied either as heat (bath, hot air, red light therapy, sauna, hot packs, hot sand, hot water baths, mud bath, etc.) or cold applications (cold packs, cryotherapy, icing sprays, cold room, cryojet, etc.).

Hydrotherapy is very often quite effective especially for chronic pain, if used as a hot bath, water massage, balneotherapy with peloids, or climatic bath.

Neuropsychology

The optimum method of neuropsychology is typically determined by a neurologist, psychologist, or, more recently, a psychiatrist with fellowship training. Following is a brief description of the listed non-pharmacological methods of neuropsychology.

Biofeedback utilizes specialized equipment to allow the patient to monitor body signs such as circulation, EEG- or EMG-tracings, and correlate those signs with the sensation of pain. By learning to self-regulate those body signs, the patient may be able to reduce pain.

Psychotherapy, hypnotherapy, and group therapy — administered by a neurologist or psychologist — come rather close to the methods used by faith healers and often result in significant success.

Pharmacological Modalities

When physical medicine or neuropsychology are not sufficiently effective in reducing pain, the escalation to pharmacological modalities is indicated. The practitioner is confronted with two basic choices: if the severity of pain is not too great, non-steroidal anti-inflammatories (NSAIDs) may be used, however for the most severe pain, opioids are the drug of choice.

In using NSAIDs, one should carefully attend to side effects on the stomach since most drugs in this group may damage the gastric mucosa and produce ulcers. To counteract this negative side effect, the practitioner may simultaneously prescribe drugs to protect the gastric mucosa.4

Opioids also have side effects but the most irritating side effect for any patient is obstipation which is best treated with laxative upon first use. Sometimes the obstipation is so massive that an obstructive lesion is suspected. Application of opioids as an epidural injection tends to minimize some general side effects. However, because of potentially serious side effects, opioids are typically prescribed as a last resort for inoperable, intractable pain where all other modalities have failed.

Electrical Modalities

The author regards the DC-variety of TENS as an intermediate method between non-operative and operative methods, since this version of TENS functionally interrupts the pathways running in certain nerves. A practitioner must be trained in neurophathology and neurophysiology (normal and pathological) in order to understand and effectively modulate the neurophysiological events in these pathways.

The DC-variety TENS uses a rather small electrode as an anode and a much larger one as the cathode. The small anode focusses dense electric field lines, allowing accurate placement along a nerve pathway, whereas the cathode has more diffuse electric field lines. The small anode is placed directly on the skin over the nerve transmitting the pain impulses and the cathode over the opposite surface of the trunk or extremity. Successful pain reduction is dependent on selecting either a somatic or a sympathetic nerve fiber group through which the noxious impulses from the site of pain are traveling. TENS in the DC-form, used in conjunction with pharmacological modalities, is able to reduce the required dose of analgesics (or opioids) by more than fifty-three percent.5 This type of TENS alone may be very effective when opioids fail to help in the cases of secondary lesions in bones.6

Due to the electrophysiological attributes of nerve cells in the conduction of pain impulses, the optimum frequency of TENS is in the range 20 and 50 cycles/second. The author finds that the midpoint frequency of 35 cycles/second is convenient because one is able to visually confirm this frequency by means of the so-called flimmer fusion frequency: a higher frequency is seen as a continuous light. The benefit is a confirmation of the target frequency without relying on the accuracy of instrument calibration.

Operative Modalities

The operative methods of pain elimination are regarded by the author as a last resort when all other modalities have failed. Among theses, there are a number of non-destructive methods to surgically influence the sensation of pain. The latest techniques employed by neurosurgeons are those which functionally interrupt certain pain pathways by stimulating these paths electrically. These nerve blocks may be accomplished by either open peripheral nerve stimulation (PNS) or pathways within the central nervous system — either in the cerebrum (DCS) or cerebellum — depending on the desired outcome.

A neurosurgeon may sometimes employ somewhat antiquated methods which destroy certain nervous structures such as (e.g. cordotomy, comissurotomy), or more recently, dorsal root entry zone destruction. There are various levels of intervention depending on the site of pain and the neural pathways targeted for destruction. Physiological testing is mandatory before such operative procedures.

Pain Reduction Success Rates

The author has documented the composite success rates for various diagnoses over 13 years as head of the multidisciplinary pain clinic Ambulatorium Süd in Vienna. Table 3 presents a summary of diagnoses and the corresponding percentages of success in pain reduction one year after therapy.

Diagnoses and Pain Reduction Success Rates7
Diagnoses Cases % of Group % All Patients Success Rate%
A. Neuralgias - total 9,420 100.0 53.7 75.2
Cervical neuralgia 6,461 68.6 36.8 74
Post-herpetic neuralgia 619 6.6 3.5 70
Trigeminal neuralgia 603 6.4 3.4 84
Lumbalgia (low back pain) 343 3.6 2.0 68
Intercostal neuralgia 297 3.2 1.7 76
Phantom pain 151 1.6 0.9 69
Sciatica 116 1.2 0.7 64
Sacral neuralgia 64 0.7 0.4 55
Ulnar neuralgia 26 0.3 0.1 84
Neuralgias, other 740 7.9 4.2 72
B. Sympathetic Dystrophies, Circulatory Disturbances - total
  1,801 100.0 10.3 71.5
Circulatory disturbances:
 brain 728 40.4 4.2 73
 lower extremity 392 21.8 2.2 71
 upper extremity 321 17.8 1.8 69
Hyperhidrosis 178 9.9 1.0 62
Sudeck's atrophy 64 3.6 0.4 74
Lymphedema of arm, post ablatio 35 1.9 0.2 97
Pancreatitis, subacute & chronic 64 3.6 0.4 77
Meniere's syndrome and disease 11 0.6 0.1 84
Precordial pain 8 0.4 0.0 82
C. Articular Pain - total 4,436 100.0 25.3 76.7
Sacro-iliac pain 2,210 49.8 12.6 84
Periarthropathy, humero-scapular 847 19.1 4.8 72
Epicondylitis, radial and ulnar 718 16.2 4.1 68
Coxarthrosis (via obturator nerve) 182 4.1 1.0 66
Gonarthrosis 123 2.8 0.7 64
Peritendinoses 126 2.8 0.7 66
Omarthrosis 15 0.3 0.1 68
Talo-calcaneal pain 11 0.2 0.1 66
Arthroses, other 204 4.6 1.2 67
D. Benign Diseases, Various - total 651 100.0 3.7 82.4
Vertebral fractures, non recent 515 79.1 2.9 84
Various neurological disorders 68 10.4 0.4 88
Undiagnosed complaints, periarticular 33 5.1 0.2 71
Spasm of ureter, acute pain 26 4.0 0.1 78
E. Benign Tumors - total 18 100.0 0.1 50-93
F. Malignomas - total 1,189 100.0 6.8 60
Primary lesions of:
  bladder 26 2.2 0.1 45
  stomach 20 1.7 0.1 97
  testes 13 1.1 0.1 23
  other 31 2.6 0.2 68
Secondary lesions of:
  mammae 418 35.2 2.4 72
  bronchi 259 21.8 1.5 58
  recti, sigmoid 176 14.8 1.0 49
  prostate 42 3.5 0.2 64
  uterus 18 1.5 0.1 60
  epithelial tumors 26 2.2 0.1 66
Unclassified primary tumors 87 7.3 0.5 68
Other occult primary neoplasms 73 6.1 0.4 49-67
Total Number of Patients 17,537      
Pain reduction in first 2,000 patients 2,000     65.0
Pain reduction in first 1,537 patients 1,537     92.0

Table 3. Diagnoses and pain reduction success rates.7

Note that the composite success rates shown do not take into account evolving treatment modalities during the same period which resulted in higher success rates for later patients. During this period, usage of TENS (DC-type) increased rapidly while general conventional physiotherapy decreased steadily. Nerve blocks with a local anesthetic disappeared entirely from the list of preferred methods and were supplanted by electrical blocks instead.

In the experience of the author, the latest non-pharmacological methods to reduce pain are very effective in 75% of all cases.6 Pharmacological modalities — disregarding non-prescribed over-the-counter analgesics — account for the remaining 25%.

Conclusion

Years of experience in a large multi-disciplinary pain center dictate that pain treatment is a continuum starting with physical/neuropsychology techniques escalating to NSAIDs, narcotics and opioids, and finally operative interventions. After diagnosing a patient and evaluating his/her level pf pain, selection of the method with the best chance for optimal reduction of pain with the least occurrence of side effects is indicated.

The World Health Organization (WHO) guidelines for pain reduction procedures, however, ignore physical medicine and neuropsychology completely in favor of exclusive reliance on pharmacological modalities. This critical omission is due, no doubt, to the lack of equipment and personnel trained in such disciplines in most underdeveloped countries.

It is the author’s hope that the World Health Organization will revise its guidelines to reflect non-pharmacological therapies, which have been found to be very efficacious and usually devoid of undesirable side effects. Rather than reduce guidelines to the least-common denominator of available resources, the author urges the WHO to promote all proven effective means of pain reduction. Codifying such vital information will help foster development of the requisite skills in underdeveloped countries and improve outcomes for more of the world’s population.

Last updated on: January 6, 2012
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