What Is Myofascial Pain Syndrome?

Overview

Myofascial pain syndrome (MPS) is pain related to inflammation or irritation of muscle or the fascia surrounding the muscle.¹ It is common in patients with pre-existing musculoskeletal pain problems. The overall frequency of MPS as observed in the common population, is 30 to 85%, with most being commonly aged between  27 to 50 years and a gender predilection that remains debated in literature; however, assigned females at birth are more likely to report this than their gender counterparts.¹ The pain may be localized in a definite area or might be referred to as pain in different areas, such as the ears or the neck. Clinical examination is primarily focused on identifying the trigger points that are common in the muscles that help in chewing our food.^1,3 The pain and tenderness may originate from these identified trigger points. MPS can affect several different regions simultaneously or in an isolated manner. However, the most commonly reported painful areas are in the neck, shoulders, upper arm, lower back, and jaws.² MPS can be classified as acute (shorter) and Chronic (long-lasting) forms depending on the duration of pain. Acute MPS may subside by itself or with treatments, but chronic MPS may last for 6 months or longer.² Chronic pain due to MPS may also significantly affect the quality of life of the individual and their immediate social circle due to mental health distress caused by it.² 

Causes

MPS is a painful muscular disorder that may arise from an isolated or repeated trauma spontaneously or over time with differing individual patterns of pain.³ When in use, our muscles contract- when used for long or overused, they may fail to relax from these contractions, causing “Knots” known as “Trigger points”, thus resulting in myofascial pain.^1,3 The exact aetiology of trigger points is not known, yet pain is correlated  to occur due to many factors:³

• No exercise or movement/Inactive lifestyle
• Accidental trauma or injury to muscles 
• Repeated actions, over-activity, excessive exercise, or muscle strain, such as clenching your teeth repeatedly
• Incorrect posture
• Weakness in arms or legs due to continuous cast placement after any fracture
• Chilling environment: Prolonged air-conditioner exposure to the body sleeping in front of it or residing in a cold climate
• Muscle tension due to stress or depression
• Scoliosis (Spine is twisted and curves to the side)
• Nutritional deficiencies or hormonal changes (menopause, Post  menstrual syndrome, etc.)
• Some individuals have an extensive range of movement: they can move their limbs into positions others find impossible.
• Different lengths of the pair of arms or legs
• Hypothyroidism
• Infections or conditions like gall bladder inflammation, heart attack, appendicitis, etc
• Lack of energy or generalised  fatigue 
• Stress and anxiety 

Some further helpful reading around this can also be found here.

Myofascial pain syndrome and fibromyalgia

Signs and symptoms

Pain, which is the most common sign and symptom of MPS, is commonly localised in the muscles of mastication (i.e., the muscles that help us chew our food and open and close our mouths). The masseter muscle (a muscle located on the outer side of the lower jaw just behind the cheeks) is one of the most common sites of myofascial pain, followed by the temporalis muscle (a muscle located near your temples).⁵ Symptoms in MPS may vary amongst individuals as the pain (the most common sign and symptom) may vary from being spontaneous to dull and constant or cyclical.⁵ Myofascial pain commonly involves your back, neck, mouth, or face.^4,5 The chronic pain may commonly radiate from the myofascial trigger points, which are focal portions of inflammation in the tender muscles.⁵  

Types of myofascial trigger points:⁶

1. Active trigger point - With movement, pain occurs within the muscle, causing local or referred pain.^1,6
2. Latent trigger point - On compression, expressed as a sensitive spot with uneasiness.^1,6
3. Secondary trigger point - A  knot in the muscle, apart from the active trigger point. Both active trigger points and secondary trigger points can be aggravated together.^1,6
4. Satellite trigger point- Continuous radiating pain from the active trigger point may lead to the development of a satellite trigger point, which is localized in the referred zone of the active trigger point.^1,6

Some of the  common signs and symptoms of MPS:⁶

• Persistent deep pain- Spontaneous, localized, or referred pain; deep and throbbing pain resulting in stiff and tight muscles 
• Trigger points-  Painful small knots or bands in the muscle that may increase/cause pain when palpated⁶ 
• Sore muscles- In patients with constant overuse, such as clenching or bruxing (clenching your teeth while sleeping), the muscles are generally sore after use or in the morning after waking up. Muscle weakness- Painful muscles might feel weak, and the person makes more attempts to perform normal movements, resulting in further fatigue.
• Compromised movement 
• Additional symptoms such as headache, depression, anxiety, fatigue 

Diagnosis

MPS is assessed from the medical history and clinical evaluation commonly carried out by specialist dentists.

• Medical History- Includes asking for any of the above-listed symptoms,  a detailed pain history, and any relevant past medical conditions, muscular strain, spasms, recent injuries, and repetitive pain(localized or generalized).⁷
• Clinical Examination and palpation- This is the gold standard in the diagnosis of MPS. Clinical examination involved palating for the presence of taut bands in muscles. These affected muscles have tight and painful palpation with the tender and trigger points commonly causing a sharp increase in pain. Trigger points are hyperirritable or sore⁷
• Sleep studies- To check masticatory muscles To check for clenching of teeth at night (bruxism) is a commonly known cause of MPS.⁷ 
• Needle Electromyography- To assess the severity of the muscular pain 
• Magnetic resonance elastography- To identify specific areas of inflammation for further treatment.⁷ Sonoelastography with Doppler imaging- Clinical ultrasound technique for finding the active trigger points and latent trigger points.^1,7
• Radiographs- To rule out any bone(skeletal) deformities: spondylosis, scoliosis, foraminal stenosis, from other entities.^1,7
• Lab tests- To estimate any hormonal or nutritional deficiencies.^1,7

Differential Diagnosis-  This is done based on the patterns and location of pain on history, examination and palpation. Some examples of these would be Fibromyalgia tendinopathy, arthritis, bursitis, and nerve entrapment.^1,7 

Treatment

1. Conservative Management:⁸
   • Patients should be educated and accordingly counselled about the disorder and its triggers.
   • Appropriate rest for healing
   • Stretching, exercises, and manual techniques to relieve muscle tension
   • Heat and cold treatment for decreasing the pain and muscle tension
   • Improving the posture for lowering stress on affected muscles
   • Reducing stress to rule out any further damage

2. Medications⁸:According to the patient’s need 
   • Nonsteroidal anti-inflammatory medication  for pain and inflammation
   • Muscle relaxants for muscle tension and spasms
   • Anti-depressants  
   • Pain relievers to provide relief
   • Usage of Lidocaine patches on painful muscle locations

3. Trigger points injections⁸
   • Injections of Local anesthetics and corticosteroid injections 

4. Dry needling⁸
   • It works on trigger points to release muscle knots and improve blood flow.

5. Manual massage⁸
   • Massage for muscle relaxation

6. Acupuncture, Relaxation, and Cognitive Behavioral Treatment
   • Ensures better sleep and decreases anxiety⁸  

7. Low-level laser therapy⁸
   • To stimulate pain-relieving chemicals

8. Transcutaneous electrical nerve stimulation (TENS)⁸
   • Small pads are attached to the skin near the affected muscles to which low voltage electrical signals are sent to trigger points.⁸

9. Oral appliances
   • Oral devices can prevent bruxism, snoring, or jaw pain

10. Lifestyle modifications⁸
    • Appropriate workstation positioning and sitting arrangement for comfort and to prevent strain
    • Adequate sleep helps in muscle recovery
    • Regular exercise 

11. Proper Nutrition⁸
    • Balanced diet for proper muscle health

12. Multidisciplinary approach
    • Collaborative care involves various healthcare professionals: doctors, rheumatologists, orthopaedics, physical therapists, and psychologists as per the case or severity.⁸ 

Risk factor

The exact cause is not known but:^1,8

• Injury or over usage of muscles- This may create trigger points; continuous or more than normal movements of affected muscles or improper posture may increase the risk of MPS.
• Stress and anxiety- Causes increased abnormal use of the muscle and may also make it difficult to relax the muscle 
• Skeletal disorders

Complications

• Poor quality of life due to chronic pain¹,⁸
• Increased reliance on pain medication to function normally^1,8 
• May predispose individuals to severe mental health distress^1,8

FAQs

How can I prevent myofascial pain syndrome?

MPS is not completely preventable, but some measures might reduce the risk to a significant extent:¹,⁸

• Healthy lifestyle
• Appropriate posture and comfortable sitting arrangement in the workplace
• Regular exercise
• Managing stress
• Avoid overuse of muscles such as clenching or wearing a plate to avoid clenching at night.

How common is myofascial pain syndrome

 The overall frequency of MPS as observed in the common population, is 30% to 85%, with most individuals being commonly aged between 27 to 50 years of age and a gender predilection that remains debated in literature. However, it is noted more commonly that assigned females at birth are more likely to report Myofascial pain than their counterparts.¹

When should I see a doctor?

If you notice any of the above-listed symptoms, such as soreness in your muscles along the side of the face, pain or tenderness, you should book an appointment to see your local general dental practitioner as soon as possible. 

Summary

Myofascial pain syndrome (MPS) is a disorder characterized by localized facial muscle pain.^1,8 It is commonly caused by muscle overuse, such as clenching your teeth during the day or overnight, injury to the facial muscles, or stress-induced muscular overuse.^1,8 Myofascial pain is generally either spontaneous or dull and constant or can be cyclical as well. This condition can result in severe chronic pain that may significantly impact the normal functioning of the jaws, such as chewing food, and it may also affect the overall quality of life of the individual quite severely.^1,8 Treatment involves a combination of therapies such as physical therapy, medications, trigger point injections, oral/dental appliances, dental treatment and lifestyle modifications to alleviate pain, improve muscle function, and enhance overall well-being.^1,8 Myofascial pain is commonly known to subside in a few months after removal of the trigger or with timely intervention.