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SPECIAL ARTICLE
Year : 2009  |  Volume : 53  |  Issue : 5  |  Page : 575-581 Table of Contents     

Fibromyalgia and Myofascial Pain Syndrome - A Dilemma


1 Professor and Head, Department of Anaesthesiology and Critical Care, M.L.N. Medical College, Allahabad, India
2 P G Student, Department of Anaesthesiology and Critical Care, M.L.N. Medical College, Allahabad, India

Date of Web Publication3-Mar-2010

Correspondence Address:
Arunangshu Chakraborty
P G Student, Department of Anaesthesiology and Critical Care, M.L.N. Medical College, Allahabad
India
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Source of Support: None, Conflict of Interest: None


PMID: 20640108

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Pain and fatigue associated to the musculoskeletal system are among the leading causes of patients to visit their physicians and nearly one-third of such patients suffer from fibromyalgia. Fibromyalgia syndrome (FMS) is a chronic debilitating disorder characterized by widespread pain with tenderness in specific areas, leading to fatigue, headache and sleep disorder. Myofaseial Pain Syndrome (NIPS), is also a localized musculoskeletal pain producing condition whose diagnostic and management criteria differ from FMS but still considered by many only a subtype of FMS.Till date no exact cause has been held responsible for these painful conditions, therefore treatment of these disorders is always a challenge. The therapies are not precise but multimodal including pharmacological and alternative ap­proaches. This article describes the existing knowledge pertaining to these conditions in regard of causative factors diagnosis and management.

Keywords: Myofascial pain, Fibromyalgia, Taut bands, Trigger points


How to cite this article:
Chandola H C, Chakraborty A. Fibromyalgia and Myofascial Pain Syndrome - A Dilemma. Indian J Anaesth 2009;53:575-81

How to cite this URL:
Chandola H C, Chakraborty A. Fibromyalgia and Myofascial Pain Syndrome - A Dilemma. Indian J Anaesth [serial online] 2009 [cited 2019 Dec 14];53:575-81. Available from: http://www.ijaweb.org/text.asp?2009/53/5/575/60336


   Introduction Top


Musculoskeletal system is the largest organ sys­tem by weight in the human body comprising ofmore than 400 skeletal muscles [1] . Problems associated with pain or fatigue to this system are among the leading reasons for patients to visit their cluiicians. [2],[3] Majority of these patients fall under the category of either fibromyalgia (FMS) or its subtype myofascial pain syn­drome (MPS ). Fibromyalgia syndrome (FMS) is a sys­temic disorder of widespread pain, a consequence of abnormal pain processing within the central nervous system (CNS). As corroborative evidence, recent stud­ies have found increased levels of glutamate, an excita­tory neurotransmitterinCNS of fibromyalgiapatients [4] . It is one of anuimber of overlapping functional somatic syndromes which includes chronic idiopathic lower back pain, tension headache, irritable bowel syndrome, chronic fatigue syndrome, disturbed sleep and others.

Fibromyalgia had been included in the tenth revi­sion ofthe International Statistical Classification of Dis­eases and Related Health Problems" (ICD-10) along with rheumatism and fibrositis by WHO in 1992 (M 79.0) but is currently classified as a separate entity M 79.7 [5] . May 12 th has been designated as the Interna­tional Awareness Day for FMS and other chronic im­munological and neurological diseases. Thereby fibromyalgia has emerged from past obscurity and is being recognized with more importance as an "underdiagnosed"but common disease.

One more condition similar to FMS named myofascial pain syndrome (MPS) was described as early as 1843 [6] but debate over its existence as a sepa­rate clinical entity from FMS still continues and many consider it only a subtype of FMS. It is true that the diagnostic criteria, clinical features and perhaps the etio­pathogenesis of MPS differ from FMS, so the treat­ment and prognosis [7] . Hams et al (1999) described the differentiating features ofMPS from FMS [Table 1].

The common important feature to both conditions is muscle pain along with the taut or rope like bands in the muscles. In MPS, the painful points in the `taut bands' are called "trigger points" (TP). These points are so pre­cise and painful that ontheir palpation, patient shows a ` jump sign" associated with referred pain. The "tender points" within the sore muscle of fibromyalgia are not associated with jump sign or referred pain.

Pain patterns and identification of TPs may be come easier if structural and physiological principles of muscle contractions are well understood.

Mechanism of contraction of skeletal muscle:

Each skeletal muscle comprises of bundle of fasicles and each fascicle is composed of about 100 muscle fibres. A muscle fibre consist of 1000- 2000 myofibrils. Each myofibril is made up of chains of sarcomeres, connected end to end in a serial manner. A sarcomere is a basic contractile unit. Sarcomeres connected by "Z lines" are composed of actin and myosin molecules [Figure 1]. Actin and myosin molecules form cross bridges in the presence of ionized calcium (Ca ++ ). Actin-myosin bridges remain relaxed till ATP molecules are bound to myosin. Breakdown of ATP to ADP by hydrolysis causes cross-bridging of actin and myosin molecules. Soon ADP molecules leave the myosin causing it to bend which gives a pull on actin and results in shortening of sarcomere. Attachment of another ATP again relaxes the cross bridge to restart the cycle. Repetition of these cycles causes muscle to contract in presence of Ca ++ . Removal of Ca ++ from the site causes termination of contraction. If additional ATP is not provided because of any reason the cross bridges remain attached and the muscle remains taut or stiff.

Reduced calcium metabolism in the sarcoplasmic reticulum can give rise to a trigger point in a resting muscle similar to a sustained contraction or "tetany".

Ca ++ release through the sarcoplasmic reticulum is controlled by release of acetyl choline at the motor end plate. The TPs of MPS are initially involved with motor end plates [8] . This pain can be relieved by stretching back the sarcomere, thus removing the overlap of actin and myosin and restoring the muscle length [9] .

Factors generating trigger points:

No single factor can be held responsible for the production of TPs. The possible causes are mentioned below.

  1. Trauma to: - musculoskeletal system, -intervertebral discs
  2. Inflammatory conditions e.g. cholecystitis, appendicitis, gastritis.
  3. Myocardial ischemia,
  4. Excessive or lack of exercise and malpositions
  5. Generalized fatigue, lack of sleep and emotional stress.
  6. Hormonal changes as in post menopausal syndrome.
  7. Nutritional deficiencies.
  8. Intense cooling of body areas… as sleeping in front of A.C.
  9. Obesity [10]


Types of Trigger Points:

TPs maybe one of the following types : [12]

1. Active TP: It is a classical TP which is present within a taut band of muscle giving rise to a"Junip sign" on palpation.

2. Latent TP: In this case the patient maypresent a nodular area in a taut band within muscle but does not produce pain on palpation. It is a dormant area that can potentially behave like an active TP later on.

3. Secondary TP: It is a hyperirritable point in a muscle that becomes active as a muscular overactivity of another muscle.

4. Satellite myofascial point: It is a hyperirri­table spot that becomes active because the muscle harbouring it is located within the region of another TP

Identification of TPS:

Pain diagrams depicting TPs on human body [13] and some other criteria as essential and confirmatory [14] have been laid down to identify TPs.

i Essential Criteria:-

  • Palpable taut band in muscle
  • Spot tenderness of a nodule in band
  • Patient's recognition of current pain complaint to pressure on nodule
  • Painful limit to stretch motion.


ii Confrrmatory observation:-

  • Visual or tactile identification of local pathology
  • Observation of a local twitch response induced by needle penetration of a tender nodule.
  • Altered sensation or pain on pressure on nod­ule alongthe area of expected distribution.
  • Demonstration of spontaneous electromyo­graphic activity characteristic of active foci in the nod­ule or band.


Laboratory Tests:

The pathogenesis of FINS is unknown and there is no single precise test for its diagnosis. Following bio­chemical changes have been found:

  1. Significant rise in proinflammatory cytokines IL-8 and TNF á [15] but no significant changes in IL-4, IL-6, and IL- 10 have been reported.
  2. High plasma levels of MCP-1 and eotaxin have been found. [16]
  3. Low serum cortisol due to an adrenocortical deficit has been described [17]


Treatment of MPS and FMS:

Although many theories have been put forward no clear causative factors responsible for MPS and FMS have been isolated. Association of prolonged static pos­tures, lack of exercise, high body mass index (BMI), sleep disturbance and emotional stress have been found. The treatment at present described for these conditions is therefore multimodal in nature and can be categorized as Pharmacological and Non-pharmacological therapies. The present practice combines non-pharmacological approaches with short term pharmacological therapies for longer lasting and maximal benefits.

1. Pharmacological therapies:

Non pharmacological approaches may be com­mon to both conditions but phannacological manage­ments of MPS and FMS differ.

A. MPS:

i) Trigger point injections:
Injection of TPs with 3% promethazine hydrochloride, 0.5% Procaine or 1% plain lignocaine have been advocated. This therapy is effective when there are only few and precisely located TPs. International Association for the Study of Pain (IASP) recommends some standards and precautions while injecting TPs [18] .

ii) Spray and stretch with vapocoolant: The physician uses a heating pad or moist heat on the area for 5-10 min after stretching the affected muscle (around TP). The skin is then sprayed with repeated parallel sweeps ofvapocoolant slowly at 10 cm/sec speed and not exceeding two passes over the same area. Some physicians prefer "spray-stretch-spray" sequence [19] . In place of moist heat ice- stroking and coolant like fluorimethane [19] have also proven useful. Fluori-meth­ane is being replaced by liquid nitrogen or ethylchloride since the former causes damage to the ozone layer [20] .

iii) Topical analgesics: Sprays, sport creams and ointments having analgesic properties can be useful to control MPS's pain. Topical application of menthol, peppermint, eucalyptus oil, capsaicin and other herbal preparations can also relieve pain [21] . Capsaicin applied topically degranulates and depletes the substance P store in nerve endings, thereby decreasing pain. Clini­cal trial of Capsaicin 0.1 % (500mcg) hydrogel 2.5 cm diameter patch applied over TPs for cervical myofascial pain is in the second phase.

iv) Glucosamine and Methylsulfomethane: When taken orally for a prolonged period they are ben­eficial owingto their anti-inflammatory and muscle re­laxing properties. Many other nutrients e. g. vitamin E, vitamin C, Zinc, Copper and herbal preparations have also been advocated. Recently L-acetyl Carnitine has been found to be effective infibromyalgia patients. [22]

v) NSAIDS: These medications are given only for a short period especially in acute stages to reduce pain and inflammation and to enhance relaxation. They have not been proven to increase healing of affected areas. Anumber of analgesics and anti-inflammatory drugs e.g. aspirin, acetaminophen, ibuprofen are avail­able withtheirmerits and demerits.

vi) Botulinumtoxin (botox) has been used with mixed results. Injection directly in the TP produces in­consistent effects. [23] Early reports suggest its use in cor­recting abnormal biomechanics that incite a myofascial response. [24]

B. Fibromyalgia:

Fibromyalgia shares common underlying neuro­biological mechanisms along with physical, cognitive and behavioral co-morbidities. Pain in FMS is supposed to be "central" in origin; the pain relievers like NS AIDS and opioids which are effective on "peripheral" pain are not so effective in this condition. Antidepressants, antiepileptic drugs and a number ofneuroactive com­pounds seem to be more effective in this sort of pain [25] .

i) Oral pregabalin, a Ca ++ channel á (2) o sub­unit ligand with antiepileptic, analgesic and anxiolytic properties has recently been approved in USA for FM [26],[27] .

ii) Oral antidepressant drugs like duloxetine [28] and milnacipran [29] the combined noradrenaline and seroto­nin uptake inhibitors are quite effective as pain reliev­ers in FMS. Duloxetine in the dosages of 60-120 mg/ day for a long period [28] and milnacipran 200 mg/day for 27 weeks [30] appear to be safe, well tolerated and efficacious.

iii) Tropisetron, a 5 HT3 receptor antagonist may also provide significant pain relief but requires i.v route [31] .

iv) Pramipexole, a doparnine (DA 3 ) receptor an­tagonist in the dosages of 4.5 mg/day for weeks also causes improvement in pain, fatigue& global status [32] .

v) Mirtazepine, which blocks á2 auto (NA) and heteroreceptors (5HT) is also a promising antidepres­sant drug [33] that has been proven useful.

vi) Central muscle relaxants maybe combined with analgesics especially inback pain when it is thoughtto be due to muscle spasm. Cyclobenzaprine, carisopro­dol, tizanidine, methocarbamol and metaxalone are the examples of centrally acting muscle relaxants [34],[35] Ad­verse effects e. g. dizziness, drowsiness and drug abuse restricts their use only for a short term.

Non pharmacological therapies for MPS and FMS:



Due to lack of definitive etiological elucidation and treatment of FMS many alternative approaches have been advocated by pain therapists. The popular ap­proaches have been mentioned below:

i) Choosing correct chair, mattress, and posture to sit or sleep.

ii) Backbraces can be used to stabilize the verte­bral column or support fatigued muscles.

iii) Traction devices can be used carefully as a temporary pain relief method.

iv) Mechanical massage: Regular massage by the devices available can penetrate deeply through atap­ping or percussion action dispersing lactic acid in the soft tissue causing improvement in circulation and re­laxation of knotted muscles.

v) Whole body vibration withtraditional exercise programme for six weeks was also found to reduce pain and fatigue score. [36]

vi) Chiropractic management combined with aero­bic exercises and cognitive behavioral therapy, acupunc­ture and spa therapy also have strong evidences in their favoui [37] .

vii) Yoga: Regular yogic breathing practices, muscle stretching and progressive deep relaxation by "shavasana" are known to have positive effect on FMS.

viii) Ischaemic acupressure or `Shiatsu' [38] : In this technique the clinician applies thumb pressure (TP) in a particular manner for 1 minute. In next minute the pres­sure is increased suddenly aggravating pain and a sen­sation of"giving away" is felt underneaththe thumb in muscle as the pressure is released gradually.

ix) Hot and cold therapies:

- Cold and hot packs: Ice packs can reduce in­flammation and pain if applied within 72 hrs of an in­jury. Ice should not be applied in a single areaformore than 20 mills owing to `reverse reaction' phenomenon.

- Hot packs are effective if applied after third day of injury. Moist heat is believed to be better in pain and inflmnnration improvement.

- Whirlpool and Jacuzzi jet massaging therapy are also examples of moist heat treatment.

- `Waon' (soothing warmth) therapy [39] employs far infrared ray dry sauna bath at 60° C for 15 min followed by transferring the patients to a room at 26 ° C covered with blanket for 30 min. Such 2-5 cycles in a week have significant effects on pain reduction.

x) Electrical stimulation: Such devices also prove effective but under medical supervision. Often called "dry needling" the technique of electrical stimulation by a needle passed in to TP has been successfully demon­strated to relieve shoulder and cervical myofascial pain as well as improve microcirculation. [40]

xi) Ultrasound therapy: Sound waves from ultra­sound machine are transmitted through sound conduct­ing gel to the tissues. The ultrasound waves break down scartissue, relax muscle and improve local circulation.

xii) Leser therapy: Short period application of in­frared low level 904 nm Ga As laser therapy have been found to be effective in pain relief and functional ability but its benefit when combined with muscle stretching physiotherapy has been questioned [41] .

The underlying causes of frbromyalgia and myofascial pain syndrome are not yet fully understood and there still remains a controversy about the inde­pendent existence of MPS but a high distressing inci­dence prevails in human population. The acceptance and awareness of these complex disorders has gener­ated the need of new researches in all medical and para­medical fields. At present the combined and collective approaches hold the key to the management of frbromyalgia.



 
   References Top

1.Robert B Salter. Normal structure and function of mus­culoskeletal tissues. In: Textbook of disorders and injuries of the musculoskeletal system. 31 rd edition, Lippincott Williams andWilkins 1999 - ,23.  Back to cited text no. 1      
2.Victoria Wapf, Andre Busato. Main health related prob­lems patients attended their physicians for. BMC complementary and alternative medicine 2007; 7: 41.  Back to cited text no. 2      
3.Schneider M, Veron H, Ko G, Lawson G et al. Chiroprac­tic management of fibromyalgia syndrome, a systematic review of the literature. J Manipulative Physiol Ther 2009;32:25-40.  Back to cited text no. 3      
4.Harris RE, SundgrenPC, Pang Y, HsuM, et al. Dynamic levels of glutamate within the insula are associated with improvements in multiple pain domains in fibromyalgia. Arthritis Rheum 2008 - ,58: 903-7.  Back to cited text no. 4      
5.ICD version 2007: Vk rld Health Organization online re­source. http://apps.who.int/classifications/apps/icd/ icdl0online/  Back to cited text no. 5      
6.M. Cummings, P. Baldry. Regional myofascial pain: di­agnosis and management. Best Practice& Research in Clinical Rheumatology 2007 -1 21 - .367-387.  Back to cited text no. 6      
7.Hans SC, Harrison P Myofascial pain syndrome and trigger point management. RegAnesth 1999 - ,22 - .89-101.  Back to cited text no. 7      
8.Leesa P Huquenin. Myofascial trigger point: the cur­rent evidence. Physical Therapy in Sport 2004; 5: 2-12.  Back to cited text no. 8      
9.Valencia M, Alonso B, Alvarez MJ, Barrientos MJ et al. Effects of 2 physiotherapy programs on pain percep­tion, muscular flexibility, and illness impact in women with fibromyalgia: a pilot study. J Manipulative Physiol Ther 2009 -1 32 - .84-92.  Back to cited text no. 9      
10.Saber AA, Boros MJ, Mancl T, Elgamal MH, et al. The effect of Roux-en-Y bypass on fibromyalgia. Obes Surg 2008;18:652-5.  Back to cited text no. 10      
11.Weingarten TN, Podduturu VR, Hooten WM, Thomp­son JM, et al. Impact of tobacco use in patients present­ing to a multidisciplinary outpatient treatment program for fibromyalgia. Clin J Pain 2009 - ,25: 39-43.  Back to cited text no. 11      
12.Peggy A Houglum. Myofascial Trigger Points. Thera­peutic Exercise for Musculoskeletal Injuries: 2 nd ed. Human Kinetics 2005; 165.  Back to cited text no. 12      
13.Rachlin ES: History and physical examination for re­gional myofascial pain syndrome. Myofascial Pain and Fibromyalgia Trigger Point Management. St Louis, Mosby- Yearbook 1994 -1 169.  Back to cited text no. 13      
14.Simmons D, Travell J, Simmons S. Trigger PointManual, vol-1, 2 nd edition. Williams& Wilkins 1999;132.  Back to cited text no. 14      
15.Wang H, Buchner M, Moser MT, Daniel V, et al. Circu­lating cytokine levels compared to pain in patients with fibromyalgia. Clin J Pain 2009; 25: 1-4.  Back to cited text no. 15      
16.Zhang Z, Cherryholmes G, Mao A, Marek C. High plasma levels of MCP-1 and eotaxin provide evidence for animmunological basis of fibromyalgia. Exp Biol Med 2008; 233:1171-80.  Back to cited text no. 16      
17.Klingmann PO, Kugler J, Steffke Ts, Bellingrath S. Sex specific prenatal programming: a risk for fibromyalgia? AnnN Y Acad Sci 2008;1148:446-55.  Back to cited text no. 17      
18.Hong, CZ. Considerations& recommendations regard­ing myofascial trigger point injection. J Mus Pain 1994; 2:29-59.  Back to cited text no. 18      
19.Richard S Weiner (ed), AmericanAcademy ofPain Man­agement. Manual Therapy (of Myofascial Pain). In: Pain Management. 6 th, ed; CRC Press 2006: 238.  Back to cited text no. 19      
20.Lucy W Ferguson, Robert Gerwin. Abdominal Pain of Myofascial Origin. In: Clinical Mastery in the Treatment of Myofascial Pain Lippincott Williams& Wilkins 2004: 320.  Back to cited text no. 20      
21.Charles E Argoff. A review of the use of topical analge­sics for myofascial pain. Current Pain& Headache Re­ports 2002; 6:375-378.  Back to cited text no. 21      
22.Di Munno 0, Valentini G, Bianchi G, et al. Double-blind, multicenter trial comparing acetyl 1-carnitine with pla­cebo in the treatment of fibromyalgia patients. Clin Exp Rheumatol 2007; 25:182-8.  Back to cited text no. 22      
23.Jabbari B. Botulinum neurotoxins in the treatment of refractory pain. NatClin PractNeurol 2008 -1 4: 676-85.  Back to cited text no. 23      
24.Jeynes LC, Gauci CA. Evidence for the use of botuli­num toxin in the chronic pain setting-a review of the literature. Pain Pract 2008; 8: 269-76.  Back to cited text no. 24      
25.Rao SG, Clauw DJ. The management of fibromyalgia: Drugs Today (Barc) 2004; 40:539-54.  Back to cited text no. 25      
26.Lyseng-WilliamsonKA, Siddiqui MA. Pregabalin: Are­view of its use infibromyalgia. Drugs 2008; 68: 2205-23.  Back to cited text no. 26      
27.Owen RT. Pregabalin: Its efficacy, safety and tolerabil­ity profile in FMS. Drugs Today (Bart) 2007 - ,43 - .857-63.  Back to cited text no. 27      
28.Russel IJ, Mease PJ, Smith TR, Kajdasz DK. Efficacy and safety of duloxetine for treatment of fibromyalgia. Pain 2008;136: 432-44.  Back to cited text no. 28      
29.Owen RT. Milnacipran hydrochloride: its efficacy, safety and tolerability profile in fibromyalgia syndrome. Drugs Today 2008 - ,44 - .653-60.  Back to cited text no. 29      
30.Mease PJ, Clauw DJ, Gendreau RM, Rao SG, et al. The efficacy and safety of milnacipran for treatment of fibromyalgia. J Rheumatol 2009; 36: 398-409.  Back to cited text no. 30      
31.Spath M, Stratz T, Neeck G, Kotter 1, et al. Efficacy and tolerability of intravenous tropisetron in the treatment of fibromyalgia. Scand J Rheumatol 2004 -1 33 - .267-270.  Back to cited text no. 31      
32.HolmanAJ. Pragmatic consideration of recent random­ized, placebo-controlled clinical trials for treatment of fibromyalgia. Curr Pain Headache Rep 2008; 12:393-8.  Back to cited text no. 32      
33.Samborski W, Lezanska-Szpera M, Rybakowski JK.Open trial of mirtazapine in patients with fibromyalgia. Pharmacopsychiatry 2004; 37:168-70.  Back to cited text no. 33      
34.See S, Ginzburg R. Choosing a skeletal muscle relaxant. Am Fam Physician 2008 - ,78 - .365-70.  Back to cited text no. 34      
35.Tofferi JK, Jackson JL, O'Malley PG. Treatment of fibromyalgia with cyclobenzaprine: Am eta-analysis. Arthritis Rheum 2004 - ,51 :9-13.  Back to cited text no. 35      
36.Alentorn-Geli E, Padilla J, Ivloras G, Lazaro Haro C, et al. Six weeks of whole-body vibration exercise improves pain and fatigue in women with fibromyalgia. J Altern Complement Med 2008 - ,14:975-8 1.  Back to cited text no. 36      
37.Schneider M, Vernon H, Ko G, Lawson G, Perera J. Chiro­practic management of fibromyalgia syndrome: a sys­tematic review of the literature. J Manipulative Physiol Ther 2009 - ,32: 25-40.  Back to cited text no. 37      
38.David H. Track, Frances Chamberlain. Tools for manag­ing your fibromyalgia. In: Healing Fibromyalgia. John Wiley& Sons 2007; 159.  Back to cited text no. 38      
39.Matsushita K, Masuda A, Tei C. Efficacy of Waon therapy for fibromyalgia. Intern Ivied 2008; 47:1473-6.  Back to cited text no. 39      
40.Lee SH, Chen CC, Lee CS, et al. Effects ofneedle electri­cal intramuscular stimulation on shoulder and cervical myofascial pain syndrome andmicrocirculation. J Chin MedAssoc 2008; 71: 200-6.  Back to cited text no. 40      
41.Matsutani LA, Marques AP, Ferreira EA, Assumpgao A et al. Effectiveness of muscle stretching exercises with and without laser therapy at tender points for patients with fibromyalgia. Clin Exp Rheumatol 2007 - 25 - .410-5.  Back to cited text no. 41      


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