Myofascial Pain Syndrome

Myofascial pain syndrome is caused by injury or damage to the fascia. The syndrome can cause chronic pain in muscles throughout the body.

Fascia is a tough connective tissue covering muscles which when injured becomes tight and may put painful pressure on surrounding tissues.

Myofascial pain syndrome is characterized by presence of trigger points, a knot or band in the muscle which is  sensitive to even light pressure and generate pain  not only at the site, but also refer to surrounding areas.

Myofascial pain syndrome is characterized by pain, tenderness, and spasm  which affects muscles and occur  asymmetrically [in contrast to fibromyalgia which is diffuse and symmetric areas of the body. Poor sleep, fatigue, and stiffness are common in myofascial pain syndrome. Myofascial pain syndromes have been linked to headaches, jaw pain, neck pain, low back pain, pelvic pain, and arm and leg pain. Depression, fatigue, anxiety, or mood disturbances may occur.

Causes

The cause of myofascial pain syndrome is not clear. Prior injury, poor sleep patterns, stressful life situations, and depression are common underlying conditions that have been suggested to play a role in activation and perpetuation of myofascial pain syndrome.

Trauma,  herniated discs, muscle overload and injury, prolonged immobilization, prior surgery, hormonal disturbances etc have been suggested as possible causes.

Presentation

Myofascial pain syndrome usually develops between ages 20 to 40 and is more common in women and people with sedentary lifestyles. Myofascial pain syndrome causes localized muscle pain. Depending on the muscle affected the presentation may differ.

Different Types of Myofascial Pain Syndromes

The most frequently encountered muscles developing myofascial pain syndromes

• Head -  Masseter, temporalis, lateral pterygoid, and medial pterygoid

• Head and neck- Trapezius and sternocleidomastoid

• Neck- Levator scapulae and scalenes

• Shoulder and arm- Infraspinatus and supinator

•  Back and hip- Quadratus lumborum and piriformis.

Masseter

The patient has pain simulating sinusitis, pain in temporomandibular joints, upper or lower molar pain, and hypersensitivity of teeth. Tinnitud in the same side ear can be present.
 The pain may refer to teeth and gums, eyebrows, and ear.

Normal chewing may be tolerated. Bruxism may be the cause of activation.

Sometimes compression of pterygoid venous plexus results in engorgement, leading to infraorbital puffiness and hemifacial edema.

Temporalis

There is headache in temporal region. There may be pain above and behind the eye, and maxillary toothache.
 The pain may referred to temporoparietal and supraorbital region up to upper incisor and temporomandibular joint

Lateral pterygoid

There is frequent complaint of temporomandibular joint dysfunction. There may be increased sinus secretions resembling sinusitis.

Pain may br referred to temporomandibular joint and maxilla. There may be complaint on pain on chewing. If buccal nerve is entrapped,  paresthesias of the cheek and gum and weakness of the buccinator muscle.

Medial pterygoid

Pain in the throat, difficulty in swallowing which is also painful, feeling of stuffy ear and restriction of jaw opening are main complaints.

Pain may be referred to  back of the mouth, pharynx, and tongue. Teeth are spared. Temporomandibular joint and ear may have pain

Trapezius

Pain in haed and neck and in suprascapular area. The pain is burning in nature. Dizziness may occur due to activation of sternocleidomastoid muscle trigger points.

Pain may refer to neck and up to acromion. The cause may be acute trauma as with falls or whiplash.[Link]

Prolonged elevation and extension of the arms as when typing may also be causative factor.

Sternocleidomastoid

Facial pain associated d with visual blurring, tearing, and ptosis (due to spasm of orbicularis spasm) are seen. Trigger points in clavicular part  can cause tension headaches, postural dizziness, and loss of equilibrium.

Pain is not referred to neck.

Protracted neck rotation  neck extension  may lead to activation of trigger points.

Entrapment of the spinal accessory nerve as it emerges through the sternocleidomastoid muscle may cause paresis of the ipsilateral trapezius muscle.

Levator scapulae

It is the most common cause of stiff neck. This leads to painful limitation of neck rotation on the affected side.

The pain may refer to the medial scapular border and posterior shoulder.  Prolonged turning of head and neck and unilateral shoulder shrugging may be responsible causes.

Scalene

There are symptoms similar to thoracic outlet syndrome that includes of ulnar pain and numbness, hand weakness, and swelling. The pain may radiate to pectoral muscles and medial part of scapula, extending down lateral arm and radial aspect of forearm, thumb, and index finger. Pulling, lifting, or tugging are the activities responsible for activity and perpetuation. Referred pain from cervical spine frequently activates and perpetuate s scalene trigger points.

Entrapment of Lower trunk of brachial plexus compression elicits ulnar pain, paresthesias, and the unexpecteactivitiesd dropping of objects. Edema of fingers may occur following subclavian vein compression

Infraspinatus

There is pain in the shoulder joint that causes difficulty in sleeping on either side. There may behind the back.

The pain may radiate to anterior deltoid pain, extending to anterolateral region of the arm. At times, it might reach to radial aspect of hand.

The syndrome activation and perpetuation results from overload reaching backward and up.

Supinator

Pain similar to tennis elbow with activity or rest. Hand weakness may occur at times. Pain refers to lateral epicondyle, and often the dorsal aspect of the web and base of thumb. The pain results from excessively forceful, repetitive, or sustained supination of the hand.

Entrapment of deep radial nerve may cause weakness with extension of the hand, fingers, and thumb.

Quardatus lumborum

Deep aching low back pain at rest which might become severe in unsupported standing or sitting. The pain may refer to sacroiliac joint and lower buttock. Superficial trigger points refer to hip, iliac crest, and groin. Awkward lifting or repetitive trauma as when walking with a limp may be causative factors.

Piriformis

Trigger points entrap the nerve  and gluteal vessels and contribute to sacroiliac joint dysfunction and referred hip pain.
 Pain gets referred to sacroiliac region, buttock, and posterior thigh. Trigger point pain is increased with walking, sitting or standing.

Acute overload from forceful rotations on one leg or a fall, prolonged positioning during obstetric or urologic procedures with knees spread apart may be cause of in this pain pattern.

Trigger points may entrap multiple nerves and vessels at the sciatic foramen. Sciatic and gluteal neurovascular compression evoke numbness and pain with the pudendal nerve causing sexual dysfunction.

It is also common for patients with myofascial pain syndrome to have poor sleep patterns and frequent  awakening feeling unrested and daytime fatigue.
The diagnosis of  myofascial pain syndrome based on the muscle involved and associated tenderness during a physical examination.

Investigations

Extensive laboratory testing is usually unnecessary.

Treatment of Myofascial Pain Syndrome

Optimal treatment of myofascial pain syndrome can includes patient education,  stress reduction, stretching and exercise, sleep improvement, and medications.

Myofascial pain syndrome resolves with treatment but many patients with myofascial pain syndrome may continue to have symptoms for years.

Factors  that make the condition worse like injury, stress should be avoided. Underlying depression should be treated and optimal sleep should be restored.

Physical Therapy

Myofascial release techniques, massage, cervical stretch and stabilization are integral parts of this approach. The primary goal of physical therapy is to restore balance between muscles working as a functional unit. Postural retraining is crucial.

Trigger Point Injection

One of the most accepted means of treating myofascial pain besides physical therapy and exercise. Injection is performed most commonly with local anesthetic, although dry needling is equally effective.

Stretch and spray

This technique is performed using a vapocoolant spray applied to the affected muscle after it has been placed in passive stretch.

Ischemic Compression

Ischemic compression involves application of sustained pressure on the trigger point. With muscle in a fully stretched position, press firmly on the trigger point with a thumb. Gradually increase the pressure as the pain lessens.

Drug Therapy

Analgesics

Non steroidal anti-inflammatory drugs  are the drugs of choice for the initial treatment of myofascial pain. Ibuprofen, Indomethacin, naproxen, diclofenac and ketoprofen are commonly used drugs.

Opioid analgesics like tramadol can also be used.

Tricyclic Antidepressants

Tricyclic antidepressants like amitriptyline are commonly used for chronic pain. They also help to treat assocoiated insomnia.

Muscle Relaxants

Cyclobenzaprine, baclofen, carisoprodol, tizanidine are commonly used muscle relaxants.

Anticonvulsants

Gabapentin has been shown to be effective in treating myofascial and neuropathic pain.