Scan Painlessly Pinpoints Muscle Stiffness

[webslave]

From Reuters. I have replicated it here for archival purposes.

Scan Painlessly Pinpoints Muscle Stiffness

NEW YORK (Reuters Health) - An experimental technique that uses widely available imaging technology is a painless way to measure muscle stiffness, researchers report.

The tool is several years away from routine use, but eventually it could serve a variety of purposes, including evaluating injuries, stroke-related muscle damage and degenerative diseases, such as multiple sclerosis, a Mayo Clinic researcher told New Scientist magazine.

The technique, known as magnetic resonance elastography (MRE), involves the same scanner used to perform magnetic resonance imaging (MRI), a technique that provides a good view of the internal structures of the body, particularly soft tissue, the brain, spinal cord and joints. MRI can also be used to detect and track some types of cancer.

A test called electromyography is often used to measure electrical activity and stiffness in a muscle. This approach, however, can only be used on a small amount of muscle at a time and is invasive if used to evaluate deep tissue.

MRE gets around these problems, according to a team led by Dr. Kai-Nan An at the Mayo Clinic in Rochester, Minnesota.

"Since is based on MRI technology, any muscle, however deep, can be interrogated using equipment commonly available in most health care facilities," An and his colleagues point out in an article to be published in the December issue of the Journal of Biomechanics.

Within an MRI scanner, the skin is vibrated, which causes waves to penetrate tissue and to multiply in muscle. Doctors take an image of these waves and then measure them to evaluate muscle stiffness.

In the New Scientist article, An predicted that MRE will be available within five years.

"It could be used for many things," An said. People recovering from injuries as well as people who experience muscle stiffness due to a stroke or cerebral palsy may benefit from the technique, he said.

MRE eventually may also help doctors monitor the progress of diseases that lead to muscle degeneration, including multiple sclerosis and hypothyroidism, An said.

SOURCE: New Scientist, November 15, 2003.

SOURCE: Journal of Biomechanics, December 2003.

SOURCE: Clinical Biomechanics, July 2003.

[critthinker]

Webslave, do you know if MRE is being used yet to identify trigger points and areas of restriction? Also, one other question...I vaguely recall there being a study which measured electrical activity in TrPs compared to non-TrP sites. Do you have a citation for this? Additionally, is it possible that restricted muscle can cause similar symptoms (even in the absence of trigger points)? I feel a profound increase in pain when I'm stressed and tremendous pain relief (almost 100%) after meditating for long periods (2-3 hours). This is starting to make me think that this problem isn't (or isn't solely) one of sympathetic nervous system overload, but rather one related to shortened muscle in my pelvic floor.

[webslave]

I'm not sure, but you'll find a wealth of information on TrPs on Pubmed, which just goes to show that they are becoming part of mainstream medicine, contrary to what critics claim.

Go here and enter "trigger points"
http://www.ncbi.nlm.nih.gov/pubmed

Here are some interesting recent studies I found doing that:

Curr Pain Headache Rep. 2009 Oct;13(5):365-9.
Current studies on myofascial pain syndrome.

Kuan TS.
Department of Physical Medicine and Rehabilitation, College of Medicine, National Cheng-Kung University, 138 Sheng-Li Road, Tainan, 704, Taiwan.

Abstract

Recent studies have clarified the nature of myofascial trigger points (MTrPs). In an MTrP region, multiple hyperirritable loci can be found. The sensory components of the MTrP locus are sensitized nociceptors that are responsible for pain, referred pain, and local twitch responses. The motor components are dysfunctional endplates that are responsible for taut band formation as a result of excessive acetylcholine (ACh) leakage. The concentrations of pain- and inflammation-related substances are increased in the MTrP region. It has been hypothesized that excessive ACh release, sarcomere shortening, and release of sensitizing substances are three essential features that relate to one another in a positive feedback cycle. This MTrP circuit is the connection among spinal sensory (dorsal horn) neurons responsible for the MTrP phenomena. Recent studies suggest that measurement of biochemicals associated with pain and inflammation in the MTrP region, the sonographic study of MTrPs, and the magnetic resonance elastography for taut band image are potential tools for the diagnosis of MTrPs. Many methods have been used to treat myofascial pain, including laser therapy, shockwave therapy, and botulinum toxin type A injection.

PMID: 19728962 [PubMed - indexed for MEDLINE]

Neurourol Urodyn. 2007;26(1):59-62.
Levator ani trigger point injections: An underutilized treatment for chronic pelvic pain.

Langford CF, Udvari Nagy S, Ghoniem GM.
Section of Voiding Dysfunction, Female Urology and Reconstruction, Department of Urology, Cleveland Clinic, Weston, Florida 33331, USA.

Abstract

AIMS: We conducted this study to examine the role of trigger point injections in females with chronic pelvic pain (CPP) of at least 6 months duration and specific levator ani trigger points. METHODS: This prospective study included 18 consecutive female patients with CPP and specific palpable levator ani trigger points. Pain was evaluated before and after trigger point injection on a Visual Analog Scale (VAS). Patient global satisfaction (PGS) and cure rates (PGC) were also measured by a VAS on a scale of 0-100%. The trigger points were identified manually by intravaginal palpation of the levator ani bilaterally. A mixture of 10 cc of 0.25% bupivacaine, 10 cc of 2% lidocaine and 1 cc (40 mg) of triamcinolone was used for injection of 5 cc per trigger point. A 5.5'' Iowa trumpet pudendal needle guide was used for injection. All but one injection were performed in the office setting without sedation. Pelvic floor muscle exercises were taught for use after injection. Success was defined as a decrease in pain as measured by a VAS of 50% or more, as well as PGS and PGC scores of 60% or greater. There was a mean follow up of 3 months after trigger point injection. RESULTS: Thirteen of 18 women improved with the first trigger point injection resulting in a comprehensive success rate of 72%. Six (33%) of 18 women were completely pain free. CONCLUSION: In the management of CPP, a non-surgical office-based therapy such as trigger point injections can be effective in selected patients. Copyright 2006 Wiley-Liss, Inc.

PMID: 17195176 [PubMed - indexed for MEDLINE]

[critthinker]

Hmm, interesting stuff. I'm going to do some research to see if MRE is available for patients like us. I'm very curious about this because I've been to 3 different PTs, but ultimately my tightness keeps coming back (not trigger points, just shortened muscle). I feel the PTs have done a great job identifying and eliminating my TrPs, but not such a great job letting me know where my restricted muscle is.