Sunday, November 7, 2010

The Myofascial Pain Syndrome and Trigger Point Therapy


HISTORY

DR. JANET TRAVELL

Dr. travell was born in 1901, and followed in her father's footsteps to become a doctor. she initially specialized in cardiology but soon became interested in pain relief, as had her father. she joined her father's practice, taught at cornell university medical college, and pioneered and researched new pain treatments, including trigger point injections. in her private practice, she began treating senator john f. kennedy, who at the time was using crutches due to crippling back pain, and almost unable to walk down three stairs. this was at a time when television was bringing images of politicians into the nation's living rooms, and it had become important for presidential candidates to appear physically fit. being on crutches probably would have cost president john f. kennedy the election. dr. travell became the first female white house physician, and after president kennedy died, she stayed on to treat president johnson. she resigned a year and a half later to return to her passion for teaching, lecturing, and writing about chronic myofascial pain. she continued to work into her 90's, and died at the age of 95 on august 1, 1997.

DR. DAVID G. SIMONS

Dr. simons started out his career as an aerospace physician, and met dr. travell when she lectured at the school of aerospace medicine at brooks air force base in texas in the 1960's. he quickly teamed up with dr. travell. dr. simons began researching the international literature for any references to the treatment of pain, and discovered there were a few others out there who were also discovering trigger points, but using different terminology. he studied and documented the physiology of trigger points in both the laboratory and the clinic, and tried to find scientific explanations for trigger points. together, doctors travell and simons produced a comprehensive two-volume text written for physicians on the causes and treatment of trigger points.


The Myofascial Pain Syndrome and Trigger Point Therapy


The myofascial pain syndrome, MPS is one of the most common overlooked diagnoses in chronic pain. Up to 85% of patients with chronic pain have an underlying MPS. The terms MPS, myofascial trigger point, taut band, local twitch response and their definitions were first published in the fifties by Dr. Janet Travell. In 1983, together with Dr. David Simons, Travell published  the groundbreaking Trigger Point Manuals which are now in their second edition and have been translated into 12 different languages. Today Travell and Simons can be considered as true medical pioneers.

The Foundations of Trigger Point Therapy

The goals of successful trigger point therapy are releasing local sarcomere contractions, increasing local blood flow as well as inhibiting local inflammatory processes. The more precisely trigger points are treated the better the results achieved. There is a worldwide consensus among specialists that the combination of manual trigger point therapy and dry needling are the most effective approaches in the treatment of trigger points.

Diagnosis

The hallmark of the MPS are myofascial trigger points. Imaging techniques to diagnose trigger points and taut bands exist. However they have little value in clinical practice. The characteristic features of trigger points can be manually identified by palpation. The accepted diagnostic criteria are:
  • taut band
  • local tenderness within the taut band
  • referred pain
  • local twitch response
Many studies have shown a high interrater reliability among trained clinicians for the diagnostic criteria of trigger points. The MPS can be local or widespread. It can affect one, two or more quadrants. This is one of the reasons why the MPS is often mistaken for fibromyalgia. Trigger Points have characteristic referred pain patterns.

Pathophysiology of Myofascial Trigger Points


Integrated Hypothesis

Expanded Integrated Hypothesis, hand drawn by David G. Simons
Muscle lesions (e.g. trauma, RSI) can cause ruptures of the sarcoplasmatic reticulum which leads to an uncontroled release of calcium ions from the sarcoplasmatic reticulum. This in turn causes persistent sarcomere contractions. Many contracted sarcomeres and muscle fibres cause the taut band. Taut bands are palpable and can be visualized by ultrasound and MRI. On the one hand prolonged contractions have an increased energy demand and on the other hand they compress vessels, which leads to a decreased energy supply. The result is an energy crisis. Due to the lack of ATP there is also a decreased reuptake of calcium ions into the sarcoplasmatic reticulum which perpetuates contractions. As a result there is a local release of bradykinin and CGRP which lower the threshold of nociceptive endings. Many studies confirm the energy crisis theory. The integrated hypothesis is an expansion of the energy crisis theory and is the most accepted model for the explanation of trigger points. It postulates that the energy crisis process takes place in the vicinity of motor endplates. This leads to an incresed release of acetylcholine and therefore perpetuates the vicious circle of prolonged contraction.